So, without a doubt, nuclear power fails the safety, economic and reliability tests. Is it, however, flexible? Not so much.

Over the last year it became much more clear that the problem with nuclear (and coal) power stations is that they are too inflexible to be able to fit in energy system with higher percentages of renewable sources.

The nuclear industry responded by saying that reactors could ‘load-follow’ (which means they rapidly adjust their power output according to fluctuating demands for electricity). However this depends very much on the power plant design.

French nuclear corporation AREVA’s so-called state of the art third generation EPR reactor design has already been criticised for lacking this flexibility. French utility EDF who are building an EPR at Flamanville in France have tried to prove the contrary and ordered design changes that would make the reactor able to respond to changing power demands.

Unfortunately this ambition has been stymied by the EPR’s own safety system. The proposed design for the EPR’s reactor core means that it will not be able to rapidly increase or decrease its power output. That is, it won’t be able to ‘load-follow’.

Countries looking to adopt the EPR may now face a choice: lots of centralised, inflexible electricity generation or decentralised flexible power generated by renewables. The two don’t go together at all well.

Expect a lot of pressure from the centralised power industry in the coming months. The battle for the control of the grid is about to begin.

(With thanks to Jan Haverkamp, Greenpeace EU Policy Campaigner on dirty energy)