Hacker News: micro2588

New comment by micro2588 in "America's Geothermal Breakthrough"

micro2588 — Sun, 26 Apr 2026 05:23:10 +0000

These are typically representative of cost performance per watt of one part of a more complex deployed energy system. Things like the aluminum / steal for the container / framing, copper / aluminum for the transmission and wiring, land and labor for installation decline at much less aggressive rates or increase over time.

In almost all pareto optimal least cost energy system models that I've seen, high penetration of solar, wind, batteries plus some minority amount of (clean) baseload power is the most capital efficient energy system.

New comment by micro2588 in "America's Geothermal Breakthrough"

micro2588 — Sun, 26 Apr 2026 04:55:57 +0000

The water at these temperature / depths has a lot of dissolved salts and minerals so it's not (human / ag) usable. Modern designs are closed loop systems where production wells bringing the hot water to the surface go through a heat exchanger to a different working fluid to drive the turbine and then is re-injected back into the reservoir. There is consumptive water use for fracking the reservoirs in these types of enhanced geothermal systems, but beyond that it's more water redistribution in the area around the well systems where re-injection and production lead to different pressurization from pumping / natural ground water replenishment rates.

New comment by micro2588 in "America's Geothermal Breakthrough"

micro2588 — Sun, 26 Apr 2026 04:24:13 +0000

Newberry Volcano is too good to be true in that there are few (outside of Yellowstone) equivalent sources of geothermal awesomeness at similar depths in the USA. Good for research bad for generalization of drilling costs to hit similar temperatures. There are federal protections for geothermal drilling anywhere near Yellowstone.

New comment by micro2588 in "America's Geothermal Breakthrough"

micro2588 — Sun, 26 Apr 2026 03:49:02 +0000

It does work technically I think it is still an open question if it can work economically. There are issues of commercially viable flow rates / thermal decline rates that are harder physical limits you run up against and the pilot design doesn't address. In human timescale terms it's more like heat mining rather than renewable heat due to thermal depletion rate vs replenishment rate. These systems have a targeted lifetime of ~20-30 years and net power will decline over this timespan.

New comment by micro2588 in "America's Geothermal Breakthrough"

micro2588 — Sun, 26 Apr 2026 03:27:13 +0000

The core breakthroughs were working with partners to develop PDC bits that enable high rates of penetration in drilling out these horizontal wells in high temp granitic rock and then demonstrating plug / perf fracture networks that have a high engineered permeability in these source rocks to support economical flow rates and heat transfer. These were considerable advances over previous efforts.

There will be other learning by doing advances in how you structure your power plant design to take advantage of these to make practical long term power production possible (well spacing and injection / production placement / flow rate and temperature decline management).

New comment by micro2588 in "America's Geothermal Breakthrough"

micro2588 — Sun, 26 Apr 2026 03:09:52 +0000

In traditional fault hosted (not magmatic) geothermal the convection of the water up the fault brings the thermal energy closer to the surface where drilling depths are economical. This convection heats the surrounding rock and over hundred thousand - million of years brings the background temperature around a large volume at depth surrounding these systems considerably above traditional background geothermal gradients. By drilling into a much larger volume of impermeable hot rock surrounding a very small permeable fault hosted section you can considerably enhance the power potential of a traditional fault hosted geothermal system (the E in EGS). That is what Fervo is doing and why their projects are situated right next to traditional geothermal power plants.

The assumption is that if you can increase drilling efficiencies enough then you don't even need a fault hosted or similar system to bring that energy close to the surface, you can just drill down deep enough to get at similar temperatures. That is a big assumption in the economics.

New comment by micro2588 in "America's Geothermal Breakthrough"

micro2588 — Sun, 26 Apr 2026 02:55:47 +0000

Fervo uses engineered reservoirs in granitic basement rock so this is less of an issue. Hot rock in a working fluid can still dissolve silicates out of the granite and lead to scaling / degradation of the flow rates through the reservoir and that is a risk but chemical anti scaling treatments are used to reduce this.

CA has the worlds largest geothermal power complex in the Geysers. That one field produces an equivalent amount of power as all the geothermal in Iceland and there are others.

New comment by micro2588 in "America's Geothermal Breakthrough"

micro2588 — Sun, 26 Apr 2026 02:47:57 +0000

In geothermal there is still a lot of interest in efficiency and exploring different working fluids because binary systems now have efficiencies of 10-20%. That is why you see companies like Sage Geosystems working on developing / deploying supercritical CO2 turbines to try and boost practical power densities.

New comment by micro2588 in "Geothermal power is a climate moon shot beneath our feet"

micro2588 — Mon, 03 Mar 2025 00:23:28 +0000

They do a good job of publishing their results in technical industry publications (advancing the field overall in a surprisingly open way) but I agree can be misleading in their marketing.

It will be interesting to see the results of the Cape project once they do multi-well laterals from a single pad power plant with larger diameter wells. That is really more a demonstration of power plant economics beyond the technical feasibility of creating a horizontally fracked reservoir that can be operated for a year.

New comment by micro2588 in "Geothermal power is a climate moon shot beneath our feet"

micro2588 — Mon, 03 Mar 2025 00:07:34 +0000

Supercritical geothermal is similar to talking about the economics of fusion. There is a DOE enhanced geothermal test site near the Newberry Volcano in central Oregon which has temperatures close to this range at reachable depths. That is more of a demonstration site for drilling technology.

New comment by micro2588 in "Geothermal power is a climate moon shot beneath our feet"

micro2588 — Sun, 02 Mar 2025 23:37:35 +0000

I think as a tech demonstration project it was successful because they were a bit conservative in some ways that will make the economics look worse. I agree it's far from "geothermal everywhere" which seems to be the hype. You can't extrapolate that from one successful EGS well literally right next to an existing geothermal power plant.

New comment by micro2588 in "Geothermal power is a climate moon shot beneath our feet"

micro2588 — Sun, 02 Mar 2025 23:24:53 +0000

There is no way to tell yet what the longevity of the resource will be as it's too early. In fracked resources the main issue is "short circuiting" where increased flow rates travel along preferential paths between the doublet wells as the source rock cools and cooling rate of the source rock in general. This causes the MWt of the resource to decline per injection / production well. Fervo is getting around this by drilling extra wells per pad to be turned on in response. Many geothermal resources decline over time as heat is slowly extracted and these declines are somewhat manageable by tuning the injection production well rates and drilling new wells. They are built into the economics of existing plants. Geothermal is kind of extractive and not "renewable" in this way over medium term time scales, you need to continuously keep drilling at a certain rate. Rock is a good insulator and it takes a long, long time for it to heat back up.

New comment by micro2588 in "Geothermal power is a climate moon shot beneath our feet"

micro2588 — Sun, 02 Mar 2025 23:12:45 +0000

You are right there is no getting around that relatively low grade heat in geothermal is a big barrier for scaling in terms of energy production. Binary /organic rankine cycle geothermal plants used for these low / medium temperature resources operate at ~10% efficiency. Dry / flash steam resources are higher but produce waste in terms of emitted GHG and / or crap in the geothermal brine.

New comment by micro2588 in "Geothermal power is a climate moon shot beneath our feet"

micro2588 — Sun, 02 Mar 2025 23:04:27 +0000

Ormat (NYSE ORA) is a publicly traded geothermal company and they are profitable.

New comment by micro2588 in "Geothermal power is a climate moon shot beneath our feet"

micro2588 — Sun, 02 Mar 2025 22:52:38 +0000

Fervo's initial demonstration project was next to an existing power plant in Nevada which previously failed to produce at it's stated capacity over time (Battle Mountain) so they were able to tie in extra MWt capacity to an existing ORC turbine. Fervo's technology has to be located somewhat near existing traditional hydrothermal geothermal resources because it's the convection along an exiting fault for hundreds of thousands of years that produces an above background thermal gradient near enough to the surface for it to be economical. That is true for their demonstration area in Utah which is located near the existing Blundel geothermal power plant in Milford Utah.

New comment by micro2588 in "Back to the Future: Lisp as a Base for a Statistical Computing System [pdf]"

micro2588 — Wed, 19 Jul 2017 01:15:51 +0000

Julia has been designed for single core performance fullstop. Functional collections may work well with a state of the art GC, with Julia's not so much. The fact that Julia can interop seemlessly with C code (easily) kind of bounds the design of the GC.

I think it is a little disingenuous to say that a Julia programmer does not have to worry about types. Type inference alleviates many burdens, but correct typing of arguments is essential (and hidden promotions or casting can kill performance). So while you can write correct programs easily, for efficient programs you end up worrying about this quite a lot.

New comment by micro2588 in "How a comment on Hacker News led to 4½ new Unicode characters"

micro2588 — Thu, 23 Jun 2016 23:17:37 +0000

Will this eventually solve the "Julia does not like Pizza" issue (https://github.com/JuliaLang/julia/issues/3721)?

New comment by micro2588 in "Stanza: A New Optionally-Typed General Purpose Language from UC Berkeley"

micro2588 — Sat, 21 May 2016 13:08:59 +0000

Hi Patrick, can you point to a paper / resource that describes this recent work?

New comment by micro2588 in "Matrices in Julia"

micro2588 — Mon, 24 Aug 2015 01:15:22 +0000

You can do this using the SymPY.jl package. As a good chunk of matrix functionality is parametric on element type, you can do matrix operations on SymPY's symbolic variables.

See example 6 in: https://github.com/andreasnoack/andreasnoack.github.io/blob/...

The problems of method extension working with multiple dispatch

micro2588 — Mon, 17 Mar 2014 22:40:41 +0000

Article URL: https://github.com/JuliaLang/julia/issues/6190

Comments URL: https://news.ycombinator.com/item?id=7418593

Points: 5

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