Rolls-Royce Holdings Plc raised 455 million pounds ($617 million) to fund the development of small modular nuclear reactors, with almost half of the financing coming from the U.K. government.

Britain has committed 210 million pounds to the project, secured by private-sector funding of 245 million pounds, according to statements. That will allow the jet-engine maker to proceed with obtaining design approval for the reactors and identifying locations for on-site assembly of the plants.

The U.K. is supporting nuclear as the best way to back up intermittent renewable generation and to eliminate fossil fuels from power plants by 2035. The Treasury will allocate 1.7 billion pounds to bringing forward a final investment decision on at least one large-scale nuclear project, most likely Electricite de France SA’s Sizewell C. Smaller modular reactors would be sited across the country to address more specific needs.

Rolls-Royce is pouring funding into the plan as its main business of making jet engines for the world’s largest aircraft faces an uncertain future amid a global push to move beyond kerosene-fueled planes.

Synthetic Fuels

In addition to powering households and industry, Rolls-Royce says the modules could be used to help manufacture the synthetic fuels and hydrogen on which aviation is expected to rely in coming years.

The shares traded 5.4% higher at 149.46 pence as of 9:39 a.m. in London, taking gains this year to 34%.

Small modular reactors are potentially cheaper and quicker to build than big conventional stations that have been in use for decades. Companies led by Rolls-Royce are working on 16 such reactors by 2050.

They “offer exciting opportunities to cut costs and build more quickly,” U.K. Business Secretary Kwasi Kwarteng said in a statement. Developing them can “also position our country as a global leader in innovative nuclear technologies we can potentially export elsewhere,” he said.

Rolls-Royce, BNF Resources U.K. Ltd. and Exelon Generation Ltd. will invest 195 million pounds over three years. Rolls-Royce had already committed 50 million pounds to phase two of the project and says it needs about 2 billion pounds to bring its plans to fruition.

“Discussions will also continue with the U.K. government on identifying the delivery models that will enable long-term investment in this vital, net-zero enabling technology,” the engine-maker said.