On-grid domestic battery storage

bloke.in.a.fix

That's a pity. It seems so backwards to rely on heating up a brick that takes up space on the wall, when that energy could be stored in a battery out on the balcony.

Martyn1981

bloke.in.a.fix wrote: »

That's a pity. It seems so backwards to rely on heating up a brick that takes up space on the wall, when that energy could be stored in a battery out on the balcony.

Is there any opportunity to install some ASHP's (air con units) as these would be about 3x as efficient, and the battery idea might work a bit better since daytime air temps would improve efficiency slightly, so perhaps 18kWh thermal from 6kWh battery charged at night rates? But that's not much, so just a top up to aid the hard work done at night.

But for a flat, even modern quiet units may cause issues with neighbours?

bloke.in.a.fix

Thanks Martyn. The flat already has air con installed, which is convenient, but I'm not too keen on the hot air heating that these provide. Having had underfloor heating in a previous flat, it's definitely my preferred style of heating.

zeupater

bloke.in.a.fix wrote: »

Thanks Martyn. The flat already has air con installed, which is convenient, but I'm not too keen on the hot air heating that these provide. Having had underfloor heating in a previous flat, it's definitely my preferred style of heating.

Hi

... If the flat has heap-pump heating, what are the storage heaters for & why doesn't the EPC reflect the efficiency of the heat-pump (?!) ....

I really think that the BRE need to be taken to task on RdSAP as it has so many inconsistencies related to heating ...

For example, with storage heaters it's likely that the environmental impact rating is ridiculously impacted due to the electricity energy source mix, however, in order to avoid having to continually reissue EPCs in line with decarbonising the grid (wind, solar etc), the RdSAP impact has to assume a constant standardised mix, which no longer represents the real world ... this simply makes GCH look to have a far better relative impact on the environment than electricity ...

In addition, where there are multiple sources of heat provision, RdSAP doesn't have a mechanism for fair apportionment ... a primary source is selected & that's about it .... in cases similar to the above with both HP & storage heaters, the price of electricity would deem that the occupier would logically prefer to use the lowest cost source for the majority of the time and be the primary heating source, yet with the storage heaters likely having a larger total heating capacity they'd most likely be considered the primary heat source within the EPC rating and be used to establish the cost of heating & potential savings (/improvements) recommendations ....

HTH
Z

Hexane

bloke.in.a.fix wrote: »

The flat already has air con installed, which is convenient, but I'm not too keen on the hot air heating that these provide. Having had underfloor heating in a previous flat, it's definitely my preferred style of heating.

Could you say a little more about this, please? Would be very useful to those of us considering heat pumps at some distant point in the future. What do you not like about the air con hot air - the way it blows the air as a draft, or something else? The way it dries out the air? Several people on these forums appear to have been delighted with their air-air heat pumps, so it would be really good to get an alternative perspective.

1961Nick

bloke.in.a.fix wrote: »

Thanks Martyn. The flat already has air con installed, which is convenient, but I'm not too keen on the hot air heating that these provide. Having had underfloor heating in a previous flat, it's definitely my preferred style of heating.

If you already have an ASHP then batteries & electric U/F heating might be do-able for background heating.....but at quite a cost. Even for a flat, you're probably going to need at least 20 kWh of battery storage (£7000). The ASHP would probably still be needed to top up during the depths of winter if you don't want peak rate import.

Any idea how many kWh your storage heaters are consuming?

bloke.in.a.fix

zeupater wrote: »

... If the flat has heap-pump heating, what are the storage heaters for & why doesn't the EPC reflect the efficiency of the heat-pump (?!) ....

The EPC does not mention the heatpump, but specifically complains about the inefficiency of the ancient storage heaters. Decision to have both is previous owner's choice, not mine.

Hexane wrote: »

What do you not like about the air con hot air - the way it blows the air as a draft, or something else? The way it dries out the air?

I only recently acquired the property so not had the chance to evaluate the units in a real life situation, but my previous experience of forced hot air heating has been that it's noisy, draughty and dries the air.

1961Nick wrote: »

If you already have an ASHP then batteries & electric U/F heating might be do-able for background heating.....but at quite a cost. Even for a flat, you're probably going to need at least 20 kWh of battery storage (£7000). The ASHP would probably still be needed to top up during the depths of winter if you don't want peak rate import.

This AHSP/UHF combo is currently my preferred solution. I can imagine, for example, programming the ASHP to blast the lounge/diner with hot air before we get up, or before we come home from work, then using UHF to top up as needed, and on weekends. I'd skip the battery though, at least until battery prices come down or energy prices go up.

mmmmikey

Hi - a couple of extra thoughts on this....

1. The EPC rating makes no distinction between 40 year old storage heaters with poor insulation and crap controls and 10 year old storage heaters with good insulation and controls. The newer ones can work very well if properly sized and set up in accordance with the instructions (and in storage heater terms, 10 years old is still new!)

2. Don't confuse efficiency with running costs. Even if you waste a bit of energy because you can't control the output well enough to heat the house when you don't want to, don't forget that with Economy 7 you are paying far, far less for the energy that you're losing. To put this in perspective, I halved my electricity bill by selling the hugely expensive Fischer Future heaters the previous owner had installed and going back to reconsitioned storage heaters on an E7 tarriff, saving £500+ per year.

I can't help thinking it would be a good idea to run the storage heaters over the coming winter and see how you get on with them - you may be pleasantly surprised....

bloke.in.a.fix

On closer inspection, it tuns out the flat does not even have an Economy 7 meter!

Martyn1981

Not sure if this is new news, but yet another entrant into the domestic storage market. I suspect there is/will be growing duplication as batteries from one supplier get re-packaged by more and more companies.

Q CELLS takes aim at UK flexible energy market with home battery solution