Report: 100% Renewable Energy

We Have the Power

Realizing clean, renewable energy’s potential to power America
Released by: Environment Illinois Research and Education Center

Executive summary

It is time for America to move beyond fossil fuels. Coal, oil and gas are responsible for a rapidly warming planet, for hundreds of thousands of deaths in the U.S. each year from air pollution, and for untold environmental damage. A shift to emission-free energy from the wind, sun and other renewable sources can solve many of America’s most pressing environmental and public health challenges.

America has the power to build an energy system in which our energy comes from clean, renewable sources like the wind and sun. There are many potential paths America can take to build on our abundant clean energy potential and help America rapidly achieve a renewable energy system.

Policymakers at the local, state and federal level should make concrete commitments to move toward 100% clean and renewable energy by 2050 at the latest. By doing so, they will be building on the example set by seven states and more than 170 cities around the United States that have committed to clean electricity or clean energy.1

Renewable energy has tremendous promise as a tool to fight climate change, clean our air, and safeguard our environment.

  • Pollution from burning fossil fuels is estimated to be responsible for more than one in 10 deaths in the United States each year – more than 350,000 total deaths in 2018.2
  • Oil, coal and gas are responsible for 80%of all U.S. greenhouse gas emissions. Fossil fuels harm the climate when we burn them for energy and as a result of methane leaks that occur during mining, distribution and other parts of the fossil fuel life cycle.3
  • Research shows that, even considering the life-cycle impacts of manufacturing and installing solar panels and wind turbines, a rapid transition to emission-free renewable energy would create a vastly cleaner, healthier, and more sustainable nation.4

America has abundant renewable energy resources capable of powering the nation. Data from the National Renewable Energy Laboratory (NREL) shows that America has access to enough sun and wind to power the nation many times over.

  • America’s solar energy resources – counting just utility-scale and rooftop PV – have the technical potential to produce 284 million GWh of electricity each year, equivalent to 78 times U.S. electricity use in 2020.5 And America’s wind power resources, both onshore and offshore, have the technical potential to produce 40 million GWh of electricity each year, equivalent to 11 times U.S. electricity use in 2020.6
  • Every single state has either the wind or solar technical potential to power that state’s current electricity use at least once over.7 Eighteen states have the solar resources to power current electricity needs 100 times over, and five states have the wind resources to do so.
  • Every single state other than Connecticut has either enough wind or solar technical potential to provide all of its electricity needs under a 2050 scenario in which transportation, buildings and other applications have largely been made to run on electricity.8

Figure ES-1. America’s enormous wind and solar energy resources

Renewable energy can power our society 24/7/365. Research from academic and government sources has described many viable pathways by which America can meet our energy needs 24 hours a day, 365 days a year while relying mostly or entirely on renewable energy.9 While researchers have disagreements on the best or most economical way to build a renewable energy system, there is broad agreement that an energy system largely powered by renewable sources is feasible.

  • A 2019 article from the journal Energy reviewed 181 studies from around the world assessing the concept of 100% renewable electricity or total energy systems.10 The article concluded that “[t]he majority of the reviewed studies find that 100% [renewable energy] is possible from a technical perspective, while only few publications argue against this.”11
  • Researchers have largely concluded that the technology we need for a renewable future is already available. As one study from Nature Communications put it, “currently available generation and storage technologies are sufficient for nearly 100% power system operation.”12 And from another study from Renewable and Sustainable Energy Reviews: “The technologies required for renewable scenarios are not just tried-and-tested, but also proven at a large scale.”13
  • NREL has used sophisticated modeling to simulate electric grids running on high levels of renewable energy. In its most recent study, focused on Los Angeles, NREL concluded that “[r]eliable, 100% renewable electricity is achievable — and, if coupled with electrification of other sectors, provides significant greenhouse gas, air quality, and public health benefits.”14
  • Researchers have identified key strategies that can help the U.S. achieve a largely renewable energy system in the shortest time and at the lowest cost. Such strategies include investing in transmission infrastructure to send solar or wind energy across the country to where it is needed, and building sufficient wind and solar power capacity to reduce the amount of storage needed for periods of lower power output.

Figure ES-2. Solar panels and wind turbines are getting more efficient and powerful15

The keys to a 100% renewable future are within reach. The nation has ample potential to move forward rapidly in four key areas essential to a renewable energy future: building out renewable energy; modernizing the grid; reducing and managing energy use; and repowering our economy to take full advantage of clean energy.

1. Rapidly deploy clean energy. Over the last 20 years, the amount of electricity produced by wind and solar power in the U.S. grew more than 60-fold, accounting for 12% of all the electricity produced in America in 2020.16 Technology and price trends point the way toward far faster progress in the years to come.

  • Today’s wind turbines and solar panels produce more energy, in less space, for less cost, and with more flexibility than ever before. The cost of wind power fell by 71% and utility-scale solar by 90% from 2009 to 2020.17 In 2019, the median new residential solar panel was 37% more efficient than one installed in 2010.18 And in 2019, the average installed wind turbine had 42% greater power capacity than one installed in 2010.19
  • New renewable energy technologies that could one day help provide more stable and diverse options for providing renewable energy are on the way. Floating offshore wind turbines, which are dropping in price and have been successfully deployed in pilot projects, can be located in deep waters and provide access to wind resources off the West Coast of the U.S.20 And advances in enhanced geothermal technology may soon allow more regions of the U.S. to tap into the nation’s enormous potential for generating electricity using underground heat.21

2. Modernize the grid. The U.S. has laid the groundwork for providing reliable renewable power when we need it with a modern grid capable of storing energy, delivering energy across long distances, and reacting to changes in weather conditions.

  • Battery storage capacity has skyrocketed as the cost per watt-hour of utility-scale battery storage has fallen dramatically, down 70% from 2015 to 2018.22 Batteries are now often deployed alongside new wind and solar farms both for their ability to store energy for when energy output is low and to assist grid function by helping regulate grid frequency and respond to grid disturbances.23 Long-term or seasonal energy storage solutions, like renewably-produced hydrogen, are being developed that could one day help the grid achieve renewable energy penetrations approaching 100%.24
  • Expanding transmission connections allows for more efficient and flexible use of renewable resources, such as in Texas where new transmission lines helped unlock enormous wind resources in rural parts of the state.25 Improving technology and falling costs for high-voltage direct current lines could soon allow the creation of important new transmission connections, including between the eastern and western U.S. grid systems.26
  • New technologies and tools are ready to help build a smarter, more modern grid. Smart inverters, along with strategies like extracting stored kinetic energy from wind turbines, are already allowing clean energy technologies to respond to changes in grid conditions.27 And sophisticated computing tools are making possible advanced forecasting that can provide grid operators with precise and granular information about renewable generation.28

3. Reduce and manage energy demand. The U.S. has enormous potential to cut energy use and make energy demand more flexible, which would reduce the amount of new infrastructure needed for a shift to renewable energy.

  • Energy efficiency can cut U.S. energy use in half by 2050, according to research from the American Council for an Energy-Efficient Economy.29 The U.S. can achieve large energy reductions through advanced new strategies like geotargeted efficiency programs and energy management and information systems, as well as expanding access to older tried-and-true methods.30 For example, more than nine in 10 homes in the United States had not had an energy audit as of 2015.31
  • Demand response programs can reduce peak energy demand and enable the grid to respond to changes in renewable energy supply. Research from 2019 found that by 2030 demand response could provide 200 GW of “economically feasible load potential,” equivalent to 20% of peak load levels.32
  • In 2018, utilities reported a total enrolled demand response capacity of 20.8 GW, equivalent to the power capacity of about 10,000 wind turbines.33 Now, new technologies like smart thermostats and advanced metering infrastructure are enabling advanced demand response programs that can help create a more flexible and responsive electric grid.34

4. Repower everything with renewables. Technology is available to repower most direct uses of petroleum or gas with electricity, and to tap the nation’s enormous potential for renewable heat and light.

  • Electric vehicles (EVs) and buildings are far more efficient than fossil fuel technologies. A fully electrified and renewable energy system could cut primary energy consumption by at least half.35
  • Proven technologies are readily available for electrifying light-duty vehicles, residential buildings and commercial buildings, which account for 45% of fossil fuel end-use combustion in the U.S.36 EV technology in particular has dramatically improved in the last decade: The cost per watt-hour for EV batteries fell by 89% from 2010 to 2020, while the median driving range of EVs quadrupled.37
  • New technologies could soon allow us to power more activities with clean energy. Advanced battery technology is becoming available for powering medium- and heavy-duty freight, and a recent Deloitte study found that, among surveyed manufacturers, companies aimed to electrify nearly 45% of their processes by 2035.38
  • The U.S. can also tap into large amounts of renewable energy in the form of heat. The U.S. Department of Energy estimates that the U.S. has the economic potential for more than 17,500 geothermal district heating installations nationwide, with much of the potential located near major population centers including in the Northeast.39

The stage is set for a rapid transition to renewable energy. But time is of the essence. Policymakers must do all they can to accelerate a shift away from fossil fuels to an energy system in which the vast majority of our energy comes from renewable sources like the wind and sun. Policymakers at every level of government should set ambitious goals to transition both electricity and other energy uses to clean, renewable sources. And they should ensure those goals are achieved through policies that provide clean energy with the financial and regulatory support that it needs.

Figure ES-3. The rapid fall of clean energy prices40



  1. States with 100% electricity goals: Environment America, 100% Renewable, archived on 9 April 2021 at cities with 100% electricity: Sierra Club, What are 100% Clean Energy Commitments?, archived on 28 March 2021 at↩︎
  2. See supplementary table S2 from Karn Vohra et al., “Global mortality from outdoor fine particle pollution generated by fossil fuel combustion: Results from GEOS-Chem,” Environmental Research, doi: 10.1016/j.envres.2021.110754, April 2021.↩︎
  3. See table ES-4: U.S. Environmental Protection Agency, Draft Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2019, date of draft version not provided, archived at↩︎
  4. Doug Arent et al., “Implications of high renewable electricity penetration in the U.S. for water use, greenhouse gas emissions, land-use, and materials supply,” Applied Energy, 15 June 2014, doi: 10.1016/j.apenergy.2013.12.022, available at↩︎
  5. These are conservative estimates, as the 2012 NREL source assumes less efficient renewable generation technology. Sources for solar technical potential: Utility-scale solar (urban and rural utility-scale PV): Anthony Lopez et al., National Renewable Energy Laboratory, U.S. Renewable Energy Technical Potentials: A GIS-Based Analysis, July 2012, data available at; rooftop solar (although the 2012 study includes rooftop solar, this is the more recent analysis): Pieter Gagnon et al., National Renewable Energy Laboratory, Rooftop Solar Photovoltaic Technical Potential in the United States: A Detailed Assessment (Table 6), January 2016, archived at U.S. 2020 electricity demand downloaded as retail sales from: U.S. Energy Information Administration, Electricity Data Browser, accessed at on 1 March 2020.↩︎
  6. These are conservative estimates, as the 2012 NREL source assumes less efficient renewable generation technology. Sources for wind technical potential: Onshore wind: Anthony Lopez et al., National Renewable Energy Laboratory, U.S. Renewable Energy Technical Potentials: A GIS-Based Analysis, July 2012, data available at; offshore wind (although the 2012 study includes offshore wind, this is the more recent analysis): Walt Musial et al., National Renewable Energy Laboratory, 2016 Offshore Wind Energy Resource Assessment for the United States (Appendix I), September 2016; U.S. 2020 electricity demand downloaded as retail sales from: U.S. Energy Information Administration, Electricity Data Browser, accessed at on 1 March 2020.↩︎
  7. See notes 5 and 6, for which all sources contain both state and national data.↩︎
  8. Based on comparison of renewable technical potential to NREL’s “electrification technical potential” scenario, with MMBTU converted to GWh assuming 3,412 Btu per kWh for all 2050 entries in which “final energy” is “electricity.” NREL scenario data available from: National Renewable Energy Laboratory, Electric Technology Adoption and Energy Consumption – Final Energy Demand, downloaded from on 1 March 2021.↩︎
  9. Kenneth Hansen et al., “Status and perspectives on 100% renewable energy systems,” Energy, 175:471-480, doi: 10.1016/, 15 May 2019.↩︎
  10. Ibid.↩︎
  11. Ibid.↩︎
  12. Dmitrii Bogdanov et al., “Radical transformation pathway towards sustainable electricity via evolutionary steps,” Nature Communications, Volume 10, doi: 10.1038/s41467-019-08855-1, 2019.↩︎
  13. T.W. Brown et al., “Response to ‘Burden of proof: A comprehensive review of the feasibility of 100% renewable-electricity systems’,” Renewable and Sustainable Energy Reviews, 92:834-847, doi: 10.1016/j.rser.2018.04.113, September 2018.↩︎
  14. National Renewable Energy Laboratory, LA100: The Los Angeles 100% Renewable Energy Study – Executive Summary, March 2021, available at↩︎
  15. Wind power (see summary data Excel sheet for average capacity height and diameter): see note 18; solar efficiency: see note 17.↩︎
  16. U.S. Energy Information Administration, Electricity Data Browser, accessed at on 1 March 2021.↩︎
  17. Lazard, Lazard’s Levelized Cost of Energy Analysis — Version 14.0, October 2020, archived at↩︎
  18. Based on summary data tables from: Lawrence Berkeley Lab National Laboratory, Tracking the Sun 2020 Data Update, December 2020, downloaded from↩︎
  19. Based on data summary tables from: Lawrence Berkeley Lab National Laboratory, Wind Technologies Market Report, August 2020, downloaded from↩︎
  20. Jason Deign, “So, what exactly is floating offshore wind?,” Greentech Media, 19 October 2020, available at↩︎
  21. U.S. Department of Energy, Geovision: Harnessing the Heat Beneath Our Feet, 2019, archived at↩︎
  22. U.S. Energy Information Administration, “Utility-scale battery storage costs decreased nearly 70% between 2015 and 2018,” Today in Energy (blog), 23 October 2020, archived at↩︎
  23. U.S. Energy Information Administration, Battery Storage in the United States: An Update on Market Trends, July 2020, archived at↩︎
  24. Omar Guerra, “The value of seasonal energy storage technologies for the integration of wind and solar power,” Energy & Environmental Science, doi: 10.1039/D0EE00771D, 2020; write-up: National Renewable Energy Laboratory, “Answer to Energy Storage Problem Could Be Hydrogen,” Transforming Energy, archived at↩︎
  25. David Schechter, “Verify: Does conservative Texas actually lead the U.S. in green energy?,” WFAA, 16 February 2020, available at↩︎
  26. Based on the study’s “High VG” scenario. Aaron Bloom et al., National Renewable Energy Laboratory, The Value of Increased HVDC Capacity Between Eastern and Western U.S. Grids: The Interconnections Seam Study (Preprint), October 2020, archived at has published a useful analysis of the study: David Roberts, “We’ve been talking about a national grid for years. It might be time to do it.,” Vox, 3 August 2018, archived at falling costs and technology improvements: Abdulrahman Alassi et al., “HVDC Transmission: Technology Review, Market Trends and Future Outlook,” Renewable and Sustainable Energy Reviews, 112:530-554, doi: 10.1016/j.rser.2019.04.062, September 2019.↩︎
  27. Smart inverters: Kelsey Misbrener, “Smart inverters redefine relationship between DERs and the grid,” Solar Power World, 12 March 2019, archived at stored kinetic energy: Paul Denholm et al., National Renewable Energy Laboratory, Inertia and the Power Grid: A Guide Without the Spin, May 2020, archived at↩︎
  28. International Renewable Energy Agency, Advanced Forecasting of Variable Renewable Power Generation, 2020, available at↩︎
  29. Steven Nadel and Lowell Ungar, Halfway There: Energy Efficiency Can Cut Energy Use and Greenhouse Gas Emissions in Half by 2050, September 2019, archived at↩︎
  30. Grace Relf et al., American Council for an Energy Efficient Economy, The 2020 Utility Energy Efficiency Scorecard, 20 February 2020, available at↩︎
  31. Tom Shiel, “Energy efficiency: It’s time to reach above the ‘low-hanging fruit’,” EPRI Journal, 11 September 2020, archived at↩︎
  32. Smart Electric Power Alliance, 2019 Utility Demand Response Market Snapshot, September 2019, available at↩︎
  33. Assuming average turbine capacity of 2 MW. Enrolled DR capacity: Ibid. The typical land-based wind turbine installed over the last decade has had a capacity of roughly 2 MW: See note 18.↩︎
  34. U.S. Department of Energy, Demand Response, archived on 18 March 2021 at↩︎
  35. Reduction of 49% before efficiency measures and reduced energy processing costs are taken into account: See note 13.↩︎
  36. Primary fossil fuel energy use by sector for 2019: U.S. Energy Information Administration, Total Energy (tables 2.2 through 2.5), accessed at on 15 March 2021; transportation energy use divided into light-duty vehicles and other transportation based on energy use shares from Figure 2.6 in: Stacy C. Davis and Robert G. Boundy, Transportation Energy Data Book: Edition 39, February 2021, available at↩︎
  37. Batteries: BloombergNEF, Battery Pack Prices Cited Below $100/kWh for the First Time in 2020, While Market Average Sits at $137/kWh, 16 December 2020, archived at driving ranges (see full dataset link): U.S. Department of Energy, FOTW# 1167, January 4, 2021: Median Driving Range of All-Electric Vehicles Tops 250 Miles for Model Year 2020, 4 January 2021, downloaded from↩︎
  38. Stanley Porter et al., Deloitte, Electrification in Industrials, 12 August 2020, archived at↩︎
  39. See figure 4-7 from note 20.↩︎
  40. See notes 16, 17, 36, 21 and 106.↩︎