Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The time has finally come for geothermal energy

newyorker.com

Post reply on HN
Print view View original

211–220 of 282 posts

Re: The time has finally come for geothermal energy

#211

Post by robocat »

bryanlarsen wrote: post #170
robocat wrote: post #162

Earlier quoted context omitted.

> pumped hydro for long term storage. You are using long-term in an extremely vague way. Pumped hydro is not a solution for seasonal storage or yearly storage. Seasonal variation can be a problem in higher latitudes. For example we have a serious problem in New Zealand where our existing "green" hydro lakes are sometimes low and our economy is affected: creating national power crises during dry years. We use coal-bur…

Long term storage is definitely the weak point of moving to 100% carbon free electricity. Unfortunately geothermal does not cover this need. If we want to cover a dankelflaute with geothermal, we basically need enough geothermal to cover ~100% of our power needs. Pumped hydro is the best answer we have at the moment, even if it isn't a great answer. What will likely happen is that people will decide that "99% is good…

I would guess dankelflaute is mostly irrelevant in New Zealand because our hydro lakes (assuming rivers are flowing) can smooth out generation shortfalls shorter than say a month (kinda equivalent to pumped hydro or batteries). A 3 day dankelflaute as given in the Wikipedia example would likely not matter in New Zealand. Plus our weather is variable, and generation is spread out.

  New Zealand's hydro storage is less than a sixth of the country's total yearly electricity use. Hydro generation typically accounts for over 50% of our annual electricity generation, making us reliant on river flows. The maximum storage (full lakes) is around 5 TWh.
The lakes can't smooth out over long periods.

About 20% of New Zealand electricity comes from geothermal. I would guess political and environmental issues would dominate costs for increasing geothermal generation (plus I would assume we've taken all the low hanging fruit).

https://en.wikipedia.org/wiki/Dunkelflaute

Re: The time has finally come for geothermal energy

#212

Post by pfdietz »

bryanlarsen wrote: post #170
robocat wrote: post #162

Earlier quoted context omitted.

> pumped hydro for long term storage. You are using long-term in an extremely vague way. Pumped hydro is not a solution for seasonal storage or yearly storage. Seasonal variation can be a problem in higher latitudes. For example we have a serious problem in New Zealand where our existing "green" hydro lakes are sometimes low and our economy is affected: creating national power crises during dry years. We use coal-bur…

Long term storage is definitely the weak point of moving to 100% carbon free electricity. Unfortunately geothermal does not cover this need. If we want to cover a dankelflaute with geothermal, we basically need enough geothermal to cover ~100% of our power needs. Pumped hydro is the best answer we have at the moment, even if it isn't a great answer. What will likely happen is that people will decide that "99% is good…

> Unfortunately geothermal does not cover this need.

Artificial geothermal could though.

https://www.orcasciences.com/articles/standard-thermal

The size is orders of magnitude smaller than the depth of natural geothermal wells, and the temperature much higher. Even so, they are aiming for heat loss of < 1%/month, entirely adequate for seasonal energy storage.

Re: The time has finally come for geothermal energy

#214

Post by pfdietz »

toomuchtodo wrote: post #22
yawaramin wrote: post #19

It's nuclear fission. It's always been nuclear fission (well, at least since the '50s) and it will continue to be until we commercialize fusion reactors. Everything else is nice to have but it's like NIH syndrome.

Geothermal is fission, and wind, solar, and batteries are fusion at a distance. In both cases, the failure scenarios are benign vs traditional fission generation. It's fine to keep striving for fusion humans control, but the problem (global electrification and transition to low carbon generation) is already solved with the tech we have today. It took the world 68 years to achieve the first 1TW of solar PV. The next 1…

> Geothermal is fission

Geothermal is not nuclear fission. The heat comes from a combination of primordial heat (from the gravitational energy turned to heat as the Earth formed) and radioactive decay (which is some combination of alpha and beta decays; spontaneous fission is extremely rare.)

Re: The time has finally come for geothermal energy

#215

Post by robocat »

icehawk wrote: post #200
iso1631 wrote: post #106

Earlier quoted context omitted.

Not grid following inverters, or "any DC source", as we saw in Spain in Summer

From what I saw: In Spain, inverters are not allowed to provide voltage control, and what we saw in Spain, was a voltage spike that caused generators to drop offline, which then caused frequency issues.

See report and first comment: https://news.ycombinator.com/item?id=44358668

It looked to me that regulators wanted to make solar the scapegoat for political reasons.

The report indicates to me that different operators were using a random monkey theory to make changes until the grid stabilised (they clearly didn't have a handle on the root cause of the instabilities). The regulator screwed up: they are supposed to engineer the network so it can be stable (even in the face of political pressure).

Re: The time has finally come for geothermal energy

#216

Post by kragen »

ahmeneeroe-v2 wrote: post #203
kragen wrote: post #192

Earlier quoted context omitted.

The US and Russian Navies deciding to remain mostly petroleum-fueled is one of the strongest arguments against nuclear becoming very cheap: surely they would do it if it wasn't ruinously expensive, because it eliminates the national security risk of a petroleum blockade and simplifies at-sea logistics immediately.

Don't presume too much about the US Navy's fleet decisions. Using that same logic you could presume that smaller, aged and poorly maintained fleets are advantageous for naval supremacy since that appears to be the choice of the US Navy for a couple generations now. Or you could presume that the complete inability to build a merchant marine fleet was also a strategic advantage!

It's not just the US Navy. It's also the Russian Navy, the French Navy, the Chinese navy of the PLA, the British Navy, the Indian Navy. If nuclear power were cheaper than oil, or anything other than much more expensive, at least one of those would have gone all-nuclear.

Re: The time has finally come for geothermal energy

#217

Post by davidw »

inglor_cz wrote: post #138
psunavy03 wrote: post #100

Earlier quoted context omitted.

People want houses. Planners can either yell and stomp their feet about this or adapt to circumstances. It's like electric cars. People want cars. Better they have the ability to have an electric SUV or pickup, because if you try to force them into little tiny econoboxes or lecture them about how they should really be using mass transit, they're just going to flip you the bird and walk away. Similarly, better to have…

"People want houses." (Source needed. This probably depends on a lot of variables in play.) Plenty of people in dense urban areas are happy with living in an apartment and, where I live, buying a condo in the city is at least as frequent as buying a house 20 km away from it for the same price. Living in suburbia has its downsides - long commute, very limited entertainment and cultural possibilities, very limited choi…

People want a lot of things, many of them conflicting. I'd love a huge house on a large lot in a walkable area and it to be cheap, and also close to nature. Letting markets work is a good way of resolving people's revealed preferences. Some will prefer a condo in a walkable area, others a large lot outside a less expensive city, others will pay through the nose to have a single detached unit in a high cost of living area.

Re: The time has finally come for geothermal energy

#218

Post by phreeza »

To me the most important fact to keep in mind about geothermal is that the energy flow across the crust is ~0.1W/m^2. Compare that to the sun which has >100W/m^2 even at high latitudes. Of course this does not mean geothermal is useless (in particular heat pumps, if you count those, are great), but it goes a long way to explaining why geothermal isn't seeing the same explosion as solar.

Re: The time has finally come for geothermal energy

#219

Post by pfdietz »

hvb2 wrote: post #173
bryanlarsen wrote: post #97

Earlier quoted context omitted.

> Solar and batteries may be amazing but global supply chains can be disrupted. Solar and batteries aren't consumables, so they're not particularly vulnerable to supply chain disruption. If we lose our supply of batteries, we'll have ~10 years or so to find an alternate supply. We won't be able to do new installations during the disruption, but existing installations don't stop working. Unlike a fossil plant when the…

You may need small amounts of rare earth elements. Those are definitely a supply chain nightmare.

Not for solar, and not for most forms of Li-ion batteries.

Re: The time has finally come for geothermal energy

#220

Post by parineum »

marcosdumay wrote: post #197
parineum wrote: post #181

Earlier quoted context omitted.

I brought up the mirror plant because the molten salt crucible is an example of an attempt to make solar work after hours. It wasn't viable. Solar+storage is not a solved problem. The storage problem gets continually hand waived away in the conversations about how cheap solar is. As I said in a sibling comment, I don't think the people running energy companies are stupid. If solar really was cheaper as a baseline pow…

> If solar really was cheaper as a baseline power supply, what it needs to be to replace fossil fuels, they'd be doing it. So, you haven't looked at what energy companies are doing for the last 3 years...

Sure. Building out renewables while still keeping their coal/methane plants running. Then again, with the abundance of rooftop solar where it's economical, there's really no need for utility level solar. Wind is good still but also inconsistent.

With the way power demand is growing, new fossil plants aren't being built really because renewables can pick up a lot of the new demand but solar is at the point in some places where utilities don't want your excess power.

Renewables are great in the places they fit but they don't fit everywhere.

Post reply on HN