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Geothermal may beat batteries for energy storage
71–80 of 293 posts
Re: Geothermal may beat batteries for energy storage
#72There is a school close to where I live that does something like this. During the summer they heat the bedrock using solar panels (thermal and electric via a heapump) to heat the bedrock far down using water pipes. In winter they extract this energy for heating, electricity and hot water making the school self sufficient for energy. Here is a write-up from the municipality about it, but it's in Norwegian https://www.…
That's just a ground heat pump no? I have the same on my house. It's pretty great. I get cooling in summer and heat in the winter.
If you're in an area that gets hot enough in summer for you to want cooling, then yes you'll be pumping heat into the ground during summer and extracting it in the winter. For those of us who don't get hot enough in summer to want cooling, we're always extracting heat from the ground, and so the ground we're extracting heat from gets cold, which reduces the efficiency of the system. Having a solar powered mechanism for putting some heat back into the ground in summer would help alleviate this problem.
Re: Geothermal may beat batteries for energy storage
#73Earlier quoted context omitted.
I saw a video like a month ago on YouTube where somebody pumped something like 250 liters of water on his roof (7 meters elevation, if I remember correctly) and let it run through a homebuild generator. The power capacity of that setup was like that of an AA battery, if I remember correctly. You need huge amounts of water and lots of height difference.
Based on some extremely back of napkin math (e.g. doing one of those activities where you cycle to power a light bulb) that seems pretty far off. Was the flow rate extremely low? Have a link?
Sounds like this one:
https://www.youtube.com/watch?v=CMR9z9Xr8GM
They do say it is about equivalent to a single AA alkaline. It is not exactly an optimized efficient setup, but still, it gets the point across. Pumped hydro is a grid scale option, in places that have the ability to store a lot of water.
Re: Geothermal may beat batteries for energy storage
#74Earlier quoted context omitted.
All of the oligopolies? Do you really believe that, e.g, tech companies are "fighting" each other? What about Big Pharma? The Food industry? In any case, you are arguing semantics. Competition can be friendly.
The tech, food and pharma industries fight each other tooth and nail. I don't think this "friendly competition" happens in the business world. It's just an ordinary fight.
I guess we have different ideas for "fighting tooth and nail".
- Steve Jobs and Eric Schmidt would regularly discuss matters together.
- They have pretty solid "do not poach" agreements.
- None of them actively blocks their products from running on each other platforms
- None of them launch products with the sole intent of destroying each others cash cow. E.g, Google could release flagship products at budget prices forever, just to take from Apple's market share. They certainly wouldn't lose money over it. Why don't they do it?
Competition? Ok, but it never comes to the point where they actually want to inflict damage on one another. This is as friendly as it gets.
Re: Geothermal may beat batteries for energy storage
#75Earlier quoted context omitted.
It can work, it's just a cost equation. You need a large amount of mass to get meaningful amounts of energy stored. So pumped hydro is nice because you are basically using natural reservoirs and some cheap pumps and pipes. A water tower needs to be built first and only stores a limited amount of potential energy. The problem is not the efficiencies but the cost of building a big enough tower. A tower with the same ca…
Why would you need a water tower? If you're in flat geography at sea level, you could probably access tidal energy to drive generators. If you're flat and far from water, couldn't you dig a shallow hole and a deeper hole, and put the generator and pumps in between? I mean, even in Kansas it's not that hard to find an elevation difference of 50 feet.
> If you're in flat geography at sea level, you could probably access tidal energy to drive generators
There are projects testing this, but ocean water is highly corrosive and maintenance is a nightmare.
Re: Geothermal may beat batteries for energy storage
#76Earlier quoted context omitted.
That's just a ground heat pump no? I have the same on my house. It's pretty great. I get cooling in summer and heat in the winter.
If you're in an area that gets hot enough in summer for you to want cooling, then yes you'll be pumping heat into the ground during summer and extracting it in the winter. For those of us who don't get hot enough in summer to want cooling, we're always extracting heat from the ground, and so the ground we're extracting heat from gets cold, which reduces the efficiency of the system. Having a solar powered mechanism f…
> the ground we're extracting heat from gets cold
Not if you’re using deep drilled holes (100m+). You can run a heat pump of the differential indefinitely
Re: Geothermal may beat batteries for energy storage
#77Many of the greenhouse Youtube channels I watch do a smaller DIY version of this. They have either dark barrels of water in the greenhouse with the windows facing south to the sun, or a thin metal wall filled with clay and pipes acting as a sun-heat-battery. They pump the water through the barrels or clay battery into pipes that are under ground to store the heat. In winter time they extract the heat from the ground…
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…
Water can freeze.
Re: Geothermal may beat batteries for energy storage
#78Earlier quoted context omitted.
I saw a video like a month ago on YouTube where somebody pumped something like 250 liters of water on his roof (7 meters elevation, if I remember correctly) and let it run through a homebuild generator. The power capacity of that setup was like that of an AA battery, if I remember correctly. You need huge amounts of water and lots of height difference.
Based on some extremely back of napkin math (e.g. doing one of those activities where you cycle to power a light bulb) that seems pretty far off. Was the flow rate extremely low? Have a link?
250L x 7m is 17kN, or about 5W/h, or about 2 AA 2450mAh cells from IKEA.
Pumped storage scales well though, as the stored volume scales squarely to the required container material (e.g. storing 25,000L will only take 10x the material while storing 100x the energy).
Re: Geothermal may beat batteries for energy storage
#79Many of the greenhouse Youtube channels I watch do a smaller DIY version of this. They have either dark barrels of water in the greenhouse with the windows facing south to the sun, or a thin metal wall filled with clay and pipes acting as a sun-heat-battery. They pump the water through the barrels or clay battery into pipes that are under ground to store the heat. In winter time they extract the heat from the ground…
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…
> I was always wondering why there are no systems converting the unused electricity in potential energy by moving water to a higher ground. And more importantly: Why there are no water storages on the roof.
Gravity is an incredibly feeble force, compared to electromagnetism (i.e. chemical bonds). Storing a practical amount of energy require a large mass × height.
Re: Geothermal may beat batteries for energy storage
#80Many of the greenhouse Youtube channels I watch do a smaller DIY version of this. They have either dark barrels of water in the greenhouse with the windows facing south to the sun, or a thin metal wall filled with clay and pipes acting as a sun-heat-battery. They pump the water through the barrels or clay battery into pipes that are under ground to store the heat. In winter time they extract the heat from the ground…
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 and off the shelf heat pumps.