overall cost of installing Solar panels

[Jambo85]

NorthernUproar said:

Jambo85 said:

JagDroid Man said:

Especially now that the majority of UK energy is generated from renewable sources, how can all of the above be a positive environmental impact when you can simply draw electricity via the existing grid?

Majority can be a misleading word, it's still 40-50% gas, around 30 TWh per quarter which is fkload of gas and CO2! We've made incredible progress and gas is better than oil and coal but there's still a way to go with current electricity consumption. And then there's the longer term issue that electricity consumption is going to increase as EVs and heat pumps become the norm, and that we are going to see a decrease in our nuclear output in coming years (considered renewable). There will be a mixture of solutions to this, including more wind turbines, interconnects and perhaps large scale battery storage - however I also firmly believe there will be an increase in gas fuelled generation.

This article has plenty of good facts in it but you need to read beyond the anti fossil fuel bias in the text and do your own analysis:

https://www.carbonbrief.org/analysis-uk-renewables...

eg. in the opening paragraph he compares 29.5 TWh from renewables vs "just" 29.1 TWh from fossil fuels - laughable.

Also if you look at the graphs there you will see that total consumption has also decreased over the last decade - a mixture of causes but one of them is "behind the meter" generation such as roof top PV panels which for the most part can only be measured as a decrease in consumption.

Absolute garbage. Throwing rocks at the moon, screaming at the tide utter rubbish.

I own a renewable energy installation business, we primarily have always done ground source heating systems. This last year we can not keep up with demand for solar PV installs as the payback for 95% of domestic clients is 4-6 years.

There’s a £30k package for standard homes that the government will get behind with funding in 2023 that’ll see domestic settings capable of becoming 65% self generating.

You think we’re in an energy crisis with prices now? We haven’t even started.

Hope the hangover isn’t too bad, what is it you disagree with?

[AW10]

NorthernUproar said:

I own a renewable energy installation business, we primarily have always done ground source heating systems. This last year we can not keep up with demand for solar PV installs as the payback for 95% of domestic clients is 4-6 years.

I would love to see the calcs on this please.

[irc]

AW10 said:

NorthernUproar said:

I own a renewable energy installation business, we primarily have always done ground source heating systems. This last year we can not keep up with demand for solar PV installs as the payback for 95% of domestic clients is 4-6 years.

I would love to see the calcs on this please.

Indeed. Our electricity is about £800 a year. Assuming solar could cover a third of our usage a 6 year payback would require a system costing £1600.

Are they that cheap?

The third assumption coming from an actual user whose system covers 30% of his usage



https://www.theguardian.com/environment/2022/aug/2...

He points out

"This estimate overlooks the important fact that most electricity is produced in summer, and all of it in daylight, while most consumption is in winter and at night.

Our 4kW system has produced about 4,000kWh a year for the last 10 years. Although that is equivalent to our annual consumption we only consume about 30% of what we produce, despite having a household of three stay-at-home pensioners and electric cooking and water heating."

[jason61c]

Jambo85 said:

NorthernUproar said:

Jambo85 said:

JagDroid Man said:

Especially now that the majority of UK energy is generated from renewable sources, how can all of the above be a positive environmental impact when you can simply draw electricity via the existing grid?

Majority can be a misleading word, it's still 40-50% gas, around 30 TWh per quarter which is fkload of gas and CO2! We've made incredible progress and gas is better than oil and coal but there's still a way to go with current electricity consumption. And then there's the longer term issue that electricity consumption is going to increase as EVs and heat pumps become the norm, and that we are going to see a decrease in our nuclear output in coming years (considered renewable). There will be a mixture of solutions to this, including more wind turbines, interconnects and perhaps large scale battery storage - however I also firmly believe there will be an increase in gas fuelled generation.

This article has plenty of good facts in it but you need to read beyond the anti fossil fuel bias in the text and do your own analysis:

https://www.carbonbrief.org/analysis-uk-renewables...

eg. in the opening paragraph he compares 29.5 TWh from renewables vs "just" 29.1 TWh from fossil fuels - laughable.

Also if you look at the graphs there you will see that total consumption has also decreased over the last decade - a mixture of causes but one of them is "behind the meter" generation such as roof top PV panels which for the most part can only be measured as a decrease in consumption.

Absolute garbage. Throwing rocks at the moon, screaming at the tide utter rubbish.

I own a renewable energy installation business, we primarily have always done ground source heating systems. This last year we can not keep up with demand for solar PV installs as the payback for 95% of domestic clients is 4-6 years.

There’s a £30k package for standard homes that the government will get behind with funding in 2023 that’ll see domestic settings capable of becoming 65% self generating.

You think we’re in an energy crisis with prices now? We haven’t even started.

Hope the hangover isn’t too bad, what is it you disagree with?

can you show the maths on how you've got payback calculated in 4-6 years? Do you also think its adds 10% to the property value?

[OutInTheShed]

irc said:

Indeed. Our electricity is about £800 a year. Assuming solar could cover a third of our usage a 6 year payback would require a system costing £1600.

Are they that cheap?

The third assumption coming from an actual user whose system covers 30% of his usage



https://www.theguardian.com/environment/2022/aug/2...

He points out

"This estimate overlooks the important fact that most electricity is produced in summer, and all of it in daylight, while most consumption is in winter and at night.

Our 4kW system has produced about 4,000kWh a year for the last 10 years. Although that is equivalent to our annual consumption we only consume about 30% of what we produce, despite having a household of three stay-at-home pensioners and electric cooking and water heating."

You can get 15p a kWh for export, so that might be 2/3 of 4000 x .15 = £400 a year export and 1/3 x 4000 x .49 = £650 saving at today's prices, so a grand a year is not totally unreasonable.

It might be best to understand your use/export split and look at all the tariff permutations, but we can't predict the tariffs for very long and neither do we know what the prices of panels and installation will do.

[AW10]

OutInTheShed said:

You can get 15p a kWh for export, so that might be 2/3 of 4000 x .15 = £400 a year export and 1/3 x 4000 x .49 = £650 saving at today's prices, so a grand a year is not totally unreasonable.

It might be best to understand your use/export split and look at all the tariff permutations, but we can't predict the tariffs for very long and neither do we know what the prices of panels and installation will do.

Shouldn’t that be 1/3 x 4000 x 0.34 = £450 ?

[irc]

AW10 said:

OutInTheShed said:

You can get 15p a kWh for export, so that might be 2/3 of 4000 x .15 = £400 a year export and 1/3 x 4000 x .49 = £650 saving at today's prices, so a grand a year is not totally unreasonable.

It might be best to understand your use/export split and look at all the tariff permutations, but we can't predict the tariffs for very long and neither do we know what the prices of panels and installation will do.

Shouldn’t that be 1/3 x 4000 x 0.34 = £450 ?

The saving from using his power is 30% of 4000Kw=1200 x O.34 = £408

The cash from selling the exports on an Octopus Agile Tariff is 2800Kw x £0.15 = £420.

So £800 saving a year assuming both current high power prices and good export rates last.

This link suggest £5000 for a 4Kw system.

https://www.greenmatch.co.uk/solar-energy/solar-sy...

So a 5 year payback needs a system installed for £4000.




Though this calculator suggests annual generation for my roof in SCotland of 2396Kw per year which obviously drastically changes the numbers.

https://www.pvfitcalculator.energysavingtrust.org....

Edited by irc on Saturday 29th October 22:28

[anonymous-user]

My system is costing £16,000 with a predicted production if 6,600kWh per year (similar quotes by 4 separate sources.)

I should be able to use all of that with a combination of daytime use, a 10.4 kWh battery, solar iBoost to divert excess to an immersion heater in the summer and the key ability to plug a 77kWh EV in to charge during the day in Summer as I WFH 3 days per week.

If you can use nearly or all the electricity you produce and can fit a big enough system for economies of scale (adding more panels is proportionately cheaper compared to the whole installation cost) it gets much more cost effective.

This would pay back in 7 years at 34p per kWh

If elec prices rise as predicted to 60p then the payback drops to 4 years. I wouldn’t bet on prices staying that high for long though but it illustrates just how much the economics around solar panels have shifted.

[rustyuk]

Tobermory said:

My system is costing £16,000 with a predicted production if 6,600kWh per year (similar quotes by 4 separate sources.)

I should be able to use all of that with a combination of daytime use, a 10.4 kWh battery, solar iBoost to divert excess to an immersion heater in the summer and the key ability to plug a 77kWh EV in to charge during the day in Summer as I WFH 3 days per week.

If you can use nearly or all the electricity you produce and can fit a big enough system for economies of scale (adding more panels is proportionately cheaper compared to the whole installation cost) it gets much more cost effective.

This would pay back in 7 years at 34p per kWh

If elec prices rise as predicted to 60p then the payback drops to 4 years. I wouldn’t bet on prices staying that high for long though but it illustrates just how much the economics around solar panels have shifted.

So your current electricity bill is more than £2300 a year?

Is anyone 100% self-sufficient with solar? If not then your current bill might need to be much more than £2300 to hit the 7 year timeline.

[anonymous-user]

rustyuk said:

So your current electricity bill is more than £2300 a year?

Is anyone 100% self-sufficient with solar? If not then your current bill might need to be much more than £2300 to hit the 7 year timeline.

Yes the current use (before getting an EV) is around 6600


The key to understanding this is that the prime consideration is to install the most cost effective system you can while still using all the electricity generated and trying not to have to sell any of it on.

You can’t be self sufficient because you just can’t make enough in winter but you make too much to use in the summer. If you spec a system to provide enough in Winter (and you have enough roof space for the 40kWp or so you would need) you will produce far too much in Summer and have to sell it in at a pitiful rate. You wouldn’t get permission from the DNO for such a system anyway

BUT if you add in an EV you can soak up all extra and effectively use all of your production over the year. Of course you will end up buying off the grid to fuel the EV and provide some domestic but you would be doing that anyway without solar panels. Essentially you need increase your Summer electricity usage enough that you can use the full amount produced even in Summer


The key to make a solar installation pay back is not to aim to become 100% self sufficient year round but instead to make sure that you buy the most cost effective system (kWp per £ capital invested) that you can still use all of the power from in this way. You then avoid having to sell back your ROI at 5-15p per kWh which is too low to make sense.

There will be an upper limited dictated either by your roof size or the amount you need to charge your car in Summer to use your excess.

But using this approach you can make solar pay back in 7 years at the current cap and 4 years at the predicted April 2023 rate, yes.

(Note when I say increase your electricity usage, I mean in a good way such as converting from ICE to EV, I’m not advocating everyone going out and buying a hot tub!)

Edited by anonymous-user on Sunday 30th October 09:21

[dmsims]

irc said:

This link suggest £5000 for a 4Kw system.

Whilst that may have been true once the current rip off prices means it will be a lot more

[AW10]

Have you done the calcs to assure yourself that you're going to use the EV enough between solar PV charge sessions that there's "room" to store more PV-generated kWh?

I get what you say about the diminishing cost of adding kWp but at the same time you're also at risk of not being able to fully utilise the further kWp.

£16K in solar PV and associated batteries and controllers is a pretty big "bet". Please post a summary of the proposed system - location, kWp, battery capacity, etc. And what's the miles/kWh factor for your EV?

[dmsims]

AW10 said:

Have you done the calcs to assure yourself that you're going to use the EV enough between solar PV charge sessions that there's "room" to store more PV-generated kWh?

I get what you say about the diminishing cost of adding kWp but at the same time you're also at risk of not being able to fully utilise the further kWp.

£16K in solar PV and associated batteries and controllers is a pretty big "bet". Please post a summary of the proposed system - location, kWp, battery capacity, etc. And what's the miles/kWh factor for your EV?

Indeed - let's not forget that charging will (normally) be limited to 7kW

Also you have to factor in that you can still get cheap off peak tariffs for an EV so a more realistic calculation is in order

[HarryW]

I recently looked into this and dismissed it as the 10+ years to break even is barking.
If the government are truly interested in going green then the Export tariff needs to be linked to the price of units paid by the customers.
Effectively on a sunny day your solar could be powering next door and the electricity company cream profits from your output with zero effort.
Also by giving a fairer export price to domestic users it will also help prevent covering arable lands in panels
The whole system needs a shake up..

[MaxFromage]

I'm all for solar installs if the economics exist or for other reasons. People previously suggested stock market investing as a reason not to invest in solar, but of course that brings greater risk. With 'risk free' interest rates of 4-5% now available, that needs to be factored into the payback calculations. It's going to make the payback much longer, or indeed not at all.

[OutInTheShed]

HarryW said:

I recently looked into this and dismissed it as the 10+ years to break even is barking.
If the government are truly interested in going green then the Export tariff needs to be linked to the price of units paid by the customers.
Effectively on a sunny day your solar could be powering next door and the electricity company cream profits from your output with zero effort.
Also by giving a fairer export price to domestic users it will also help prevent covering arable lands in panels
The whole system needs a shake up..

I think the system is being shaken up.

It's unfair to dismiss the costs of providing a grid, metering and billing services etc as 'zero effort'.
All that infrastructure costs real money.

[Evoluzione]

HarryW said:

I recently looked into this and dismissed it as the 10+ years to break even.
If the government are truly interested in going green then the Export tariff needs to be linked to the price of units paid by the customers.
Effectively on a sunny day your solar could be powering next door and the electricity company cream profits from your output with zero effort.
Also by giving a fairer export price to domestic users it will also help prevent covering arable lands in panels
The whole system needs a shake up..

You're forgetting that it's not only the private houses which make an excess in Summer, but all the solar farms do aswell.
If we carry on as per your plan we'll end up with far too much in Summer.
The answer is to make more in Winter, either by covering the whole country with solar panels or creating more with wind and water.

I wonder how much solar power we would need to power the whole country in Winter?
Or taking the above into account, how much investment is needed to go totally renewable in Winter?

[AW10]

dmsims said:

Also you have to factor in that you can still get cheap off peak tariffs for an EV so a more realistic calculation is in order

I think there could be a second set of calculations using a smaller PV system and relaying more on off peak charging. In some ways these calculations might be more reliable as one of the bigger assumptions (the existence of cheap off-peak charging) is a more robust bet than PV based EV charging impacted by the weather/season and EV useage variations.

[OutInTheShed]

AW10 said:

I think there could be a second set of calculations using a smaller PV system and relaying more on off peak charging. In some ways these calculations might be more reliable as one of the bigger assumptions (the existence of cheap off-peak charging) is a more robust bet than PV based EV charging impacted by the weather/season and EV useage variations.

I don't think I'd bet on cheap off peak staying in its current form for very long.

The writing is very much on the wall with Octopus moving into 'demand management' and all the smart grid stuff we were talking about 15 years ago.

We can see where it's going I'm sure, but when it will get there is a harder question.

[AW10]

Evoluzione said:

You're forgetting that it's not only the private houses which make an excess in Summer, but all the solar farms do aswell.
If we carry on as per your plan we'll end up with far too much in Summer.
The answer is to make more in Winter, either by covering the whole country with solar panels or creating more with wind and water.

I wonder how much solar power we would need to power the whole country in Winter?
Or taking the above into account, how much investment is needed to go totally renewable in Winter?

Before TSHTF in Ukraine Germany had so much excess solar and wind generated electricity on some summer days that the wholesale price of electricity went negative during the day. No idea if that was still the case this past summer.

I think diversity of supply is the answer. Solar, hydro, wind, possibly wave, nuclear and the burning of something or another. PV solar generation in the winter is v low. And can't help but wonder if some degree of fossil fuel based generation will be part of the long term answer as a flexible and cost effective way of smoothing out the peaks and troughs.