Storage Heaters

[AGT]

Fitted and on test for a few hours….
Another one for Nowty’s energy storage list.
That makes 2x 1740watt units and 4x870 watt units.

[nowty]

Fitted and on test for a few hours….
Another one for Nowty’s energy storage list.
That makes 2x 1740watt units and 4x870 watt units.

I’ll have some catching up to do when I finally get home.

[AGT]

This time last year, I added about £400 extra to my energy bill, additional. PV and extra storage heater saving a bit of cash now…

[Joeboy]

This time last year, I added about £400 extra to my energy bill, additional. PV and extra storage heater saving a bit of cash now…

It's mildly odd in that it is difficult to compare year on year when one is running the path of ongoing upgrades. I used to judge my progress off of dropping annual NG consumption, then on rising PV generation, now we are onto PV export and that's going to be knocked out the park with the ASHP install. I draw solace that the new Victron SC & 3G will hopefully be a plateau afterwhich it is mild tweaking only.

Wouldn't change a thing, it has been an excellent learning curve which I have passed to the kids.

Likely at least one 800W SH will.make it's way from our place to No1 son's house and he can do the 6 hr Winter boogie on his soon to be IO tarriff.

[Stinsy]

This time last year, I added about £400 extra to my energy bill, additional. PV and extra storage heater saving a bit of cash now…

It's mildly odd in that it is difficult to compare year on year when one is running the path of ongoing upgrades. I used to judge my progress off of dropping annual NG consumption, then on rising PV generation, now we are onto PV export and that's going to be knocked out the park with the ASHP install. I draw solace that the new Victron SC & 3G will hopefully be a plateau afterwhich it is mild tweaking only.

Wouldn't change a thing, it has been an excellent learning curve which I have passed to the kids.

Likely at least one 800W SH will.make it's way from our place to No1 son's house and he can do the 6 hr Winter boogie on his soon to be IO tarriff.

SH are great in many ways:

• Shift usage into cheap period powered by Octopus’ generous ToU tariffs.

• Multi-decade reliability with zero maintenance.

• 100% efficient.

They are a really great part of the puzzle when transitioning form burning FF locally to an all-electric house while maximising offpeak:peak ratio.

However once you’ve achieved the above, the next step is to reduce the amount of off-peak electric you consume, and a HP is a really great way to do that. The 300-400% efficiency and low/slow power usage means that a HP plays nicely with a battery/inverter too.

[Joeboy]

This time last year, I added about £400 extra to my energy bill, additional. PV and extra storage heater saving a bit of cash now…

It's mildly odd in that it is difficult to compare year on year when one is running the path of ongoing upgrades. I used to judge my progress off of dropping annual NG consumption, then on rising PV generation, now we are onto PV export and that's going to be knocked out the park with the ASHP install. I draw solace that the new Victron SC & 3G will hopefully be a plateau afterwhich it is mild tweaking only.

Wouldn't change a thing, it has been an excellent learning curve which I have passed to the kids.

Likely at least one 800W SH will.make it's way from our place to No1 son's house and he can do the 6 hr Winter boogie on his soon to be IO tarriff.

SH are great in many ways:

• Shift usage into cheap period powered by Octopus’ generous ToU tariffs.

• Multi-decade reliability with zero maintenance.

• 100% efficient.

They are a really great part of the puzzle when transitioning form burning FF locally to an all-electric house while maximising offpeak:peak ratio.

However once you’ve achieved the above, the next step is to reduce the amount of off-peak electric you consume, and a HP is a really great way to do that. The 300-400% efficiency and low/slow power usage means that a HP plays nicely with a battery/inverter too.

Once I'm up & running I'll see if we can set up a curve that benefits the overnight slots by a degree in temp on the ashp. Defo running a TRV on our bedroom rad. The rest we will let equalise. I'm interested in seeing what the ashp will modulate down to?

[Stinsy]

It's mildly odd in that it is difficult to compare year on year when one is running the path of ongoing upgrades. I used to judge my progress off of dropping annual NG consumption, then on rising PV generation, now we are onto PV export and that's going to be knocked out the park with the ASHP install. I draw solace that the new Victron SC & 3G will hopefully be a plateau afterwhich it is mild tweaking only.

Wouldn't change a thing, it has been an excellent learning curve which I have passed to the kids.

Likely at least one 800W SH will.make it's way from our place to No1 son's house and he can do the 6 hr Winter boogie on his soon to be IO tarriff.

SH are great in many ways:

• Shift usage into cheap period powered by Octopus’ generous ToU tariffs.

• Multi-decade reliability with zero maintenance.

• 100% efficient.

They are a really great part of the puzzle when transitioning form burning FF locally to an all-electric house while maximising offpeak:peak ratio.

However once you’ve achieved the above, the next step is to reduce the amount of off-peak electric you consume, and a HP is a really great way to do that. The 300-400% efficiency and low/slow power usage means that a HP plays nicely with a battery/inverter too.

Once I'm up & running I'll see if we can set up a curve that benefits the overnight slots by a degree in temp on the ashp. Defo running a TRV on our bedroom rad. The rest we will let equalise. I'm interested in seeing what the ashp will modulate down to?

HPs generally modulate down to 25% of their nameplate capacity. The stories you read in the press with people finding their HP expensive to run tend to be: oversized units cycling on and off frequently because they’re unable to modulate down low enough, and people using them like a gas boiler switching on-and-off several times a day.

It seems to me that it is best to fit an undersized HP and rely on secondary heating (log burner, resistive electric, etc.) on the very coldest days.

[Ken]

"
"It seems to me that it is best to fit an undersized HP and rely on secondary heating (log burner, resistive electric, etc.) on the very coldest days."

Thats my philosphy also but the MSE does not allow it so they put in big HPs that will not modulate down enough and change rads and pipes to achieve MSE objectives for a few days a yr.

I struggle to imagine that a small HP (3-5kw) running 24/7 is not enough. That is 72-120 kwh/day! How many people use more than that ?
Come on tell me if you need more than 5kw 24/7.

[Marcus]

"
"It seems to me that it is best to fit an undersized HP and rely on secondary heating (log burner, resistive electric, etc.) on the very coldest days."

Thats my philosphy also but the MSE does not allow it so they put in big HPs that will not modulate down enough and change rads and pipes to achieve MSE objectives for a few days a yr.

I struggle to imagine that a small HP (3-5kw) running 24/7 is not enough. That is 72-120 kwh/day! How many people use more than that ?
Come on tell me if you need more than 5kw 24/7.

That's pretty much spot on. My 10.5kw grant hp if run continuously would inevitably cycle - although there is some justification in sizing a bit bigger so you can run it intermittently on TOU tariffs:- i don't actually run it that way in practice as i try to use it late morning - mid afternoon to make best use of solar and ambient temp.

I'm still looking for a way to force the grant to run at a lower delta T than 5°C to effectively run at <10kw, as this would offer some efficiency savings (eg when heating the Grant HWC the hp runs flat out at 10.5kw until 50°C, pulling >3kw in cold weather towards the top. It would be much easier to run on solar/hydro if it ran at half power as there's no real urgency in getting the water hot).

[Stinsy]

"
"It seems to me that it is best to fit an undersized HP and rely on secondary heating (log burner, resistive electric, etc.) on the very coldest days."

Thats my philosphy also but the MSE does not allow it so they put in big HPs that will not modulate down enough and change rads and pipes to achieve MSE objectives for a few days a yr.

I struggle to imagine that a small HP (3-5kw) running 24/7 is not enough. That is 72-120 kwh/day! How many people use more than that ?
Come on tell me if you need more than 5kw 24/7.

I agree. Sizing for the worst day of the year will always be poor practice. A SH or WBS is a perfectly acceptable way to augment a HP that is sized for normal conditions.