Iberian Peninsula's geothermal power can generate current electrical capacity five times over

Originally posted by DeepThought
Night time electricity use in the U.K. is I believe of the order of 20GW, I doubt that a geothermal plant would satisfy that.

Well you wouldn't want one power plant supplying the whole of the UK anyway. You would need multiple power plants. The question is whether the UK has enough suitable sites to go entirely geothermal at reasonable cost.

Storage requires a pump, some water, a mountain, and a turbine. I don't think it is as ruinously expensive as you think.
It is cheap enough that it is used in some places. I believe South Africa has two such facilities.

I think the whole argument of "Do we turn of geothermal when we don't need it" is kind of a moot point for the foreseeable future. Maybe once we've replaced ALL fuel-based energy sources and all of our energy is coming from wind/solar/tidal/hyrdo/geothermal source, we would have to worry about what to do with extra energy when we don't need it.

Until that time, we will just turn off any fuel based power plants when we don't need the extra energy, and leave the renewable source running full bore all the time.

Originally posted by twhitehead
And that seems a reasonable thing to do if the costs of adjusting output are lower than the cost of keeping it on full power. With solar, that is not the case, I do not know what the situation is with geothermal.

[b]I would agree.
Then your OP makes no sense. You said it would complement wind and solar, but now you admit that there is no benefit t ...[text shortened]... are they if the GPP is supplying enough energy for all needs? How do they 'complement' the GPP?[/b]

You said it would complement wind and solar,

correct -but obviously only where the geothermal power would not fully satisfied peak demand.

but now you admit that there is no benefit to adding wind and solar.

ONLY where geothermal power DOES fully satisfied peak demand else, no, I don't 'admit' that.

It all depends on costs, and whether or not that extra power can be exported to other areas.

That is I believe kind of what I said.

And I am confused about your OP which somehow fits in solar and wind. What use are they if the GPP is supplying enough energy for all needs?

I didn't say GPPs would supply all our needs and I also assumed it wouldn't in the OP. I think this is where you must have misunderstood me here.

Originally posted by DeepThought
Night time electricity use in the U.K. is I believe of the order of 20GW, I doubt that a geothermal plant would satisfy that. However the alternative for the Spanish is to export their surplus power.

Storage requires a pump, some water, a mountain, and a turbine. I don't think it is as ruinously expensive as you think.

Better to extract it onl ...[text shortened]... there while you don't.

You seem a little confused about the concept of renewable energy.

Night time electricity use in the U.K. is I believe of the order of 20GW, I doubt that a geothermal plant would satisfy that.

Unless a cost effective way of exploiting it from much deeper underground is developed so it can be made cost effective even where the local geology for it is not particularly favorable, I doubt there is much potential for geothermal energy in the U.K. Anyway. In the mean time, I think geothermal energy is really more for other countries blessed with the more favorable geology for it.

Originally posted by forkedknight
I think the whole argument of "Do we turn of geothermal when we don't need it" is kind of a moot point for the foreseeable future. Maybe once we've replaced ALL fuel-based energy sources and all of our energy is coming from wind/solar/tidal/hyrdo/geothermal source, we would have to worry about what to do with extra energy when we don't need it.

Unti ...[text shortened]... n we don't need the extra energy, and leave the renewable source running full bore all the time.

for now I agree. But I have a suspicion it would be not as long as most people would naturally imagine before renewables would be replacing all fossil fuels asp when you consider the fantastic promising progress in the resent research for making more cost-effective solar panels. I don't think most laypeople have quite grasped the magnitude of the increased rate of progress in renewables with just a few parts of the world currently going or have already gone completely renewable when previously they depended heavily on fossil fuels.

Originally posted by humy
correct -but obviously only where the geothermal power would not fully satisfied peak demand.

Then your OP makes no sense, because it specifically says that they compliment each other because you can switch off the geothermal power.

The OP seems to be saying that geothermal provides the equivalent of off-the-grid energy storage maybe I am missing something there. Are you saying that by turning it off, it builds up extra steam and thus produces more power when turned back on?

Originally posted by twhitehead
Then your OP makes no sense, because it specifically says that they compliment each other because you can switch off the geothermal power.

The OP seems to be saying that geothermal provides the equivalent of off-the-grid energy storage maybe I am missing something there. Are you saying that by turning it off, it builds up extra steam and thus produces more power when turned back on?

No.
I cannot understand your confusion here.
Lets say peak demand for a country is 10 GW and there is no transmission of power in or out of that country. Lets say the country has gone totally 100% renewable with just the 3 renewables of geothermal, solar and wind.
Lets say, when the geothermal is full on, it can supply 5 GW (and lets say it unfortunately isn't cost effective to make more geothermal plants to make that 10 GW ) . Lets be simplistic here and say simplistically for the sake of argument that, when the sun is out, solar also supplies 5 GW and when the wind blows, the wind turbines also supply 5 GW (obviously it all would be much more complex than that in reality ) . So none of the three power sources alone can supply peak demand unless you have at least some energy storage. And sometimes there isn’t any sun or wind at peak demand so there is a need for some storage because, with geothermal power, you can only absolutely guarantee 5 GW at any one time and peak demand is double that. If the country has successfully gone 100% renewable without any blackouts ever then that means if you kept all three power sources full on all the time, you would eventually fill up whatever finite energy storage capacity you have to overflowing so that is not a sustainable option. In this scenario which is the one I imagined in my OP, the presence of geothermal would help because it can be easily powered down whenever there is a danger of overfilling whatever finite energy storage capacity you have to overflowing. But, the presence of geothermal would also help because, unlike solar and wind, it can be easily powered back up when you are straining to get enough energy from the other renewables and, obviously by being able to do this, you are reducing the required energy storage capacity precisely because you can control its power output.

OK, think of it this way; in the above hypothetical scenario, with a sufficient large energy storage, you could go completely without geothermal if you had enough solar and wind. Lets say you need X amount of energy storage to make that work while guaranteeing the lights will never go out at peak demand. BUT now if you add geothermal to that mix with its controlled power output, that X can surely now be reduced became you can have up to 5 GW of extra power when you need it and simply power it down when you don't need it for either storage nor immediate use -something you cannot readily do with solar or wind. Thus, although you would still need some energy storage, you save some cost by not making the extra energy storage you would need without geothermal -simple.

Originally posted by humy

Night time electricity use in the U.K. is I believe of the order of 20GW, I doubt that a geothermal plant would satisfy that.

Unless a cost effective way of exploiting it from much deeper underground is developed so it can be made cost effective even where the local geology for it is not particularly favorable, I doubt there is much poten ...[text shortened]... hermal energy is really more for other countries blessed with the more favorable geology for it.

Yeah, it's just I knew the demand figures for Britain. Although I don't see why not, it's just a matter of drilling. Also it would be a lot less unsafe and a lot more popular than fracking.

Originally posted by DeepThought
Yeah, it's just I knew the demand figures for Britain. Although I don't see why not, it's just a matter of drilling. Also it would be a lot less unsafe and a lot more popular than fracking.

and a lot more popular than fracking.

oh I don't know -the same kind of ignorant historical anti-science anti-industry people that are paranoid about GM would probably be paranoid against it and protest against it saying it could start earthquakes or massively crack the Earth's crust and alter the rotation of the Earth creating a chain reaction that would end entire world 😛

Originally posted by humy
In this scenario which is the one I imagined in my OP, the presence of geothermal would help because it can be easily powered down whenever there is a danger of overfilling whatever finite energy storage capacity you have to overflowing.

I think this is where I am not understanding you. Are you saying solar and wind cannot be powered down?
I do see the advantage of geothermal in that it is typically able to run at any time of day and is not dependent on weather conditions. My confusion is that I fail to see how the ability to power down gives it an advantage or helps it complement wind and solar. Surely for any power station you can simply disconnect it from the grid if you don't want to cause and overload?

Originally posted by twhitehead
I think this is where I am not understanding you. Are you saying solar and wind cannot be powered down?
I do see the advantage of geothermal in that it is typically able to run at any time of day and is not dependent on weather conditions. My confusion is that I fail to see how the ability to power down gives it an advantage or helps it complement wind ...[text shortened]... ower station you can simply disconnect it from the grid if you don't want to cause and overload?

Are you saying solar and wind cannot be powered down?

Not so readily without wasting a lot of energy, yes. If the sun is out but there is currently no demand for the electric from the solar panels, what do you think happens to all that solar energy absorbed by the solar panels? -if no current is drawn from the panels, it is just wasted as waste heat and it has also occurred to me that this waste heat would radiate out and may contribute to a tiny bit of extra global warming if the solar is done on a vast enough scale. (admittedly this can be made different with wind because you can design the turbines to have power output control but wind, like solar, is still fickle ) This contrasts with geothermal power plants which wastes no energy when you power it down. The geothermal power could also help reduce the amount of required energy storage for the reasons I was at great pains to tediously explain in great length in that previous post.

Originally posted by humy
Not so readily without wasting a lot of energy, yes.

And that is where I am confused. How does turning off wind or solar waste energy, but turning off geothermal not waste energy? I believe all three sources are similar in that the main cost is building the plant, and from then on, it is most economic to keep them on whenever demand exists. But if production exceeds demand, I see no reason why geothermal should be switched off in preference to solar and wind. In fact wind is probably the easiest to balance as you simply adjust the blade angles and you control power output. I am not sure how solar is controlled, whether you short out the power or simply don't collect it off the panels. I know that for small panels, not drawing power is no problem, but I don't know if this applies to large panels.
Solar power plants that use rotatable mirrors, can simply rotate the mirrors another direction.
The two big plus' of geothermal are the fact that it can supply power 24/7 and that it can be used as a direct heat source rather than generating electricity.

Originally posted by twhitehead
And that is where I am confused. How does turning off wind or solar waste energy, but turning off geothermal not waste energy? I believe all three sources are similar in that the main cost is building the plant, and from then on, it is most economic to keep them on whenever demand exists. But if production exceeds demand, I see no reason why geothermal sh ...[text shortened]... y power 24/7 and that it can be used as a direct heat source rather than generating electricity.

I have already implicitly answered most of the above questions in my last post!

How does turning off wind or solar waste energy,

Not necessarily wind (because I have already just said “....(admittedly this can be made different with wind because you can design the turbines to have power output control ...” ) but solar. I just said “...If the sun is out but there is currently no demand for the electric from the solar panels, what do you think happens to all that solar energy absorbed by the solar panels? -if no current is drawn from the panels, it is just wasted as waste heat ...“ which appears to answer your question -yes? Energy absorbed by photoelectric cells but with no current drawn from the cell is just converted into waste heat that is just dissipated and wasted -right?

but turning off geothermal not waste energy?

how could not bring up the heat from far below the ground be wasting energy? The energy just stays down there while it is not being used and, unlike unused waste heat from a solar panel with no current drawn from the panel, is not just immediately dissipated into air where it is just wasted.

But if production exceeds demand, I see no reason why geothermal should be switched off in preference to solar and wind.

I am not sure about wind (as I already indicated ) but all the time you are not drawing current from the panels then all that solar is radiated as waste heat and, as I just said, “...this waste heat would radiate out and may contribute to a tiny bit of extra global warming if the solar is done on a vast enough scale.... “ i.e. it may contribute towards global warming if you waste it by turning it off so that it becomes just waste heat and not using it as electrical energy on the grid. It, in effect, contributes to global warming by decreasing the albedo of the Earth.

Solar power plants that use rotatable mirrors, can simply rotate the mirrors another direction.

Yes, in which case my argument doesn't apply. However, I was thinking in terms of solar panels with no mirrors involved because I assume photoelectric cell solar panels (with no mirrors involved ) would be the ones generally used on roof tops. With such solar panels, my argument applies.

Originally posted by humy
I have already implicitly answered most of the above questions in my last post!

How does turning off wind or solar waste energy,

Not necessarily wind (because I have already just said “....(admittedly this can be made different with wind because you can design the turbines to have power output control ...” ) but solar. I just said “...If ...[text shortened]... ed ) would be the ones generally used on roof tops. With such solar panels, my argument applies.

it may contribute towards global warming if you waste it by turning it off so that it becomes just waste heat and not using it as electrical energy on the grid.

How much of the Sun's visible spectrum radiation makes it back into space? I'm wondering whether if the solar panel were not there then the light would just be absorbed by the ground and contribute to global warming anyway. So I suspect that heating from underused solar panels wouldn't contribute to global warming. A more realistic objection is that solar panel production probably isn't the most ecologically friendly activity.

Originally posted by DeepThought

it may contribute towards global warming if you waste it by turning it off so that it becomes just waste heat and not using it as electrical energy on the grid.

How much of the Sun's visible spectrum radiation makes it back into space? I'm wondering whether if the solar panel were not there then the light would just be absorbed by the grou ...[text shortened]... objection is that solar panel production probably isn't the most ecologically friendly activity.

Solar panels have a significantly lower albedo than most dirt surfaces.

They are designed to absorb light after all.

And the atmosphere is much more transparent to visible light than infrared.
So if the panels absorb visible light, and then re-radiate infrared, then that
will heat up the atmosphere much more than reflected visible light would.


However you are correct that the bigger cost is wasting lifetime of energy
expensive solar panels.