Solar panels and battery - any real world reccomendations?

We’re new to ASHPs. House has been sat at 20.5*C 24hrs a day in -3*C
More battery storage is on the cards for certain as we’re on Octopus Agile.

Our average unit price is ~20p/kWh but if we could avoid more import 4-7pm that’d help!
 
NoNameNoNumber said:
We’re new to ASHPs. House has been sat at 20.5*C 24hrs a day in -3*C
More battery storage is on the cards for certain as we’re on Octopus Agile.

Our average unit price is ~20p/kWh but if we could avoid more import 4-7pm that’d help!
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I run my heat pump harder overnight to overshoot my target temperature (20C) when its cheap and it shuts down at 05:30 for a few hours, even in this weather. I drop the target temp 1C at 21:00 so the unit shuts down and the house cools a bit for bed time and it restarts sometime after I have gone to sleep when it ever drops below 18.5C (19C target) or 02:00 where its targeting 22C.

The solar and my 13.5kwh battery have got me through to this point which is good going IMO. I'm on Octopus Intelligent which will be back to 7p in about 90 mins or so.

I'm at 26.8 import plus 9.7 solar at the moment although the battery has just gone to idle and shut down so we are now back on grid. In total my heat pump has consumed 26.4 kwh, it was just into double digits when I woke up at 6AM this morning. I'll report back what my average unit rate was but it will be around 8-9p for today.
 
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Wow those figures are no different to my gas heating a house with nearly 3000 SQF. However, my log burner takes the brunt.
 
I spoke to my boss earlier and he reckoned he has seen up to 50 quid a day. So I was here to query actual consumption. I didn't realise it was quite this bad!
 
dlockers said:
I spoke to my boss earlier and he reckoned he has seen up to 50 quid a day. So I was here to query actual consumption. I didn't realise it was quite this bad!
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It’s pointless looking at £ spent as it’s completely unique to an individual property. They may also have a **** install if he is hitting £50 in a day, that’s 200kwh at price cap prices. You need to look at heat produced for the cost.

according to octopus I spent £1.88 yesterday, I imported 25.2kwh so my average unit cost was 7.4p.

The heat pump consumed 14.35 kWh and would have produced over 50kwh of heat which cost me £1.05.

You aren’t matching that with gas, it would have been over £3.50 once factoring in boiler efficiency. If I was paying the price cap for the electric it would have also cost £3.50.

At price cap prices, running costs should be pretty much the same.
 
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Nathan said:
Wow those figures are no different to my gas heating a house with nearly 3000 SQF. However, my log burner takes the brunt.
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At process cap prices yes, that’s always been the case because the price of electricity is tied to the price of gas currently.

Heat pumps have never been about saving any money. If it was people would just install them and it wouldn’t need a £7500 government grant to make the retrofit make sense.

The only way to actually lower your bills is to exploit time of use tariffs alongside solar and battery storage. That’s something you can’t do with gas.

There are other benefits such as better comfort from having a heating system which is correctly installed and has good controls (unlike nearly all gas systems).

It’s also quieter, a lot quieter. I couldn’t tell you when my heat pump is running at full tilt, I could immediately tell tell you whenever my old gas boiler fired up.
 
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b0rn2sk8 said:
I'll report back what my average unit rate was but it will be around 8-9p for today.
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I said I’d report back on yesterday.

In the end I imported 30.2 kWh at a cost of £2.38 so my average import cost was 7.88p/kwh.

I generated 9.7kwh which you could cost at £1.455p if I sold it to the grid at 15p rather than using it.

So my total ‘cost’ for the day was £3.83 of which only £2.38 actually left my pocket.

Paying for electricity and gas from the grid for yesterday’s consumption would have cost multiple times that number. Not only that my house was 20-21C for the entire day.

Today will be more expensive though as the battery has already ran out so I’ll probably be buying 5-10kwh from the grid at 25p/kwh.

Edit: I’ve worked out that at least 25% of my consumption needs to come from peak time over the course of a month to make switching to Cosy beneficial. I’m well off that at the moment and temperatures rise rapidly over the weekend.
 
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I'm in the middle of planning an extension. I'm looking at the roof layout and am thinking about how many panels I can fit, and at what orientation.

I've got a choice between a hipped roof and gable roof. Let's assume I could get the same overall number of panels on each option. The hipped roof would be 3 panels West facing, and 3 panels South facing. The gable roof would allow for 6 south facing panels.

Which would be the better option? I'm guessing the gable option would provide more overall energy, and would possibly be cheaper to install as it's just one long run of racking?
 
Yes, both more energy and cheaper. If you are optimising for solar then it’s gabled all the way.

A south facing panel will produce ~25-30% more energy than a west facing one.

If the panels are all facing the same orientation, you can also do in roof and you’ll save money on roof tiles. Solar panels are actually cheaper than roof tiles per square meter.
 
just a side issue-I had a telephone conversation with a solar installer. Basically I am replacing my roof to take the inlaid solar panels (and also to remove that (my opinion) stupid and destructive spray foam loft roof insulate that the government encourage you to get). Does anyone have any knowledge?

Also what is the latest recommendation for the givenergy, fox, solax or Ecoflow inervortors and batteries? Each installer sings the virtues of their respective systems and its difficult to get an independent review of them.
 
If you want high end, its either Tesla or Sigenergy for off the shelf. In all honesty, the vast majority of the systems on the market are very similar in terms of the offer, a lot of it comes down to who is offering the best price and support.

Givenergy have their take on the Tesla Powerwall 3 coming out in a few weeks and it will need to be either better or cheaper.
 
I wouldn't get Solax. For a few reasons, but mainly:

1) Support lie. I had my installers on site to do a battery change due to one of their tech people diagnosing a fault. For some reason they wanted the installer to call the support line, they didn't say why.
The support person got confused by the call, but said "I have checked your system and its all working perfectly"
2) The UI sucks. Its always sucked, they do fancy graphics and stuff, but you cannot even get your generated numbers from it if you have batteries and do any charging from the grid.
3) Dumb stuff like the advanced settings needed to turn battery heating on/off being in the installer menu.
4) Battery capacity being calculated in a way they wont be used in the real world. Real world will be like 20% lower than their tests.

Avoid IMO.
 
To update. Having gone with a planned power wall 3 + 15 panels system it all got a bit complicated when install started. Roof was shot and so we’ve ended up reroofing (£££) and got 18 panels in roof now (look much better). Powerwall 3 lead times were silly and not firm so we’ve switched to sigeenergy 16kwh system as lead times shorter and installer is doing for the same price (as I thought there is a big margin on this in London). Just waiting for it to be commissioned.
 
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