Geothermal has been underinvested for some years, but a deal cut this week by the venture capital groups of both BP and Chevron aims to change all that – backing Eavor, a Canadian startup intent on moving geothermal away from volcanic heat sources. It makes a change but this investment is not fronted by Bill Gates, because if it had his platform, this would be screaming out for 10 times this amount of money and opening a big opportunity, once its system is both proven, and scaled. This week those backers gave $40 million, well beyond what is normally given to a pilot effort and Eavor says this is enough cash to fully commercialize its offering and it can use…