It Makes More Sense To Produce Hydrogen With Nuclear, Not Renewables

Authored by Ross Pomeroy via RealClearEnergy,

Hydrogen is often thought to be linchpin of a future 100% renewable economy. To make up for wind and solar’s deal-breaking intermittency and to rid industry of energy-dense fossil fuels, the surplus cheap electricity that renewables produce during times of abundance would need to be channeled into electrolyzers that split water molecules into hydrogen and oxygen. The hydrogen could then be collected, stored, transported, and eventually combusted for on-demand energy.

But is this scenario really the most cost-effective and environmentally-friendly option? Would it make more sense, for instance, to produce hydrogen from another carbon-free source – nuclear power?

A trio of scientists in the Department of Civil and Industrial Engineering at the University of Pisa in Italy explored that question. Utilizing data from the International Atomic Energy Agency Hydrogen Economic Evaluation Programme, the group performed a feasibility assessment to compare various methods of producing hydrogen from futuristic Gen IV nuclear reactors. Their findings are published in the journal energies.

Two methods of producing hydrogen from nuclear power rose to the top. First, engineers could construct an attached electrolyzer system just like with renewable energy. Since a nuclear reactor is almost constantly running as “baseload” power, plant operators could simply divert power to the electrolyzers when grid demand wanes. The researchers estimate the cost of hydrogen with this setup would be 2.71 USD/kg with paltry carbon emissions of 0.3 kgCO2e/kgH2. 

Second, the authors envisioned a system where futuristic Gen IV reactors operating at high temperatures (between 550 and 1000 °C)  can produce hydrogen through the hot steam they emit. This high-temperature steam electrolysis is similar to how hydrogen is produced from steam reforming via natural gas. They predict costs here to be 3.57 USD/kg with slightly higher emissions of 0.8 kgCO2e/kgH2. Costs are higher because it a more novel system, even though it is “the most efficient coupling since it better exploits the electrical and thermal energy resources produced by the reactor,” the researchers write.

Costs and carbon emissions for both methods compare favorably with current costs of hydrogen produced from fossil fuels and renewables. In Europe in 2023, hydrogen made via methane reforming cost 3.76 EUR/kg (4.39 USD) and produced emissions of at least 11.6 kgCO2e/kgH2. Hydrogen made from a direct connection to renewables cost 6.61 EUR/kg (7.71 USD) with emissions similar to production from nuclear.

The researchers’ assessment is highly preliminary, of course. There’s only one commercial nuclear reactor in operation today that matches the reactor they modeled. It’s in China. Their cost estimates could also be overly rosy, and it’s likely that the cost to produce hydrogen with renewables will come down over time as solar panels grow more efficient. 

The world currently produces 52.6 million tons of hydrogen per year, used mostly to make ammonia for fertilizer. The process of making this hydrogen accounts for two percent of the world’s total energy consumption and contributes roughly the same proportion of global carbon dioxide emissions. Even if hydrogen doesn’t find wider use in industry, transportation, and grid storage, we still need a lot of it to feed the world, preferably produced in a far cleaner manner than it is currently. Nuclear energy could provide it in abundance.

Source: Buzzetti, R.; Lo Frano, R.; Cancemi, S.A. Sustainable Hydrogen Production from Nuclear Energy. Energies 2025, 18, 4632. https://doi.org/10.3390/en18174632