There's Finnish company called Norsepower that makes these. Their page does mention that the idea also came up around the same time to Finnish inventor Sigurd

There's Finnish company called Norsepower that makes these. Their page does mention that the idea also came up around the same time to Finnish inventor Sigurd Savonius who also held some patents around this area. Linked wiki entry didn't seem to mention him thought. https://en.m.wikipedia.org/wiki/Sigurd_Johannes_Savonius https://en.m.wikipedia.org/wiki/Sigurd_Johannes_Savonius And https://www.norsepower.com/ https://www.norsepower.com/ Ps. I don't know anything about the topic - just internet rabbit hole for me as I recently came to know that Norsepower's CMO is well known ex-musician in Finland and startup entrepreneur.