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

181–190 of 282 posts

Re: The time has finally come for geothermal energy

#181

Post by parineum »

marcosdumay wrote: post #81
glenstein wrote: post #43

Earlier quoted context omitted.

You're exactly right and it raises a question for me. Why do energy generation topics bring people out of the woodworks who cite some very idiosycratic one-off and use it to make out-of-proportion declarations about the utility of a given technology? This is the second one I've seen suggesting solar is doomed when they mean mirrors. On twitter I saw someone claim PV is useless for heat because non-PV solar water heat…

> Why do energy generation topics bring people out of the woodworks who cite some very idiosycratic one-off and use it to make out-of-proportion declarations about the utility of a given technology? They either have only read propaganda pieces from fossil fuel producers or are trying to create some of those. I would expect the number of people that honestly don't know anything but propaganda to be way higher than the…

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 power supply, what it needs to be to replace fossil fuels, they'd be doing it.

Re: The time has finally come for geothermal energy

#182

Post by PaulDavisThe1st »

bryanlarsen wrote: post #97
jmward01 wrote: post #85

Earlier quoted context omitted.

The right answer is 'yes to all the above'. Yes, we need solar. Yes, we need wind. Yes, we need batteries and, yes, we should be looking at geothermal. Solar has shown us, again, how artificially holding back a technology for decades has massive costs. Investing a few billion into geothermal right now is cheap and can only lead to a more durable energy infrastructure in the future. There are all sorts of benefits to…

> 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…

> but existing installations don't stop working.

They will, albeit slowly.

Re: The time has finally come for geothermal energy

#183

Post by PaulDavisThe1st »

robocat wrote: post #162
bryanlarsen wrote: post #57

Baseload generation is useless in 2025. It's in the name; it's called "base load", not "base generation". Base generation was a cost optimization. Planners noticed that load never dropped below a specific level, and that cheapest power was from a plant designed to run 100% of the time rather than one designed to turn on and off frequently. So they could reduce cost by building a mix of base and peaker generation plan…

> 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…

> Although the lakes themselves are large, they don't have enough capacity to cover a dry year.

It was shocking to me to drive by many of the California lakes/reservoirs that were overfull in the spring of 2019 only to hear that they were basically running dry two years later, and realize that as substantial a water storage system as they are, they're not multi-year scale against the required water supply.

Re: The time has finally come for geothermal energy

#184

Post by PaulDavisThe1st »

thedrbrian wrote: post #144
bryanlarsen wrote: post #57

Baseload generation is useless in 2025. It's in the name; it's called "base load", not "base generation". Base generation was a cost optimization. Planners noticed that load never dropped below a specific level, and that cheapest power was from a plant designed to run 100% of the time rather than one designed to turn on and off frequently. So they could reduce cost by building a mix of base and peaker generation plan…

Its so easy that you can’t name me a single city of more than 10000 people that runs entirely off renewables.

Weakly defined. What does "run entirely off renewables" mean?

We know that in North America, for example, significant energy use comes from transportation and heating requirements, and that at this time, very little transportation is powered by renewables, and not a whole lot of heat either (though both are growing).

On the other hand, the entire current residential electrical demand of the city of Santa Fe (about 82k people) can be met with a single relatively small PV+BESS plant (and might just be if it manages to get built).

Re: The time has finally come for geothermal energy

#185

Post by kragen »

cameldrv wrote: post #77
nickcw wrote: post #30

Earlier quoted context omitted.

Why not is explained in David McKay's book Sustainable Energy - without the hot air https://www.withouthotair.com/c16/page_96.shtml The problems are that rock isn't a good conductor of heat, so once you've cooled a bit down, you have to wait for it to warm up. Warming only happens very slowly at the rate of < 50mW / m² which limits the amount of power you can get out.

Couldn't you frac the rock like they do with oil and gas drilling or have a branching borehole?

Yes, that's what this article is about.

Re: The time has finally come for geothermal energy

#186

Post by kragen »

fuoqi wrote: post #15
hodgehog11 wrote: post #3

I've always been curious why a cost-effective widespread implementation of geothermal energy has never been considered a holy grail of energy production, at least not in the public debate. Much of the discussion is so focussed on nuclear fusion, which seems so much harder and less likely to be reliable.

Because unless you sit on top of a volcano, amount of renewable geothermal energy is minuscule. In most places on Earth it's somewhere around 40 mW/m2 (i.e. accounting for conversion losses you need to capture heat from ~500 m2 to renewably power one LED light bulb!). In other words, in most places geothermal plant acts more like a limited battery powered by hot rock, so unless drilling is extremely cheap, it does no…

While it's true that a geothermal plant is a limited battery powered by hot rock, that doesn't mean it doesn't make economic sense compared to other energy sources.

Re: The time has finally come for geothermal energy

#187

Post by kragen »

dns_snek wrote: post #48
fuoqi wrote: post #15

Earlier quoted context omitted.

Because unless you sit on top of a volcano, amount of renewable geothermal energy is minuscule. In most places on Earth it's somewhere around 40 mW/m2 (i.e. accounting for conversion losses you need to capture heat from ~500 m2 to renewably power one LED light bulb!). In other words, in most places geothermal plant acts more like a limited battery powered by hot rock, so unless drilling is extremely cheap, it does no…

> In most places on Earth it's somewhere around 40 mW/m2 (i.e. accounting for conversion losses you need to capture heat from ~500 m2 to renewably power one LED light bulb!) Ground-source heat pumps extract about 1000 times more power from ground loops, where does the difference come from?

Ground-source heat pumps are irrelevant to geothermal energy sources, and it's unfortunate that the article mentioned them. Ground-source heat pumps are just storing heat from the air during the summer and retrieving it during the winter.

Re: The time has finally come for geothermal energy

#188

Post by kragen »

xienze wrote: post #6
hodgehog11 wrote: post #3

I've always been curious why a cost-effective widespread implementation of geothermal energy has never been considered a holy grail of energy production, at least not in the public debate. Much of the discussion is so focussed on nuclear fusion, which seems so much harder and less likely to be reliable.

Probably because not everywhere on earth has the same easy access that Iceland has. The article mentions this: > There aren’t gates of Hell just anywhere. A kilometre below ground in Kamchatka is considerably hotter than a kilometre below ground in Kansas. There is also readily accessible geothermal energy in Kenya (where it provides almost fifty per cent of the country’s energy), New Zealand (about twenty per cent),…

It also explains why this is no longer a problem.

Re: The time has finally come for geothermal energy

#189

Post by mcswell »

hluska wrote: post #95
jimbokun wrote: post #84

Earlier quoted context omitted.

What does "Rejected Energy" mean in that graph? Great chart, by the way.

I live in a part of the world that is far below freezing for a significant portion of the year. Thus a large portion of my annual energy usage goes into not freezing to death. When I drive my daughter to school when it’s -40 fucking degrees, a lot of the energy I use goes into heating my vehicle, swearing, moving and swearing. But this energy also leaks through my windshield, through my exhaust system and through my…

"when it’s -40 fucking degrees" Celsius, or Fahrenheit? Oh yeah, it's the same either way :).

Re: The time has finally come for geothermal energy

#190

Post by kragen »

cbmuser wrote: post #119
nagisa wrote: post #70

Earlier quoted context omitted.

The options in the '70s were much different from those of today. And for France specifically what they have underground (lots of uranium, no oil, no gas & no coal) strongly suggested exactly one way forward.

Wind and solar existed in the 70s as well. Plus, Germany invested 500 billion Euros in its energy transition and is STILL heavily dependent on coal.

> Wind and solar existed in the 70s as well.

This is basically nonsense to the extent that it is becoming difficult to extend the presumption of good faith to you. In the 70s solar panels cost US$25+ per peak watt, in 02021-adjusted dollars: https://en.wikipedia.org/wiki/Solar_energy#/media/File:Solar...

Now they cost 5.9¢ per peak watt: https://www.solarserver.de/photovoltaik-preis-pv-modul-preis...

Installing a gigawatt of solar power generation capacity for US$25 billion is in no way comparable to installing a gigawatt of solar power generation capacity for US$59 million.

Wind power has experienced a similar but less extreme cost decline.

Post reply on HN