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

America's Geothermal Breakthrough

oilprice.com

Post reply on HN
Print view View original

141–150 of 183 posts

Re: America's Geothermal Breakthrough

#141

Post by Y-bar »

thinkcontext wrote: post #104
hunterpayne wrote: post #50

Earlier quoted context omitted.

"I don't know how economical that is" Sure you do. Think about it. Its just drilling a hole and making electricity from the heat. We have been able to do this for a very long time. So if people aren't really doing it much, its not economical. If it was now becoming economical, the article would describe some new way of doing it that makes it economical. The article doesn't, so you "know" it isn't. PS This has been tr…

> Its just drilling a hole and making electricity from the heat District heating does not involve making electricity.

Sometimes district heating and electricity generation does combine though:

> Wärtsilä’s combined power generation and heat recovery plant offering comprises solutions for combined heat and power (CHP) including dynamic district heating (DDH), district cooling and power (DCAP) and trigeneration for applications that require both heating and cooling.

https://www.wartsila.com/energy/engine-power-plant-solutions...

Re: America's Geothermal Breakthrough

#142

Post by glaucon »

Animats wrote: post #91
lostlogin wrote: post #12

Earlier quoted context omitted.

> if you want to generate power, you need to get down to where temperatures can boil water. That's deeper than most oil wells. That’s going to be very dependant on location. Here in NZ there are regions where water is boiling at surface level. According to the below, 18% of our power is produced with it. https://www.eeca.govt.nz/insights/energy-in-new-zealand/rene...

"New Zealand has an abundant supply of geothermal energy because we are located on the boundary between two tectonic plates. ... Total geothermal electricity capacity in New Zealand stands at over 900 MW, making us the fifth largest generator of geothermal in the world. It has been estimated that there is sufficient geothermal resource for another 1,000 MW of electricity generation." That's not all that much. That to…

> That's not all that much

May not be much in world terms but here in NZ national demand maxes out at around 5.5GW so bringing another GW on stream would be quite handy. Most of the geothermal is a lot closer to Auckland* than our hydro is so so that would be another positive aspect.

* Auckland has 25% of the population so a corresponding amount of energy has to be pushed its way.

Re: America's Geothermal Breakthrough

#144

Post by quickthrowman »

gambiting wrote: post #27
quickthrowman wrote: post #18

Earlier quoted context omitted.

District heating and chilled water is uneconomical for single-family homes. It does work well in medium to high density areas.

I don't know how economical that is, but just as an anecdote - the town I'm from in Poland has district heating to all single family homes, town of about 20k people. And coincidentally, I now live in the UK and a new estate near me has district heating to all the houses they are building, not apartment blocks. So it must make some sense to someone, or they wouldn't be outfitting 100+ houses this way.

It’s uneconomical in an already built out area or a non central planned economy, and also the US is special case since we have dirt cheap natural gas that is used for heating.

Digging up streets to run distribution lines, running service drops to every existing house, installing a heat exchanger and valves in every house is astronomically expensive given the amount of energy used by a single residence.

If you’re building out a new neighborhood on a greenspace plot, installing the district heating/cooling piping is much cheaper since you’re already laying electric, water, sewer, and mane gas lines.

Re: America's Geothermal Breakthrough

#145

Post by quickthrowman »

thinkcontext wrote: post #104
hunterpayne wrote: post #50

Earlier quoted context omitted.

"I don't know how economical that is" Sure you do. Think about it. Its just drilling a hole and making electricity from the heat. We have been able to do this for a very long time. So if people aren't really doing it much, its not economical. If it was now becoming economical, the article would describe some new way of doing it that makes it economical. The article doesn't, so you "know" it isn't. PS This has been tr…

> Its just drilling a hole and making electricity from the heat District heating does not involve making electricity.

Not always, but as the sibling noted, there are plenty of combined heat and power plants. They recover as much of the energy as possible from the exhaust gas streams and run pretty efficiently.

Re: America's Geothermal Breakthrough

#146

Post by sgerenser »

hvb2 wrote: post #122
IncreasePosts wrote: post #92

Earlier quoted context omitted.

Air source heat pumps are insanely more efficient and just plain better these days too. It used to be that if the air was below 40F you couldn't heat your house with a heat pump. Now, you can heat your house even when it's -10F

> Air source heat pumps are insanely more efficient Citation needed? Efficient how? I'm sure a heat pump designed for a narrow range of input temperatures AND working with water which can transport a lot more heat should easily be more efficient. https://www.energysage.com/heat-pumps/compare-air-source-geo... Seems to disagree

I assuming he means insanely more efficient than they used to be, not more efficient than ground-source (awkward wording though). I suppose they can also be described as more efficient in installation time, cost and equipment than ground source, but clearly not in operating efficiency.

Re: America's Geothermal Breakthrough

#147

Post by bialpio »

Animats wrote: post #9
WarOnPrivacy wrote: post #2

I worked on geothermal control systems a decade or so back. There are some less obvious applications for geothermal that reduce electric use (as opposed to generating electricity). The systems I worked on were for cooling larger structures like commercial greenhouses, gov installations and mansions. 64° degree water would be pumped up from 400' down, run thru a series of chillers (for a/c) and then returned undergrou…

Shallow geothermal works fine for heating. And you can use the ground as a heat sink. But if you want to generate power, you need to get down to where temperatures can boil water. That's deeper than most oil wells. Fervo Energy claims to have found 270C at 3350 meters well depth. That's progress.

> But if you want to generate power, you need to get down to where temperatures can boil water.

Why is that the case? Can't you go down to where it's like 70-80 deg C and close the gap using heat pumps? Yes, you need to put some energy in, but I would expect that the whole process would still be energy-positive at some temperature that's lower than 100C?

Re: America's Geothermal Breakthrough

#148

Post by zdragnar »

Y-bar wrote: post #129
zdragnar wrote: post #84

Earlier quoted context omitted.

There's a pretty significant upfront cost in getting them drilled, and many homes need the vertical drilling if they don't have sufficient yard space for a horizontal system. It gets harder if you have your own septic drain field too, as that will complete for yard space. The cost difference is pretty massive- 3-10x for a vertical system. If you live in a city or a suburb with tiny lots, that's your only option thoug…

I paid about EUR 4500 for a 114 meter drill hole including installation of brine (ethanol in my case actually) and removal of spoils. My 8kW heat+water pump was about EUR 7000. I can spec out a gas burner for about EUR 4000 and a central AC for EUR 5000, but I bet the efficiency of the ground source heater would quickly trump the cost of buying gas regularly.

That's insanely cheap compared to what we can get around here. Most installs I've heard of from people in the US are in the $20-50,000 range, depending on the size of their home and number of wells needed.
Post reply on HN