Two laws, one technology, two different answers
A power plant that burns garbage for electricity earns a federal tax credit meant for renewable energy. In California, the same activity does not count toward the state law that requires power companies to buy renewable electricity. Both rules are real, both apply right now, and both are correct on their own terms, because a federal tax law and a state purchase requirement are answering 2 different questions.
What counted toward 24% in 2025
Renewable sources supplied 24% of United States electricity generation in 2025, reports the Energy Information Administration. Natural gas supplied 41%, coal 17%, and nuclear power 18%. No law in this article counts nuclear power as renewable, though some state clean energy standards count it as a separate clean category without calling it renewable. Inside the 24% renewable share, wind supplied 11%, solar power 7%, hydropower 6% and biomass 1%. Geothermal energy supplied under 1% and is too small to show as its own bar.
Renewables, natural gas, coal and nuclear power add up to 100% of United States electricity generation in 2025.
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| Natural gas | 41 |
| Renewables total | 24 |
| Nuclear | 18 |
| Coal | 17 |
Geothermal energy supplied under 1% of United States electricity generation in 2025 and is too small to show as its own bar.
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| Wind | 11 |
| Solar, photovoltaic and thermal combined | 7 |
| Hydropower | 6 |
| Biomass | 1 |
The 9 technologies the federal tax credit names
26 United States Code Section 45 funds a federal tax credit for producing renewable electricity, and it names 9 technologies as qualified energy resources. Wind. Biomass grown specifically to be burned for electricity, called closed loop biomass. Biomass from existing plant material, called open loop biomass. Geothermal energy, heat drawn from underground. Solar energy. Small irrigation power. Municipal solid waste, meaning burning garbage for electricity. Qualified hydropower production, meaning added power at an existing dam or new power at a dam that never generated electricity before. Marine and hydrokinetic energy, power drawn from waves, tides and currents, that excludes anything using a dam. Nuclear power is not on this list.
California draws the line differently
Public Utilities Code Section 399.12 of California is the law behind the state renewable portfolio standard, the requirement that power companies buy a growing share of renewable electricity. It states plainly that a facility burning municipal solid waste is not considered an eligible renewable energy resource, with one exception for a plant in Stanislaus County that was already operating before September 1996. So the same activity, burning garbage for electricity, earns a federal tax credit under 1 law and gets refused under another law in the same country. The federal text reflects amendments effective July 4, 2025. The California law was last amended effective January 1, 2017.
A size limit for hydropower, not a ban
State law also caps the size of a dam that can count as renewable, not hydropower as a whole. California caps an existing small hydroelectric facility at 30 megawatts or less, and sets a separate 40 megawatt limit for a small hydroelectric unit built into an existing water supply system. Connecticut caps eligible hydropower at 30 megawatts. The Tier 1 renewable category in Maryland includes a small hydroelectric plant under 30 megawatts. A dam producing more power than these limits allow does not count as renewable under any of these 3 state laws.
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| California, an existing small hydroelectric facility | 30 |
| Connecticut, eligible hydropower | 30 |
| Maryland, Tier 1 small hydroelectric plant | 30 |
| California, a unit built into an existing water supply system | 40 |