Is solar power cheaper than nuclear power today?

Originally published July 27, 2010. Updated August 27, 2026.

Solar power is cheaper than nuclear power today, on a straight cost basis. Unsubsidized utility-scale solar costs $38 to $78 per megawatt-hour, while a newly built US nuclear plant costs $141 to $220, according to Lazard’s 2025 cost analysis. That’s roughly a two to five times gap. But solar panels only generate power 20% to 30% of the time in a year, while a nuclear reactor runs near 90% of the time, so these two numbers aren’t measuring the same thing on their own.

What a megawatt-hour costs today

Lazard, the financial advisory firm that publishes the industry’s most closely watched cost benchmark, put out its 2025 unsubsidized cost report in June. The ranges below strip out every state and federal subsidy, so they show what it costs to build and run each kind of plant:

Figures from Lazard LCOE+, June 2025.

Solar and wind land in roughly the same range, and both come in well under half of nuclear’s cheapest case. Pairing solar with batteries costs more than solar alone, but even at its most expensive, storage still undercuts new nuclear’s least expensive case by $10 per megawatt-hour.

What EIA’s numbers show, and why they don’t match Lazard’s

The US Energy Information Administration publishes its own annual outlook, and its 2025 projections for plants entering service in 2030 show solar at $29.58 per megawatt-hour and a solar-plus-battery hybrid at $53.44. Advanced nuclear comes in at $81.45 in the same projections. Those numbers sit much closer together than Lazard’s, and that’s because they answer a different question. EIA’s figures include federal tax credits from the Inflation Reduction Act, while Lazard’s strip every subsidy out. A subsidized number and an unsubsidized number aren’t measuring the same cost. The EIA table shows what a developer might pay after credits. Lazard’s shows what a plant costs to build and run before any credits apply.

What the last two US reactors cost

Lazard’s nuclear range is built on the only new US reactors completed in the past three decades, Vogtle Units 3 and 4 in Georgia. The project was budgeted at roughly $14 billion, targeting service around 2017. Instead, Unit 3 started producing power in mid-2023 and Unit 4 followed in April 2024, six to seven years behind schedule, and the total project cost passed $31 billion, or roughly 121% over the original $14 billion budget. Add Westinghouse’s $3.7 billion settlement for walking away from the build, and the total climbs to about $35 billion, or roughly 150% over budget. Lazard’s $141 to $220 nuclear range assumes a follow-on reactor gets a 30% cost discount from lessons learned on Vogtle, spread over a 70-year operating life. Skip that assumption, and a new US reactor built today would likely cost even more.

Why cost per megawatt-hour isn’t the whole story

A megawatt-hour of solar and a megawatt-hour of nuclear aren’t delivered the same way. Lazard assumes utility-scale solar runs at a 20% to 30% capacity factor. New nuclear runs at 89% to 92%. That gap is what the industry calls capacity factor, and it’s the reason a cost-per-megawatt-hour number can’t stand alone.

Pairing panels with battery storage is how a solar plant keeps delivering power after dark, and that added equipment is a large part of why the storage line in Lazard’s table, $50 to $131 per megawatt-hour, costs more than solar by itself. Even storage’s most expensive case still comes in under nuclear’s cheapest case. None of these levelized-cost figures capture the extra grid costs, like backup capacity and transmission upgrades, that show up once solar makes up a large share of what one grid delivers.

The 2010 Duke study that started this argument

This question isn’t new. In July 2010, Energy Collective writer Osha Davidson covered a Duke University economist’s finding that solar had crossed nuclear on price in North Carolina. Duke economist John Blackburn, in a study commissioned by the advocacy group NC WARN, found new solar contracts in the state had reached about 14 cents per kilowatt-hour, or $140 per megawatt-hour, below new nuclear’s projected 14 to 18 cents, or $140 to $180. Phys.org’s coverage of the same study put solar’s number at 16 cents, or $160 per megawatt-hour, still under nuclear’s line. The comparison was specific to North Carolina, and the 14-cent figure only held with subsidies included. Blackburn predicted unsubsidized solar would compete within about a decade.

It took closer to fifteen years, and the eventual gap ended up bigger and more national than his 2010 comparison described. By 2025, unsubsidized utility solar had fallen to $38 to $78 per megawatt-hour, against new nuclear’s $141 to $220, an outcome that went well past what a subsidized, state-specific crossover implied.

Was Gemasolar’s storage worth the price?

Energy Collective writer Nathan Wilson raised a related question from a different direction, about whether pairing solar with storage could compete on cost the way plain solar panels do. Gemasolar, a 19.9-megawatt concentrated solar power tower in Fuentes de Andalucía, Spain, commissioned in 2011, stores heat in molten salt so it can keep generating after dark. Wikipedia lists its capacity factor at 45.9%, well above Lazard’s range for ordinary solar panels, though physicist Tom Murphy’s independent estimate at UC San Diego put the figure at 63.1%.

That capacity factor came at a cost. The same UC San Diego analysis put Gemasolar’s capital cost at roughly $33,000 per kilowatt of average output, a different way of pricing a plant than the per-megawatt-hour figures above, but one the analysis itself called expensive at the time. Solar paired with batteries is priced today at $50 to $131 per megawatt-hour unsubsidized.

What would change this answer

On unsubsidized cost, solar wins by a wide margin today. Nuclear still has one advantage these levelized-cost numbers don’t fully capture. A reactor can run without storage or extra pairing, day and night, for months at a stretch.

That case gets stronger under different financing assumptions. The International Energy Agency and the OECD’s Nuclear Energy Agency, using a lower discount rate and a longer assumed plant life, rated nuclear the cheapest dispatchable low-carbon option in their 2020 cost report, a more nuclear-favorable conclusion than Lazard’s 2025 US figures. Nuclear’s levelized cost is far more sensitive to the discount rate and plant lifespan assumed than solar’s is.

If a US utility starts and finishes another large reactor without repeating Vogtle’s six-to-seven-year delay, Lazard’s assumed cost-learning discount for future nuclear plants gets tested against a real project instead of an assumption. If battery prices keep falling, solar-plus-storage’s current $131 per megawatt-hour ceiling has room to drop further, and the gap described here gets wider before nuclear’s case has a chance to catch up.