Solar Panels - increasing price of energy make them more worthwhile?

jimjames

As above check the shading on your roof and the orientation. If you are working from home and that's likely to continue then solar could well be worthwhile as it should mean you can make most use of the output during the day. If you can set washing machine etc to run in daylight hours then it will maximise your use of the solar generated. Our roof is pretty much unshaded all day and faces due South so we're on about the maximum output you're likely to get which is 3300kWh for 3kWp solar panels. If you had a battery you'd then be able to use the generated power overnight as well.

jimjames

QrizB said:

DeletedUser said:

My logic is born out by whats been happening for a long time. We are constantly told by OFGEM, that we are all using LESS energy year on year. (Look at their 'typical figures' for the last 10 years). Yet there has been a long upward trend in prices. (54% increase since 2010).

<citation required>

Where exactly is your evidence of "a long upward trend in prices"?

When we had our solar panels installed in 2011 one installer quoted prices rising at 15% pa indefinitely as part of their dodgy sales tactics. At the time the rate was quoted as 13p per kWh, by now it should be 34p. I've been paying 12p with Symbio so we're nowhere near that level of increase although the cap at 20p will get closer.

[Deleted User]

jimjames said:

As above check the shading on your roof and the orientation. If you are working from home and that's likely to continue then solar could well be worthwhile as it should mean you can make most use of the output during the day. If you can set washing machine etc to run in daylight hours then it will maximise your use of the solar generated. Our roof is pretty much unshaded all day and faces due South so we're on about the maximum output you're likely to get which is 3300kWh for 3kWp solar panels. If you had a battery you'd then be able to use the generated power overnight as well.

A major ‘weakness’ of solar is that it doesn’t work when the sun doesn’t shine. I say that as someone who has invested in a 7kWp array and a 13.5kWh battery. Daily outputs last December ranged from 10kWhs to 300Whs. Do I regret paying for my system (outwith the FIT Scheme), the answer is ‘no’. 

PS. I am a little surprised that you think that a 3kWp array can produce 3300kWhs/year: that would be 110% efficiency when most systems (I have had two) have an efficiency loss of up to 20%. My 7kWp array produced just under 5900kWhs in the past 12 months which was above the MCS prediction.

QrizB

Dolor said:

PS. I am a little surprised that you think that a 3kWp array can produce 3300kWhs/year: that would be 110% efficiency when most systems (I have had two) have an efficiency loss of up to 20%. My 7kWp array produced just under 5900kWhs in the past 12 months which was above the MCS prediction.

I'm not sure what your "110% efficiency" relates to?

Output does depend on where you are in the country. The sunnier parts of the south can potentially generate more than 1kW per Wp over the year. PVGIS forecasts 1096W/Wp per year in west Cornwall or 1139W/Wp in East Sussex for example, even after 14% system losses.

Near York, however, PVGIS forecasts 934W/Wp, and near Dundee 912W/Wp.

jimjames

Dolor said:

jimjames said:

As above check the shading on your roof and the orientation. If you are working from home and that's likely to continue then solar could well be worthwhile as it should mean you can make most use of the output during the day. If you can set washing machine etc to run in daylight hours then it will maximise your use of the solar generated. Our roof is pretty much unshaded all day and faces due South so we're on about the maximum output you're likely to get which is 3300kWh for 3kWp solar panels. If you had a battery you'd then be able to use the generated power overnight as well.

PS. I am a little surprised that you think that a 3kWp array can produce 3300kWhs/year: that would be 110% efficiency when most systems (I have had two) have an efficiency loss of up to 20%. My 7kWp array produced just under 5900kWhs in the past 12 months which was above the MCS prediction.

It's not a "think", it's our actual generation. Generation meter currently on 32300 and we're a couple of months under 10 years. As I said it's around the maximum you can get under best conditions, you're unlikely to get more than that.

http://solar-panels-review.321web.co.uk/index.php/yearly-comparison-of-solar-pv

Three most recent complete years below:

2018 was 3325 kWh
2019 was 3338 kWh
2020 was 3378 kWh

countryhouse39

Rodders53 said:

I think your energy use of 18-19 MWh per annum in Scotland are pretty reasonable for a 5 bed, 3 reception home.
Here is Bedfordshire we use about the same with oil heating and electricity totalled up, but just the two of us and it's a fairly modern home.

https://www.thegreenage.co.uk/how-much-energy-does-my-home-use/ see figure 7 as a high user you should be nearer to 22.6 MWh per annum in total. 
Say 18.6MWh less 4.6 'normal electric' = 12MWh heating cf 18MWh for gas.  Is that an average COP of 1.5?
Your heat pump is obviously working OK if not brilliantly, perhaps?  But you may need to drill down to how much heat it produces for the electric input in more detail?

Matelodave may have some tricks to ensure your heat pump is not doing silly things (like a COP 1 immersion boost heater cutting in too often).

Thanks for this. I had thought that we were using an awful lot, so while it doesn't help on the bills front at least I know its not a totally unreasonable amount. I am not an expert in this stuff at all, but would like to be able to work out how to make better use of the heat pump as I feel a COP of 1.5 is pretty crap tbh . Do you have any tips on how I can 'drill down' in more detail? 

We are in the process of doing all we can in terms of insulating the property better - the roof spaces are now massively insulated so there's not much more we can do there, windows are much more expensive, but we are probably 70% double glazed now. The plan of the house is not very efficient  - its long and thin so lots of external walls. I am worried about our bills soaring, so keen to do what we can in terms of reducing it.

[Deleted User]

QrizB said:

DeletedUser said:

My logic is born out by whats been happening for a long time. We are constantly told by OFGEM, that we are all using LESS energy year on year. (Look at their 'typical figures' for the last 10 years). Yet there has been a long upward trend in prices. (54% increase since 2010).

<citation required>

Where exactly is your evidence of "a long upward trend in prices"?

Ye of little faith. Happy to oblige:-

https://www.nimblefins.co.uk/average-cost-electricity-kwh-uk

Which is reflected in my own records for said period.

QrizB

DeletedUser said:

QrizB said:

DeletedUser said:

My logic is born out by whats been happening for a long time. We are constantly told by OFGEM, that we are all using LESS energy year on year. (Look at their 'typical figures' for the last 10 years). Yet there has been a long upward trend in prices. (54% increase since 2010).

<citation required>

Where exactly is your evidence of "a long upward trend in prices"?

Ye of little faith. Happy to oblige:-

https://www.nimblefins.co.uk/average-cost-electricity-kwh-uk

Which is reflected in my own records for said period.

That's not CPI-adjusted, is it? Which is odd, as the UK Government publishes perfectly good CPI-adjusted figures which the owner of that website has chosen to ignore.

Over the same period, prices in general rose 31%. See https://www.bankofengland.co.uk/monetary-policy/inflation/inflation-calculator

[Deleted User]

QrizB said:

That's not CPI-adjusted, is it? Which is odd, as the UK Government publishes perfectly good CPI-adjusted figures which the owner of that website has chosen to ignore.

Over the same period, prices in general rose 31%. See https://www.bankofengland.co.uk/monetary-policy/inflation/inflation-calculator

I see, so assuming your information is correct, a 31% increase is not an upward trend?

QrizB

Here, try this table:

https://www.gov.uk/government/statistical-data-sets/monthly-domestic-energy-price-stastics