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What it will take to unleash the potential of geothermal power? (2021)

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Re: What it will take to unleash the potential of geothermal power? (2021)

#61

Post by Retric »

Gibbon1 wrote: post #32
hn_throwaway_99 wrote: post #9

Earlier quoted context omitted.

I don't understand what that second sentence means. What do they mean by "capacity" if it's not electricity generation capability?

The napkin math factor I use is to get the average power you need to divide solar and wind's name plate power by about 4. So to get the same amount of total yearly energy as a 1GW nuke plant that runs 24/7 you need 4GW of solar. Because solar produces about 6 hours of power per 24 hour day. From a capital cost perspective this is not nice at all. Too be fair upside of solar/wind is solar and wind farms don't go down…

Grid PV in a good location is more like 30% capacity factor. They typically use 1 axis tracking to collect more power in morning and evening due to the demand curve.

Ex: 32.8% https://en.wikipedia.org/wiki/Solar_Star

Re: What it will take to unleash the potential of geothermal power? (2021)

#62

Post by KptMarchewa »

thechao wrote: post #57
applied_heat wrote: post #42

Earlier quoted context omitted.

I was hopeful that all of the unused drilling capacity after the shale boom/bust would allow some of the know how and equipment to be reallocated to geothermal but the grid operators and markets are not offering the premium to firm capacity that is required for the longer lead time and increased capital requirements and increased risk in geothermal projects vs wind and solar which can be augmented with battery storag…

I'm trying to imagine the apocalyptic scenario that'd have all of Texas windless and cloudy for a week? Nameplate values for Texas wind & solar will eventually be well above peak required: excess power can be sold for silly things like bitcoin, desalination, fabbing, etc.

Right now wind is running at 16% capacity producing 6GW; you'd need ~308GW capacity to cover Texas needs from wind alone. Good luck.

Re: What it will take to unleash the potential of geothermal power? (2021)

#63

Post by KptMarchewa »

adrianN wrote: post #55
applied_heat wrote: post #42

Earlier quoted context omitted.

I was hopeful that all of the unused drilling capacity after the shale boom/bust would allow some of the know how and equipment to be reallocated to geothermal but the grid operators and markets are not offering the premium to firm capacity that is required for the longer lead time and increased capital requirements and increased risk in geothermal projects vs wind and solar which can be augmented with battery storag…

For week long storage there is always hydrogen, if alternative battery chemistries don’t pan out.

Hydrogen conversion is not only very inefficient, the hydrogen plants are also extremely costly.

Batteries are better bet.

Re: What it will take to unleash the potential of geothermal power? (2021)

#64

Post by pjdesno »

WarOnPrivacy wrote: post #24

HVAC geo scales up. You could do a neighborhood utility and homes can heat/cool for the cost of air circ. You'll wind up with a novelty, an HOA that benefits every home (fees for for power/maint pumps). A couple of generations ago, we had neighborhood sewage utilities all around here. Neighborhood geo seems less complex than that.

There are some places (e.g. https://heet.org/geo/) that are looking at neighborhood "geothermal" - basically using ground temperature as a heat reservoir for heat pumps. They're getting buy-in from natural gas utilities, some of whom see it as a way to keep using their capital, rights of way, and expertise in digging holes in the ground (and maybe in billing folks, too) to keep making money as households convert to heat pumps.

Re: What it will take to unleash the potential of geothermal power? (2021)

#65

Post by dtgriscom »

echelon wrote: post #27
iancmceachern wrote: post #20

Make drilling cheaper. This would also help with water access. The biggest cost of small geothermal and water projects is always the drilling. Drill rig time is always a limiting factor.

> Make drilling cheaper. How?

Agreed: how? Drilling companies have been competing on price for a hundred years; anyone who came up with a significantly cheaper drilling system would be raking in the dough until everyone else caught up.

Re: What it will take to unleash the potential of geothermal power? (2021)

#66

Post by dgllghr »

KptMarchewa wrote: post #62
thechao wrote: post #57

Earlier quoted context omitted.

I'm trying to imagine the apocalyptic scenario that'd have all of Texas windless and cloudy for a week? Nameplate values for Texas wind & solar will eventually be well above peak required: excess power can be sold for silly things like bitcoin, desalination, fabbing, etc.

Right now wind is running at 16% capacity producing 6GW; you'd need ~308GW capacity to cover Texas needs from wind alone. Good luck.

That is why there is also solar

Re: What it will take to unleash the potential of geothermal power? (2021)

#67

Post by pi-e-sigma »

angiosperm wrote: post #35
zdragnar wrote: post #21

Earlier quoted context omitted.

You could use it for district heating of buildings in winter, but that's about it. As the article mentions, you need to get above the phase transition between liquid and gas at high pressure (they mention 150c) to be able to reliably and quickly convert the thermal energy into kinetic, then into electrical inductance (gas expansion moving a turbine, moving a dynamo). Maybe if you went into business making pot roast,…

There are fluids other than water that have usefully different boiling points. Problem is that mature turbines are designed for steam. Turbines for other fluids cannot approach their market volume.

That's not true at all. If any other liquids were more useful they would have been used long time ago, even in places where the cost is not of primary concern, such as nuclear submarines.

Re: What it will take to unleash the potential of geothermal power? (2021)

#68

Post by shagie »

megaman821 wrote: post #60
applied_heat wrote: post #42

Earlier quoted context omitted.

I was hopeful that all of the unused drilling capacity after the shale boom/bust would allow some of the know how and equipment to be reallocated to geothermal but the grid operators and markets are not offering the premium to firm capacity that is required for the longer lead time and increased capital requirements and increased risk in geothermal projects vs wind and solar which can be augmented with battery storag…

I wonder if geothermal can offer mild battery storage by using excess energy to pre-heat the water.

Yes, though its not geothermal preciously - https://en.wikipedia.org/wiki/Drake_Landing_Solar_Community

> The Drake Landing Solar Community (DLSC) is a planned community in Okotoks, Alberta, Canada, equipped with a central solar heating system and other energy efficient technologies.

> In 2012 the installation achieved a world record solar fraction of 97%; that is, providing that amount of the community's heating requirements with solar energy over a one-year time span.

> In 2015–2016 season the installation achieved a solar fraction of 100%. This was achieved by the borehole thermal storage system (BTES) finally reaching high temperature after years of charging, as well as improving control methods, operating pumps at lower speed most of the time, reducing extra energy need as well using weather forecasts to optimize transfer of heat between different storage tanks and loops. During some other years, auxiliary gas heaters are used for a small fraction of the year to provide heat to a district loop. The systems operate at coefficient of performance of 30.

https://www.dlsc.ca

https://www.sciencedirect.com/topics/engineering/drake-landi...

http://proceedings.ises.org/paper/swc2017/swc2017-0033-Mesqu...

Re: What it will take to unleash the potential of geothermal power? (2021)

#69

Post by Bedon292 »

megaman821 wrote: post #60
applied_heat wrote: post #42

Earlier quoted context omitted.

I was hopeful that all of the unused drilling capacity after the shale boom/bust would allow some of the know how and equipment to be reallocated to geothermal but the grid operators and markets are not offering the premium to firm capacity that is required for the longer lead time and increased capital requirements and increased risk in geothermal projects vs wind and solar which can be augmented with battery storag…

I wonder if geothermal can offer mild battery storage by using excess energy to pre-heat the water.

I don't know about directly as a battery, but there is potential for energy storage. If you have geothermal HVAC at home, it can (sometimes) be use to heat water in a water heater. Dumping the extra heat into it. And I have heard stuff about using excess energy in the grid to put extra heat into home water tanks as well, so demand is reduced later. It is not getting converted back to electricity, but still a store for energy.

Re: What it will take to unleash the potential of geothermal power? (2021)

#70

Post by jameshart »

megaman821 wrote: post #60
applied_heat wrote: post #42

Earlier quoted context omitted.

I was hopeful that all of the unused drilling capacity after the shale boom/bust would allow some of the know how and equipment to be reallocated to geothermal but the grid operators and markets are not offering the premium to firm capacity that is required for the longer lead time and increased capital requirements and increased risk in geothermal projects vs wind and solar which can be augmented with battery storag…

I wonder if geothermal can offer mild battery storage by using excess energy to pre-heat the water.

I don’t think thermodynamics lets that work. You can’t move heat from something cold to something hot so unless you are preheating your water to a temperature higher than your deep borehole rocks, all you’re doing is putting the first N joules of heat energy into the water you’re going to pump into your steam turbines using excess grid energy instead of geothermal energy.
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