171–180 of 293 posts
Heat, maybe, but electrical to heat and back to electrical, no way. You're limited by basic thermodynamics.
They have a web site.[1] Not that it has any useful information.
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> 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.
they do it a lot in NZ. Solar hot water heating.
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they do it a lot in NZ. Solar hot water heating.
Solar hot water is great, but that's not gravitational storage, e.g. pumping water up a hill with pumps and later using the flow of water back down to generate power.
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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…
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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…
There is a great youtube channel that tests out different energy storage and harvesting setups, a lot of them focused around water. This is one where they use solar to pump water to the roof, and then use the potential energy overnight: https://www.youtube.com/watch?v=CMR9z9Xr8GM
He would be so much better off just charging a cheap battery. All the money wasted on pumps, wood, barrel, pipes....
I guess we'll see.
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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…
interesting. i have a PV system. i want to use the half installed central heating system (only piping laid down) (no boiler or FCU/room unit) and i have this crazy idea. use solar water heater to heat water, that feeds into a water storage tank, that water gets heated MORE by an air source water heater and a small circulation pump uses that water storage to heat the house. i am hoping, since we currently have 0 whole…
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 fan coil units but I am not sure how do do that. If you have an idea, please share.
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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
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Even a modern air source heat pump typically doesn't beat gas for $/kwh. Even in europe where gas prices are sky high, electricity still costs more when you look at the seasonal efficiency of heat pumps, which is typically advertised around 4.4, but various studies show that in most real world scenarios you typically won't reach the quoted lab numbers, so expect to get more like 2.5-3.0. Study: https://www.sciencedir…
This seems like a (regulated) pricing error. There should be no economic way that a high efficiency turbine produces and distributes electricity to heat homes at a greater than 1:1 ratio compared to storing, pressurizing, and delivering, then burning in irregularly maintained consumer homes. Likely the error is that gas pipes to the house are subsidized (albeit the electrical likely is too, with heat pumps and induct…
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250 litres x 7 metres is 1750 kilogram-force-metres. Wolfram Alpha [0] says this is about 5 Watt-hours, and gives some other handy comparisons: > ≈ 0.45 × metabolic energy of one gram of fat ( ≈ 38000 J ) > ≈ 0.63 × energy released by burning 1 gram of ethanol ( ≈ 27000 J ) > ≈ metabolic energy of one gram of sugar or protein ( ≈ 17000 J ) > ≈ (0.02 to 0.09) × typical kinetic energy of a car at highway speeds ( 20000…
Would you be able to help me figure out the gravitational potential energy of the red hill tanks? https://www.epa.gov/red-hill/what-red-hill-bulk-fuel-storage... They were recently decommissioned due to leaks, but I've often wondered if they could be repurposed as gravity battery storage. edit: if you want to check my math. I calculated the tanks at ~567 million liters, and am saying there is 120 meters of vertical d…
Oahu uses about 225MW on average in residential electricity [0], so this could store an hour or so of excess capacity. That's not nothing, but you might want to 5x or 10x it to really smooth out demand and supply peaks for the island.
Note that you also need a set of tanks or a lake at the bottom of the hill. The tanks are 75m tall, so how are you accounting for that in your 120m of vertical distance?
[0] https://www.eia.gov/todayinenergy/detail.php?id=49036 gives 2,018 kWh per person in Hawaii