UK power technology group Rolls-Royce claimed it's on track to grid-connect mini nuclear reactors that can match renewables such as wind power on cost of electricity produced.

The group’s chief technology officer Paul Stein said its small modular reactor (SMR) technology, which uses prefabricated components that can be transported on a truck and assembled on site for scalable projects, can revive the prospects of nuclear as a source of zero-carbon energy by avoiding the pitfalls of massive, gigawatt-scale power station builds.

Stein told the BBC: “We think we can get the cost of a power station producing 440MW … to about £1.75bn ($2.23bn).

“If you go through the maths of the cost of capital, it means we’re selling electricity below £60/MWh ($78.5/MWh) which puts it into the territory of many of the renewables.”

Stein added that Rolls-Royce is “certain the maths is right” and confident it can drive the cost down further when advances in manufacturing and economies of scale feed through, with first grid-connections by 2029.

UK onshore wind – reckoned to be the cheapest source of new zero-carbon power in Britain – was last year coming in at £46/MWh, according to figures from consultants Cornwall Insight, which noted that onshore itself is coming under pressure from ever-cheaper offshore wind.

Commenting on Rolls-Royce's claims, Tom Edwards, senior modeller at Cornwall Insight, told Recharge: “Nuclear is unlikely ever to be cheaper than wind or solar projects per megawatt-hour.

“However, given the extra power demand Great Britain will need to meet as we head to net-zero, it will be all hands to the pump and nuclear could have a place in the energy mix.”

The SMRs would initially be located at the sites of existing nuclear stations coming out of service, said Stein, adding that the aero-engines group is in discussions with “a number of foreign governments” about exporting the technology.

Rolls-Royce hopes the SMR can offer a fresh role for nuclear in the push for zero-carbon energy.

As elsewhere in the world, the UK nuclear sector has become enmired in controversy over costs and safety, symbolised by EDF’s 3.2GW Hinkley Point C nuclear station being built in southwest England, which has a 35-year government deal to deliver power at £92.50/MWh (at 2012 prices) despite costing more than £22bn to build.

Rolls-Royce claims SMRs use “proven technologies that present a class leading safety outlook and attractive market offering with minimum regulatory risk”.