3 ms·

Pumped hydro. Pump the water into header tanks, then it doesn't need electricity to water the grass, and you could generate electricity too. Or... Just don't

Pumped hydro. Pump the water into header tanks, then it doesn't need electricity to water the grass, and you could generate electricity too. Or... Just don't water the grass?

llukas 7y ago
I wonder how viable is to cool down some thermal mass? (similar to HVAC systems taking advantage of cheap electricity at night). Fridge can be "pre-cooled" and cut power usage at night.
- icebraining 7y ago
  Joey Hess (the git-annex developer, also lives off-grid) has done a lot of experimentation with his fridge, including adding a thermal mass: https://fridge0.branchable.com/thermal_mass/ https://fridge0.branchable.com/thermal_mass/
  - adamcharnock 7y ago
    That is very interesting to me, thank you!
- ElKrist 7y ago
  In winter I turn up the max temperature of my water heater. This way I can soak more energy into it when it's "off-peak" (cheaper) hours for electricity. You just have to be careful not opening the tap on the hottest temperatures anymore. I don't see how you picture it with the fridge though. Aren't you limited by the fact that you can't go down much below 0°C ? Or perhaps you add some new mass? Where do you actually put this mass when the fridge is already full?
  - llukas 7y ago
    Right with fridge there is not much wiggle room - but each fridge contains freezer compartment?
adamcharnock 7y ago
> Pumped hydro. Yes, I did some beer-matt calculations on this. I believe it is 10J to raise 1kg by 1m. So to raise 2000lt of water (2000kg) by 10m it would need 10J * 2000 * 10 = 200,000J. Call it 0.5MJ to take possible losses into account. A kWh is 3.6MJ. Which basically means I would get 0.14kWh storage as a reward for building a 10m high tower which can support 2 tonnes. When my batteries can store 10kWh (in theory), it just doesn't seem to make sense to me. Of course if I had a lake on the top of a hill that could be a different matter. It would also be a different matter if I didn't need 10m head (1bar). Sprinklers do require pressure though. > Or... Just don't water the grass? A good point. There are two reasons I do this: 1) I'm from the UK, green grass feels homely to me, 2) forest fires are an actual part of life here, and stopping the area around one's house being flamable is important. Paving, gravelling, tarmacking, and watering are all ways to deal with this.
- benj111 7y ago
  Yeah, I wasn't being entirely serious with the pumped hydro, nice in theory... But if you've done the rest of the infrastructure for it. What about seeper hoses, or have you looked into hydraulic ram pumps? That might give you enough pressure to drive a sprinkler.

Pumped hydro. Pump the water into header tanks, then it doesn't need electricity to water the grass, and you could generate electricity too. Or... Just don't water the grass?

llukas 7y ago

I wonder how viable is to cool down some thermal mass? (similar to HVAC systems taking advantage of cheap electricity at night). Fridge can be "pre-cooled" and cut power usage at night.

icebraining 7y ago
Joey Hess (the git-annex developer, also lives off-grid) has done a lot of experimentation with his fridge, including adding a thermal mass: https://fridge0.branchable.com/thermal_mass/ https://fridge0.branchable.com/thermal_mass/
- adamcharnock 7y ago
  That is very interesting to me, thank you!
ElKrist 7y ago
In winter I turn up the max temperature of my water heater. This way I can soak more energy into it when it's "off-peak" (cheaper) hours for electricity. You just have to be careful not opening the tap on the hottest temperatures anymore. I don't see how you picture it with the fridge though. Aren't you limited by the fact that you can't go down much below 0°C ? Or perhaps you add some new mass? Where do you actually put this mass when the fridge is already full?
- llukas 7y ago
  Right with fridge there is not much wiggle room - but each fridge contains freezer compartment?

adamcharnock 7y ago

> Pumped hydro. Yes, I did some beer-matt calculations on this. I believe it is 10J to raise 1kg by 1m. So to raise 2000lt of water (2000kg) by 10m it would need 10J * 2000 * 10 = 200,000J. Call it 0.5MJ to take possible losses into account. A kWh is 3.6MJ. Which basically means I would get 0.14kWh storage as a reward for building a 10m high tower which can support 2 tonnes. When my batteries can store 10kWh (in theory), it just doesn't seem to make sense to me. Of course if I had a lake on the top of a hill that could be a different matter. It would also be a different matter if I didn't need 10m head (1bar). Sprinklers do require pressure though. > Or... Just don't water the grass? A good point. There are two reasons I do this: 1) I'm from the UK, green grass feels homely to me, 2) forest fires are an actual part of life here, and stopping the area around one's house being flamable is important. Paving, gravelling, tarmacking, and watering are all ways to deal with this.

benj111 7y ago
Yeah, I wasn't being entirely serious with the pumped hydro, nice in theory... But if you've done the rest of the infrastructure for it. What about seeper hoses, or have you looked into hydraulic ram pumps? That might give you enough pressure to drive a sprinkler.