Opting for nuclear energy is the safest and cheapest option, according to Belgium’s Federal Planning Bureau (FPB), which has compared various energy scenarios to achieve climate neutrality by 2050.
The study released today forecasts a dramatic rise in electricity demand, from 88 terawatt hours (TWh) in 2020 to more than 200 TWh by 2050, as fossil fuels are phased out.
The FPB’s analysis estimates that eight big new reactors would be required to reach 8 GW of nuclear power by mid-century.
“We are heading towards an unprecedented demand for electricity,” Alex Van Steenbergen, coordinator of the FPB’s energy team, told news outlet De Tijd.
The researchers modelled three different approaches, using the PRIMES energy system model as the analytical tool.
One pathway assumes a full nuclear phase-out by 2035, combined with existing offshore wind plans.
Another also keeps the nuclear exit but expands offshore wind to the maximum, drawing additionally on imports from neighbouring North Sea countries.
A third keeps nuclear in the mix, adding new reactors alongside a full build-out of offshore wind in Belgian waters.
Solar power and onshore wind expand significantly on all three pathways but the overall cost and reliability of supply vary sharply.
According to the FPB, the nuclear-inclusive scenario comes out cheapest, with estimated system costs of €115 per megawatt hour.
Scenarios without nuclear are projected to cost 25–35 per cent more, largely due to heavier reliance on imports and back-up for intermittent renewables.
The report stresses that cost is not the only factor. Relying on nuclear would mean importing uranium, raising questions of energy dependence. Large nuclear plants are also notorious for delays and budget overruns, as seen in recent projects abroad.
If capital costs spiral by 150 per cent, the FPB estimates Belgium would only build 5 gigawatts (GW) of nuclear rather than the optimal 8 GW.
Still, the nuclear scenario reduces the need for electricity imports dramatically. In the “maximum offshore” pathway without nuclear, almost 40 per cent of Belgium’s power would have to be imported by 2050 – about equal to today’s entire annual consumption.
Until recently, Belgium’s energy law mandated a nuclear phase-out by 2035, a policy championed by the Greens.
But, with demand set to soar, the political tide has shifted. For the government of Prime Minister Bart De Wever, the FPB study offers fresh arguments in favour of what some have called a “nuclear revival”.
Energy minister Mathieu Bihet has already signalled support for extending the life of existing reactors and building new capacity.
“Achieving climate neutrality will require major choices about our energy mix,” said FPB Commissioner Baudouin Regout.
“It is not just about costs, but also about strategic dependence. These decisions need to be made soon, given the years it takes to build both production and grid infrastructure.”
The findings align with earlier studies by EnergyVille and grid operator Elia.
Belgium’s grid operator Elia has warned that the country could face blackouts – due to an excess supply of solar energy. https://t.co/FcRbk2y7YZ
— Brussels Signal (@brusselssignal) April 7, 2025
