Renewable energy commercialization

Renewable energy commercialization involves the deployment of three generations of renewable energy technologies dating back more than 100 years. First-generation technologies, which are already mature and economically competitive, include biomass, hydroelectricity, geothermal power and heat. Second-generation technologies are market-ready and are being deployed at the present time; they include solar heating, photovoltaics, wind power, solar thermal power stations, and modern forms of bioenergy. Third-generation technologies require continued R&D efforts in order to make large contributions on a global scale and include advanced biomass gasification, hot-dry-rock geothermal power, and ocean energy.<ref name="IEA">International Energy Agency (2007). Renewables in global energy supply: An IEA facts sheet (PDF) OECD, 34 pages.</ref> In 2019, nearly 75% of new installed electricity generation capacity used renewable energy<ref>Carrington, Damian (6 April 2020). "New renewable energy capacity hit record levels in 2019". The Guardian. ISSN 0261-3077. Retrieved 22 October 2023.</ref> and the International Energy Agency (IEA) has predicted that by 2025, renewable capacity will meet 35% of global power generation.<ref>Ellerbeck, Stefan (16 March 2023). "IEA: More than a third of the world's electricity will come from renewables in 2025". World Economic Forum. Retrieved 22 October 2023.</ref>

Public policy and political leadership helps to "level the playing field" and drive the wider acceptance of renewable energy technologies.<ref name="renewableenergyfocus.com">Donald W. Aitken. Transitioning to a Renewable Energy Future, International Solar Energy Society, January 2010, p. 3.</ref><ref name="map.ren21.net"/><ref name=ren212011>REN21 (2011). "Renewables 2011: Global Status Report" (PDF). pp. 11–13. Archived from the original (PDF) on 5 September 2011.{{cite web}}: CS1 maint: numeric names: authors list (link)</ref> Countries such as Germany, Denmark, and Spain have led the way in implementing innovative policies which has driven most of the growth over the past decade. As of 2014, Germany has a commitment to the "Energiewende" transition to a sustainable energy economy, and Denmark has a commitment to 100% renewable energy by 2050. There are now 144 countries with renewable energy policy targets.

Renewable energy continued its rapid growth in 2015, providing multiple benefits. There was a new record set for installed wind and photovoltaic capacity (64GW and 57GW) and a new high of US$329 Billion for global renewables investment. A key benefit that this investment growth brings is a growth in jobs.<ref>Editorial, Green Gold, Nature Energy, 2016.</ref> The top countries for investment in recent years were China, Germany, Spain, the United States, Italy, and Brazil.<ref name="map.ren21.net">REN21 (2012). Renewables Global Status Report 2012 Archived 15 December 2012 at the Wayback Machine p. 17.</ref><ref name="REN21 2011 35">REN21 (2011). "Renewables 2011: Global Status Report" (PDF). p. 35. Archived from the original (PDF) on 5 September 2011.{{cite web}}: CS1 maint: numeric names: authors list (link)</ref> Renewable energy companies include BrightSource Energy, First Solar, Gamesa, GE Energy, Goldwind, Sinovel, Targray, Trina Solar, Vestas, and Yingli.<ref name=top>Top of the list, Renewable Energy World, 2 January 2006.</ref><ref name=keith>Keith Johnson, Wind Shear: GE Wins, Vestas Loses in Wind-Power Market Race, Wall Street Journal, 25 March 2009, accessed on 7 January 2010.</ref>

Climate change concerns<ref name=ieapress>International Energy Agency. IEA urges governments to adopt effective policies based on key design principles to accelerate the exploitation of the large potential for renewable energy 29 September 2008.</ref><ref name=UNEP2>REN21 (2006). Changing climates: The Role of Renewable Energy in a Carbon-constrained World (PDF) Archived 11 June 2007 at the Wayback Machine p. 2.</ref><ref name=Stern>HM Treasury (2006). Stern Review on the Economics of Climate Change.</ref> are also driving increasing growth in the renewable energy industries.<ref name=UNnews>New UN report points to power of renewable energy to mitigate carbon emissions UN News Centre, 8 December 2007.</ref><ref name=mak>Joel Makower, Ron Pernick and Clint Wilder (2008). Clean Energy Trends 2008, Clean Edge, p. 2.</ref> According to a 2011 projection by the IEA, solar power generators may produce most of the world's electricity within 50 years, reducing harmful greenhouse gas emissions.<ref name=ieaiea2011>Ben Sills (29 August 2011). "Solar May Produce Most of World's Power by 2060, IEA Says". Bloomberg.</ref>

Background

Rationale for renewables

Climate change, pollution, and energy insecurity are significant problems, and addressing them requires major changes to energy infrastructures.<ref name=WWS2010>Jacobson, Mark Z. & Delucchi, Mark A. (2010). "Providing all Global Energy with Wind, Water, and Solar Power, Part I: Technologies, Energy Resources, Quantities and Areas of Infrastructure, and Materials" (PDF). Energy Policy.</ref> Renewable energy technologies are essential contributors to the energy supply portfolio, as they contribute to world energy security, reduce dependency on fossil fuels, and some also provide opportunities for mitigating greenhouse gases.<ref name="IEA" /> Climate-disrupting fossil fuels are being replaced by clean, climate-stabilizing, non-depletable sources of energy:

...the transition from coal, oil, and gas to wind, solar, and geothermal energy is well under way. In the old economy, energy was produced by burning something — oil, coal, or natural gas — leading to the carbon emissions that have come to define our economy. The new energy economy harnesses the energy in wind, the energy coming from the sun, and heat from within the earth itself.<ref>Lester R. Brown. Plan B 4.0: Mobilizing to Save Civilization, Earth Policy Institute, 2009, p. 135.</ref>

In international public opinion surveys there is strong support for a variety of methods for addressing the problem of energy supply. These methods include promoting renewable sources such as solar power and wind power, requiring utilities to use more renewable energy, and providing tax incentives to encourage the development and use of such technologies. It is expected that renewable energy investments will pay off economically in the long term.<ref>Council on Foreign Relations (18 January 2012). "Public Opinion on Global Issues: Chapter 5b: World Opinion on Energy Security". Archived from the original on 29 November 2009.</ref>

EU member countries have shown support for ambitious renewable energy goals. In 2010, Eurobarometer polled the twenty-seven EU member states about the target "to increase the share of renewable energy in the EU by 20 percent by 2020". Most people in all twenty-seven countries either approved of the target or called for it to go further. Across the EU, 57 percent thought the proposed goal was "about right" and 16 percent thought it was "too modest." In comparison, 19 percent said it was "too ambitious".<ref name="worldpublicopinion.org">"Large Majorities in US and Europe Endorse Focus on Renewable Energy". World Public Opinion. 18 January 2012. Archived from the original on 15 March 2012.</ref>

As of 2011, new evidence has emerged that there are considerable risks associated with traditional energy sources, and that major changes to the mix of energy technologies is needed:

Several mining tragedies globally have underscored the human toll of the coal supply chain. New EPA initiatives targeting air toxics, coal ash, and effluent releases highlight the environmental impacts of coal and the cost of addressing them with control technologies. The use of fracking in natural gas exploration is coming under scrutiny, with evidence of groundwater contamination and greenhouse gas emissions. Concerns are increasing about the vast amounts of water used at coal-fired and nuclear power plants, particularly in regions of the country facing water shortages. Events at the Fukushima nuclear plant have renewed doubts about the ability to operate large numbers of nuclear plants safely over the long term. Further, cost estimates for "next generation" nuclear units continue to climb, and lenders are unwilling to finance these plants without taxpayer guarantees.<ref>Synapse Energy Economics (16 November 2011). "Toward a Sustainable Future for the U.S. Power Sector: Beyond Business as Usual 2011" (PDF).</ref>

The 2014 REN21 Global Status Report says that renewable energies are no longer just energy sources, but ways to address pressing social, political, economic and environmental problems:

Today, renewables are seen not only as sources of energy, but also as tools to address many other pressing needs, including: improving energy security; reducing the health and environmental impacts associated with fossil and nuclear energy; mitigating greenhouse gas emissions; improving educational opportunities; creating jobs; reducing poverty; and increasing gender equality... Renewables have entered the mainstream.<ref>REN21 (2014). Renewables 2014 Global Status Report (PDF). ISBN 978-3-9815934-2-6. {{cite book}}: |work= ignored (help)CS1 maint: numeric names: authors list (link)</ref>

Growth of renewables

Renewable energy capacity has steadily grown, led by solar photovoltaic power.<ref name=IEA_202306>Source for data beginning in 2017: "Renewable Energy Market Update Outlook for 2023 and 2024" (PDF). IEA.org. International Energy Agency (IEA). June 2023. p. 19. Archived (PDF) from the original on 11 July 2023. IEA. CC BY 4.0. ● Source for data through 2016: "Renewable Energy Market Update / Outlook for 2021 and 2022" (PDF). IEA.org. International Energy Agency. May 2021. p. 8. Archived (PDF) from the original on 25 March 2023. IEA. Licence: CC BY 4.0</ref>

Clean energy investment has benefited from post-pandemic economic recovery, a global energy crisis involving high fossil fuel prices, and growing policy support across various nations.<ref name=IEA_20230525>"World Energy Investment 2023 / Overview and key findings". International Energy Agency (IEA). 25 May 2023. Archived from the original on 31 May 2023. Global energy investment in clean energy and in fossil fuels, 2015-2023 (chart) — From pages 8 and 12 of World Energy Investment 2023 (archive).</ref>

The countries most reliant on fossil fuels for electricity vary widely on how great a percentage of that electricity is generated from renewables, leaving wide variation in renewables' growth potential.<ref name=BP-Ember_20211103>Data: BP Statistical Review of World Energy, and Ember Climate (3 November 2021). "Electricity consumption from fossil fuels, nuclear and renewables, 2020". OurWorldInData.org. Our World in Data consolidated data from BP and Ember. Archived from the original on 3 November 2021.</ref>

In 2008 for the first time, more renewable energy than conventional power capacity was added in both the European Union and United States, demonstrating a "fundamental transition" of the world's energy markets towards renewables, according to a report released by REN21, a global renewable energy policy network based in Paris.<ref name=Mart>Eric Martinot and Janet Sawin. Renewables Global Status Report 2009 Update, Renewable Energy World, 9 September 2009.</ref> In 2010, renewable power consisted about a third of the newly built power generation capacities.<ref name="UNEP_GT_2011_Fig24">UNEP, Bloomberg, Frankfurt School, Global Trends in Renewable Energy Investment 2011 Archived 1 November 2011 at the Wayback Machine、Figure 24.</ref>

By the end of 2011, total renewable power capacity worldwide exceeded 1,360 GW, up 8%. Renewables producing electricity accounted for almost half of the 208 GW of capacity added globally during 2011. Wind and solar photovoltaics (PV) accounted for almost 40% and 30%.<ref name="ReferenceA">Renewables 2012 Global status report Archived 15 December 2012 at the Wayback Machine Executive summary REN21</ref> Based on REN21's 2014 report, renewables contributed 19 percent to our energy consumption and 22 percent to our electricity generation in 2012 and 2013, respectively. This energy consumption is divided as 9% coming from traditional biomass, 4.2% as heat energy (non-biomass), 3.8% hydro electricity and 2% electricity from wind, solar, geothermal, and biomass.<ref name="ria21-GSR2014">REN21 (2014). "Renewables 2014: Global Status Report" (PDF). pp. 13, 17, 21, 25. Archived from the original (PDF) on 15 September 2014.{{cite web}}: CS1 maint: numeric names: authors list (link)</ref>

During the five-years from the end of 2004 through 2009, worldwide renewable energy capacity grew at rates of 10–60 percent annually for many technologies, while actual production grew 1.2% overall.<ref>http://fs-unep-centre.org/sites/default/files/media/sefi2011finallowres.pdf Archived 16 November 2013 at the Wayback Machine pg25graph</ref><ref name=ren15>REN21 (2010). Renewables 2010 Global Status Report Archived 16 April 2012 at the Wayback Machine p. 15.</ref> In 2011, UN under-secretary general Achim Steiner said: "The continuing growth in this core segment of the green economy is not happening by chance. The combination of government target-setting, policy support and stimulus funds is underpinning the renewable industry's rise and bringing the much needed transformation of our global energy system within reach." He added: "Renewable energies are expanding both in terms of investment, projects and geographical spread. In doing so, they are making an increasing contribution to combating climate change, countering energy poverty and energy insecurity".<ref name=invest2011/>

According to a 2011 projection by the International Energy Agency, solar power plants may produce most of the world's electricity within 50 years, significantly reducing the emissions of greenhouse gases that harm the environment. The IEA has said: "Photovoltaic and solar-thermal plants may meet most of the world's demand for electricity by 2060 – and half of all energy needs – with wind, hydropower and biomass plants supplying much of the remaining generation". "Photovoltaic and concentrated solar power together can become the major source of electricity".<ref name="ieaiea2011"/>

Selected renewable energy global indicators	2008	2009	2010	2011	2012	2013	2014	2015	2016	2017	2018	2019	2020
Investment
Investment in new renewable capacity (annual) (billion USD)	182	178	237	279	256	232	270	285.9	241.6	279.8	289	302	304
Power
Renewables power capacity (existing) (GWe)	1,140	1,230	1,320	1,360	1,470	1,578	1,712	1,849	2,017	2,195	2,378	2,588	2,839
Hydropower capacity (existing) (GWe)	885	915	945	970	990	1,018	1,055	1,064	1,096	1,114	1,132	1,150	1,170
Solar PV capacity (grid-connected) (GWe)	16	23	40	70	100	138	177	227	303	402	505	627	760
Wind power capacity (existing) (GWe)	121	159	198	238	283	319	370	433	487	539	591	651	743
Heat
Solar hot water capacity (existing) (2008-2018 GW_th, 2019-2020 EJ)	130	160	185	232	255	373	406	435	456	472	480 GW_th (1.4 EJ<ref name="FOOTNOTEREN21 Renewables Global Status Report202035">REN21 Renewables Global Status Report 2020, p. 35.</ref>)	1.4	1.5
Transport
Ethanol production (annual) (billion litres)	67	76	86	86	83	87	94	98.8	98.6	106	112	114	105
Biodiesel production, fatty acid methyl ester (annual) (billion litres)	12	17.8	18.5	21.4	22.5	26	29.7	30.1	30.8	31	34	47	39
Policy
Countries with renewable energy targets	79	89	98	118	138	144	164	173	176	179	169	172	165
Source: REN21<ref name="FOOTNOTEREN21 Renewables Global Status Report2009">REN21 Renewables Global Status Report 2009.</ref><ref name="FOOTNOTEREN21 Renewables Global Status Report2010">REN21 Renewables Global Status Report 2010.</ref><ref name="FOOTNOTEREN21 Renewables Global Status Report2011">REN21 Renewables Global Status Report 2011.</ref><ref name="FOOTNOTEREN21 Renewables Global Status Report2012">REN21 Renewables Global Status Report 2012.</ref><ref name="FOOTNOTEREN21 Renewables Global Status Report2013">REN21 Renewables Global Status Report 2013.</ref><ref name="FOOTNOTEREN21 Renewables Global Status Report2014">REN21 Renewables Global Status Report 2014.</ref><ref name="FOOTNOTEREN21 Renewables Global Status Report2015">REN21 Renewables Global Status Report 2015.</ref><ref name="FOOTNOTEREN21 Renewables Global Status Report201619">REN21 Renewables Global Status Report 2016, p. 19.</ref><ref name="FOOTNOTEREN21 Renewables Global Status Report201721">REN21 Renewables Global Status Report 2017, p. 21.</ref><ref name="FOOTNOTEREN21 Renewables Global Status Report201819">REN21 Renewables Global Status Report 2018, p. 19.</ref><ref name="FOOTNOTEREN21 Renewables Global Status Report201919">REN21 Renewables Global Status Report 2019, p. 19.</ref><ref name="FOOTNOTEREN21 Renewables Global Status Report202035">REN21 Renewables Global Status Report 2020, p. 35.</ref><ref name="FOOTNOTEREN21 Renewables Global Status Report202140">REN21 Renewables Global Status Report 2021, p. 40.</ref>

In 2013, China led the world in renewable energy production, with a total capacity of 378 GW, mainly from hydroelectric and wind power. As of 2014, China leads the world in the production and use of wind power, solar photovoltaic power and smart grid technologies, generating almost as much water, wind and solar energy as all of France and Germany's power plants combined. China's renewable energy sector is growing faster than its fossil fuels and nuclear power capacity. Since 2005, production of solar cells in China has expanded 100-fold. As Chinese renewable manufacturing has grown, the costs of renewable energy technologies have dropped. Innovation has helped, but the main driver of reduced costs has been market expansion.<ref name=chinaen>John A. Mathews & Hao Tan (10 September 2014). "Economics: Manufacture renewables to build energy security". Nature. 513 (7517): 166–168. Bibcode:2014Natur.513..166M. doi:10.1038/513166a. PMID 25209783. S2CID 4459313.</ref>

See also renewable energy in the United States for US-figures.

Economic trends

Renewable energy technologies are getting cheaper, through technological change and through the benefits of mass production and market competition. A 2011 IEA report said: "A portfolio of renewable energy technologies is becoming cost-competitive in an increasingly broad range of circumstances, in some cases providing investment opportunities without the need for specific economic support," and added that "cost reductions in critical technologies, such as wind and solar, are set to continue."<ref name=henning>Henning Gloystein (23 November 2011). "Renewable energy becoming cost competitive, IEA says". Reuters.</ref> As of 2011^[update], there have been substantial reductions in the cost of solar and wind technologies:

The price of PV modules per MW has fallen by 60 percent since the summer of 2008, according to Bloomberg New Energy Finance estimates, putting solar power for the first time on a competitive footing with the retail price of electricity in a number of sunny countries. Wind turbine prices have also fallen – by 18 percent per MW in the last two years – reflecting, as with solar, fierce competition in the supply chain. Further improvements in the levelised cost of energy for solar, wind and other technologies lie ahead, posing a growing threat to the dominance of fossil fuel generation sources in the next few years.<ref name=invest2011>"Renewables Investment Breaks Records". Renewable Energy World. 29 August 2011.</ref>

Hydro-electricity and geothermal electricity produced at favourable sites are now the cheapest way to generate electricity. Renewable energy costs continue to drop, and the levelised cost of electricity (LCOE) is declining for wind power, solar photovoltaic (PV), concentrated solar power (CSP) and some biomass technologies.<ref name=irena111>International Renewable Energy Agency (2012). "Renewable Power Generation Costs in 2012: An Overview" (PDF). Archived from the original (PDF) on 15 July 2019. Retrieved 3 April 2013.</ref>

Renewable energy is also the most economic solution for new grid-connected capacity in areas with good resources. As the cost of renewable power falls, the scope of economically viable applications increases. Renewable technologies are now often the most economic solution for new generating capacity. Where "oil-fired generation is the predominant power generation source (e.g. on islands, off-grid and in some countries) a lower-cost renewable solution almost always exists today".<ref name=irena111/> As of 2012, renewable power generation technologies accounted for around half of all new power generation capacity additions globally. In 2011, additions included 41 gigawatt (GW) of new wind power capacity, 30 GW of PV, 25 GW of hydro-electricity, 6 GW of biomass, 0.5 GW of CSP, and 0.1 GW of geothermal power.<ref name=irena111/>

Three generations of technologies

Renewable energy includes a number of sources and technologies at different stages of commercialization. The International Energy Agency (IEA) has defined three generations of renewable energy technologies, reaching back over 100 years:

"First-generation technologies emerged from the industrial revolution at the end of the 19th century and include hydropower, biomass combustion, geothermal power and heat. These technologies are quite widely used.<ref name="IEA"/>
Second-generation technologies include solar heating and cooling, wind power, modern forms of bioenergy, and solar photovoltaics. These are now entering markets as a result of research, development and demonstration (RD&D) investments since the 1980s. Initial investment was prompted by energy security concerns linked to the oil crises of the 1970s but the enduring appeal of these technologies is due, at least in part, to environmental benefits. Many of the technologies reflect significant advancements in materials.<ref name="IEA"/>
Third-generation technologies are still under development and include advanced biomass gasification, biorefinery technologies, concentrating solar thermal power, hot-dry-rock geothermal power, and ocean energy. Advances in nanotechnology may also play a major role".<ref name="IEA"/>

First-generation technologies are well established, second-generation technologies are entering markets, and third-generation technologies heavily depend on long-term research and development commitments, where the public sector has a role to play.<ref name="IEA"/>

First-generation technologies

First-generation technologies are widely used in locations with abundant resources. Their future use depends on the exploration of the remaining resource potential, particularly in developing countries, and on overcoming challenges related to the environment and social acceptance.

Biomass

Biomass, the burning of organic materials for heat and power, is a fully mature technology. Unlike most renewable sources, biomass (and hydropower) can supply stable base load power generation.<ref name="Carneiro2012">Carneiro, Patrícia; Carneiro, Paula Ferreira (30 January 2012). "The economic, environmental and strategic value of biomass" (PDF). Renewable Energy. 44: 17–22. doi:10.1016/j.renene.2011.12.020. hdl:1822/19563. Retrieved 17 July 2021.</ref>

Biomass produces CO₂ emissions on combustion, and the issue of whether biomass is carbon neutral is contested.<ref name="Harvey2018">Harvey, Chelsea; Heikkinen, Niina (23 March 2018). "Congress Says Biomass Is Carbon-Neutral, but Scientists Disagree". Scientific American. Retrieved 17 July 2021.</ref> Material directly combusted in cook stoves produces pollutants, leading to severe health and environmental consequences. Improved cook stove programs are alleviating some of these effects.

The industry remained relatively stagnant over the decade to 2007, but demand for biomass (mostly wood) continues to grow in many developing countries, as well as Brazil and Germany.

The economic viability of biomass is dependent on regulated tariffs, due to high costs of infrastructure and ingredients for ongoing operations.<ref name="Carneiro2012"/> Biomass does offer a ready disposal mechanism by burning municipal, agricultural, and industrial organic waste products. First-generation biomass technologies can be economically competitive, but may still require deployment support to overcome public acceptance and small-scale issues.<ref name="IEA" /> As part of the food vs. fuel debate, several economists from Iowa State University found in 2008 "there is no evidence to disprove that the primary objective of biofuel policy is to support farm income."<ref>Rubin, Ofir D.; Carriquiry, Miguel; Hayes, Dermot J. (February 2008). Implied Objectives of U.S. Biofuel Subsidies. CARD Working Papers (Report). Vol. 493. Iowa State University. Abstract. Retrieved 17 July 2021.</ref>

Hydroelectricity

The 22,500 MW Three Gorges Dam in the People's Republic of China, the largest hydroelectric power station in the world

Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. In 2015 hydropower generated 16.6% of the worlds total electricity and 70% of all renewable electricity<ref>http://www.ren21.net/wp-content/uploads/2016/06/GSR_2016_Full_Report_REN21.pdf^{[bare URL PDF]}</ref> and is expected to increase about 3.1% each year for the next 25 years. Hydroelectric plants have the advantage of being long-lived and many existing plants have operated for more than 100 years.

Hydropower is produced in 150 countries, with the Asia-Pacific region generating 32 percent of global hydropower in 2010. China is the largest hydroelectricity producer, with 721 terawatt-hours of production in 2010, representing around 17 percent of domestic electricity use. There are now three hydroelectricity plants larger than 10 GW: the Three Gorges Dam in China, Itaipu Dam across the Brazil/Paraguay border, and Guri Dam in Venezuela.<ref name=wi2012>Worldwatch Institute (January 2012). "Use and Capacity of Global Hydropower Increases". Archived from the original on 24 September 2014. Retrieved 25 February 2013.</ref> The cost of hydroelectricity is low, making it a competitive source of renewable electricity. The average cost of electricity from a hydro plant larger than 10 megawatts is 3 to 5 U.S. cents per kilowatt-hour.<ref name=wi2012/>

Geothermal power and heat

Geothermal power plants can operate 24 hours per day, providing baseload capacity. Estimates for the world potential capacity for geothermal power generation vary widely, ranging from 40 GW by 2020 to as much as 6,000 GW.<ref>

Bertani, R., 2003, "What is Geothermal Potential?" Archived 26 July 2011 at the Wayback Machine, IGA News, 53, page 1-3.

</ref><ref name="IPCC Geothermal 2008">

Fridleifsson, I.B., R. Bertani, E. Huenges, J. W. Lund, A. Ragnarsson, and L. Rybach (2008). The possible role and contribution of geothermal energy to the mitigation of climate change Archived 8 March 2010 at the Wayback Machine. In: O. Hohmeyer and T. Trittin (Eds.), IPCC Scoping Meeting on Renewable Energy Sources, Proceedings, Luebeck, Germany, 20–25 January 2008, p. 59-80.</ref>

Geothermal power capacity grew from around 1 GW in 1975 to almost 10 GW in 2008.<ref name="IPCC Geothermal 2008"/> The United States is the world leader in terms of installed capacity, representing 3.1 GW. Other countries with significant installed capacity include the Philippines (1.9 GW), Indonesia (1.2 GW), Mexico (1.0 GW), Italy (0.8 GW), Iceland (0.6 GW), Japan (0.5 GW), and New Zealand (0.5 GW).<ref name="IPCC Geothermal 2008"/><ref>

Islandsbanki Geothermal Research, United States Geothermal Energy Market Report, October 2009, accessed through website of Islandbanki^{[permanent dead link]}.

</ref> In some countries, geothermal power accounts for a significant share of the total electricity supply, such as in the Philippines, where geothermal represented 17 percent of the total power mix at the end of 2008.<ref>

Leonora Walet. Philippines targets $2.5 billion geothermal development, Reuters, 5 November 2009.</ref>

Geothermal (ground source) heat pumps represented an estimated 30 GWth of installed capacity at the end of 2008, with other direct uses of geothermal heat (i.e., for space heating, agricultural drying and other uses) reaching an estimated 15 GWth. As of 2008^[update], at least 76 countries use direct geothermal energy in some form.<ref name=renewables/>

Second-generation technologies

Second-generation technologies have gone from being a passion for the dedicated few to a major economic sector in countries such as Germany, Spain, the United States, and Japan. Many large industrial companies and financial institutions are involved and the challenge is to broaden the market base for continued growth worldwide.<ref name="IEA"/><ref name=UNEP2 />

Solar heating

Solar heating systems are a well known second-generation technology and generally consist of solar thermal collectors, a fluid system to move the heat from the collector to its point of usage, and a reservoir or tank for heat storage. The systems may be used to heat domestic hot water, swimming pools, or homes and businesses.<ref>Brian Norton (2011) Solar Water Heaters: A Review of Systems Research and Design Innovation, Green. 1, 189–207, ISSN (Online) 1869–8778</ref> The heat can also be used for industrial process applications or as an energy input for other uses such as cooling equipment.<ref>International Energy Agency. Solar assisted air-conditioning of buildings Archived 5 November 2012 at the Wayback Machine</ref>

In many warmer climates, a solar heating system can provide a very high percentage (50 to 75%) of domestic hot water energy. As of 2009^[update], China has 27 million rooftop solar water heaters.<ref>Lester R. Brown. Plan B 4.0: Mobilizing to Save Civilization, Earth Policy Institute, 2009, p. 122.</ref>

Photovoltaics

President Barack Obama speaks at the DeSoto Next Generation Solar Energy Center.

Photovoltaic (PV) cells, also called solar cells, convert light into electricity. In the 1980s and early 1990s, most photovoltaic modules were used to provide remote-area power supply, but from around 1995, industry efforts have focused increasingly on developing building integrated photovoltaics and photovoltaic power stations for grid connected applications.

Many plants are integrated with agriculture and some use innovative tracking systems that follow the sun's daily path across the sky to generate more electricity than conventional fixed-mounted systems. There are no fuel costs or emissions during operation of the power stations.

Wind power

Some of the second-generation renewables, such as wind power, have high potential and have already realised relatively low production costs.<ref>"Stabilizing Climate" (PDF) Archived 26 September 2007 at the Wayback Machine in Lester R. Brown, Plan B 2.0 Rescuing a Planet Under Stress and a Civilization in Trouble (NY: W.W. Norton & Co., 2006), p. 189.</ref><ref name="clean">Clean Edge (2007). The Clean Tech Revolution... the costs of clean energy are declining (PDF) Archived 31 August 2007 at the Wayback Machine p.8.

</ref> Wind power could become cheaper than nuclear power.<ref>UK offshore wind 'will lower energy bills' more than nuclear The Guardian</ref> Global wind power installations increased by 35,800 MW in 2010, bringing total installed capacity up to 194,400 MW, a 22.5% increase on the 158,700 MW installed at the end of 2009. The increase for 2010 represents investments totalling €47.3 billion (US$65 billion) and for the first time more than half of all new wind power was added outside of the traditional markets of Europe and North America, mainly driven, by the continuing boom in China which accounted for nearly half of all of the installations at 16,500 MW. China now has 42,300 MW of wind power installed.<ref>David Beattie (18 March 2011). "Wind Power: China Picks Up Pace". Renewable Energy World.</ref> Wind power accounts for approximately 19% of electricity generated in Denmark, 9% in Spain and Portugal, and 6% in Germany and the Republic of Ireland.<ref>New Report a Complete Analysis of the Global Offshore Wind Energy Industry and its Major Players</ref> In Australian state of South Australia wind power, championed by Premier Mike Rann (2002–2011), now comprises 26% of the state's electricity generation, edging out coal fired power. At the end of 2011 South Australia, with 7.2% of Australia's population, had 54% of the nation's installed wind power capacity.<ref>Center for National Policy, Washington DC: What States Can Do, 2 April 2012</ref>

Wind power's share of worldwide electricity usage at the end of 2014 was 3.1%.<ref>http://www.ren21.net/wp-content/uploads/2015/07/REN12-GSR2015_Onlinebook_low1.pdf pg31</ref>

The wind industry is able to produce more power at lower cost by using taller wind turbines with longer blades, capturing the faster winds at higher elevations. This has opened up new opportunities and in Indiana, Michigan, and Ohio, the price of power from wind turbines built 300 feet to 400 feet above the ground can now compete with conventional fossil fuels like coal. Prices have fallen to about 4 cents per kilowatt-hour in some cases and utilities have been increasing the amount of wind energy in their portfolio, saying it is their cheapest option.<ref>Diane Cardwell (20 March 2014). "Wind Industry's New Technologies Are Helping It Compete on Price". New York Times.</ref>

Solar thermal power stations

View of Ivanpah Solar Electric Generating System from Yates Well Road, San Bernardino County, California. The Clark Mountain Range can be seen in the distance.

Solar thermal power stations include the 354 megawatt (MW) Solar Energy Generating Systems power plant in the US, Solnova Solar Power Station (Spain, 150 MW), Andasol solar power station (Spain, 100 MW), Nevada Solar One (USA, 64 MW), PS20 solar power tower (Spain, 20 MW), and the PS10 solar power tower (Spain, 11 MW). The 370 MW Ivanpah Solar Power Facility, located in California's Mojave Desert, is the world's largest solar-thermal power plant project currently under construction.<ref name=woody>

Todd Woody. In California's Mojave Desert, Solar-Thermal Projects Take Off Archived 5 November 2010 at the Wayback Machine Yale Environment 360, 27 October 2010.

</ref> Many other plants are under construction or planned, mainly in Spain and the USA.<ref name=global>REN21 (2008). Renewables 2007 Global Status Report (PDF) Archived 8 April 2008 at the Wayback Machine p. 12.</ref> In developing countries, three World Bank projects for integrated solar thermal/combined-cycle gas-turbine power plants in Egypt, Mexico, and Morocco have been approved.<ref name=global/>

Modern forms of bioenergy

Global ethanol production for transport fuel tripled between 2000 and 2007 from 17 billion to more than 52 billion litres, while biodiesel expanded more than tenfold from less than 1 billion to almost 11 billion litres. Biofuels provide 1.8% of the world's transport fuel and recent estimates indicate a continued high growth. The main producing countries for transport biofuels are the US, Brazil, and the EU.<ref>United Nations Environment Programme (2009). Assessing Biofuels Archived 22 November 2009 at the Wayback Machine, p.15.</ref>

Brazil has one of the largest renewable energy programs in the world, involving production of ethanol fuel from sugar cane, and ethanol now provides 18 percent of the country's automotive fuel. As a result of this and the exploitation of domestic deep water oil sources, Brazil, which for years had to import a large share of the petroleum needed for domestic consumption, recently reached complete self-sufficiency in liquid fuels.<ref>

America and Brazil Intersect on Ethanol Archived 26 September 2007 at the Wayback Machine Renewable Energy Access, 15 May 2006.

</ref><ref>

New Rig Brings Brazil Oil Self-Sufficiency Washington Post, 21 April 2006.</ref>

Nearly all the gasoline sold in the United States today is mixed with 10 percent ethanol, a mix known as E10,<ref>

Erica Gies. As Ethanol Booms, Critics Warn of Environmental Effect The New York Times, 24 June 2010.

</ref> and motor vehicle manufacturers already produce vehicles designed to run on much higher ethanol blends. Ford, DaimlerChrysler, and GM are among the automobile companies that sell flexible-fuel cars, trucks, and minivans that can use gasoline and ethanol blends ranging from pure gasoline up to 85% ethanol (E85). The challenge is to expand the market for biofuels beyond the farm states where they have been most popular to date. The Energy Policy Act of 2005, which calls for 7.5 billion US gallons (28,000,000 m³) of biofuels to be used annually by 2012, will also help to expand the market.<ref name="world">Worldwatch Institute and Center for American Progress (2006). American energy: The renewable path to energy security (PDF)</ref>

The growing ethanol and biodiesel industries are providing jobs in plant construction, operations, and maintenance, mostly in rural communities. According to the Renewable Fuels Association, "the ethanol industry created almost 154,000 U.S. jobs in 2005 alone, boosting household income by $5.7 billion. It also contributed about $3.5 billion in tax revenues at the local, state, and federal levels".<ref name="world" />

Third-generation technologies

Third-generation renewable energy technologies are still under development and include advanced biomass gasification, biorefinery technologies, hot-dry-rock geothermal power, and ocean energy. Third-generation technologies are not yet widely demonstrated or have limited commercialization. Many are on the horizon and may have potential comparable to other renewable energy technologies, but still depend on attracting sufficient attention and research and development funding.<ref name="IEA" />

New bioenergy technologies

Selected Commercial Cellulosic Ethanol Plants
in the U.S.<ref>Decker, Jeff. Going Against the Grain: Ethanol from Lignocellulosics, *Renewable Energy World*, 22 January 2009.</ref><ref>"Building Cellulose" (PDF). Retrieved 8 July 2010.</ref>
Company	Location	Feedstock
Abengoa Bioenergy	Hugoton, KS	Wheat straw
BlueFire Ethanol	Irvine, CA	Multiple sources
Gulf Coast Energy	Mossy Head, FL	Wood waste
Mascoma	Lansing, MI	Wood
POET LLC	Emmetsburg, IA	Corn cobs
SunOpta	Little Falls, MN	Wood chips
Xethanol	Auburndale, FL	Citrus peels
Note: plants are either operational or under construction

According to the International Energy Agency, cellulosic ethanol biorefineries could allow biofuels to play a much bigger role in the future than organizations such as the IEA previously thought.<ref> International Energy Agency (2006). World Energy Outlook 2006 (PDF) Archived 20 November 2009 at the Wayback Machine. </ref> Cellulosic ethanol can be made from plant matter composed primarily of inedible cellulose fibers that form the stems and branches of most plants. Crop residues (such as corn stalks, wheat straw and rice straw), wood waste, and municipal solid waste are potential sources of cellulosic biomass. Dedicated energy crops, such as switchgrass, are also promising cellulose sources that can be sustainably produced in many regions.<ref>Biotechnology Industry Organization (2007). Industrial Biotechnology Is Revolutionizing the Production of Ethanol Transportation Fuel pp. 3–4.</ref>

Ocean energy

Ocean energy is all forms of renewable energy derived from the sea including wave energy, tidal energy, river current, ocean current energy, offshore wind, salinity gradient energy and ocean thermal gradient energy.<ref name=OE1>Ocean energy Archived 31 October 2012 at the Wayback Machine EPRI Ocean Energy Web Page</ref>

The Rance Tidal Power Station (240 MW) is the world's first tidal power station. The facility is located on the estuary of the Rance River, in Brittany, France. Opened on 26 November 1966, it is currently operated by Électricité de France, and is the largest tidal power station in the world, in terms of installed capacity.

First proposed more than thirty years ago, systems to harvest utility-scale electrical power from ocean waves have recently been gaining momentum as a viable technology. The potential for this technology is considered promising, especially on west-facing coasts with latitudes between 40 and 60 degrees:<ref name=je>Jeff Scruggs and Paul Jacob. Harvesting Ocean Wave Energy, Science, Vol. 323, 27 February 2009, p. 1176.</ref>

In the United Kingdom, for example, the Carbon Trust recently estimated the extent of the economically viable offshore resource at 55 TWh per year, about 14% of current national demand. Across Europe, the technologically achievable resource has been estimated to be at least 280 TWh per year. In 2003, the U.S. Electric Power Research Institute (EPRI) estimated the viable resource in the United States at 255 TWh per year (6% of demand).<ref name=je/>

There are currently nine projects, completed or in-development, off the coasts of the United Kingdom, United States, Spain and Australia to harness the rise and fall of waves by Ocean Power Technologies. The current maximum power output is 1.5 MW (Reedsport, Oregon), with development underway for 100 MW (Coos Bay, Oregon).<ref name=OPT>Projects Archived 1 April 2012 at the Wayback Machine Ocean Power Technologies Projects</ref>

Enhanced geothermal systems

As of 2008^[update], geothermal power development was under way in more than 40 countries, partially attributable to the development of new technologies, such as Enhanced Geothermal Systems.<ref name=renewables>REN21 (2009). Renewables Global Status Report: 2009 Update Archived 12 June 2009 at the Wayback Machine pp. 12–13.</ref> The development of binary cycle power plants and improvements in drilling and extraction technology may enable enhanced geothermal systems over a much greater geographical range than "traditional" Geothermal systems. Demonstration EGS projects are operational in the US, Australia, Germany, France, and the United Kingdom.<ref>Bertani, Ruggero (2009). "Geothermal Energy: An Overview on Resources and Potential" (PDF). www.geothermal-energy.org. Retrieved 4 September 2021.</ref>

Advanced solar concepts

Beyond the already established solar photovoltaics and solar thermal power technologies are such advanced solar concepts as the solar updraft tower or space-based solar power. These concepts have yet to (if ever) be commercialized.

The Solar updraft tower (SUT) is a renewable-energy power plant for generating electricity from low temperature solar heat. Sunshine heats the air beneath a very wide greenhouse-like roofed collector structure surrounding the central base of a very tall chimney tower. The resulting convection causes a hot air updraft in the tower by the chimney effect. This airflow drives wind turbines placed in the chimney updraft or around the chimney base to produce electricity. Plans for scaled-up versions of demonstration models will allow significant power generation, and may allow development of other applications, such as water extraction or distillation, and agriculture or horticulture. To view a study on the solar updraft tower and its affects click here<ref>Das, Pritam; Chandramohan, V. P. (1 April 2019). "Computational study on the effect of collector cover inclination angle, absorber plate diameter and chimney height on flow and performance parameters of solar updraft tower (SUT) plant". Energy. 172: 366–379. doi:10.1016/j.energy.2019.01.128. ISSN 0360-5442. S2CID 115161178.</ref>

A more advanced version of a similarly themed technology is the Vortex engine (AVE) which aims to replace large physical chimneys with a vortex of air created by a shorter, less-expensive structure.

Space-based solar power (SBSP) is the concept of collecting solar power in space (using an "SPS", that is, a "solar-power satellite" or a "satellite power system") for use on Earth. It has been in research since the early 1970s. SBSP would differ from current solar collection methods in that the means used to collect energy would reside on an orbiting satellite instead of on Earth's surface. Some projected benefits of such a system are a higher collection rate and a longer collection period due to the lack of a diffusing atmosphere and night time in space.

Renewable energy industry

Total investment in renewable energy reached $211 billion in 2010, up from $160 billion in 2009. The top countries for investment in 2010 were China, Germany, the United States, Italy, and Brazil.<ref name="REN21 2011 35"/> Continued growth for the renewable energy sector is expected and promotional policies helped the industry weather the 2009 economic crisis better than many other sectors.<ref name=obama>Joel Makower, Ron Pernick and Clint Wilder (2009). Clean Energy Trends 2009 Archived 18 March 2009 at the Wayback Machine, Clean Edge, pp. 1–4.</ref>

Wind power companies

As of 2010^[update], Vestas (from Denmark) is the world's top wind turbine manufacturer in terms of percentage of market volume, and Sinovel (from China) is in second place. Together Vestas and Sinovel delivered 10,228 MW of new wind power capacity in 2010, and their market share was 25.9 percent. GE Energy (USA) was in third place, closely followed by Goldwind, another Chinese supplier. German Enercon ranks fifth in the world, and is followed in sixth place by Indian-based Suzlon.<ref>Tildy Bayar (4 August 2011). "World Wind Market: Record Installations, But Growth Rates Still Falling". Renewable Energy World.</ref>

Photovoltaic market trends

The solar PV market has been growing for the past few years. According to solar PV research company, PVinsights, worldwide shipment of solar modules in 2011 was around 25 GW, and the shipment year over year growth was around 40%. The top 5 solar module players in 2011 in turns are Suntech, First Solar, Yingli, Trina, and Sungen. The top 5 solar module companies possessed 51.3% market share of solar modules, according to PVinsights' market intelligence report.

2013 Ranking	Solar Module Company	Change from 2012	Country
1	Yingli Green Energy	–	China
2	Trina Solar	+1	China
3	Sharp Solar	+3	Japan
4	Canadian Solar	–	Canada
5	Jinko Solar	+3	China
6	ReneSola	+7	China
7	First Solar	−2	United States
8	Hanwha Solarone	+2	South Korea
9	Kyocera	+5	Japan
10	JA Solar	−3	China
Sources:<ref>Top 10 PV module suppliers in 2013</ref><ref>Renewables 2012 Global Status Report Archived 15 December 2012 at the Wayback Machine</ref>

The PV industry has seen drops in module prices since 2008. In late 2011, factory-gate prices for crystalline-silicon photovoltaic modules dropped below the $1.00/W mark. The $1.00/W installed cost, is often regarded in the PV industry as marking the achievement of grid parity for PV. These reductions have taken many stakeholders, including industry analysts, by surprise, and perceptions of current solar power economics often lags behind reality. Some stakeholders still have the perspective that solar PV remains too costly on an unsubsidized basis to compete with conventional generation options. Yet technological advancements, manufacturing process improvements, and industry re-structuring, mean that further price reductions are likely in coming years.<ref name=reconsidering>M Bazilian; I Onyeji; M Liebreich; I MacGill; J Chase; J Shah; D Gielen... (2013). "Re-considering the economics of photovoltaic power" (PDF). Renewable Energy (53). Archived from the original (PDF) on 31 May 2014. Retrieved 30 May 2014.</ref>

Non-technical barriers to acceptance

Many energy markets, institutions, and policies have been developed to support the production and use of fossil fuels.<ref name=jacob2010>Delucchi, Mark A. and Mark Z. Jacobson (2010). "Providing all Global Energy with Wind, Water, and Solar Power, Part II: Reliability, System and Transmission Costs, and Policies" (PDF). Energy Policy.

</ref> Newer and cleaner technologies may offer social and environmental benefits, but utility operators often reject renewable resources because they are trained to think only in terms of big, conventional power plants.<ref name=epsov/> Consumers often ignore renewable power systems because they are not given accurate price signals about electricity consumption. Intentional market distortions (such as subsidies), and unintentional market distortions (such as split incentives) may work against renewables.<ref name=epsov>Benjamin K. Sovacool. "Rejecting Renewables: The Socio-technical Impediments to Renewable Electricity in the United States," Energy Policy, 37(11) (November 2009), p. 4500.</ref> Benjamin K. Sovacool has argued that "some of the most surreptitious, yet powerful, impediments facing renewable energy and energy efficiency in the United States are more about culture and institutions than engineering and science".<ref> Benjamin K. Sovacool. "The Cultural Barriers to Renewable Energy in the United States," Technology in Society, 31(4) (November 2009), p. 372.</ref>

The obstacles to the widespread commercialization of renewable energy technologies are primarily political, not technical,<ref> Mark Z. Jacobson and Mark A. Delucchi. A Path to Sustainable Energy by 2030, Scientific American, November 2009, p. 45. </ref> and there have been many studies which have identified a range of "non-technical barriers" to renewable energy use.<ref>Lathia, Rutvik Vasudev; Dadhaniya, Sujal (February 2017). "Policy formation for Renewable Energy sources". Journal of Cleaner Production. 144: 334–336. doi:10.1016/j.jclepro.2017.01.023.</ref><ref name=ieapress/><ref name="NREL">National Renewable Energy Laboratory (2006). Nontechnical Barriers to Solar Energy Use: Review of Recent Literature, Technical Report, NREL/TP-520-40116, September, 30 pages.</ref><ref name=GREMS> United Nations Department of Economic and Social Affairs, (2005). Increasing Global Renewable Energy Market Share: Recent Trends and Perspectives Final Report.</ref> These barriers are impediments which put renewable energy at a marketing, institutional, or policy disadvantage relative to other forms of energy. Key barriers include:<ref name="NREL" /><ref name=GREMS />

Difficulty overcoming established energy systems, which includes difficulty introducing innovative energy systems, particularly for distributed generation such as photovoltaics, because of technological lock-in, electricity markets designed for centralized power plants, and market control by established operators. As the Stern Review on the Economics of Climate Change points out:

"National grids are usually tailored towards the operation of centralised power plants and thus favour their performance. Technologies that do not easily fit into these networks may struggle to enter the market, even if the technology itself is commercially viable. This applies to distributed generation as most grids are not suited to receive electricity from many small sources. Large-scale renewables may also encounter problems if they are sited in areas far from existing grids."<ref name=Stern2>
HM Treasury (2006). Stern Review on the Economics of Climate Change p. 355.</ref>

Lack of government policy support, which includes the lack of policies and regulations supporting deployment of renewable energy technologies and the presence of policies and regulations hindering renewable energy development and supporting conventional energy development. Examples include subsidies for fossil-fuels, insufficient consumer-based renewable energy incentives, government underwriting for nuclear plant accidents, and complex zoning and permitting processes for renewable energy.
Lack of information dissemination and consumer awareness.
Higher capital cost of renewable energy technologies compared with conventional energy technologies.
Inadequate financing options for renewable energy projects, including insufficient access to affordable financing for project developers, entrepreneurs and consumers.
Imperfect capital markets, which includes failure to internalize all costs of conventional energy (e.g., effects of air pollution, risk of supply disruption)<ref>Matthew L. Wald.

Fossil Fuels’ Hidden Cost Is in Billions, Study Says The New York Times, 20 October 2009.</ref> and failure to internalize all benefits of renewable energy (e.g., cleaner air, energy security).

Inadequate workforce skills and training, which includes lack of adequate scientific, technical, and manufacturing skills required for renewable energy production; lack of reliable installation, maintenance, and inspection services; and failure of the educational system to provide adequate training in new technologies.
Lack of adequate codes, standards, utility interconnection, and net-metering guidelines.
Poor public perception of renewable energy system aesthetics.
Lack of stakeholder/community participation and co-operation in energy choices and renewable energy projects.

With such a wide range of non-technical barriers, there is no "silver bullet" solution to drive the transition to renewable energy. So ideally there is a need for several different types of policy instruments to complement each other and overcome different types of barriers.<ref name=GREMS /><ref>Diesendorf, Mark (2007). Greenhouse Solutions with Sustainable Energy, UNSW Press, p. 293.</ref>

A policy framework must be created that will level the playing field and redress the imbalance of traditional approaches associated with fossil fuels. The policy landscape must keep pace with broad trends within the energy sector, as well as reflecting specific social, economic and environmental priorities.<ref>IEA Renewable Energy Working Party (2002). Renewable Energy... into the mainstream, p. 48.</ref> Some resource-rich countries struggle to move away from fossil fuels and have failed thus far to adopt regulatory frameworks necessary for developing renewable energy (e.g. Russia).<ref>Indra Overland, ‘The Siberian Curse: A Blessing in Disguise for Renewable Energy?’, Sibirica Journal of Siberian Studies, Vol. 9, No. 2, pp. 1-20. https://www.researchgate.net/publication/263524693</ref>

Public policy landscape

Public policy has a role to play in renewable energy commercialization because the free market system has some fundamental limitations. As the Stern Review points out: "In a liberalised energy market, investors, operators and consumers should face the full cost of their decisions. But this is not the case in many economies or energy sectors. Many policies distort the market in favour of existing fossil fuel technologies."<ref name=Stern2 /> The International Solar Energy Society has stated that "historical incentives for the conventional energy resources continue even today to bias markets by burying many of the real societal costs of their use".<ref>Donald W. Aitken. Transitioning to a Renewable Energy Future, International Solar Energy Society, January 2010, p. 4.</ref>

Fossil-fuel energy systems have different production, transmission, and end-use costs and characteristics than do renewable energy systems, and new promotional policies are needed to ensure that renewable systems develop as quickly and broadly as is socially desirable.<ref name=jacob2010/> Lester Brown states that the market "does not incorporate the indirect costs of providing goods or services into prices, it does not value nature's services adequately, and it does not respect the sustainable-yield thresholds of natural systems".<ref name="Br" /> It also favors the near term over the long term, thereby showing limited concern for future generations.<ref name="Br">Brown, L.R. (2006). Plan B 2.0 Rescuing a Planet Under Stress and a Civilization in Trouble Archived 11 July 2007 at the Wayback Machine W.W. Norton & Co, pp. 228–232.</ref> Tax and subsidy shifting can help overcome these problems,<ref name="Brown">Brown, L.R. (2006). Plan B 2.0 Rescuing a Planet Under Stress and a Civilization in Trouble Archived 11 July 2007 at the Wayback Machine W.W. Norton & Co, pp. 234–235.</ref> though is also problematic to combine different international normative regimes regulating this issue.<ref>Farah, Paolo Davide; Cima, Elena (2013). "Energy Trade and the WTO: Implications for Renewable Energy and the OPEC Cartel". Journal of International Economic Law (JIEL), Georgetown University Law Center. 4. SSRN 2330416.</ref>

Shifting taxes

Tax shifting has been widely discussed and endorsed by economists. It involves lowering income taxes while raising levies on environmentally destructive activities, in order to create a more responsive market. For example, a tax on coal that included the increased health care costs associated with breathing polluted air, the costs of acid rain damage, and the costs of climate disruption would encourage investment in renewable technologies. Several Western European countries are already shifting taxes in a process known there as environmental tax reform.<ref name="Br" />

In 2001, Sweden launched a new 10-year environmental tax shift designed to convert 30 billion kroner ($3.9 billion) of income taxes to taxes on environmentally destructive activities. Other European countries with significant tax reform efforts are France, Italy, Norway, Spain, and the United Kingdom. Asia's two leading economies, Japan and China, are considering carbon taxes.<ref name="Br" />

Shifting subsidies

Just as there is a need for tax shifting, there is also a need for subsidy shifting. Subsidies are not an inherently bad thing as many technologies and industries emerged through government subsidy schemes. The Stern Review explains that of 20 key innovations from the past 30 years, only one of the 14 was funded entirely by the private sector and nine were totally publicly funded.<ref>HM Treasury (2006). Stern Review on the Economics of Climate Change p. 362.</ref> In terms of specific examples, the Internet was the result of publicly funded links among computers in government laboratories and research institutes. And the combination of the federal tax deduction and a robust state tax deduction in California helped to create the modern wind power industry.<ref name="Brown" /> At the same time specifically US tax credits systems for renewable energy have been described as an "opaque" financial instrument dominated by large investors to reduce their tax payments while greenhouse gas reduction targets are being treated as a side effect.<ref>Knuth, Sarah (6 December 2021). "Rentiers of the low-carbon economy? Renewable energy's extractive fiscal geographies". Environment and Planning A: Economy and Space. 55 (6): 1548–1564. doi:10.1177/0308518x211062601. ISSN 0308-518X. S2CID 244932021.</ref>

Lester Brown has argued that "a world facing the prospect of economically disruptive climate change can no longer justify subsidies to expand the burning of coal and oil. Shifting these subsidies to the development of climate-benign energy sources such as wind, solar, biomass, and geothermal power is the key to stabilizing the earth's climate."<ref name="Brown"/> The International Solar Energy Society advocates "leveling the playing field" by redressing the continuing inequities in public subsidies of energy technologies and R&D, in which the fossil fuel and nuclear power receive the largest share of financial support.<ref>Donald W. Aitken. Transitioning to a Renewable Energy Future, International Solar Energy Society, January 2010, p. 6.</ref>

Some countries are eliminating or reducing climate-disrupting subsidies and Belgium, France, and Japan have phased out all subsidies for coal. Germany is reducing its coal subsidy. The subsidy dropped from $5.4 billion in 1989 to $2.8 billion in 2002, and in the process Germany lowered its coal use by 46 percent. China cut its coal subsidy from $750 million in 1993 to $240 million in 1995 and more recently has imposed a high-sulfur coal tax.<ref name="Brown" /> However, the United States has been increasing its support for the fossil fuel and nuclear industries.<ref name="Brown" />

In November 2011, an IEA report entitled Deploying Renewables 2011 said "subsidies in green energy technologies that were not yet competitive are justified in order to give an incentive to investing into technologies with clear environmental and energy security benefits". The IEA's report disagreed with claims that renewable energy technologies are only viable through costly subsidies and not able to produce energy reliably to meet demand.<ref name="henning"/>

A fair and efficient imposition of subsidies for renewable energies and aiming at sustainable development, however, require coordination and regulation at a global level, as subsidies granted in one country can easily disrupt industries and policies of others, thus underlining the relevance of this issue at the World Trade Organization.<ref>Farah, Paolo Davide; Cima, Elena (2015). "World Trade Organization, Renewable Energy Subsidies and the Case of Feed-In Tariffs: Time for Reform Toward Sustainable Development?". Georgetown International Environmental Law Review (GIELR). 27 (1). SSRN 2704398. and "WTO and Renewable Energy: Lessons from the Case Law". 49 JOURNAL OF WORLD TRADE 6, Kluwer Law International. SSRN 2704453.</ref>

Renewable energy targets

Setting national renewable energy targets can be an important part of a renewable energy policy and these targets are usually defined as a percentage of the primary energy and/or electricity generation mix. For example, the European Union has prescribed an indicative renewable energy target of 12 percent of the total EU energy mix and 22 percent of electricity consumption by 2010. National targets for individual EU Member States have also been set to meet the overall target. Other developed countries with defined national or regional targets include Australia, Canada, Israel, Japan, Korea, New Zealand, Norway, Singapore, Switzerland, and some US States.<ref name=UNEP3>United Nations Environment Program (2006). Changing climates: The Role of Renewable Energy in a Carbon-constrained World Archived 28 September 2007 at the Wayback Machine pp. 14–15.</ref>

National targets are also an important component of renewable energy strategies in some developing countries. Developing countries with renewable energy targets include China, India, Indonesia, Malaysia, the Philippines, Thailand, Brazil, Egypt, Mali, and South Africa. The targets set by many developing countries are quite modest when compared with those in some industrialized countries.<ref name=UNEP3 />

Renewable energy targets in most countries are indicative and nonbinding but they have assisted government actions and regulatory frameworks. The United Nations Environment Program has suggested that making renewable energy targets legally binding could be an important policy tool to achieve higher renewable energy market penetration.<ref name=UNEP3 />

Levelling the playing field

The IEA has identified three actions which will allow renewable energy and other clean energy technologies to "more effectively compete for private sector capital".

"First, energy prices must appropriately reflect the "true cost" of energy (e.g. through carbon pricing) so that the positive and negative impacts of energy production and consumption are fully taken into account". Example: New UK nuclear plants cost £92.50/MWh,<ref name=bbcstrike>"UK nuclear power plant gets go-ahead". BBC News. 21 October 2013.</ref><ref name=telestrike>Roland Gribben & Denise Roland (21 October 2013). "Hinkley Point nuclear power plant to create 25,000 jobs, says Cameron". Daily Telegraph. Archived from the original on 21 October 2013.</ref> whereas offshore wind farms in the UK are supported with €74.2/MWh<ref>Erin Gill. "France & UK offshore costs higher than average" Windpower Offshore, 28 March 2013. Accessed: 22 October 2013.</ref> at a price of £150 in 2011 falling to £130 per MWh in 2022.<ref>Christopher Willow & Bruce Valpy. "Offshore Wind Forecasts of future costs and benefits – June 2011 Archived 23 October 2013 at the Wayback Machine" Renewable UK, June 2011. Accessed: 22 October 2013.</ref> In Denmark, the price can be €84/MWh.<ref>"No consensus on offshore costs" Windpower Monthly, 1 September 2009. Accessed: 22 October 2013.</ref>
"Second, inefficient fossil fuel subsidies must be removed, while ensuring that all citizens have access to affordable energy".
"Third, governments must develop policy frameworks that encourage private sector investment in lower-carbon energy options".<ref>IEA (2012). "Tracking Clean Energy Progress" (PDF).</ref>

Green stimulus programs

In response to the global financial crisis in the late 2000s, the world's major governments made "green stimulus" programs one of their main policy instruments for supporting economic recovery. Some Template:US$ in green stimulus funding had been allocated to renewable energy and energy efficiency, to be spent mainly in 2010 and in 2011.<ref name=ren27>REN21 (2010). Renewables 2010 Global Status Report Archived 20 August 2010 at the Wayback Machine p. 27.</ref>

Energy sector regulation

Public policy determines the extent to which renewable energy (RE) is to be incorporated into a developed or developing country's generation mix. Energy sector regulators implement that policy—thus affecting the pace and pattern of RE investments and connections to the grid. Energy regulators often have authority to carry out a number of functions that have implications for the financial feasibility of renewable energy projects. Such functions include issuing licenses, setting performance standards, monitoring the performance of regulated firms, determining the price level and structure of tariffs, establishing uniform systems of accounts, arbitrating stakeholder disputes (like interconnection cost allocations), performing management audits, developing agency human resources (expertise), reporting sector and commission activities to government authorities, and coordinating decisions with other government agencies. Thus, regulators make a wide range of decisions that affect the financial outcomes associated with RE investments. In addition, the sector regulator is in a position to give advice to the government regarding the full implications of focusing on climate change or energy security. The energy sector regulator is the natural advocate for efficiency and cost-containment throughout the process of designing and implementing RE policies. Since policies are not self-implementing, energy sector regulators become a key facilitator (or blocker) of renewable energy investments.<ref name="PURC">Frequently Asked Questions on Renewable Energy and Energy Efficiency, Body of Knowledge on Infrastructure Regulation, [1]</ref>

Energy transition in Germany

The Energiewende (German for energy transition) is the transition by Germany to a low carbon, environmentally sound, reliable, and affordable energy supply.<ref name="bmwi-and-bmu-2010"> Federal Ministry of Economics and Technology (BMWi); Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) (28 September 2010). Energy concept for an environmentally sound, reliable and affordable energy supply (PDF). Berlin, Germany: Federal Ministry of Economics and Technology (BMWi). Archived from the original (PDF) on 6 October 2016. Retrieved 1 May 2016.</ref> The new system will rely heavily on renewable energy (particularly wind, photovoltaics, and biomass) energy efficiency, and energy demand management. Most if not all existing coal-fired generation will need to be retired.<ref name="acatech-etal-2016-a"> acatech; Lepoldina; Akademienunion, eds. (2016). Flexibility concepts for the German power supply in 2050: ensuring stability in the age of renewable energies (PDF). Berlin, Germany: acatech — National Academy of Science and Engineering. ISBN 978-3-8047-3549-1. Retrieved 28 April 2016.^{[permanent dead link]}</ref> The phase-out of Germany's fleet of nuclear reactors, to be complete by 2022, is a key part of the program.<ref name="bruninx-etal-2013"> Bruninx, Kenneth; Madzharov, Darin; Delarue, Erik; D'haeseleer, William (2013). "Impact of the German nuclear phase-out on Europe's electricity generation — a comprehensive study". Energy Policy. 60: 251–261. doi:10.1016/j.enpol.2013.05.026. Retrieved 12 May 2016.</ref>

Legislative support for the Energiewende was passed in late 2010 and includes greenhouse gas (GHG) reductions of 80–95% by 2050 (relative to 1990) and a renewable energy target of 60% by 2050.<ref name="bmwi-2015-b"> The Energy of the Future: Fourth "Energy Transition" Monitoring Report — Summary (PDF). Berlin, Germany: Federal Ministry for Economic Affairs and Energy (BMWi). November 2015. Archived from the original (PDF) on 20 September 2016. Retrieved 9 June 2016.</ref> These targets are ambitious.<ref name="buchan-2012"> Buchan, David (June 2012). The Energiewende — Germany's gamble (PDF). Oxford, UK: Oxford Institute for Energy Studies. ISBN 978-1-907555-52-7. Retrieved 12 May 2016.</ref> The Berlin-based policy institute Agora Energiewende noted that "while the German approach is not unique worldwide, the speed and scope of the Energiewende are exceptional".<ref name="agora-2015-a">Agora Energiewende (2015). Understanding the Energiewende: FAQ on the ongoing transition of the German power system (PDF). Berlin, Germany: Agora Energiewende. Archived from the original (PDF) on 2 June 2016. Retrieved 29 April 2016.</ref> The Energiewende also seeks a greater transparency in relation to national energy policy formation.<ref name="acatech-etal-2016-b"> acatech; Lepoldina; Akademienunion, eds. (2016). Consulting with energy scenarios : requirements for scientific policy advice (PDF). Berlin, Germany: acatech — National Academy of Science and Engineering. ISBN 978-3-8047-3550-7. Retrieved 9 November 2016.</ref>

Germany has made significant progress on its GHG emissions reduction target, achieving a 27% decrease between 1990 and 2014. However Germany will need to maintain an average GHG emissions abatement rate of 3.5% per annum to reach its Energiewende goal, equal to the maximum historical value thus far.<ref name="hillebrandt-etal-2015"> Hillebrandt, Katharina; et al., eds. (2015). Pathways to deep decarbonization in Germany (PDF). Sustainable Development Solutions Network (SDSN) and Institute for Sustainable Development and International Relations (IDDRI). Retrieved 28 April 2016.</ref>

Germany spends €1.5 billion per annum on energy research (2013 figure) in an effort to solve the technical and social issues raised by the transition.<ref name="schiermeier-2013"> Schiermeier, Quirin (10 April 2013). "Renewable power: Germany's energy gamble: an ambitious plan to slash greenhouse-gas emissions must clear some high technical and economic hurdles". Nature. Bibcode:2013Natur.496..156S. doi:10.1038/496156a. Retrieved 1 May 2016.</ref> This includes a number of computer studies that have confirmed the feasibility and a similar cost (relative to business-as-usual and given that carbon is adequately priced) of the Energiewende.

These initiatives go well beyond European Union legislation and the national policies of other European states. The policy objectives have been embraced by the German federal government and has resulted in a huge expansion of renewables, particularly wind power. Germany's share of renewables has increased from around 5% in 1999 to 22.9% in 2012, surpassing the OECD average of 18% usage of renewables.<ref name="economist-2012"> "Germany's energy transformation Energiewende". The Economist. 28 July 2012. Retrieved 14 June 2016.</ref> Producers have been guaranteed a fixed feed-in tariff for 20 years, guaranteeing a fixed income. Energy co-operatives have been created, and efforts were made to decentralize control and profits. The large energy companies have a disproportionately small share of the renewables market. However, in some cases poor investment designs have caused bankruptcies and low returns, and unrealistic promises have been shown to be far from reality.<ref name="latsch-etal-2014"> Latsch, Gunther; Seith, Anne; Traufetter, Gerald (30 January 2014). "Gone with the wind: weak returns cripple German renewables". Der Spiegel. Retrieved 14 June 2016.</ref> Nuclear power plants were closed, and the existing nine plants will close earlier than planned, in 2022.

One factor that has inhibited efficient employment of new renewable energy has been the lack of an accompanying investment in power infrastructure to bring the power to market. It is believed 8,300 km of power lines must be built or upgraded.<ref name="economist-2012"/> The different German States have varying attitudes to the construction of new power lines. Industry has had their rates frozen and so the increased costs of the Energiewende have been passed on to consumers, who have had rising electricity bills.

Voluntary market mechanisms for renewable electricity

Voluntary markets, also referred to as green power markets, are driven by consumer preference. Voluntary markets allow a consumer to choose to do more than policy decisions require and reduce the environmental impact of their electricity use. Voluntary green power products must offer a significant benefit and value to buyers to be successful. Benefits may include zero or reduced greenhouse gas emissions, other pollution reductions or other environmental improvements on power stations. <ref>"Voluntary and mandatory markets". United States Environmental Protection Agency. 25 March 2013. Retrieved 18 April 2013.</ref>

The driving factors behind voluntary green electricity within the EU are the liberalized electricity markets and the RES Directive. According to the directive, the EU Member States must ensure that the origin of electricity produced from renewables can be guaranteed and therefore a "guarantee of origin" must be issued (article 15). Environmental organisations are using the voluntary market to create new renewables and improving sustainability of the existing power production. In the US the main tool to track and stimulate voluntary actions is Green-e program managed by Center for Resource Solutions.<ref>"About Green-e". Center for Resource Solutions. 2013. Retrieved 18 April 2013.</ref> In Europe the main voluntary tool used by the NGOs to promote sustainable electricity production is EKOenergy label.<ref>"Frequently asked questions". EKOenergy Network. March 2013. Archived from the original on 4 July 2013. Retrieved 18 April 2013.</ref>

Recent developments

A number of events in 2006 pushed renewable energy up the political agenda, including the US mid-term elections in November, which confirmed clean energy as a mainstream issue. Also in 2006, the Stern Review<ref name=Stern /> made a strong economic case for investing in low carbon technologies now, and argued that economic growth need not be incompatible with cutting energy consumption.<ref>United Nations Environment Programme and New Energy Finance Ltd. (2007), p. 11.</ref> According to a trend analysis from the United Nations Environment Programme, climate change concerns<ref name=UNEP2 /> coupled with recent high oil prices<ref name=high>

High oil price hits Wall St ABC News, 16 October 2007. Retrieved on 15 January 2008.</ref> and increasing government support are driving increasing rates of investment in the renewable energy and energy efficiency industries.<ref name=UNnews/><ref name="UNEP">United Nations Environment Programme and New Energy Finance Ltd. (2007), p. 3.</ref>

Investment capital flowing into renewable energy reached a record US$77 billion in 2007, with the upward trend continuing in 2008.<ref name=mak/> The OECD still dominates, but there is now increasing activity from companies in China, India and Brazil. Chinese companies were the second largest recipient of venture capital in 2006 after the United States. In the same year, India was the largest net buyer of companies abroad, mainly in the more established European markets.<ref name="UNEP" />

New government spending, regulation, and policies helped the industry weather the 2009 economic crisis better than many other sectors.<ref name=obama/> Most notably, U.S. President Barack Obama's American Recovery and Reinvestment Act of 2009 included more than $70 billion in direct spending and tax credits for clean energy and associated transportation programs. This policy-stimulus combination represents the largest federal commitment in U.S. history for renewables, advanced transportation, and energy conservation initiatives. Based on these new rules, many more utilities strengthened their clean-energy programs.<ref name=obama/> Clean Edge suggests that the commercialization of clean energy will help countries around the world deal with the current economic malaise.<ref name=obama/> Once-promising solar energy company, Solyndra, became involved in a political controversy involving U.S. President Barack Obama's administration's authorization of a $535 million loan guarantee to the Corporation in 2009 as part of a program to promote alternative energy growth.<ref name="bare_url">Solar Energy Company Touted By Obama Goes Bankrupt, ABC News, 31 August 2011</ref><ref>Obama's Crony Capitalism, Reason, 9 September 2011</ref> The company ceased all business activity, filed for Chapter 11 bankruptcy, and laid-off nearly all of its employees in early September 2011.<ref>McGrew, Scott (2 September 2011). "Solyndra to Declare Bankruptcy". NBC News.</ref><ref>Solyndra files for bankruptcy, looks for buyer Archived 25 December 2011 at the Wayback Machine. Bloomberg Businessweek. Retrieved: 20 September 2011.</ref>

In his 24 January 2012, State of the Union address, President Barack Obama restated his commitment to renewable energy. Obama said that he "will not walk away from the promise of clean energy." Obama called for a commitment by the Defense Department to purchase 1,000 MW of renewable energy. He also mentioned the long-standing Interior Department commitment to permit 10,000 MW of renewable energy projects on public land in 2012.<ref name="Lindsay Morris">Lindsay Morris (25 January 2012). "Obama: Sticking to "Promise of Clean Energy"". Renewable Energy World.^{[permanent dead link]}</ref>

As of 2012, renewable energy plays a major role in the energy mix of many countries globally. Renewables are becoming increasingly economic in both developing and developed countries. Prices for renewable energy technologies, primarily wind power and solar power, continued to drop, making renewables competitive with conventional energy sources. Without a level playing field, however, high market penetration of renewables is still dependent on robust promotional policies. Fossil fuel subsidies, which are far higher than those for renewable energy, remain in place and quickly need to be phased out.<ref>REN21. (2013). Renewables 2013 Global Status Report, (Paris: REN21 Secretariat), ISBN 978-3-9815934-0-2.</ref>

United Nations' Secretary-General Ban Ki-moon has said that "renewable energy has the ability to lift the poorest nations to new levels of prosperity".<ref>Steve Leone (25 August 2011). "U.N. Secretary-General: Renewables Can End Energy Poverty". Renewable Energy World.</ref> In October 2011, he "announced the creation of a high-level group to drum up support for energy access, energy efficiency and greater use of renewable energy. The group is to be co-chaired by Kandeh Yumkella, the chair of UN Energy and director general of the UN Industrial Development Organisation, and Charles Holliday, chairman of Bank of America".<ref>Mark Tran (2 November 2011). "UN calls for universal access to renewable energy". The Guardian.</ref>

Worldwide use of solar power and wind power continued to grow significantly in 2012. Solar electricity consumption increased by 58 percent, to 93 terawatt-hours (TWh). Use of wind power in 2012 increased by 18.1 percent, to 521.3 TWh.<ref name=vitals>Matt Lucky; Michelle Ray & Mark Konold (30 July 2013). "Growth of Global Solar and Wind Energy Continues to Outpace Other Technologies" (PDF). Vital Signs.</ref> Global solar and wind energy installed capacities continued to expand even though new investments in these technologies declined during 2012. Worldwide investment in solar power in 2012 was $140.4 billion, an 11 percent decline from 2011, and wind power investment was down 10.1 percent, to $80.3 billion. But due to lower production costs for both technologies, total installed capacities grew sharply.<ref name=vitals/> This investment decline, but growth in installed capacity, may again occur in 2013.<ref>Sally Bakewell. "Clean Energy Investment Headed for Second Annual Decline" Bloomberg Businessweek, 14 October 2013. Accessed: 17 October 2013.</ref><ref>"Global Trends in Renewable Energy Investment 2013 Archived 18 October 2013 at the Wayback Machine" Bloomberg New Energy Finance, 12 June 2013. Accessed: 17 October 2013.</ref> Analysts expect the market to triple by 2030.<ref>"Renewables investment set to triple by 2030" BusinessGreen, 23 April 2013. Accessed: 17 October 2013.</ref> In 2015, investment in renewables exceeded fossils.<ref>Randall, Tom (14 January 2016). "Solar and Wind Just Did the Unthinkable". Bloomberg Businessweek.</ref>

100% renewable energy

The incentive to use 100% renewable energy for electricity, transport, or even total primary energy supply globally, has been motivated by global warming and other ecological as well as economic concerns. In the Intergovernmental Panel on Climate Change's reviews of scenarios of energy usage that would keep global warming to approximately 1.5 degrees, the proportion of primary energy supplied by renewables increases from 15% in 2020 to 60% in 2050 (median values across all published pathways).<ref name="FOOTNOTESR15 ReportC.2.4.2.1">SR15 Report, C.2.4.2.1.</ref> The proportion of primary energy supplied by biomass increases from 10% to 27%,<ref name="FOOTNOTESR15 Report2.4.2.1, Table 2.6.1">SR15 Report, 2.4.2.1, Table 2.6.1.</ref> with effective controls on whether land use is changed in the growing of biomass.<ref name="FOOTNOTESR15 Report111">SR15 Report, p. 111.</ref> The proportion from wind and solar increases from 1.8% to 21%.<ref name="FOOTNOTESR15 Report2.4.2.1, Table 2.6.1">SR15 Report, 2.4.2.1, Table 2.6.1.</ref>

At the national level, at least 30 nations around the world already have renewable energy contributing more than 20% of energy supply.

Mark Z. Jacobson, professor of civil and environmental engineering at Stanford University and director of its Atmosphere and Energy Program says producing all new energy with wind power, solar power, and hydropower by 2030 is feasible and existing energy supply arrangements could be replaced by 2050. Barriers to implementing the renewable energy plan are seen to be "primarily social and political, not technological or economic". Jacobson says that energy costs with a wind, solar, water system should be similar to today's energy costs.<ref name=enpol2011>Mark A. Delucchi & Mark Z. Jacobson (2011). "Providing all global energy with wind, water, and solar power, Part II: Reliability, system and transmission costs, and policies" (PDF). Energy Policy. Elsevier Ltd. pp. 1170–1190.</ref>

Renewable projects must be sited at distant locations due to high land prices in urban areas or for the renewable resource itself which require transmission construction costs.<ref>Hertz-Shargel, Ben. Ensuring Energy Security in a Renewables World. Atlantic Council, 2021. JSTOR, http://www.jstor.org/stable/resrep31086. Accessed 31 Oct. 2023.</ref>

Similarly, in the United States, the independent National Research Council has noted that "sufficient domestic renewable resources exist to allow renewable electricity to play a significant role in future electricity generation and thus help confront issues related to climate change, energy security, and the escalation of energy costs … Renewable energy is an attractive option because renewable resources available in the United States, taken collectively, can supply significantly greater amounts of electricity than the total current or projected domestic demand."<ref name=NRC>National Research Council (2010). Electricity from Renewable Resources: Status, Prospects, and Impediments. National Academies of Science. p. 4. ISBN 9780309137089.</ref>

The most significant barriers to the widespread implementation of large-scale renewable energy and low carbon energy strategies are primarily political and not technological. According to the 2013 Post Carbon Pathways report, which reviewed many international studies, the key roadblocks are: climate change denial, the fossil fuels lobby, political inaction, unsustainable energy consumption, outdated energy infrastructure, and financial constraints.<ref name="John Wiseman et al">John Wiseman; et al. (April 2013). "Post Carbon Pathways" (PDF). University of Melbourne. Archived from the original (PDF) on 20 June 2014.</ref>

Energy efficiency

Moving towards energy sustainability will require changes not only in the way energy is supplied, but in the way it is used, and reducing the amount of energy required to deliver various goods or services is essential. Opportunities for improvement on the demand side of the energy equation are as rich and diverse as those on the supply side, and often offer significant economic benefits.<ref>

InterAcademy Council (2007). Lighting the way: Toward a sustainable energy future Archived 28 November 2007 at the Wayback Machine</ref>

A sustainable energy economy requires commitments to both renewables and efficiency. Renewable energy and energy efficiency are said to be the "twin pillars" of sustainable energy policy. The American Council for an Energy-Efficient Economy has explained that both resources must be developed in order to stabilize and reduce carbon dioxide emissions:<ref name=am>

American Council for an Energy-Efficient Economy (2007). The Twin Pillars of Sustainable Energy: Synergies between Energy Efficiency and Renewable Energy Technology and Policy Report E074.</ref>

Efficiency is essential to slowing the energy demand growth so that rising clean energy supplies can make deep cuts in fossil fuel use. If energy use grows too fast, renewable energy development will chase a receding target. Likewise, unless clean energy supplies come online rapidly, slowing demand growth will only begin to reduce total emissions; reducing the carbon content of energy sources is also needed.<ref name=am />

The IEA has stated that renewable energy and energy efficiency policies are complementary tools for the development of a sustainable energy future, and should be developed together instead of being developed in isolation.<ref> International Energy Agency (2007). Global Best Practice in Renewable Energy Policy Making Archived 3 June 2016 at the Wayback Machine </ref>

References

Bibliography

Aitken, Donald W. (2010). Transitioning to a Renewable Energy Future, International Solar Energy Society, January, 54 pages.
Armstrong, Robert C., Catherine Wolfram, Robert Gross, Nathan S. Lewis, and M.V. Ramana et al. The Frontiers of Energy, Nature Energy, Vol 1, 11 January 2016.
EurObserv'ER (2012). The state of renewable energies in Europe, 250 pages.
HM Treasury (2006). Stern Review on the Economics of Climate Change, 575 pages.
Template:Wikicite
- Template:Wikicite, chapters I–V
- Template:Wikicite
- Template:Wikicite, 2 pp.
- Template:Wikicite, 22 pp.
- Template:Wikicite, 24 pp.
- Template:Wikicite, 24 pp.
International Council for Science (c2006). Discussion Paper by the Scientific and Technological Community for the 14th session of the United Nations Commission on Sustainable Development, 17 pages.
International Energy Agency (2006). World Energy Outlook 2006: Summary and Conclusions, OECD, 11 pages.
International Energy Agency (2007). Renewables in global energy supply: An IEA facts sheet, OECD, 34 pages.
International Energy Agency (2008). Deploying Renewables: Principles for Effective Policies, OECD, 8 pages.
International Energy Agency (2011). Deploying Renewables 2011: Best and Future Policy Practice, OECD.
International Energy Agency (2011). Solar Energy Perspectives, OECD.
Lovins, Amory B. (2011). Reinventing Fire: Bold Business Solutions for the New Energy Era, Chelsea Green Publishing, 334 pages.
Makower, Joel, and Ron Pernick and Clint Wilder (2009). Clean Energy Trends 2009, Clean Edge.
National Renewable Energy Laboratory (2006). Non-technical Barriers to Solar Energy Use: Review of Recent Literature, Technical Report, NREL/TP-520-40116, September, 30 pages.
Pernick, Ron and Wilder, Clint (2012). Clean Tech Nation: How the U.S. Can Lead in the New Global Economy, HarperCollins.
Renewables Global Status Report: 2009 Update (PDF). Paris: REN21 Secretariat. 2009. Retrieved 18 July 2021.
Renewables 2010 Global Status Report (PDF). Paris: REN21 Secretariat. 2010. Retrieved 18 July 2021.
Renewables 2011 Global Status Report (PDF). Paris: REN21 Secretariat. 2011. Retrieved 18 July 2021.
Renewables 2012 Global Status Report (PDF). Paris: REN21 Secretariat. 2012. Retrieved 18 July 2021.
Renewables 2013 Global Status Report (PDF). Paris: REN21 Secretariat. 2013. ISBN 978-3-9815934-0-2. Retrieved 18 July 2021.
Renewables 2014 Global Status Report (PDF). Paris: REN21 Secretariat. 2014. ISBN 978-3-9815934-2-6. Retrieved 18 July 2021.
Renewables 2015 Global Status Report (PDF). Paris: REN21 Secretariat. 2015. ISBN 978-3-9815934-6-4. Retrieved 18 July 2021.
Renewables 2016 Global Status Report (PDF). Paris: REN21 Secretariat. 2016. ISBN 978-3-9818107-0-7. Retrieved 18 July 2021.
Renewables 2017 Global Status Report (PDF). Paris: REN21 Secretariat. 2017. ISBN 978-3-9818107-6-9. Archived from the original (PDF) on 10 July 2021. Retrieved 18 July 2021.
Renewables 2018 Global Status Report (PDF). Paris: REN21 Secretariat. 2018. ISBN 978-3-9818911-3-3. Archived from the original (PDF) on 8 June 2021. Retrieved 18 July 2021.
Renewables 2019 Global Status Report (PDF). Paris: REN21 Secretariat. 2019. ISBN 978-3-9818911-7-1. Archived from the original (PDF) on 18 June 2021. Retrieved 18 July 2021.
Renewables 2020 Global Status Report (PDF). Paris: REN21 Secretariat. 2020. ISBN 978-3-948393-00-7. Retrieved 25 July 2021.
Renewables 2021 Global Status Report (PDF). Paris: REN21 Secretariat. 2021. ISBN 978-3-948393-03-8. Retrieved 25 July 2021.

External links

Template:Hydropower Template:Bioenergy

v t e Lists of renewable energy topics
Wind farm lists	List of onshore wind farms List of onshore wind farms in the United Kingdom List of offshore wind farms in the United Kingdom List of offshore wind farms in the United States Lists of offshore wind farms by country Lists of offshore wind farms by water area Lists of wind farms by country List of wind farms in Australia List of wind farms in Canada List of wind farms in Iran List of wind farms in Kosovo List of wind farms in New Zealand List of wind farms in Romania List of wind farms in Sweden List of wind farms in the United States List of wind turbine manufacturers
Solar power lists	Index of solar energy articles List of concentrating solar thermal power companies List of photovoltaics companies List of photovoltaic power stations List of pioneering solar buildings List of rooftop photovoltaic installations List of solar car teams List of solar powered products List of solar thermal power stations People associated with solar power
Other lists	List of books about renewable energy List of countries by electricity production from renewable sources List of geothermal power stations Lists of hydroelectric power stations List of largest hydroelectric power stations List of people associated with renewable energy List of renewable energy organizations List of renewable energy topics by country List of U.S. states by electricity production from renewable sources

v t e Wind power
Wind power	High-altitude History By country Land vehicles Offshore Turbines on public display Windmill Panemone
Wind farms	Community-owned Farms by country Offshore farms by country Onshore farms
Wind turbines	Aerodynamics Airborne Crosswind kite Design Floating Nacelle Pitch bearing QBlade Small Unconventional Vertical-axis Savonius Darrieus Yaw system Yaw bearing Yaw drive
Wind power industry	Consulting companies Manufacturers Software
Manufacturers	Enercon GE Wind Energy including GE Offshore Wind Goldwind Nordex Senvion Siemens Gamesa Suzlon Vestas
Concepts	2020s in wind power research Betz's law Blade element momentum theory Capacity factor Energy return on investment Wind power forecasting Grid energy storage HVDC Intermittency Variability Laddermill Net energy gain Resource assessment Storage Subsidies Tip-speed ratio Virtual power plant Wind hybrid power systems Wind profile power law
Lua error in mw.title.lua at line 318: bad argument #2 to 'title.new' (unrecognized namespace name 'Portal'). Category Commons Additional portals: Renewable energy Energy

v t e Environmental technology
Appropriate technology Clean technology Environmental design Environmental impact assessment Sustainable development Sustainable technology
Pollution	Air pollution (control dispersion modeling) Industrial ecology Solid waste treatment Waste management Water (agricultural wastewater treatment industrial wastewater treatment sewage treatment waste-water treatment technologies water purification)
Sustainable energy	Efficient energy use Electrification Energy development Energy recovery Fuel (alternative fuel biofuel carbon-neutral fuel hydrogen technologies) List of energy storage projects Renewable energy commercialization transition Transportation (electric vehicle hybrid vehicle)
Conservation	Birth control Building (green natural sustainable architecture New Urbanism New Classical) Nature conservation Conservation biology Ecoforestry Environmental movement Environmental remediation Green computing Land rehabilitation Permaculture Recycling

Anonymous

Search