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Geothermal may beat batteries for energy storage

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Re: Geothermal may beat batteries for energy storage

#241

Post by pfdietz »

jandrese wrote: post #142
Mrdarknezz wrote: post #55

Energy storage is the monorail of energy technology, expensive, unnecessary and conventional technologies like nuclear, hydro and geothermal is better in every regard.

Nuclear has enormous political hurdles that translate into extreme project costs. Hydro and Geothermal are both geographically limited. Hydro especially is effectively tapped out at this point. You are chasing progressively less suitable locations for each install. Most of the best remaining places are far away from civilization and would require hundreds of kilometers of high tension wire to get to the nearest grid…

Nuclear has screwed up its costs even with political support.

The politics argument is really "people won't let us get away with papering over horrific design and construction snafus."

Re: Geothermal may beat batteries for energy storage

#242

Post by leoedin »

smileysteve wrote: post #183
dahfizz wrote: post #179

Earlier quoted context omitted.

"high efficiency" turbines are not all that efficient. Burning gas releases 100% of the available energy as heat. Converting that gas to electricity is Also, electricity from gas is relatively expensive. Other sources like coal or hydro are cheaper, which lowers the average cost of electricity.

But gas turbines should be more efficient than a burner under a boiler or a burner in a furnace. Yes, solar, wind, hydro, nuclear should be cheaper per unit (coal is not usually cheaper than gas in the US)

There's not really a "should be" in thermodynamics. All heat engine cycles have upper bounds of theoretical efficiency, and burning gas in a gas turbine to generate electricity to create resistive heat is never ever going to be more efficient than burning that gas at the point you need the heat. It's simply not possible. There's always going to be losses - the exhaust gas will contain energy, there will be mechanical and transmission losses. There is no physical way we can change that.

The best thermal power plants - combined cycle gas turbines - get about 60% efficiency. Most are closer to 45%.

What we can do is either use the excess heat from the gas turbine in district heating (which combined with resistive electrical heat probably approaches the same efficiency as a local gas boiler), or use that electricity to drive a heat pump, which gives a greater than 1x return on heat where you want it. An efficient combined cycle gas turbine driving a heat pump is going to give you more heating than the same gas being burned in a boiler. - 0.5 * 4 = 200% efficient.

You can also get (although they're much less common) gas powered heat pumps (eg propane fridges in RVs). They might have a "primary energy ratio" of 1.5-2, bringing the total system efficiency of a local gas powered heating system back up to pretty close to that of a remote generation + electrical heat pump system. The electrical system has the benefit that you can slot renewables into the mix as well.

Re: Geothermal may beat batteries for energy storage

#243

Post by mderazon »

jonstewart wrote: post #221
mderazon wrote: post #177

Earlier quoted context omitted.

I am currently looking to do something similar. I have zero heating in my house at the moment and have a 300L (65 gallon) thermosiphon solar water heater [1] (tank plus panels all in one system) that gives me plenty hot sanitary water. I am looking to install an hydronic fan coil [2] radiator in my rooms and need water to heat them - I thought to use the excess heat from the solar heater to supply hot water to the fa…

This is not so complicated, you just need tanks with heat exchanger loops. The solar water heater input comes into your tank at the bottom and goes through a copper coil, giving you domestic hot water. _Some_ tanks will have a similar coil in the middle/top of the tank. What you can do is then run the cold return from your heating units through this coil. It will heat the radiator water before going to the fan coil u…

Thanks for your input. So I understand that heating the house requires much more hot water than what my solar heater can probably provide. In that case, connecting it to the radiator system is not so beneficial, and probably better to rely on a heat pump for the radiator water (the solar heater will not provide much help to justify connecting to it)

Is that correct ?

Re: Geothermal may beat batteries for energy storage

#244

Post by Schroedingersat »

pfdietz wrote: post #239
Schroedingersat wrote: post #198

Earlier quoted context omitted.

Unenriched uranium will fission eventually, but you're talking trillions of years. In a fission reactor, the U238 atoms are placed close enough to a minority of U235 atoms and to each othekr that neutrons from one fission will trigger the next at a rate just short of running away exponentially. There are some ore bodies that are concentrated enough to fission faster, but they are rare (and not the uranium that is typ…

The uranium undergoes alpha decay first. Alpha decay is not fission.

Yes, this is correct. Thanks.

Re: Geothermal may beat batteries for energy storage

#245

Post by Mrdarknezz »

jandrese wrote: post #142
Mrdarknezz wrote: post #55

Energy storage is the monorail of energy technology, expensive, unnecessary and conventional technologies like nuclear, hydro and geothermal is better in every regard.

Nuclear has enormous political hurdles that translate into extreme project costs. Hydro and Geothermal are both geographically limited. Hydro especially is effectively tapped out at this point. You are chasing progressively less suitable locations for each install. Most of the best remaining places are far away from civilization and would require hundreds of kilometers of high tension wire to get to the nearest grid…

Batteries is not an alternative to firm energy, you still need firm energy to balance the grid wether it's from nuclear/hydro/geo or fossil.

That's why all decarbonized grids have hydro/nuclear as their main source of energy.

Re: Geothermal may beat batteries for energy storage

#246

Post by Mrdarknezz »

pfdietz wrote: post #241
jandrese wrote: post #142

Earlier quoted context omitted.

Nuclear has enormous political hurdles that translate into extreme project costs. Hydro and Geothermal are both geographically limited. Hydro especially is effectively tapped out at this point. You are chasing progressively less suitable locations for each install. Most of the best remaining places are far away from civilization and would require hundreds of kilometers of high tension wire to get to the nearest grid…

Nuclear has screwed up its costs even with political support. The politics argument is really "people won't let us get away with papering over horrific design and construction snafus."

Batteries are not cheaper than nuclear.

Re: Geothermal may beat batteries for energy storage

#247

Post by nuclearwast »

xienze wrote: post #156
jonstewart wrote: post #80

Earlier quoted context omitted.

It is probably far more cost effective to buy a new air source heatpump. They’re so efficient and work well at low temps now. I have infloor radiant heat at a rural house in upper Midwest, have thought a lot about using solar heat pipes and adding a storage tank, and it’s all so fiddly, pipes and pumps and manifolds and glycol and maintenance, all custom, all expensive. I’m almost certainly better off with PV panels…

> They’re so efficient and work well at low temps now. Can someone provide me model numbers for these heat pumps that “work well” at low temperatures? I’ve been through more than a few over the decades and currently have a Trane from last year and yep, still doesn’t hold up very well once the temperature hits freezing. Don’t get me wrong, I like heat pumps, but my eyes roll into the back of my skull when I hear over…

this was installed in my home to replace a oil furnace (air heating)

https://www.gree.ca/products/ducted-central-heat-pump?varian...

I am not sure if it's available outside of canada though.

Re: Geothermal may beat batteries for energy storage

#249

Post by dsq »

dahfizz wrote: post #108
cookiengineer wrote: post #68

Earlier quoted context omitted.

This reminds me a lot of the Earthship community in the middle of the desert, which always focusses on smart ways of reusing water for different purposes, and by not wasting water as much as possible. The houses usually have a clean/grey/blackwater + a rainwormbox system to process fecals and reuse it for growing plants. Their air conditioning system is basically just a pipe in the ground where the hot air flows thro…

> Why there are no water storages on the roof. Quick math - 100 gallons of water 15 meters up off the ground has enough potential energy to run a microwave for 30 seconds. Gravitational storage is pathetically weak. It only makes sense on massive, massive scales. In a residential setting, the storage will never outweigh the extra cost and risk of having so much water on your roof.

Thanks for that dose of information. Basic arithmetic is so lacking in all these discussions. People throw all sort of fantastic pseudo-facts with little or no anchor to reality.

Re: Geothermal may beat batteries for energy storage

#250

Post by pfdietz »

Mrdarknezz wrote: post #246
pfdietz wrote: post #241

Earlier quoted context omitted.

Nuclear has screwed up its costs even with political support. The politics argument is really "people won't let us get away with papering over horrific design and construction snafus."

Batteries are not cheaper than nuclear.

Batteries are getting cheaper quite rapidly, so don't get stuck in the dead past there.
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