While it’s obvious that, from NZ to Iceland, geothermal can be a boundless energy source for much fantasised baseload electricity, a critical factor is that Mother Nature needs to provide the large hole(s) down to the hot stuff.
After 10 years and nearly $200M, Geodynamics, drilling in remote northern SA, may have turned a small turbine. Claim was, just like drilling an oil well, except 5000m not 5000ft, big difference. Also oil well bottom is soft, porous sedimentary rock but Geodynamics blunted many expensive bits on solid granite. And hot. Fresh water is pumped down the hole, coming back up again at 150degC. The deeper hole is just 175mm so flow rate, after friction 5000m up and down, is just 30kg/sec or so. Target 1MW electrical power now looking iffy, especially comparing cost/MW of wind turbine power at Hepburn at $3M.
>read more> from Climate Spectator Tristan Edis
