I took part in the Heatflex trial last year. I did not really notice any change in actual temps or thermal comfort during the trials. I also experimented with raising the LWT prior to octopus saving sessions and then dropping the LWT during the saving session this had the same effect no change in thermal comfort but the power usage was shifted and extra savings for me.
Batteries are not a universal panacea; they are subject to efficiency constraints too. I have a V2G EV setup and the round-trip efficiency is around 81% at full charge/discharge rates; when you decrease the amount of energy you are charging or discharging with, the efficiency goes down, and I've measured the one-way efficiency as low as 66% for 730W, and that can still be useful but it does mean the input energy can be quite a bit more than the output energy. So there's a calculation to be done with a trade-off of efficiencies and that may be a fairly simple calculation but it probably varies on a case-by-case basis. I don't have a heat pump yet but that's something I'll be experimenting with when I do; I've had a survey done and apparently the heat loss is about 5kW for the house so it's probably going to be a fairly small heat pump. An efficiency curve of operation of V2G battery kit versus power level for charging and discharging is a question anyone should ask who is going for a system.
It might be that a system with a buffer tank would cope better with switching the heat pump off for a while. Also, it would be easy to move the hot water heat up period to avoid high demand times. Instinctively I think that a battery is a much better idea than changing the heat pump settings. The main thing is to have analogue signal or price per unit (rather than a simple on/off signal) going to each home. This would allow the home owner's smart controls to vary the demand just as much as needed using whatever tech it can control.
It's nice to have enough to cover that peak period 4-7 when the price jumps 10p. Alternatively or additionally you can boost the temp but .5C for one hour before to further reduce your demand at that time. This reduces the requirement for a battery, or increases the time the battery can be used for during the peak?
I took part in the Heatflex trial last year. I did not really notice any change in actual temps or thermal comfort during the trials. I also experimented with raising the LWT prior to octopus saving sessions and then dropping the LWT during the saving session this had the same effect no change in thermal comfort but the power usage was shifted and extra savings for me.
Batteries are not a universal panacea; they are subject to efficiency constraints too. I have a V2G EV setup and the round-trip efficiency is around 81% at full charge/discharge rates; when you decrease the amount of energy you are charging or discharging with, the efficiency goes down, and I've measured the one-way efficiency as low as 66% for 730W, and that can still be useful but it does mean the input energy can be quite a bit more than the output energy. So there's a calculation to be done with a trade-off of efficiencies and that may be a fairly simple calculation but it probably varies on a case-by-case basis. I don't have a heat pump yet but that's something I'll be experimenting with when I do; I've had a survey done and apparently the heat loss is about 5kW for the house so it's probably going to be a fairly small heat pump.
An efficiency curve of operation of V2G battery kit versus power level for charging and discharging is a question anyone should ask who is going for a system.
That’s really helpful Thankyou!!!
We do this with cosy octopus already. House is well insulated and we top up if necessary. No buffer tank, which I think would be a good idea.
Lots of people have been doing it a long time. It doesn’t really pay off that much though as per our accompanying video
@HeatGeekUninsulated buffer tanks don’t hold energy to load shift
It might be that a system with a buffer tank would cope better with switching the heat pump off for a while. Also, it would be easy to move the hot water heat up period to avoid high demand times. Instinctively I think that a battery is a much better idea than changing the heat pump settings.
The main thing is to have analogue signal or price per unit (rather than a simple on/off signal) going to each home. This would allow the home owner's smart controls to vary the demand just as much as needed using whatever tech it can control.
Buffers don’t hold enough energy to load shift
So I presume for heat pumps we should all have batteries to help draw at peek times.
It's nice to have enough to cover that peak period 4-7 when the price jumps 10p. Alternatively or additionally you can boost the temp but .5C for one hour before to further reduce your demand at that time. This reduces the requirement for a battery, or increases the time the battery can be used for during the peak?