Adding a battery to existing solar.

LateStarter

https://forums.moneysavingexpert.com/discussion/comment/81944240#Comment_81944240

Ooh, what are you doing to me? I have A/C in one room, and now wondering how to use the heating mode at night to supplement/offset the gas central heating. Rabbit hole, indeed

Martyn1981

https://forums.moneysavingexpert.com/discussion/comment/81944358#Comment_81944358

That's how it started for me, one rabbit hole after another.

I asked if an A/C unit might make sense, to use excess PV gen during early spring and late autumn, to reduce gas consumption, it was just one of my random ponderings, having learnt that modern A/C units, where bi-directional heatpumps. This was on a thread on this G&E board, possibly 2015(ish). A member (Zuepater) took my comment and started an actual thread looking into it. I then pottled around trying to find an installer for ~3yrs, whilst another chappie on here, put two in his bungalow, and turned off the gas.

Having got the A/C for excess, then a second, I then got a BEV, which finally made dual rate leccy worthwhile, and then realised I could 'pre-charge', the house on cheap rate overnight, right through the winter. Then batts, led to A2A use all winter, and GCH removed.

So definitely run that A2A overnight, and see how much it can help. Maybe ponder one or two more (now that the BUS will pay £2.5k towards it, if you remove the FF heating).

Co-incidentally, I've just had an e-mail today from the installers of my A2A units. I wonder if that's been prompted by the current FF crisis.

And regarding the comment about eggs and baskets, I'm not sure about that, as gas boilers need leccy to work. Even an old one (very old one) with a pilot light, still needs leccy for the pump to circulate the water. And yes, you could run that off a battery, but why not just run the A2A instead.

Edit- Ohh, just thought. Getting the gas supply disconnected, saves us ~£100pa in no longer paying standing charges. At the old 7p rate, that's about 4,000kWh(t) of heating. When we still had gas, our annual consumption was ~8,000kWh pa, including DHW and cooking. Assuming 6,000kWh for space heating, and our 1998 boiler being around 80% efficient(?), then that's ~4,800kWh(t). I'm quite surprised at that …. yet another rabbit hole for a Tuesday.

LateStarter

https://forums.moneysavingexpert.com/discussion/comment/81944460#Comment_81944460

Remove the gas boiler? Tell the other half we only have a limited supply of hot water? No chance - which is a semi-serious point that this technology change only really works if we get people to buy in. OTOH a second A/C unit sounds like a brilliant idea.

Nick_Dr1

https://forums.moneysavingexpert.com/discussion/comment/81944295#Comment_81944295

But its not really a single electrical basket, as the electricity is generated from multiple sources. Sure you can have a power cut, but other sources also run their own risk. As we are seeing, gas and oil have their own risks and gas is much more single source than electricity. Gas also require electricity to run in most households so you are exposing yourself to the need for multiple sources to be all available! But I get your point though, however electricity is probably the least single source supply there is available if you consider the whole supply chain. Its certainly the most convenient and I would argue, the least risky.

Single sourcing other things, like components for your products - that's a different story.

Heedtheadvice

I quite agree with the points bring made that when leccy goes off so does a CH pump.

However I would point out that:

if it is a combi boiler you still get hot water,

I you have a gas fire ( or multi burner for that matter ) you still have heat.

A small battery backup can easily run the leccy requirement of a gas boiler, pump and heating controls for several days ( assuming not 24hour demand)

Gas ( so far) has a much better supply ( to properties ) resilience than electricity which in some areas is quite prone to outages in storms and can be for a week, oil has a history of susceptibility ( like some on here I well remember the oil crisis in the 70s and more recently).

The multiple source of suppy to the grid is a very valid point ( type and source location) bit that does not impact on local property supply. Transformer out, trees down or too much snow the line affects immediately. I have experienced all three. Ask those affected by storm Arwen!

Even cities rather than rural areas can be affected, remember Heathrow's problem? That is why critical infrastructure, hospitals etc have backup generators. Not to say we are all that needy as those but elderly and those reliant on leccy can be in an impactfull risk situation.

Many will not ( quite correctly ) rate the risk but I suggest do not ignore it but assess the likelihood and impact and make a sensible personal judgement!

Funny how those going for or supporting PW3 batteries point out how valuable the whole house backup is.......

Qyburn

Doesn't the boiler itself need electricity?

QrizB

if it is a combi boiler you still get hot water,

A combi boiler still needs electricity to provide hot water. I don't think any domestic boiler installed in the last 20 years will do anything useful without power.

I agree that you could meet the electrical demands of a typical GCH system with a fairly small backup battery.

Netexporter

Apart from no power for the igniter, I suspect the gas valve defaults to closed, too.

JKenH

https://forums.moneysavingexpert.com/discussion/comment/81946294#Comment_81946294

I had my electrician put my boiler on a 3 pin plug so I could run my boiler from a Bluetti power pack if the grid was down. I found it quite useful when I was in the Agile tariff (before my PW3 was installed) to use the power pack to run the boiler at peak times and charge it back up overnight. I have even used the PP to run the boiler to supplement my PW3 in the depths of winter when the 14kWh of the PW3 wasn’t enough to get us through the day. I have also used the power pack to run my A2ASHP and would be doing so today if I didn’t have the PW3.

I agree it is useful to have the choice of multiple sources of energy. I used my oil boiler when oil was just over 50p/l but haven’t used the boiler now for a couple of weeks as electricity for space heating and hot water is cheaper than the replacement cost of oil.

Martyn1981

Wouldn't it be cheaper than a years gas SC, to get a propane heater (or similar) for, or even during, an emergency? And of course many properties are already electricity only, especially large flats.