Renewable energy in the United States

2014 Contributions by Renewables to US Total Energy (11%) or 9.678 Q BTU,[1]
2015 US Electric Renewables

by Alexa Huertas

The Shepherds Flat Wind Farm is an 845 megawatt (MW) wind farm in the U.S. state of Oregon.
Solar arrays at the 550 MW Desert Sunlight Solar Farm

Renewable energy in the United States accounted for 13.44 percent of the domestically produced electricity in 2015,[2] and 11.1 percent of total energy generation.[3] As of 2014, more than 143,000 people work in the solar industry and 43 states deploy net metering, where energy utilities buy back excess power generated by solar arrays.[4]

Renewable energy reached a major milestone in the first quarter of 2011, when it contributed 11.7 percent of total U.S. energy production (2.245 quadrillion BTU of energy), surpassing energy production from nuclear power (2.125 quadrillion BTU).[5] 2011 was the first year since 1997 that renewables exceeded nuclear in US total energy production.[6]

Hydroelectric power is currently the largest producer of renewable power in the U.S. It produced ar 6.14% of the nation's total electricity in 2015 which was 45.71% of the total renewable power in the U.S.[7] The United States is the fourth largest producer of hydroelectricity in the world after China, Canada and Brazil. The Grand Coulee Dam is the 5th largest hydroelectric power station in the world.

U.S. wind power installed capacity now exceeds 72,000 MW and supplies 4.1% of the nation's electricity.[8][9] Texas is firmly established as the leader in wind power development, followed by Iowa and California.[10] Since the U.S. pioneered the technology with Solar One, several solar thermal power stations have also been built. The largest of these solar thermal power stations are the Ivanpah Solar Power Facility (392 MW), southwest of Las Vegas, and the SEGS group of plants in the Mojave Desert, with a total generating capacity of 354 MW.[11] Large photovoltaic power plants in the USA include Solar Star (579 MW), near Rosamond, California, the Desert Sunlight Solar Farm, a 550 MW solar power plant in Riverside County, California[12] and the Topaz Solar Farm, a 550 MW photovoltaic power plant, in San Luis Obispo County, California.[13] The Geysers in Northern California is the largest complex of geothermal energy production in the world.

The development of renewable energy and energy efficiency marks "a new era of energy exploration" in the United States, according to President Barack Obama.[14] In a joint address to the Congress on February 24, 2009, President Obama called for doubling renewable energy within the next three years.[15] In his 2012 State of the Union address, President Barack Obama restated his commitment to renewable energy and mentioned the long-standing Interior Department commitment to permit 10,000 MW of renewable energy projects on public land in 2012.[16]

Rationale for renewables

Renewable energy technologies encompass a broad, diverse array of technologies, including solar photovoltaics, solar thermal power plants and heating/cooling systems, wind farms, hydroelectricity, geothermal power plants, and ocean power systems and the use of biomass.

The report Outlook On Renewable Energy In America explains that America needs renewable energy, for many reasons:

America needs energy that is secure, reliable, improves public health, protects the environment, addresses climate change, creates jobs, and provides technological leadership. America needs renewable energy. If renewable energy is to be developed to its full potential, America will need coordinated, sustained federal and state policies that expand renewable energy markets; promote and deploy new technology; and provide appropriate opportunities to encourage renewable energy use in all critical energy market sectors: wholesale and distributed electricity generation, thermal energy applications, and transportation.[17]

In 2009, President Barack Obama in the inaugural address called for the expanded use of renewable energy to meet the twin challenges of energy security and climate change. Those were the first references ever to the nation's energy use, to renewable resources, and to climate change in an inauguration speech of a U.S. president. President Obama looked to the near future, saying that as a nation, the United States will "harness the sun and the winds and the soil to fuel our cars and run our factories."[18]

The president's New Energy For America plan calls for a federal investment of $150 billion over the next decade to catalyze private efforts to build a clean energy future. Specifically, the plan calls for renewable energy to supply 10% of the nation's electricity by 2012, rising to 25% by 2025.[18]

In his joint address to Congress in 2009, Obama stated that: "We know the country that harnesses the power of clean, renewable energy will lead the 21st. century....Thanks to our recovery plan, we will double this nation’s supply of renewable energy in the next three years... It is time for America to lead again".[15]

According to Clean Edge, there's little doubt that the future of energy will be cleaner. The transition from carbon-intensive energy sources like wood, coal, and oil to natural gas and renewables, is well underway. For much of the developed world, and for developing nations, the "future looks increasingly like it will be built off of a mix of energy efficiency, renewables, the electrification of transport, and lower carbon fuels like natural gas".[19]

A 2010 survey conducted by Applied Materials shows that two-thirds of Americans believe solar technology should play a greater role in meeting the country's energy needs. In addition, "three-quarters of Americans feel that increasing renewable energy and decreasing U.S. dependence on foreign oil are the country's top energy priorities". According to the survey, "67 percent of Americans would be willing to pay more for their monthly utility bill if their utility company increased its use of renewable energy".[20]

In a 2010 Chicago Council on Global Affairs public opinion survey, an overwhelming 91 percent believed "investing in renewable energy" is important for the United States to remain economically competitive with other countries, with 62 percent considering this very important. The same poll found strong support for tax incentives to encourage development of renewable energy sources specifically as a way to reduce foreign energy imports. Eight in ten (80 percent) favored tax incentives, 47 percent strongly, and only 17 percent were opposed.[21]

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.[22]

Current trends

Percentage of electricity in the US generated from renewable sources 1950-2012; hydropower in blue and other renewable sources in red.

Renewable energy in the United States accounted for 13.44 percent of the domestically produced electricity in 2015.[23] California is a leading state and around 20 percent of California's electricity comes from RPS eligible renewable sources, and more if traditional hydropower sources are included.[24]

The United States has some of the best renewable energy resources in the world, which have the potential to meet a rising and significant share of the nation's energy demand. A quarter of the U.S. land area has winds strong enough to generate electricity at the same price as natural gas and coal.[25]

Many of the new technologies that harness renewables — including wind, solar, geothermal, and biofuels — are, or soon will be, economically competitive with the fossil fuels that meet 85 percent of U.S. energy needs. Dynamic growth rates are driving down costs and spurring rapid advances in technologies.[25] Energy technologies also receive government subsidies. In 2013, federal government energy-specific subsidies and supports for renewables, fossil fuels, and nuclear were $15.043 billion, $3.431 billion and $1.66 billion respectively. The subsidies and supports specific to electricity production amount to $11.678 billion, $1.591 billion and $1.66 billion respectively.[26]

All but four U.S. states now have incentives in place to promote renewable energy, while more than a dozen have enacted new renewable energy laws in recent years.[25]

Renewable energy suffered a political setback in the United States in September 2011 with the bankruptcy of Solyndra, a company that had received a $535 million federal loan guarantee.[27][28]

Renewable generation (Billion kWh, TWh)[23][29]
Year Hydro Geothermal Waste Wood CSP Utility PV Rooftop PV Onshore Wind Offshore Wind Renewable
Total 		U.S.
Total 		% Renewable
2002 264.33 14.49 15.04 38.66 0.555 10.34 0 343.44 3858.45 8.90%
2003 275.81 14.24 15.81 37.53 0.534 11.19 0 355.29 3883.18 9.15%
2004 268.42 14.81 15.42 38.12 0.575 14.14 0 351.48 3970.56 8.85%
2005 270.32 14.69 15.42 38.86 0.550 17.81 0 357.65 4055.42 8.82%
2006 289.25 14.57 16.10 38.76 0.508 26.59 0 385.77 4064.70 9.49%
2007 247.51 14.64 16.52 39.01 0.612 34.45 0 352.75 4156.74 8.49%
2008 254.83 14.84 17.73 37.30 0.864 55.36 0 417.72 4119.39 10.14%
2009 273.44 15.01 18.16 36.05 0.74 0.16 1.93 74.12 0 419.59 3950.31 10.62%
2010 257.08 15.67 18.59 37.61 0.82 0.46 3.21 94.95 0 428.38 4125.06 10.38%
2011 325.07 16.70 19.79 36.95 1.82 5.64 119.75 0 520.07 4105.73 12.67%
2012 276.24 15.56 19.82 37.8 4.33 8.45 140.82 0 513.4 4047.76 12.22%
2013 268.57 15.78 20.83 40.03 0.92 8.12 167.84 0 522.46 4058.21 12.87%
2014 259.37 15.88 21.65 42.34 2.44 15.25 9.54 181.66 548.12 4103.14 13.36%
2015 251.17 16.77 21.83 42.36 3.24 23.23 12.14 190.93 561.17 4099.52 13.69%

The United States used about 4,000 billion kWh/year of electricity in 2012, and about 98 quadrillion BTU/year (30,000 billion kWh). Efficiency improvements are expected to reduce usage to 15,000 billion kWh by 2050. The United States has the potential of installing 11 million MW of onshore wind power and 4 million MW of offshore wind power, capable of generating over 47,000 billion kWh. The U.S. has the potential of installing 10 to 20 million MW of concentrated solar power in the southwest, capable of generating over 10,000 billion kWh.[30]

Hydroelectricity

The Hoover Dam when completed in 1936 was both the world's largest electric-power generating station and the world's largest concrete structure.

Hydroelectric power is currently the largest producer of renewable power in the U.S. It produced around 6.14% of the nation's total electricity in 2015 which was 45.71% of the total renewable power in the U.S.[34] The United States is the fourth largest producer of hydroelectricity in the world after China, Canada and Brazil. The Grand Coulee Dam is the 5th largest hydroelectric power station in the world and another six U.S. hydro plants are among the 50 largest in the world. The amount of hydroelectric power generated is strongly affected by changes in precipitation and surface runoff.

Hydroelectric plants exist in at least 34 US states. Hydroelectricity projects such as Hoover Dam, Grand Coulee Dam, and the Tennessee Valley Authority have become iconic large construction projects.

The contribution over the last eleven years of hydroelectric power to the renewable power generation and to the total US power generation is shown below along with the yearly profile of the hydroelectric power generation for 2015. This shows the typical variations over the months of the year due to resource availability and needs.

2015 Hydro Electric Energy Profile
2014 Hydro Electric Energy Generation Profile
2015 Top Five Hydro StatesUS [36]
HYDRO Electric Generation in the United States[37] [38]
Year Summer Capacity (GW) Electrical energy (G kWh) Capacity factor Yearly growth of Generating Capacity Yearly growth of produced Energy Portion of renewable electrical energy Portion of total electrical energy
2015 79.74 251.17 0.360 0.6% -3.0% 45.71% 6.14%
2014 79.24 258.75 0.373 0.05% -3.66% 47.93% 6.32%
2013 79.22 268.57 0.387 0.64% -2.78% 51.44% 6.61%
2012 78.7 276.24 0.401 0.06% -13.50% 55.85% 6.82%
2011 78.65 319.36 0.464 -0.23% 22.74% 62.21% 7.79%
2010 78.83 260.2 0.377 0.39% -4.85% 60.88% 6.31%
2009 78.52 273.45 0.398 0.76% 7.31% 65.47% 6.92%
2008 77.93 254.83 0.373 0.05% 2.96% 66.90% 6.19%
2007 77.89 247.51 0.363 0.09% -14.43% 70.18% 5.95%
2006 77.82 289.25 0.424 0.36% 7.00% 74.97% 7.12%
2005 77.54 270.32 0.398 -0.13% 0.71% 75.57% 6.67%
2004 77.64 268.42 0.395 -1.33% -2.68% 76.36% 6.76%

Wind power

The 781 MW Roscoe Wind Farm in Texas, at sunrise.
Landowners typically receive $3,000 to $5,000 per year in rental income from each wind turbine, while farmers continue to grow crops or graze cattle up to the foot of the turbines.[39]

U.S. wind power installed capacity now exceeds 72 GW.[32] This capacity is exceeded only by China. The 1,320MW Alta Wind Energy Center is the largest wind farm in the world. Shepherds Flat Wind Farm in Oregon is the second largest wind farm in the world, completed in 2012, with the nameplate capacity of 845 MW.[40]

The U.S. wind industry generates tens of thousands of jobs and billions of dollars of economic activity.[41] Wind projects boost local tax bases, and revitalize the economy of rural communities by providing a steady income stream to farmers with wind turbines on their land.[39] GE Energy is the largest domestic wind turbine manufacturer.[39] In 2013 wind power received $5.936 billion in federal funding, which is 37% of all federal funding for electrity generation.[26]

In 2012 there were 8,900 MW under construction in nearly 100 projects.[42] The United States has the potential of installing 10 million MW of onshore wind power and 4 million MW of offshore wind.[43] The U.S. Department of Energy’s report 20% Wind Energy by 2030 envisioned that wind power could supply 20% of all U.S. electricity, which included a contribution of 4% from offshore wind power.[41] Additional transmission lines will need to be added, to bring power from windy states to the rest of the country.[44] In August 2011, a coalition of 24 governors asked the Obama administration to provide a more favorable business climate for the development of wind power.[45]

The contribution over the last eleven years of wind electric power to the renewable power generation and to the total US power generation is shown below along with the yearly profile of the wind electric power generation for 2015. This shows the typical variations over the months of the year due to wind availability.

2015 Wind Electric Energy Generation Profile
2014 Wind Electric Energy Generation Profile
Wind Electric Generation in the United States[54] [55]
Year Summer Capacity (GW) Electrical energy (G kWh) Capacity factor Yearly growth of Generating Capacity Yearly growth of produced Energy Portion of renewable electrical energy Portion of total electrical energy
2015 72.58 190.93 0.300 11.9% 5.00% 39.87% 4.67%
2014 64.85 181.79 0.320 8.13% 8.31% 33.68% 4.44%
2013 59.97 161.84 0.319 1.51% 19.19% 32.15% 4.13%
2012 59.08 140.82 0.272 29.33% 17.17% 28.47% 3.48%
2011 45.68 120.18 0.300 16.71% 26.97% 23.41% 2.93%
2010 39.14 94.65 0.276 14.11% 28.10% 22.15% 2.29%
2009 34.3 73.89 0.246 39.15% 33.47% 17.69% 1.87%
2008 24.65 55.36 0.256 49.21% 60.70% 14.53% 1.34%
2007 16.52 34.45 0.238 45.81% 29.56% 9.77% 0.83%
2006 11.33 26.59 0.268 30.08% 49.30% 6.89% 0.65%
2005 8.71 17.81 0.233 34.83% 25.95% 4.98% 0.44%
2004 6.46 14.14 0.250 7.67% 26.36% 4.02% 0.36%

Solar Power

Solar power will be discussed in three distinct varieties . Electric energy is generated by two different methods -Thermal and Photovoltaic. Application is either utility scale for electric grid power generation or much smaller distributed systems which may or may not be integrated into the electric grid. Utility grade systems have well documented generation but distributed systems contributions to user electric power needs are not measured or controlled. Therefore, quantitative evaluation of distributive solar to the overall US electric power environment has been lacking. Recently, the Energy Information Administration.[56][57] has begun estimating that contribution.

2006-2015 Solar Electric Energy with 2014-2015 Estimated Distributed Solar[58]

In 2015, utility scale solar[59] contributed 26.47 G kWh (billion kWh) to the grid with 23.233 G kWh from photovoltaics and 3.24 G kWh from thermal systems. In 2014 and 2015, EIA estimated that distributed solar>[60] generated 9.536 G kWh and 12.141 G kWh respectively.

2015 Major Solar Farms[61]
2015 Solar projects Capacity Factors [62]
2015 Top Five Solar States [63]

Solar thermal power utility scale

Looking north towards the Ivanpah Solar Power Facility's eastern boiler tower from Interstate 15 in California.

Prior to 2012, in six southwestern states (Arizona, California, Colorado, Nevada, New Mexico, and Utah) the US Bureau of Land Management owned nearly 98 million acres (an area larger than the state of Montana) that was open to proposals for solar power installations. To streamline consideration of applications, the BLM produced a Programmatic Environmental Impact Statement (PEIS). By the subsequent Record of Decision in October 2012, the BLM withdrew 78 percent of its land from possible solar development, leaving 19 million acres still open to applications for solar installations, an area nearly as large as South Carolina. Of the area left open to solar proposals, the BLM has identified 285 thousand acres in 17 highly favorable areas it calls Solar Energy Zones.[64][65][66]

Solar Energy Generating Systems

Solar Energy Generating Systems (SEGS) is the name given to nine solar power plants in the Mojave Desert. SEGS I-VII are located at Kramer Junction, and SEGS VIII and IX are at Harper Lake and Barstow respectively. The SEGS power plants were commissioned between 1984 and 1991.[11]

The installation uses parabolic trough solar thermal technology along with natural gas to generate electricity. The facility has a total of 400,000 mirrors and covers 1,000 acres (4 km²). The plants have a total generating capacity of 354 MW.[11]

Nevada Solar One

Nevada Solar One generates 64MW of power and in Boulder City, Nevada, and was built by the U.S. Department of Energy (DOE), National Renewable Energy Laboratory (NREL), and Solargenix Energy. Nevada Solar One started producing electricity in June 2007.

Nevada Solar One uses parabolic troughs as thermal solar concentrators, heating tubes of liquid which act as solar receivers. These solar receivers are specially coated tubes made of glass and steel. About 19,300 of these 4 metre long tubes are used in the newly built power plant. Nevada Solar One also uses a technology that collects extra heat by putting it into phase-changing molten salts. This energy can then be drawn on at night.[67]

Solar thermal power plants designed for solar-only generation are well matched to summer noon peak loads in prosperous areas with significant cooling demands, such as the south-western United States. Using thermal energy storage systems, solar thermal operating periods can even be extended to meet base-load needs.[68]

Ivanpah Solar Power Facility

The Ivanpah Solar Power Facility is a 392 megawatt (MW) solar power facility which is located in south-eastern California.[69] The facility formally opened on February 13, 2014.[70]

Others

The Solana Generating Station is a 280 MW solar power plant which is near Gila Bend, Arizona, about 70 miles (110 km) southwest of Phoenix. The 250MW Mojave Solar Project is located near Barstow, California. The Crescent Dunes Solar Energy Project is a 110 megawatt (MW) solar thermal power project near Tonopah, about 190 miles (310 km) northwest of Las Vegas.[71]

Land use issues

A 2013 study by the US National Renewable Energy Laboratory concluded that utility-scale solar power plants directly disturb an average of 2.7 to 2.9 acres per gigawatt-hour/year, and use from 3.5 to 3.8 acres per gW-hr/year for the entire sites. According to a 2009 study, this intensity of land use is less than that of the average US power plant using surface-mined coal.[72] Some of the land in the eastern portion of the Mojave Desert is to be preserved, but the solar industry is more interested in areas of the western desert, "where the sun burns hotter and there is easier access to transmission lines".[73]

Generation

2015 Solar Thermal Electric Energy Generation Profile
2014 Solar Thermal Electric Energy Generation Profile

The contribution to the US electric grid over the last eleven years of solar thermal electric power to the renewable power generation and to the total US power generation is shown below along with the yearly profile of the solar thermal power generation for 2014 and 2015. This shows the typical variations over the months of the year due to sunlight availability. Before 2008, most solar-generated electric energy was from thermal systems. By 2011, photovoltaics had overtaken thermal.

Solar Thermal Electric Generation in the United States[55][74]
Year Summer Capacity (GW) Electrical energy (G kWh) Capacity factor Yearly growth of Generating Capacity Yearly growth of produced Energy Portion of renewable electrical energy Portion of total electrical energy
2015 1.78 3.240 0.208 7.2% 32.7% 0.59% 0.08%
2014 1.66 2.446 0.168 28.68% 164.15% 0.45% 0.06%
2013 1.29 0.926 0.082 171.01% 5.71% 0.18% 0.02%
2012 0.476 0.876 0.210 1.06% 8.68% 0.18% 0.02%
2011 0.471 0.806 0.195 2.15% 0.16% 0.02%
2010 0.789 0.245 7.35% 0.18% 0.02%
2009 0.735 0.236 -6.73% 0.18% 0.02%
2008 0.788 0.195 32.21% 0.21% 0.02%
2007 0.596 20.89% 0.17% 0.01%
2006 0.493 -7.85% 0.13% 0.01%
2005 0.535 -5.98% 0.15% 0.01%
2004 0.569 0.16% 0.01%

Solar photovoltaic power utility scale

Nellis Solar Power Plant at Nellis Air Force Base. These panels track the sun in one axis.

At the end of 2014, the U.S. had 18.3 gigawatts (GW) of installed photovoltaic capacity with an additional 1.7 GW of concentrated solar power.[75] The U.S. pioneered solar farms and many key developments in photovoltaics came out of U.S. research.

The U.S. has some of the largest solar farms in the world. Solar Star is a 579 megawatt (MWAC) farm near Rosamond, California. Completed in June 2015, it uses 1.7 million solar panels, spread over 13 square kilometers (3,200 acres).[76][77][78] The Desert Sunlight Solar Farm is a 550 MW solar power plant in Riverside County, California, that uses thin-film solar photovoltaic modules made by First Solar.[12] The Topaz Solar Farm is a 550 MW photovoltaic power plant, in San Luis Obispo County, California.[13] The Blythe Solar Power Project is a 485 MW photovoltaic station planned for Riverside County, California.

Many schools and businesses have building-integrated photovoltaic solar panels on their roof. Most of these are grid connected and use net metering laws to allow use of electricity in the evening that was generated during the daytime. New Jersey leads the nation with the least restrictive net metering law, while California leads in total number of homes which have solar panels installed. Many were installed because of the million solar roof initiative.[79] California decided that it is not moving forward fast enough on photovoltaic generation and in 2008 enacted a feed-in tariff. Washington state has a feed-in tariff of 15 ¢/kWh which increases to 54 ¢/kWh if components are manufactured in the state.[80] By 2015, California, Hawaii, Arizona and some other states were lowering payments to distributed solar owners and instituting new fees for grid usage. Tesla and a handful of other companies were promoting household grid-tied batteries while some electric companies were investing in utility-scale grid energy storage including very large batteries.

The contribution to the US electric grid over the last ten years of solar photovoltaic electric power to the renewable power generation and to the total US power generation is shown below along with the yearly profile of the photovoltaic power generation for 2014 and 2015. This shows the typical variations over the months of the year due to sunlight availability. Before 2008, most solar-generated electric energy was from thermal systems. By 2011, photovoltaics had overtaken thermal.

2015 Solar PV Electric Energy Generation Profile
2014 Solar PV Electric Energy Generation Profile
Solar Photovoltaic Electric Generation in the United States[55] [74]
Year Summer Capacity (GW) Electrical energy (G kWh) Capacity factor Yearly growth of Generating Capacity Yearly growth of produced Energy Portion of renewable electrical energy Portion of total electrical energy
2015 11.63 23.233 0.228 38.9% 52.3% 4.2% 0.57%
2014 8.37 15.87 0.216 56.74% 90.55% 2.94% 0.39%
2013 5.34 8.33 0.178 98.51% 141.45% 1.60% 0.20%
2012 2.69 3.45 0.146 156.19% 241.58% 0.70% 0.09%
2011 1.05 1.01 0.110 138.77% 0.20% 0.02%
2010 0.423 0.203 169.43% 0.10% 0.01%
2009 0.157 0.206 106.58% 0.04% 0.00%
2008 0.076 0.225 375.00% 0.02% 0.00%
2007 0.016 6.67% 0.00% 0.00%
2006 0.015 -6.25% 0.00% 0.00%
2005 0.016 166.67% 0.00% 0.00%
2004 0.006 0.00% 0.00% 0.00%

Estimated Distributed Solar

Photovoltaic solar panels on a house roof

Beginning with the 2014 data year, Energy Information Administration will estimate distributed solar photovoltaic generation and distributed solar photovoltaic capacity.[81] These non-utility scale estimates project that, in 2014 the USA, generated [82] a further 9.536 GWh and in 2015 an additional 12.141 GWh of solar electricity from such distributed PV systems. State information follows:

Top Five States for Distributed Solar[83]
Estimated Distributed Solar by States with less than 600 M kWh[84]

Geothermal power

Existing and planned US geothermal power generation, as of February 2013

The USA is the world leader in online capacity and the generation of electricity from geothermal energy.[85] According to 2014 state energy data, geothermal energy provided approximately 16 billion kilowatt hours (kWh) of electricity—0.31% of the electricity consumed in the U.S. As of May 2007, geothermal electric power was generated in five U.S. states: Alaska, California, Hawaii, Nevada, and Utah. According to the Geothermal Energy Association's recent report, there were 75 new geothermal power projects underway in 12 states as of May 2007 . This is an increase of 14 projects in an additional three states compared to a survey completed in November 2006.[85]

The most significant catalyst behind new industry activity is the Energy Policy Act of 2005. This Act made new geothermal plants eligible for the full federal production tax credit, previously available only to wind power projects. It also authorized and directed increased funding for research by the Department of Energy, and gave the Bureau of Land Management new legal guidance and secure funding to address its backlog of geothermal leases and permits.[85]

Installed geothermal capacity in megawatts (MW) by state as of February 2013:[86]

StateCapacity (MW)Share of U.S total
California2,732.280.7%
Nevada517.515.3%
Utah48.11.4%
Hawaii38.01.1%
Oregon33.31.0%
Idaho15.80.5%
Alaska0.7<0.1%
Wyoming0.3<0.1%
Total3,385.9100%

The contribution over the last eleven years of geothermal power to the renewable power generation and to the total US power generation is shown below along with the yearly profile of the geothermal power generation for 2014.

2015 Geothermal Electric Energy Generation Profile
2014 Geo Thermal Electric Energy Generation Profile
Geothermal Electric Generation in the United States[55] [74]
Year Summer Capacity (GW) Electrical energy (G kWh) Capacity factor Yearly growth of Generating Capacity Yearly growth of produced Energy Portion of renewable electrical energy Portion of total electrical energy
2015 2.53 16.77 0.757 -3.0% 0.8% 3.05% 0.41%
2014 2.607 16.63 0.728 0.00% 5.39% 3.08% 0.41%
2013 2.607 15.78 0.691 0.58% 1.4% 3.02% 0.39%
2012 2.592 15.562 0.685 7.60% 1.61% 3.15% 0.38%
2011 2.409 15.316 0.726 0.17% 0.64% 2.98% 0.37%
2010 2.405 15.219 0.722 0.97% 1.40% 3.56% 0.37%
2009 2.382 15.009 0.719 6.86% 1.14% 3.59% 0.38%
2008 2.229 14.84 0.760 0.68% 1.39% 3.90% 0.36%
2007 2.214 14.637 0.755 -2.64% 0.47% 4.15% 0.35%
2006 2.274 14.568 0.731 -0.48% -0.84% 3.78% 0.36%
2005 2.285 14.692 0.734 6.18% -0.80% 4.11% 0.36%
2004 2.152 14.811 0.786 0.89% 2.68% 4.21% 0.37%

Solar water heating

The U.S. Department of Energy stated (in 2006) that more than 1.5 million homes and businesses were currently using solar water heating in the United States, representing a capacity of over 1,000 megawatts (MW) of thermal energy generation. It predicted that another 400 MW was likely to be installed over the next 3–5 years.

Assuming that 40 percent of existing homes in the United States have adequate access to sunlight, 29 million solar water heaters could be installed.[87]

Solar water heaters can operate in any climate. Performance varies depending on how much solar energy is available at the site, as well as how cold the water coming into the system is. The colder the water, the more efficiently the system operates.[87]

Solar water heaters reduce the need for conventional water heating by about two-thirds and pay for their installation within 4 to 8 years with electricity or natural gas savings. Compared to those with electric water heaters, Florida homeowners with solar water heaters save 50 to 85 percent on their water heating bills, according to the Florida Solar Energy Center.[87]

Biomass

Main article: Biomass

In 2015, biomass generated 64.19 million megawatt-hours, 1.57% of total US generated electricity. It was the largest source of total renewable energy in the US, and the third-largest renewable source of electrical power in the US, after hydropower and wind.[88]

Biomass is biological material derived from living, or recently living organisms, such as plants and trees and utilizes wastes or plant matter specifically grown to generate electricity or produce heat. The main advantage of using grown fuels, as opposed to fossil fuels such as coal, natural gas and oil, is that while they are growing they absorb the near-equivalent in carbon dioxide (an important greenhouse gas) to that which is later released in their burning. Although there is some debate over the net carbon neutrality and near term affects of using the biomass for energy a key difference is the relatively short carbon recycle period of grown biomass (several years or decades) as opposed to the millions of years it took to turn carbon into fossil fuels. With proper conservation and growing techniques biomass can be an important renewable energy source.

Biomass can be utilized for all three major energy needs: electricity, heating/cooling and transportation fuels. However, each usage is distinctly different from the others, especially regarding efficiency - the percentage of energy utilized from the biomass source. Whereas pellets for heating can be up to 90% efficient, bio-electricity plants are comparable to coal power plants, with around 30% efficiency, and biofuels from crops or algae even less.

Biomass electric generation data combines two basic categories: 1) Wood and wood derived fuels including wood/wood waste solids (including paper pellets, railroad ties, utility poles, wood chiips, bark and wood waste solids), wood waste liquids (red liquor, sludge wood, spent sulfite liquor, and other wood based liquids), and black liquor. and, 2) Other biomass fuels include municipal solid waste, landfill gas, sludge waste agricultural byproducts, other biomass solids, other biomass liquids, and other biomass gases (including digester gases, methane, and other biomass gases). The contribution from these two categories over the last ten years of biomass electric power to the renewable power generation and to the total US power generation is shown below along with the yearly profile of the electric power generation for 2014 and 2015. This shows the typical variations over the months of the year due to fuel availability and needs. |

Biomass Electric Generation in the United States[89]
Year Summer Capacity (GW) Electrical energy (G kWh) Capacity factor Yearly growth of Generating Capacity Yearly growth of produced Energy Portion of renewable electrical energy Portion of total electrical energy
2015 Wood Electric Energy Generation Profile
2015 Other Biomass Electric Energy Generation Profile
 2015 13.76 64.190 0.533 2.30% -0.10% 11.68% 1.57%
2014 13.45 64.270 0.545 3.16% 9.61% 11.91% 1.57%
2013 13.241 60.767 0.524 13.99% 10.96% 11.65% 1.49%
2012 12.319 57.602 0.534 12.15% 4.01% 11.65% 1.42%
2011 11.613 56.671 0.557 4.39% 2.36% 11.04% 1.38%
2010 11.406 56.089 0.561 2.61% 5.68% 13.13% 1.36%
2009 11.256 54.493 0.553 4.22% 0.65% 13.05% 1.38%
2008 11.05 55.034 0.569 3.65% 2.93% 14.45% 1.34%
2007 10.838 55.539 0.585 16.13% 3.30% 15.74% 1.34%
2006 10.099 54.861 0.620 6.16% 4.16% 14.22% 1.35%
2005 9.802 54.276 0.632 2.45% 1.93% 15.17% 1.34%
2004 9.711 53.538 0.629 -0.79% -0.90% 15.23% 1.35%

Biofuels

Information on pump, California.

Most cars on the road today in the U.S. can run on blends of up to 10% ethanol, 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). By mid-2006, there were approximately six million E85-compatible vehicles on U.S. roads.[90]

The challenge is to expand the market for biofuels beyond the farm states where they have been most popular to date.[91] Flex-fuel vehicles are assisting in this transition because they allow drivers to choose different fuels based on price and availability. The Energy Independence and Security Act of 2007, which calls for 15.2 billion US gallons (58,000,000 m3) of biofuels to be used annually by 2012, will also help to expand the market.[90]

The expanding 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.[90] On the other hand, in 2010, the biofuel industry received $6644 million in federal government support.[92]

Wave power

PB150 PowerBuoy with peak-rated power output of 150 kW.

Wave power in the United States is under development in several locations off the east & west coasts as well as Hawaii. It has moved beyond the research phase and is producing reliable energy. Its use to-date has been for situations where other forms of energy production are not economically viable and as such, the power output is currently modest. But major installations are planned to come on-line within the next few years.

Renewable energy research

There are numerous organizations within the academic, federal, and commercial sectors conducting large scale advanced research in the field of renewable energy. This research spans several areas of focus across the renewable energy spectrum. Most of the research is targeted at improving efficiency and increasing overall energy yields.[93] Multiple federally supported research organizations have focused on renewable energy in recent years. Two of the most prominent of these labs are Sandia National Laboratories and the National Renewable Energy Laboratory (NREL), both of which are funded by the United States Department of Energy and supported by various corporate partners.[94] Sandia has a total budget of $2.4 billion[95] while NREL has a budget of $375 million.[96]

Both Sandia National Laboratories and the National Renewable Energy Laboratory (NREL), have heavily funded solar research programs. British Petroleum was also heavily invested in solar research programs until 2008 when the company began scaling back its solar operations. The company finally shut down its forty-year-old solar business after executives decided solar power production is not economically competitive.[97] The NREL solar program has a budget of around $75 million[98] and develops research projects in the areas of photovoltaic (PV) technology, solar thermal energy, and solar radiation.[99] The budget for Sandia’s solar division is unknown, however it accounts for a significant percentage of the laboratory’s $2.4 billion budget.[100] Several academic programs have focused on solar research in recent years. The Solar Energy Research Center (SERC) at University of North Carolina (UNC) has the sole purpose of developing cost effective solar technology. In 2008, researchers at Massachusetts Institute of Technology (MIT) developed a method to store solar energy by using it to produce hydrogen fuel from water.[101] Such research is targeted at addressing the obstacle that solar development faces of storing energy for use during nighttime hours when the sun is not shining. In February 2012, North Carolina-based Semprius Inc., a solar development company backed by German corporation Siemens, announced that they had developed the world’s most efficient solar panel. The company claims that the prototype converts 33.9% of the sunlight that hits it to electricity, more than double the previous high-end conversion rate.[102]

Wind energy research dates back several decades to the 1970s when NASA developed an analytical model to predict wind turbine power generation during high winds.[103] Today, both Sandia National Laboratories and National Renewable Energy Laboratory have programs dedicated to wind research. Sandia’s laboratory focuses on the advancement of materials, aerodynamics, and sensors.[104] The NREL wind projects are centered on improving wind plant power production, reducing their capital costs, and making wind energy more cost effective overall.[105] The Field Laboratory for Optimized Wind Energy (FLOWE) at Caltech was established to research renewable approaches to wind energy farming technology practices that have the potential to reduce the cost, size, and environmental impact of wind energy production.[106]

As the primary source of biofuels in North America, many organizations are conducting research in the area of ethanol production. On the Federal level, the USDA conducts a large amount of research regarding ethanol production in the United States. Much of this research is targeted toward the effect of ethanol production on domestic food markets.[107] The National Renewable Energy Laboratory has conducted various ethanol research projects, mainly in the area of cellulosic ethanol.[108] Cellulosic ethanol has many benefits over traditional corn based-ethanol. It does not take away or directly conflict with the food supply because it is produced from wood, grasses, or non-edible parts of plants.[109] Moreover, some studies have shown cellulosic ethanol to be more cost effective and economically sustainable than corn-based ethanol.[110] Sandia National Laboratories conducts in-house cellulosic ethanol research[111] and is also a member of the Joint BioEnergy Institute (JBEI), a research institute founded by the United States Department of Energy with the goal of developing cellulosic biofuels.[112]

Over $1 billion of federal money has been spent on the research and development of hydrogen fuel in the United States.[113] Both the National Renewable Energy Laboratory[114] and Sandia National Laboratories[115] have departments dedicated to hydrogen research.

Policy and promotion

In his January 24, 2012, State of the Union address, President Barack Obama restated his commitment to renewable energy, stating 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.[16]

The 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 renewable energy, advanced transportation, and energy conservation initiatives. These new initiatives were expected to encourage many more utilities to strengthen their clean energy programs.[116] While the Department of Energy has come under criticism for providing loan guarantees to Solyndra,[117] its SunShot initiative has funded successful companies such as EnergySage[118] and Zep Solar.[119]

Initiatives

SunShot

In February 2011, the U.S. Department of Energy (DOE) launched its SunShot initiative, a collaborative national effort to cut the total cost of photovoltaic solar energy systems by 75% by 2020.[120] Reaching this goal would make unsubsidized solar energy cost-competitive with other forms of electricity and get grid parity .[121]

Wind Powering America

Wind Powering America (WPA) is another DOE initiative that seeks to increase the use of wind energy. WPA collaborates with state and regional stakeholders, including farmers, ranchers, Native Americans, rural electric cooperatives, consumer-owned utilities and schools.

WPA has focused on states with strong potential for wind energy generation but with few operational projects. WPA provides information about the challenges, benefits, and impacts of wind technology implementation.

Solar America Initiative

The Solar America Initiative (SAI)[122] is a part of the Federal Advanced Energy Initiative to accelerate the development of advanced photovoltaic materials with the goal of making it cost-competitive with other forms of renewable electricity by 2015.

The DOE Solar Energy Technology Program (SETP) intended to achieve the goals of the SAI through partnerships and strategic alliances by focusing primarily on four areas:

California Solar Initiative

As part of former Governor Arnold Schwarzenegger's Million Solar Roofs Program, California set a goal to create 3,000 megawatts of new, solar-produced electricity by 2017, with funding of $2.8 billion.[123]

The California Solar Initiative offers cash incentives on solar PV systems of up to $2.50 a watt. These incentives, combined with federal tax incentives, can cover up to 50% of the total cost of a solar panel system.[123] Financial incentives to support renewable energy are available in some other US states.[124]

EPA facilities

Environmental Protection Agency facilities in the United States use renewable energy for all or part of their supply at the following facilities:

Green Power Partnership

The EPA named the top 20 partners in its Green Power Partnership that are generating their own renewable energy on-site. Combined, they generate more than 736 million kilowatt-hours of renewable energy on-site each year, enough to power more than 61,000 average U.S. homes.[126]

Renewable portfolio standards

A Renewable Portfolio Standard refers to legislation that creates a market in tradeable renewable or green electricity certificates. Electricity distributors or wholesaler purchasers of electricity are required to source a specified percentage of their electricity (portfolio) from renewable generation sources. Liable entities that fall short of their quota can purchase certificates from accredited suppliers who have generated renewable electricity and obtained and registered certificates to sell on that market.

Sales to the grid

The Energy Policy Act of 2005 requires all public electric utilities to facilitate net metering.[127] This allows homes and businesses performing distributed generation to pay only the net cost of electricity from the grid: electricity used minus electricity produced locally and sent back into the grid. For intermittent renewable energy sources this effectively uses the grid as a battery to smooth over lulls and fill in production gaps.

Some jurisdictions go one step further and have instituted feed-in tariff, which allows any power customer to actually make money by producing more renewable energy than is consumed locally.

Distribution effects

From 2006-14, US households received more than $18 billion in federal income tax credits for weatherizing their homes, installing solar panels, buying hybrid and electric vehicles, and other "clean energy" investments. These tax expenditures went predominantly to higher-income Americans. The bottom three income quintiles received about 10% of all credits, while the top quintile received about 60%. The most extreme is the program aimed at electric vehicles, where the top income quintile received about 90% of all credits. Market mechanisms have less skewed distributional effects.[128]

Renewable energy organizations

The American Council on Renewable Energy (ACORE), is a non-profit organization with headquarters in Washington DC. It was founded in 2001 as a unifying forum for bringing renewable energy into the mainstream of American’s economy and lifestyle. In 2010 ACORE had over 700 member organizations.[129] In 2007, ACORE published Outlook On Renewable Energy In America, a two volume report about the future of renewable energy in the United States.[130] It has been said that this report exposes a "new reality for renewable energy in America."[131]

The Environmental and Energy Study Institute (EESI) is a non-profit organization which promotes environmentally sustainable societies. Founded in 1984 by a group of Congressional Members, EESI seeks to be a catalyst that moves society away from environmentally damaging fossil fuels and toward a clean energy future. EESI presents policy solutions that will result in decreased global warming and air pollution; improvements in public health, energy security and rural economic development opportunities; increased use of renewable energy sources and improved energy efficiency.

An important part of the mission of the National Renewable Energy Laboratory (NREL) is the transfer of NREL-developed technologies to renewable energy markets. NREL's Technology Transfer Office supports laboratory scientists and engineers in the successful and practical application of their expertise and the technologies they develop. R&D staff and facilities are recognized and valued by industry, as demonstrated through many collaborative research projects and licensed technologies with public and private partners. NREL's innovative technologies have also been recognized with 39 R&D 100 Awards.

The Rocky Mountain Institute (RMI) is an organization dedicated to research, publication, consulting, and lecturing in the general field of sustainability, with a special focus on profitable innovations for energy and resource efficiency. RMI is headquartered in Snowmass, Colorado, and also maintains offices in Boulder, Colorado. RMI has recently published the book Winning the Oil Endgame.

Statistics

Data from the US DOE Energy Information Administration/Electric Power Monthly[132] provide a good summary of progress being made in renewables.

Electric Production by Renewables in 2015[133]
Power Source Summer Capacity (GW) % of Renewable Capacity % of Total Capacity Capacity Factor Annual Energy (billion kWh) % of Renewable Energy % of US Generation
Hydro 79.74 43.81 7.46 0.360 251.17 45.71 6.14
Wind 72.58 39.87 6.79 0.300 190.93 34.74 4.67
Biomass 13.76 7.56 1.29 0.533 64.19 11.68 1.57
Solar 13.41 7.37 1.25 0.225 26.47 4.82 0.65
GeoThermal 2.53 1.39 0.24 0.757 16.77 3.05 0.41
Total 182.02 100.00 17.02 0.345 549.53 100.00 13.44

Note: Biomass includes wood and wood derived fuel, landfill gas, biogenic municipal solid waste and other waste biomass.

US Renewable Energy Profile 2004-2015 Actuals with projections to 2019
Yearly US Renewable Electricity Production (billion kWh) by Source[134]
Year All US Total Renewable
Hydro Wind Wood Bio
other		 Geo
Thermal		 Solar Total % of US Total
2015 4,087.39 251.17 190.93 42.36 21.83 16.77 26.47 549.53 13.44
2014 4,092.94 258.75 181.79 43.05 21.27 16.63 18.32 539.81 13.19
2013 4,065.96 268.57 167.84 39.94 20.83 15.78 9.04 522.07 12.69
2012 4,047.76 276.24 140.82 37.8 19.82 15.56 4.33 494.57 12.22
2011 4,100.7 319.4 120.2 37.4 19.2 15.3 1.814 513.4 12.52
2010 4,125.1 260.2 94.7 37.2 18.9 15.2 1.212 427.4 10.36
2009 3,950.3 273.4 73.9 36.1 18.4 15.0 0.891 417.7 10.57
2008 4,119.4 254.8 55.4 37.3 17.7 14.8 0.864 380.9 9.25
2007 4,156.7 247.5 34.5 39.0 16.5 14.6 0.612 352.7 8.49
2006 4,064.7 289.2 26.6 38.8 16.1 14.6 0.508 385.8 9.49
2005 4,055.4 270.3 17.8 38.9 15.4 14.7 0.550 357.7 8.82
2004 3,970.6 268.4 14.1 38.1 15.4 14.8 0.575 351.5 8.85
2003 3,883.2 275.8 11.2 37.5 15.8 14.4 0.534 355.3 9.15
2002 3,858.5 264.3 10.4 38.7 15.0 14.5 0.555 343.4 8.90
2001 3,736.6 217.0 6.7 35.2 14.5 13.7 0.543 287.7 7.70
2000 3,802.1 275.6 5.6 37.6 23.1 14.1 0.493 356.5 9.38
1999 3,694.8 319.5 4.5 37.0 22.6 14.8 0.495 399.0 10.80
1998 3,620.3 323.3 3.0 36.3 22.4 14.8 0.502 400.4 11.06
  1. Bio Other includes Waste, Landfill Gas, and Other.
  2. Solar includes Photovoltaics and Thermal.

Potential resources

A 2012 report by the National Renewable Energy Laboratory evaluates the potential energy resources for each state of the United States.[135][136]

In 2010, the U.S. used 3,754 TWh of electricity. Total energy used in 2010 was 98.16 quadrillion BTU (28,800 TWh, but over 30% is thermal losses).

Note: Total use is inflated to create an oil equivalence.

See also

References

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  129. ↑ American Council on Renewable Energy, Member Benefits
  130. ↑ American Council On Renewable Energy, (2007). The Outlook On Renewable Energy In America
  131. ↑ 635 GW Possible with U.S. Political Shift Renewable Energy Access, 2 May 2007.
  132. ↑ "Electric Power Monthly retrieved 2016-3-6
  133. ↑ "Electric Power Monthly retrieved 2016-3-6
  134. ↑ "Electric Power Monthly retrieved 2016-3-6
  135. ↑ U.S. Renewable Energy Technical Potentials
  136. ↑ NREL Study Shows Renewable Energy Potential in Every State
  137. ↑ 2010 Electricity Consumption
  138. ↑ Total Energy Consumption 2010

Further reading

External links

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