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The time has finally come for geothermal energy

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Re: The time has finally come for geothermal energy

#91

Post by philipkglass »

jimbokun wrote: post #84
roadside_picnic wrote: post #75

Earlier quoted context omitted.

> a holy grail of energy production Since you're comparing it to nuclear, I'm assuming you mean electricity production here, not energy production? It's always worth remembering that electricity only accounts for ~20% of global energy consumption (in the US it's closer to 33%). I suspect people confuse these two because in a residential context electricity plays a huge part of our energy usage, but as a whole it's a…

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

Rejected energy means energy that is lost as waste heat without performing any work first. For example, a coal fired power plant may generate 3 megajoules of thermal energy from coal combustion but only deliver 1 megajoule of it as electricity. The other 2 megajoules are lost as useless waste heat.

The 1 megajoule of useful electricity is also ultimately dissipated as low grade heat, but it can do work first (like generating light, or pumping water uphill).

Re: The time has finally come for geothermal energy

#92

Post by bluGill »

XorNot wrote: post #79
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…

In 2025 the power consumption of my state (NSW, Australia) on any given day will be greater then 5 GW. https://www.aemo.com.au/energy-systems/electricity/national-... This "there is no base load" idea is a ridiculous myth trivially disproven: every grid on the planet has continuous demands on it and they're quite significant (5 GW is about 50% the day time peaks). It doesn't matter what the cost is, because later thi…

You misunderstand the point though. Sure there is always 5GW of demand - but we don't need generation that always supply 5GW cheap since wind/solar is much cheaper for base load. What we need is non-base load generation that can jump in at a moment's notice when needed because wind/solar isn't enough. Previously we would use those peak plants from when there was 6GW of demand (or whatever), but now between those peak plants coming down in price and wind/solar being so cheap we don't want that 5GW from plants that cannot adjust to load anymore - we are getting the can't adjust to load from wind/solar.

Re: The time has finally come for geothermal energy

#93

Post by floatrock »

jimbokun wrote: post #84
roadside_picnic wrote: post #75

Earlier quoted context omitted.

> a holy grail of energy production Since you're comparing it to nuclear, I'm assuming you mean electricity production here, not energy production? It's always worth remembering that electricity only accounts for ~20% of global energy consumption (in the US it's closer to 33%). I suspect people confuse these two because in a residential context electricity plays a huge part of our energy usage, but as a whole it's a…

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

Only about 30% of the energy in gasoline is converted to useful work in a gasoline car (the 'make metal box go forward' part). The remaining 70% is Rejected Energy (the steam you see going out the tail pipe in winter).

Which (not sure if you did this intentionally or accidentally) brings up an interesting point on the parent comment and the LLNL sankey:

> It's always worth remembering that electricity only accounts for ~20% of global energy consumption (in the US it's closer to 33%).

That "global energy consumption" figure includes a lot of Rejected Energy going out tailpipes and smoke stacks turning burnables into electricity. A secret bonus of wind and solar is if you produce electricity without burning things, you actually decrease the energy demand! If you're not losing 70% of your energy consumption to the Rejected category, you suddenly need a lot less total energy.

Re: The time has finally come for geothermal energy

#94

Post by bluGill »

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?

A number of sources. Often the air above - ground source relies on the ground being the average temperature of the year round air once you get deep. They also tend to run in heating mode half the year, and cooling mode the other half.

Re: The time has finally come for geothermal energy

#95

Post by hluska »

jimbokun wrote: post #84
roadside_picnic wrote: post #75

Earlier quoted context omitted.

> a holy grail of energy production Since you're comparing it to nuclear, I'm assuming you mean electricity production here, not energy production? It's always worth remembering that electricity only accounts for ~20% of global energy consumption (in the US it's closer to 33%). I suspect people confuse these two because in a residential context electricity plays a huge part of our energy usage, but as a whole it's a…

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 engine. This energy (heat) doesn’t provide any benefit to anyone and just leaks out into the atmosphere (which we’ve already established is trying to kill me).

That’s rejected energy. Or when it’s below -40, rejected motherfucking energy. :)

Re: The time has finally come for geothermal energy

#96

Post by bryanlarsen »

hluska wrote: post #88
bryanlarsen wrote: post #74

Earlier quoted context omitted.

But is it usefully dispatchable? Nuclear can be made dispatchable but it's not usefully dispatchable because the costs are fairly similar whether the plant is on or off. Like nuclear, I believe geothermal has high capital cost and low running costs, suggesting that it isn't usefully dispatchable. But that's too simplistic. A big limitation of geothermal is that rock has poor thermal conductivity. So once you remove h…

That’s a lot of words to admit that geothermal has its place.

That wasn't the conclusion, though. The conclusion was that dispatchable geothermal is competing against daily cycling batteries, a competition it's likely to lose on cost.

Re: The time has finally come for geothermal energy

#97

Post by bryanlarsen »

jmward01 wrote: post #85
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…

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 supply of fuel is disrupted.

Re: The time has finally come for geothermal energy

#98

Post by iso1631 »

jmward01 wrote: post #85
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…

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…

One thing which is needed too is spinning load, the grid depends on having enough inertia to maintain the frequency. Flywheels I assume would do that.

Re: The time has finally come for geothermal energy

#99

Post by [deleted] »

1970-01-01 wrote: post #64
quacked wrote: post #24

Earlier quoted context omitted.

> We can't even declare total victory with LED bulbs over incandescent. The LED bulbs I have access to (whatever's in the aisles at Home Depot, Costco, etc.) fail much more frequently than the incandescent bulbs I used to buy, and produce an uglier light that is less warm even on the softest/warmest color settings. My suspicion is that incandescents were at the "end" of their product lifecycle (high quality available…

[CITATION NEEDED] They do not. If you take the mean, median, and mode of the failure lifetime for LED bulbs sold at these stores and compare them to the failure times of incandescent bulbs, I also guarantee you are empirically wrong here.

[deleted]

Re: The time has finally come for geothermal energy

#100

Post by psunavy03 »

davidw wrote: post #90
psunavy03 wrote: post #76

Earlier quoted context omitted.

I fully understand that waste management of fission reactors is a Very Big Deal. But I still stand behind the argument that opposing nuclear power in the 70s and onward is possibly the biggest own goal the environmental movement has ever achieved. At worst, nuclear waste contaminates a discrete section of the Earth. Climate change affects literally everywhere. The correct answer would have been to aggressively roll o…

A lot of housing politics from 'old school' environmentalist groups are a pretty big own goal as well. Denser urban living is pretty energy efficient, and forcing lengthy commutes on people because of NIMBYism is a huge waste.

People want houses. Planners can either yell and stomp their feet about this or adapt to circumstances. It's like electric cars. People want cars. Better they have the ability to have an electric SUV or pickup, because if you try to force them into little tiny econoboxes or lecture them about how they should really be using mass transit, they're just going to flip you the bird and walk away.

Similarly, better to have people be able to have reasonably energy-efficient houses than demanding they all live in apartments.

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