Earlier quoted context omitted.
This isn’t really an evaluation of the company, just explaining how they had to use different financing approaches as they grew and derisked their technology (which makes sense). Compared to some other new approaches for getting clean base load power, it seems like they’ve been pretty grounded and methodical.
They're way ahead of the microwave drilling people. There's no reason why this shouldn't work. But they've been at it for 9 years, with considerable funding, and it doesn't really work yet. That's a concern.
Geothermal has had the same problem for its entire history. That problem is that the water being heated goes through the ground (not in a pipe) to "gather" more energy. But this means that when the water comes back up, it has a lot of weird salts in it (and other things). Those salts cause corrosion, lots and lots of corrosion, far more than even a maritime environment. So the plant needs to be shutdown a lot of the time for repairs. And that's what makes it uneconomical. Also, the salts often contain things that require special handling which also increases costs.
PS This is why geothermal works in Iceland where there is so much geothermal heat they can use pipes. In CA, they can't so it doesn't work there.