Paul Dorfman is Bennett Scholar at the Bennett Institute for Innovation & Acceleration, University of Sussex and chair of the Nuclear Consulting Group

The reason is simple. Nuclear costs are huge and rising and significant delays are the norm. The result is that nuclear power faces the same fundamental challenges as fossil fuels - uncompetitive costs, stranded assets, a polluting legacy and unrivaled competition from renewables.

Now comes another vision - powering a brave new world of artificial intelligence (AI). Yet the International Energy Agency expects data centers to cause a 10th of global electricity demand growth to 2030, doubling their share of usage to just 3%. So AI won't eat the grid. Meanwhile, IEA forecasts renewables will power data-center growth 10-20 times over, with Bloomberg NEF predicting a 100-fold renewables expansion.

Deregulation

The UK's PM says nuclear "has been suffocated by regulation". Blaming regulators for things going wrong has always been a fallback excuse for the nuclear industry, but for the first time, governments are backing the nuclear industry against their own regulatory bodies, with the UK and the US leading the way.

Reporting directly to the PM, the new UK Nuclear Regulatory Taskforce says the regulation of civil and defence nuclear "has become increasingly complex and bureaucratic, leading to huge delays and ballooning costs, often for marginal benefit". The problem is there's no evidence to support this. In fact, the evidence suggests otherwise.

EDF insists they had to "substantially adapt the reactor design at Hinkley Point C to satisfy British regulations - requiring 7,000 changes, adding 35% more steel and 25% more concrete". UK Office for Nuclear Regulation, normally slow to anger, tersely replied to EDF the next day that "we do not recognise our regulatory requirements as being the principal factor in these increases".

With ramping reactor cost and time over-runs for large reactors and calls for nuclear deregulation, the small modular reactor (SMR) concept offers a rare bright point of optimism in UK government nuclear plans.

Rolls-Royce SMR has won the competition to be the first to try to build SMRs on home soil. But hold your horses, the Rolls-Royce SMR isn't an SMR. It's larger than the UK Magnox reactor, half the size of the reactors that make up the bulk of the French nuclear fleet and a third the size of the very large reactors being built at Hinkley Point C.

This matters because the Rolls design will need big sites, standard nuclear safety measures, exclusion zones, core catchers or the equivalent, aircraft crash protection and security. All this is important because in calling their design an SMR, or small, Rolls-Royce has been economical with the truth - and all that applies to their other claims, especially about time and cost.

The uncomfortable truth is that all SMR designs are a long way away and would be more expensive than large reactors per kWh - the key parameter. And as the former Chair of US government Nuclear Regulatory Commission (NRC) says, SMRs will produce more chemically and physically reactive waste than large reactors.

Renewable evolution

Cementing an alliance with the Trump administration based on nuclear risk deregulation seems doubly troubling - and makes little practical, economic or political sense to those struggling under the cost-of-living and energy crises. The US and UK governments' attack on the integrity of their own nuclear safety regulators makes no sense. Perhaps because they are unwilling to face up to the conclusion that the problem with nuclear is the technology itself.

When so much looks grim, the renewable evolution holds out real hope. The astonishing fact is that 91% of new renewable projects are now cheaper than new fossil-fuel projects and vastly less costly than new nuclear. This carries meaning for global energy policy and climate action. Time is key to climate - and it's running out.

The Intergovernmental Panel on Climate Change (IPCC) reports that renewables are now 10 times more efficient than new nuclear at CO2 mitigation. Build times for new nuclear are massively longer than for solar and wind and nuclear costs always ramp. Sizewell C new nuclear is predicted to cost £38bn, with the UK government acknowledging costs may rise significantly.

In terms of cost, time and do-ability, it's renewable expansion in all sectors, energy efficiency and management, rapidly advancing storage technologies, grid modernisation and interconnection that will power the energy transition. The compelling economics of renewables unmask those of fossil and fissile fuels. Unlike nuclear, the renewable evolution is here and now.