Surplus nuclear power can bolster hydrogen output: IEA

Surplus nuclear power could be used to produce 6mn t/yr of hydrogen by 2030 and 20mn t/yr by 2050, according to the IEA.

Hydrogen production could allow for otherwise unutilised nuclear generation capacity to be exploited, the IEA said. In its Net Zero Emissions Scenario from last year, average utilisation of global nuclear output capacity is 84pc in 2030, 76pc in 2040 and 77pc in 2050, falling as installed capacity increases and the share of renewable energy in the global power supply mix rises.

It may be possible to lift the capacity factor to 90pc in the coming decades if the surplus is used for water electrolysis to produce hydrogen, the IEA said. This could provide for 6mn t/yr additional hydrogen output in 2030, equivalent to around 4pc of overall low-carbon hydrogen production, it said. Production could rise significantly in the following decades with the projected increase in installed nuclear capacity (see table).

Using spare nuclear power to produce hydrogen "could increase the flexibility of electricity systems", and provide an additional revenue stream to plant operators, the IEA said. The potential for this could be largest in countries where nuclear accounts for a large share of overall power supply, such as France, it said.

New nuclear plants uneconomical for H2 output

But building new nuclear power plants dedicated solely to hydrogen production will probably remain uneconomical in most regions, barring a sharp drop in costs, according to the IEA.

The cost of building a new reactor would account for the vast majority of levelised hydrogen production costs from nuclear power. The IEA estimates nuclear investment costs would have to fall to around $1,000/kW, from a range of $2,800-13,000/kW currently, to allow for hydrogen production at around $2/kg by 2030 — a cost where it could be competitive with hydrogen from renewable sources at least in some places. Green hydrogen costs could be lower than $2/kg by 2030 in places with abundant renewable energy, such as Chile, Australia and parts of the US and Africa.

Even to compete with hydrogen produced from fossil fuels with carbon capture and storage, nuclear investment costs would likely have to fall substantially, especially if gas and coal prices retreat from recent highs, the IEA said.

But it said use of nuclear power for hydrogen production offers certain benefits outside of production cost considerations. These include "the ability to produce in a constant manner" and the potential to produce "large volumes of hydrogen… closer to where it is consumed", thereby "reducing the need for hydrogen transport and distribution infrastructure and, thus, delivery costs".

A number of projects exist that explore electrolysis with nuclear power, including in Sweden, Canada and the US.

By Stefan Krümpelmann