Assertion Supported
Horne: Half the US is accessible for $80/MWh geothermal
“So we've estimated that about half of the United States is accessible for EGS at 80 dollars a megawatt hour.”
Insight
Horne: Low rock conductivity fundamentally limits closed-loop geothermal heat extraction
“In the case of a drilled hole, the surface area of the hole is quite small, and therefore you depend a lot on conduction of energy, thermal energy through the rock. And rocks actually are not very good thermal conductors. Rocks are kind of insulators actually,…”
Insight
Horne: Geological uncertainty is the primary cost driver for geothermal
“The biggest cost driver for geothermal development is uncertainty. And because it's a resource, a geological resource, the fact that you don't know exactly how big it is and how long it's going to last, that translates into uncertainty in the sizing of the pla…”
Assertion Supported
Horne: Next-gen geothermal concepts have existed for 40 to 50 years
“Actually none of these ideas are actually new. Most of them have been around for 40 or 50 years, and several of them tried already. EGS, perhaps, is the one that's been around the longest, first kind of postulated back in the 19 sixties at Los Alamos National …”
Assertion Supported
Horne: Fervo's 90MW Utah EGS project is 20x larger than predecessors
“Their near-term plan is 90 megawatts, which is, you know, probably 20 times bigger than any of the former EGS projects, the old EGS projects that people have done.”
Assertion Partly supported
Horne: Conventional geothermal matches average US electricity cost of $80/MWh
“You know, the average cost of electricity in the US is somewhere around 80 dollars a megawatt hour and conventional geothermal is basically at that cost today.”
Assertion Partly supported
Horne: Iceland's supercritical well dissolved its steel casing into black steam
“So I'm reminded of the videos they showed of the supercritical well that they produced in Iceland called IDDP-II. It basically produced black steam, and the reason it produced black steam is that it was producing the steel casing together with the steam. It wa…”
Prediction Not checkable as stated
Horne: Unconventional techniques will cut geothermal drilling costs in half
“Unconventional drilling practice for the normal geothermal industry has actually basically helped or will soon bring geothermal drilling costs down perhaps to half what it was five, 10 years ago, and that really opens up many new areas because, again, you're j…”
Assertion Supported
Horne: Geothermal generates 6% of California's, 10% of Nevada's, and 50% of Kenya's electricity
“Six percent of our electricity comes from geothermal. 10% of electricity in Nevada comes from geothermal, conventional geothermal. And there are countries in the world, ah, Kenya notably takes 50% of its national electricity from geothermal.”
Insight
Horne: Rock permeability is the primary bottleneck for conventional geothermal energy
“And so, the three things that you need for your thermal resource are heat, water, and permeability. So, it's hot everywhere to, if you can drill deep enough and almost the entire planet is saturated with water, you know, at depth. But the places that don't hav…”
Assertion Supported
Horne: Binary geothermal plants release virtually zero atmospheric emissions
“Because the water never leaves, the geothermal water never leaves the heat exchanger, there's basically no emissions at all from the subsurface out into the atmosphere of the environment. The water stays in the pipe, goes back in the ground. It never sees the …”
Insight
Horne: Geothermal fractures brittle volcanic rock, unlike pliable sedimentary rock
“Oil and gas are fracturing sedimentary rocks. Which tend to be more pliable, plastic, and geothermal is fracturing volcanic rocks, which are brittle and hard, and it's a somewhat different process, and it's a somewhat different result as a consequence.”
Assertion Supported
Horne: Commercial closed-loop pilot in Germany requires 80 kilometers of drilling
“So the system, they're drawing a closed loop system, sort of the first commercial pilot or whatever in Germany right now, which they're planning. 80 kilometers of holes, if I remember that number correctly, which is feasible but quite expensive.”
Assertion Supported
Horne: Batch drilling reduced Fervo's Utah drilling times two- to threefold
“So further again in their EGS project in Utah is doing batch drilling where they're actually drilling, you know, eight wells at a time. Well, not quite eight at a time. They, they're drilling the first segments eight at a time, and then the second segment's ei…”
Dr. Roland Horne