Innovative technology start-up Stiesdal A/S — which is developing low-cost floating wind substructures, low-cost thermal energy storage, low-cost electrolysers and carbon-negative aviation fuel — has now secured “the necessary funds to execute our ambitious growth plans over the coming years” after receiving massive new investment from PensionDanmark.

The Danish pension fund — which is a part owner of several large offshore wind farms — will now become a minority shareholder in the company after a“triple-digit million investment”.

Denmark-based Stiesdal A/S is run by its founder and CEO, Henrik Stiesdal, the former Siemens Wind Power chief technology officer, whose pioneering wind turbine designs in the 1970s formed the basis of today’s wind industry.

“PensionDenmark is known for having sustainability and responsibility as key parameters in its investment strategy, focusing on renewable energy and job creation. We could not wish for a better external investor,” Stiesdal wrote on LinkedIn on Thursday evening.

“Combining the PensionDenmark investment with new investments by existing shareholders and the recent investment by the Danish utility Andel we have secured the necessary funds to execute our ambitions growth plans over the coming years.”

PensionDanmark CEO Torben Möger Pedersen said: “Stiesdal is a young business, but they’ve proven able to think innovatively, develop tangible solutions and establish partnerships that really contribute towards the green transition.

“PensionDanmark’s triple-digit million investment will be allocated towards the company’s continued product development. With four technologies, all of which offer considerable potential, there are several paths to success, and with a group of experienced people who have proven able to commercialise green energy, we’re confident that Stiesdal will make a difference.”

Stiesdal A/S’s TetraSpar foundation, which is made from cheap-to-produce tubular steel modules, is set to be installed at a demonstration project (with a 3.6MW Siemens Gamesa turbine) off Norway this summer, which is being co-developed with oil giant Shell, German utility RWE and Japanese utility Tepco.

Stiesdal A/S’s GridScale hot-rock energy storage system, which uses crushed stones to store heat for between ten hours and ten days, is due to be trialled at a solar array in Denmark. Siemens Gamesa is developing a similar technology, which stemmed from Stiesdal’s initial design idea when he was chief technology officer at Siemens Wind Power.

Stiesdal A/S’s HydroGen electrolyser is being designed with a focus on low-cost materials and ease of industrial-scale manufacturing in order to bring down the levelised cost of hydrogen.

And Stiesdal’s SkyClean carbon-negative aviation fuel is derived from plant biomass heated in the absence of oxygen inside pyrolysis ovens, to produce solid carbon (biochar) as a by-product rather than CO2. The resulting biooil and syngas is then combined with green hydrogen to produce methanol, which is then converted to jet fuel using established chemical processes.

About half of the carbon the plant material absorbed as it grew would be released back into the atmosphere when burned as jet fuel, with the other half stored for millenia as biochar, a product that can be used to enrich agricultural soil. Revenues from the biochar, as well as carbon credits, would reduce the cost of the fuel to a comparable level to existing A-1 jet fuel, Stiesdal believes.