Solar Panels?

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Discussion

RossiT

Original Poster:

345 posts

205 months

Sunday 6th March 2022
quotequote all
Good afternoon,

We’re at the very early stage to looking into solar panels for our house. We’re using around 1000kwh per month.

Just interested in peoples real life experiences with them, what size of system did you go for, cost and savings achieved?

Many Thanks

Condi

17,082 posts

170 months

Sunday 6th March 2022
quotequote all
Just be a little careful, most people will have Feed In Tariff income which has now ended. It has been replaced with SEG (Smart Export Guarantees), which are very different in that each energy company offer a differ amount and you only get paid on actual export units, rather than an assumed 50% of generation like with FITs. From memory the best SEG is about 7p/kwh, although that should increase as energy prices increase.

Basically, the more energy you can use yourself the more worthwhile they are. If you are out at work all day and come home at 6pm then don't bother.

kambites

67,460 posts

220 months

Sunday 6th March 2022
quotequote all
Are you heating with electricity to use that much? If so what sort of heating system?

RossiT

Original Poster:

345 posts

205 months

Sunday 6th March 2022
quotequote all
kambites said:
Are you heating with electricity to use that much? If so what sort of heating system?
Yes, we’re all electricity. The breakdown for Jan was 915kWh for heating and 197kWh for hot water.

Our system is an air source heat pump around 18 months old.

AW10

4,420 posts

248 months

Sunday 6th March 2022
quotequote all
1000 kWh/month is high - can you elaborate on the usage at different times of the day and how much the time of year plays into it?

To make a meaningful dent into that annual usage you would need a very large array - any idea how much roof space you have? Orientation of the roof? Is there *any* shading of the roof?

For most people solar panels generate most of their energy at the time it's least needed. The SEG is quite low and even with rising electricity prices the payback period can be up to 10 years just to recover your outlay.

Scrump

21,886 posts

157 months

Sunday 6th March 2022
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If you are hoping to use the electricity generated by the solar panels to power your heating then you may be disappointed.
My solar panels generate almost all their electricity in the summer months. In the winter when you need the heating my solar panel generate very little power.

Europa Jon

554 posts

122 months

Sunday 6th March 2022
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OP - have you insulated to the max first? That usage seems way too high.

Sheetmaself

5,663 posts

197 months

Sunday 6th March 2022
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Octopus have upped their rate to 7.5 per kW.

We got about £5 last month with a bill of around £45. Luckily for us the panels where free.

finlo

3,731 posts

202 months

Sunday 6th March 2022
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Our system is an air source heat pump around 18 months old.

[/quote]

You've found your problem.

jymmm

133 posts

42 months

Sunday 6th March 2022
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For January 1000kwh ish doesn’t seem too bad. Assuming that’s included all usage?

Should fall away to half that spring to autumn?

Better off spending £xxxx on insulation over solar.


Edited by jymmm on Sunday 6th March 19:27

Easternlight

3,424 posts

143 months

Sunday 6th March 2022
quotequote all
finlo said:
Our system is an air source heat pump around 18 months old.
You've found your problem.
Care to explain?

RossiT

Original Poster:

345 posts

205 months

Sunday 6th March 2022
quotequote all
Europa Jon said:
OP - have you insulated to the max first? That usage seems way too high.
Maximum insulation everywhere possible. Aug last year we used 32kWh. The usage is the total for heating, hot water and underfloor heating. House is 2400 sqft.

Interested to hear more about the air source pump being the cause?

Getragdogleg

8,736 posts

182 months

Sunday 6th March 2022
quotequote all
sod the feed in tariff, I'm thinking about charging batteries and using them when the sun is not shining.


finlo

3,731 posts

202 months

Sunday 6th March 2022
quotequote all
Easternlight said:
finlo said:
Our system is an air source heat pump around 18 months old.
You've found your problem.
Care to explain?
I'm yet to meet anyone with one that performs as claimed and to do so at anywhere near the cost of oil or gas!

Easternlight

3,424 posts

143 months

Sunday 6th March 2022
quotequote all
finlo said:
Easternlight said:
finlo said:
Our system is an air source heat pump around 18 months old.
You've found your problem.
Care to explain?
I'm yet to meet anyone with one that performs as claimed and to do so at anywhere near the cost of oil or gas!
I was talking to a friend today who has just had a heat pump system installed in a new build, and I asked how much heat you got out for every !kw you put in and he said 3kw!!
I didn't say any more as I don't know anything about it, but I'm sure that's impossible?

kambites

67,460 posts

220 months

Sunday 6th March 2022
quotequote all
Easternlight said:
I was talking to a friend today who has just had a heat pump system installed in a new build, and I asked how much heat you got out for every !kw you put in and he said 3kw!!
I didn't say any more as I don't know anything about it, but I'm sure that's impossible?
It's perfectly possible. If it's ground-source, a 3:1 return is about right, air-source 2:1 seems more normal. The manufacturer claims tend to be more like 4:1 and 3:1 respectively but as with so many such things, they're usually optimistic.

Condi

17,082 posts

170 months

Sunday 6th March 2022
quotequote all
Easternlight said:
I didn't say any more as I don't know anything about it, but I'm sure that's impossible?
Not impossible at all. It doesn't "make" 3Kw from 1Kw, but it uses 1Kw of electricity to move 3Kw of heat from outside to inside. Think of it like a reverse fridge - the fridge doesn't "make cold", it just moves the heat from inside to outside.

Although as has been mentioned, in the middle of winter when the outside is cold then you might get only just more than 1:1, rather than 3:1.

Easternlight

3,424 posts

143 months

Sunday 6th March 2022
quotequote all
Thanks for the replies and sorry for the thread derailment.
I get the principle of heat pumps but can't get my head around how it can be cost effictive.

mikeiow

5,284 posts

129 months

Sunday 6th March 2022
quotequote all
RossiT said:
Good afternoon,

We’re at the very early stage to looking into solar panels for our house. We’re using around 1000kwh per month.

Just interested in peoples real life experiences with them, what size of system did you go for, cost and savings achieved?

Many Thanks
Do you mean you use around 12,000kWh pa? Or is Januaries particularly high?
We use less than that, and half of ours is taken up with our EV.
Sounds like the ASHP is the prime culprit here....

I suspect you would find the best combination being to get solar+battery. A big battery, in your case!
You can then load the batteries in winter on an overnight cheap rate....let the excess solar fill them up in summer

We have solar, but from 11+ years back - so the FIT made that work. That said, we have older less efficient panels, and the same capacity (~3.8kWh) would cost far less now.

My point is that you can get some decent deals on <solar+batteries>, in part because it attracts only 5% VAT. We are looking at batteries now, but the 20% VAT alone makes the ROI less appealing!