US energy sources explained

Natural Gas, The Dominant Fuel

Natural gas became the largest US electricity source around 2016, driven by the shale gas revolution that unlocked vast domestic supplies and pushed prices to historic lows. Gas-fired power plants are relatively cheap to build, can ramp up and down quickly to match demand, and produce significantly less pollution than coal.

The downside: natural gas prices are volatile. When gas prices spike, as they did in 2022, electricity rates follow nationwide. States heavily dependent on gas are most exposed to this volatility. RateWatt's energy sources pages show each state's gas dependence.

Nuclear, Reliable but Controversial

Nuclear power generates about 18.0% of US electricity from 93 reactors at 54 plants. Nuclear's advantage is reliability, plants run 90%+ of the time and produce zero carbon emissions during operation. Existing nuclear plants produce some of the cheapest electricity in the country.

However, no new nuclear plant has been completed on time or on budget in the US in decades. The Vogtle expansion in Georgia (completed 2023-2024) cost over $30 billion, more than double the original estimate. This economic reality, combined with waste disposal challenges and public concerns, has stalled new construction. The emerging technology of small modular reactors may change this calculus.

Coal, The Declining Giant

Coal generated over 50% of US electricity in 2000. Today it's down to about 15.0% and falling. The decline is driven by cheap natural gas, tightening environmental regulations, and the rising competitiveness of renewables. Many coal plants have been retired or converted to gas. The remaining fleet is aging, with an average plant age of over 40 years.

Coal-dependent states (West Virginia, Wyoming, Kentucky) face economic transition challenges as plants close. RateWatt's state pages show which states still rely heavily on coal and how their generation mix is evolving.

Wind, The Fastest-Growing Conventional Source

Wind power now generates about 10.4% of US electricity, concentrated in the Great Plains corridor (Texas, Iowa, Oklahoma, Kansas). Texas alone has more wind capacity than most countries. Wind's cost has dropped dramatically, new wind farms often produce electricity cheaper than existing coal or gas plants.

Wind's challenge is intermittency: it generates power when the wind blows, which doesn't always align with demand. This is managed through geographic diversity, forecasting, and increasingly, battery storage. Offshore wind is a growing segment, particularly along the East Coast.

Solar, Small but Surging

Solar accounts for about 7.0% of US electricity and is growing faster than any other source. The cost of solar panels has fallen over 90% since 2010, making it the cheapest source of new electricity generation in many regions. Utility-scale solar farms and rooftop installations are both expanding rapidly.

Solar faces the same intermittency challenge as wind, compounded by the fact that solar output peaks midday while demand often peaks in early evening. Battery storage paired with solar is the fastest-growing combination in new power plant construction.

Hydroelectric, The Original Renewable

Hydroelectric power generates about 5.6% of US electricity but is concentrated in a few states: Washington, Oregon, California, and New York have the most hydro capacity. Hydro is the cheapest source of electricity, once a dam is built, the "fuel" (water) is free. States with abundant hydro consistently have the lowest electricity rates in the country.

The potential for new large-scale hydro is limited because most suitable dam sites are already developed. Climate change may affect hydro output as precipitation patterns shift, drought years reduce generation, as California experienced during 2021-2022.

Your State's Mix

Every state has a unique generation mix that determines its electricity price and carbon intensity. RateWatt shows the full breakdown for all 50 states. Check your state's page to see what powers your grid and how it compares nationally.

Frequently Asked Questions

Worked example: putting the numbers together

Consider two electricity offers in a 1,000-kWh/month household. Plan A: 8.9¢/kWh + $9 monthly fee + $4.50 distribution rider = $89 + $9 + $4.50 = $102.50/month. Plan B: 11.2¢/kWh flat with no riders = $112/month. Plan A appears 26% cheaper per kWh but is only 8.5% cheaper monthly. If the household drops to 500 kWh in shoulder months (April, October), Plan A becomes $44.50 + $13.50 = $58; Plan B becomes $56, Plan A's advantage shrinks to 3%. If the household summer-peaks at 1,800 kWh (heavy AC), Plan A becomes $160.20 + $13.50 = $173.70; Plan B becomes $201.60, Plan A's advantage widens to 13.8%. Variable-usage households benefit more from per-kWh-optimized plans; flat-usage households benefit from bundled-fee-light plans. (Illustrative offers, not live quotes, your utility's tariff sheet is authoritative.)

An electricity rate is not a price, it is a structure, and the household that wins is the one that matches its load curve to the plan's fee architecture rather than chasing the lowest advertised kWh.

How to use RateWatt to find your best electricity option

Start with how electricity rates are built to grasp the kWh-plus-fees model, then use state-level rate data to benchmark your bill against your state median. The rate-structure guide walks through fixed, tiered, and time-of-use pricing. For state-by-state comparison, the cheapest-states guide and why prices vary guide show why Idaho and Hawaii sit at opposite ends of the rate curve. The renewable cost comparison covers the levelized-cost-of-energy (LCOE) data behind shifting state generation mixes. Every rate we publish comes from EIA Form 861 (utility annual reports) and EIA Electric Power Monthly, the same data utilities file with FERC.