Are solar panels pointless?

jamesmorgan

Hexane said:

jamesmorgan said:

Hexane said:

jamesmorgan said:

In the same way as early energy saving lightbulbs were sold on the basis of extremely long lives, in real world conditions many turned out not to last as long as was originally assumed.  

wait what? I bought a bunch of early energy saving lightbulbs about 20 years ago, most of them are still occupying spots in less-used rooms (frequently used rooms now have LED instead).

as for "too early to know", you do realise that many solar PV systems owned by people on this forum have been in use for more than ten years? Do you imagine that they will suddenly start exploding once they reach 15 years old, like human teenagers?

jamesmorgan said:

If I had a spare £5-10K sitting around and wanted to invest it for optimum payback, solar panels wouldn't be very close to the top of the list. 

Really??? I have a large sum in global multi-asset funds through an ISA, and even larger sums in pension schemes that mainly invest in things like the FTSE100, but the only reason I wouldn't have invested more money in solar panels on my roof, is that my roof is only so big and I would eventually run into official opposition as the installed power passed 10kWp. Your investment priorities seem out of whack.

jamesmorgan said:

My broad thoughts are that energy generation is much better when economies of scale are used to drive efficiency.  Solar farms are a much better long term option than the cottage industry of having a generator on everyone's house.

That's exactly why I bought solar panels when I could buy 315W panels cheaply, instead of similar-sized 200W panels for a lot more. Unfortunately for me - fortunately for some others - the government took the opposite view and subsidised people who bought the 200W panels. Still a topic for merry debates to this day, but both sets of people made the right decision.

You can buy a share in a solar farm if you want to. But you might be better off signing up to Ripple Energy.

Understanding failure rates of systems is a complex area.

Thank you for pointing that out. It's good that we have someone with your level of insight and expertise to explain it to us.

Hexane said:

jamesmorgan said:

In the same way as early energy saving lightbulbs were sold on the basis of extremely long lives, in real world conditions many turned out not to last as long as was originally assumed.  

wait what? I bought a bunch of early energy saving lightbulbs about 20 years ago, most of them are still occupying spots in less-used rooms (frequently used rooms now have LED instead).

as for "too early to know", you do realise that many solar PV systems owned by people on this forum have been in use for more than ten years? Do you imagine that they will suddenly start exploding once they reach 15 years old, like human teenagers?

jamesmorgan said:

If I had a spare £5-10K sitting around and wanted to invest it for optimum payback, solar panels wouldn't be very close to the top of the list. 

Really??? I have a large sum in global multi-asset funds through an ISA, and even larger sums in pension schemes that mainly invest in things like the FTSE100, but the only reason I wouldn't have invested more money in solar panels on my roof, is that my roof is only so big and I would eventually run into official opposition as the installed power passed 10kWp. Your investment priorities seem out of whack.

jamesmorgan said:

My broad thoughts are that energy generation is much better when economies of scale are used to drive efficiency.  Solar farms are a much better long term option than the cottage industry of having a generator on everyone's house.

That's exactly why I bought solar panels when I could buy 315W panels cheaply, instead of similar-sized 200W panels for a lot more. Unfortunately for me - fortunately for some others - the government took the opposite view and subsidised people who bought the 200W panels. Still a topic for merry debates to this day, but both sets of people made the right decision.

You can buy a share in a solar farm if you want to. But you might be better off signing up to Ripple Energy.

Trusting sources with a vested interest (eg suppliers) for expected lifespans of their products can be dangerous. 

That's true, but not relevant to anything that I said, because I did not recommend doing so.

Your "too early to really know" assumption is equally dangerous, solar panels have been around a long time and there is a wealth of data which shows that in general panel performance holds up better than originally predicted. Panels now routinely come with 20 or 25 year warranties for output.

The person who started this thread began with the unsourced and bizarrely worded claim "Apparently it can take a minimum of 14 years to break even" (either that's a minimum or it can take that long, do you see the problem with the wording?) and then followed that with "do they even last that long?" The answer of course is yes they do, and to even ask something so basic in such a skewed way, leads to wondering about the motivation for the post. A post which you then jumped on with information about LED light bulb failure rates and an old article from 2014.

It should be obvious why an article from 2014 is worse than useless for answering "are solar panels pointless" in 2022, but if not then just compare the price you were paying per kWh of electricity in 2014 (or 2013 if that's when the data for that article was collected) with the price you will be paying per kWh of electricity in October 2022.

Things change fast, and people on this forum are well aware of the different variables involved. No, payback time in years is not the only variable, that's just the end result that people (like the OP) tend to grab some figure from some source of greater or lesser reliability, and then tout it as "the answer" as to whether solar panels are worth it or not. Without understanding how that figure was arrived at or why the calculations might have changed in the last six months (never mind the last eight years).

So on this forum people are aware of the removal of FiT payments and the introduction of SEG payments. They're aware of the controversially high FiT payment rates for early adopters (many of which agreements are still in place to this day), and of the benefits of FiT payment rates being inflation-linked in an era of suddenly sky high inflation. They're aware of the possibility of receiving much higher rates than the common SEG ones by signing up to hourly export tariffs with Octopus (this is not pie in the sky, some people are already doing it), and in the more distant future possibilities like vehicle to grid and vehicle to home. Already in use are contracts where an energy supplier pays to be able to use your home battery for grid stabilisation, again discussed in detail on this forum although generally not well received.

And then there's also the possibility of high energy usage customers such as EV owners using preferential overnight rates to charge their cars and therefore in theory making less savings from solar panels. But conversely, the possibility of using solar diverters to displace gas (or other) heating. And the effects on the financial benefits of this caused by whether export payments are made based on deemed export or metered export. Again, all of this discussed in detail in this forum.

And then we have the sky-high prices of solar panel installations right now compared to five years ago, and we have the knowledge that solar panels generally last far longer than predicted but inverters do not.

And then there's the actual practicalities of how much of the generated power you're actually using, what proportion of that is really a saving, and how to maximise that. Which is very much something you learn by actually doing it, not by saying "the industry standard is to estimate 50%" and then plugging that into a spreadsheet and producing a "payback time in years is X" answer.

All of that is before we even get started on home batteries, with or without islanding capability, with or without special hourly import rates designed for them, and what their current cost is today or six months from now. And whether the electrification of heating and transport, and the need for air conditioning as the climate warms, means that household energy demands will be so much higher in future.

So there are a lot of variables, not just some payback-in-years number that someone came up with in 2014 based on a finger-in-the-air quote for a "typically sized system". (For example - I paid much less per kWp installed capacity by installing a larger system.)

Many people on this forum are making solar panels "work for them", some of them in fact appear to be making colossal profits due to being early adopters. Some of those people are re-investing those profits in things like home battery systems which might not have a worthwhile ROI, but they find it interesting (or ethical) to try. There's one regular poster here who began a couple of years ago by wondering if an 8 year ROI was possible for a solar panel install, I believe we told him that it wasn't possible. His initial data after the install suggested that we were right, but now that energy prices have gone through the roof, that might not be the case any more.

"do they even last that long" and "can take up to a minimum of" and "too early to really know" is the dangerous and misleading thinking.

When is the best time to plant a fruit tree? 20 years ago. When is the second best time to plant a fruit tree? Today.

Similar applies to solar panels, the best time to buy them was just over ten years ago because of the huge profits from FiT ... the second best time to buy solar panels is still today. (Although, given the lateness of the hour, you could probably wait till Monday.)

A rather long and unnecessarily blinkered response - although perhaps for understandable reasons.    I suggest you do a little research on confirmation bias.  The OP was not asking whether it made sense 10 years ago to install solar panels, or indeed whether some people can make the numbers work for them today.  He was asking does it make sense for the average person today to install them.

The answer is it is complex and you need to do extensive research involving data from lots of different sources.  If once doing this research the payback period is greated than 10 years, then it is likely that greater invesment returns can be obtained from other sources.

One of the key issues as an investor in solar panels (rather than somone who installs solar panels for ethical/security reasons) is that once the investment is made you cannot back out of it.  As such is it very tempting to only read materials that support your initial decision and to discount any data source that seem to suggest that solar panel investment is becoming more marginal.

Of greater interest is not whether the 3% of people who have installed solar panels think that it is a good investment, but why the 97% of people who haven't, continue to think that is the best decision for them.

2nd_time_buyer

jamesmorgan said:

Hexane said:

jamesmorgan said:

Hexane said:

jamesmorgan said:

In the same way as early energy saving lightbulbs were sold on the basis of extremely long lives, in real world conditions many turned out not to last as long as was originally assumed.  

wait what? I bought a bunch of early energy saving lightbulbs about 20 years ago, most of them are still occupying spots in less-used rooms (frequently used rooms now have LED instead).

as for "too early to know", you do realise that many solar PV systems owned by people on this forum have been in use for more than ten years? Do you imagine that they will suddenly start exploding once they reach 15 years old, like human teenagers?

jamesmorgan said:

If I had a spare £5-10K sitting around and wanted to invest it for optimum payback, solar panels wouldn't be very close to the top of the list. 

Really??? I have a large sum in global multi-asset funds through an ISA, and even larger sums in pension schemes that mainly invest in things like the FTSE100, but the only reason I wouldn't have invested more money in solar panels on my roof, is that my roof is only so big and I would eventually run into official opposition as the installed power passed 10kWp. Your investment priorities seem out of whack.

jamesmorgan said:

My broad thoughts are that energy generation is much better when economies of scale are used to drive efficiency.  Solar farms are a much better long term option than the cottage industry of having a generator on everyone's house.

That's exactly why I bought solar panels when I could buy 315W panels cheaply, instead of similar-sized 200W panels for a lot more. Unfortunately for me - fortunately for some others - the government took the opposite view and subsidised people who bought the 200W panels. Still a topic for merry debates to this day, but both sets of people made the right decision.

You can buy a share in a solar farm if you want to. But you might be better off signing up to Ripple Energy.

Understanding failure rates of systems is a complex area.

Thank you for pointing that out. It's good that we have someone with your level of insight and expertise to explain it to us.

Hexane said:

jamesmorgan said:

In the same way as early energy saving lightbulbs were sold on the basis of extremely long lives, in real world conditions many turned out not to last as long as was originally assumed.  

wait what? I bought a bunch of early energy saving lightbulbs about 20 years ago, most of them are still occupying spots in less-used rooms (frequently used rooms now have LED instead).

as for "too early to know", you do realise that many solar PV systems owned by people on this forum have been in use for more than ten years? Do you imagine that they will suddenly start exploding once they reach 15 years old, like human teenagers?

jamesmorgan said:

If I had a spare £5-10K sitting around and wanted to invest it for optimum payback, solar panels wouldn't be very close to the top of the list. 

Really??? I have a large sum in global multi-asset funds through an ISA, and even larger sums in pension schemes that mainly invest in things like the FTSE100, but the only reason I wouldn't have invested more money in solar panels on my roof, is that my roof is only so big and I would eventually run into official opposition as the installed power passed 10kWp. Your investment priorities seem out of whack.

jamesmorgan said:

My broad thoughts are that energy generation is much better when economies of scale are used to drive efficiency.  Solar farms are a much better long term option than the cottage industry of having a generator on everyone's house.

That's exactly why I bought solar panels when I could buy 315W panels cheaply, instead of similar-sized 200W panels for a lot more. Unfortunately for me - fortunately for some others - the government took the opposite view and subsidised people who bought the 200W panels. Still a topic for merry debates to this day, but both sets of people made the right decision.

You can buy a share in a solar farm if you want to. But you might be better off signing up to Ripple Energy.

Trusting sources with a vested interest (eg suppliers) for expected lifespans of their products can be dangerous. 

That's true, but not relevant to anything that I said, because I did not recommend doing so.

Your "too early to really know" assumption is equally dangerous, solar panels have been around a long time and there is a wealth of data which shows that in general panel performance holds up better than originally predicted. Panels now routinely come with 20 or 25 year warranties for output.

The person who started this thread began with the unsourced and bizarrely worded claim "Apparently it can take a minimum of 14 years to break even" (either that's a minimum or it can take that long, do you see the problem with the wording?) and then followed that with "do they even last that long?" The answer of course is yes they do, and to even ask something so basic in such a skewed way, leads to wondering about the motivation for the post. A post which you then jumped on with information about LED light bulb failure rates and an old article from 2014.

It should be obvious why an article from 2014 is worse than useless for answering "are solar panels pointless" in 2022, but if not then just compare the price you were paying per kWh of electricity in 2014 (or 2013 if that's when the data for that article was collected) with the price you will be paying per kWh of electricity in October 2022.

Things change fast, and people on this forum are well aware of the different variables involved. No, payback time in years is not the only variable, that's just the end result that people (like the OP) tend to grab some figure from some source of greater or lesser reliability, and then tout it as "the answer" as to whether solar panels are worth it or not. Without understanding how that figure was arrived at or why the calculations might have changed in the last six months (never mind the last eight years).

So on this forum people are aware of the removal of FiT payments and the introduction of SEG payments. They're aware of the controversially high FiT payment rates for early adopters (many of which agreements are still in place to this day), and of the benefits of FiT payment rates being inflation-linked in an era of suddenly sky high inflation. They're aware of the possibility of receiving much higher rates than the common SEG ones by signing up to hourly export tariffs with Octopus (this is not pie in the sky, some people are already doing it), and in the more distant future possibilities like vehicle to grid and vehicle to home. Already in use are contracts where an energy supplier pays to be able to use your home battery for grid stabilisation, again discussed in detail on this forum although generally not well received.

And then there's also the possibility of high energy usage customers such as EV owners using preferential overnight rates to charge their cars and therefore in theory making less savings from solar panels. But conversely, the possibility of using solar diverters to displace gas (or other) heating. And the effects on the financial benefits of this caused by whether export payments are made based on deemed export or metered export. Again, all of this discussed in detail in this forum.

And then we have the sky-high prices of solar panel installations right now compared to five years ago, and we have the knowledge that solar panels generally last far longer than predicted but inverters do not.

And then there's the actual practicalities of how much of the generated power you're actually using, what proportion of that is really a saving, and how to maximise that. Which is very much something you learn by actually doing it, not by saying "the industry standard is to estimate 50%" and then plugging that into a spreadsheet and producing a "payback time in years is X" answer.

All of that is before we even get started on home batteries, with or without islanding capability, with or without special hourly import rates designed for them, and what their current cost is today or six months from now. And whether the electrification of heating and transport, and the need for air conditioning as the climate warms, means that household energy demands will be so much higher in future.

So there are a lot of variables, not just some payback-in-years number that someone came up with in 2014 based on a finger-in-the-air quote for a "typically sized system". (For example - I paid much less per kWp installed capacity by installing a larger system.)

Many people on this forum are making solar panels "work for them", some of them in fact appear to be making colossal profits due to being early adopters. Some of those people are re-investing those profits in things like home battery systems which might not have a worthwhile ROI, but they find it interesting (or ethical) to try. There's one regular poster here who began a couple of years ago by wondering if an 8 year ROI was possible for a solar panel install, I believe we told him that it wasn't possible. His initial data after the install suggested that we were right, but now that energy prices have gone through the roof, that might not be the case any more.

"do they even last that long" and "can take up to a minimum of" and "too early to really know" is the dangerous and misleading thinking.

When is the best time to plant a fruit tree? 20 years ago. When is the second best time to plant a fruit tree? Today.

Similar applies to solar panels, the best time to buy them was just over ten years ago because of the huge profits from FiT ... the second best time to buy solar panels is still today. (Although, given the lateness of the hour, you could probably wait till Monday.)

A rather long and unnecessarily blinkered response - although perhaps for understandable reasons.    I suggest you do a little research on confirmation bias.  The OP was not asking whether it made sense 10 years ago to install solar panels, or indeed whether some people can make the numbers work for them today.  He was asking does it make sense for the average person today to install them.

The answer is it is complex and you need to do extensive research involving data from lots of different sources.  If once doing this research the payback period is greated than 10 years, then it is likely that greater invesment returns can be obtained from other sources.

One of the key issues as an investor in solar panels (rather than somone who installs solar panels for ethical/security reasons) is that once the investment is made you cannot back out of it.  As such is it very tempting to only read materials that support your initial decision and to discount any data source that seem to suggest that solar panel investment is becoming more marginal.

Of greater interest is not whether the 3% of people who have installed solar panels think that it is a good investment, but why the 97% of people who haven't, continue to think that is the best decision for them.

My assertion is that for most people in the country with a roof(s) facing somewhere between SE and SW* which can fit at least 8 panels, then solar panels, in the current market, can be a very sound investment, which would stack up very favourably against most conventional investments.

As I said previously, I would be happy to model an installation and see how it would stack up for you. Just to be clear I have no vested interest other than intrigue. 

*and probably even East and West)

silverwhistle

The OP was not asking whether it made sense 10 years ago to install solar panels, or indeed whether some people can make the numbers work for them today.

Indeed they were, so why did you quote and suggest out of date information which rather showed you don't really know that much about it, and embarassingly for you people here can see that. Blustering "confirmation bias" really won't do.

As for the investment angle, there are plenty of other illiquid investments around, whether financial instruments or more physical assets like property. The current return on panels is very real, and a significant proportion of that 97% without, those with the means of course, are reconsidering their position.

If you'd spent very much time on here you'd have seen plenty of concrete and realistic advice given, none of it from people with any vested financial interest. 

Martyn1981

jamesmorgan said:

Hexane said:

jamesmorgan said:

Hexane said:

jamesmorgan said:

In the same way as early energy saving lightbulbs were sold on the basis of extremely long lives, in real world conditions many turned out not to last as long as was originally assumed.  

wait what? I bought a bunch of early energy saving lightbulbs about 20 years ago, most of them are still occupying spots in less-used rooms (frequently used rooms now have LED instead).

as for "too early to know", you do realise that many solar PV systems owned by people on this forum have been in use for more than ten years? Do you imagine that they will suddenly start exploding once they reach 15 years old, like human teenagers?

jamesmorgan said:

If I had a spare £5-10K sitting around and wanted to invest it for optimum payback, solar panels wouldn't be very close to the top of the list. 

Really??? I have a large sum in global multi-asset funds through an ISA, and even larger sums in pension schemes that mainly invest in things like the FTSE100, but the only reason I wouldn't have invested more money in solar panels on my roof, is that my roof is only so big and I would eventually run into official opposition as the installed power passed 10kWp. Your investment priorities seem out of whack.

jamesmorgan said:

My broad thoughts are that energy generation is much better when economies of scale are used to drive efficiency.  Solar farms are a much better long term option than the cottage industry of having a generator on everyone's house.

That's exactly why I bought solar panels when I could buy 315W panels cheaply, instead of similar-sized 200W panels for a lot more. Unfortunately for me - fortunately for some others - the government took the opposite view and subsidised people who bought the 200W panels. Still a topic for merry debates to this day, but both sets of people made the right decision.

You can buy a share in a solar farm if you want to. But you might be better off signing up to Ripple Energy.

Understanding failure rates of systems is a complex area.

Thank you for pointing that out. It's good that we have someone with your level of insight and expertise to explain it to us.

Hexane said:

jamesmorgan said:

In the same way as early energy saving lightbulbs were sold on the basis of extremely long lives, in real world conditions many turned out not to last as long as was originally assumed.  

wait what? I bought a bunch of early energy saving lightbulbs about 20 years ago, most of them are still occupying spots in less-used rooms (frequently used rooms now have LED instead).

as for "too early to know", you do realise that many solar PV systems owned by people on this forum have been in use for more than ten years? Do you imagine that they will suddenly start exploding once they reach 15 years old, like human teenagers?

jamesmorgan said:

If I had a spare £5-10K sitting around and wanted to invest it for optimum payback, solar panels wouldn't be very close to the top of the list. 

Really??? I have a large sum in global multi-asset funds through an ISA, and even larger sums in pension schemes that mainly invest in things like the FTSE100, but the only reason I wouldn't have invested more money in solar panels on my roof, is that my roof is only so big and I would eventually run into official opposition as the installed power passed 10kWp. Your investment priorities seem out of whack.

jamesmorgan said:

My broad thoughts are that energy generation is much better when economies of scale are used to drive efficiency.  Solar farms are a much better long term option than the cottage industry of having a generator on everyone's house.

That's exactly why I bought solar panels when I could buy 315W panels cheaply, instead of similar-sized 200W panels for a lot more. Unfortunately for me - fortunately for some others - the government took the opposite view and subsidised people who bought the 200W panels. Still a topic for merry debates to this day, but both sets of people made the right decision.

You can buy a share in a solar farm if you want to. But you might be better off signing up to Ripple Energy.

Trusting sources with a vested interest (eg suppliers) for expected lifespans of their products can be dangerous. 

That's true, but not relevant to anything that I said, because I did not recommend doing so.

Your "too early to really know" assumption is equally dangerous, solar panels have been around a long time and there is a wealth of data which shows that in general panel performance holds up better than originally predicted. Panels now routinely come with 20 or 25 year warranties for output.

The person who started this thread began with the unsourced and bizarrely worded claim "Apparently it can take a minimum of 14 years to break even" (either that's a minimum or it can take that long, do you see the problem with the wording?) and then followed that with "do they even last that long?" The answer of course is yes they do, and to even ask something so basic in such a skewed way, leads to wondering about the motivation for the post. A post which you then jumped on with information about LED light bulb failure rates and an old article from 2014.

It should be obvious why an article from 2014 is worse than useless for answering "are solar panels pointless" in 2022, but if not then just compare the price you were paying per kWh of electricity in 2014 (or 2013 if that's when the data for that article was collected) with the price you will be paying per kWh of electricity in October 2022.

Things change fast, and people on this forum are well aware of the different variables involved. No, payback time in years is not the only variable, that's just the end result that people (like the OP) tend to grab some figure from some source of greater or lesser reliability, and then tout it as "the answer" as to whether solar panels are worth it or not. Without understanding how that figure was arrived at or why the calculations might have changed in the last six months (never mind the last eight years).

So on this forum people are aware of the removal of FiT payments and the introduction of SEG payments. They're aware of the controversially high FiT payment rates for early adopters (many of which agreements are still in place to this day), and of the benefits of FiT payment rates being inflation-linked in an era of suddenly sky high inflation. They're aware of the possibility of receiving much higher rates than the common SEG ones by signing up to hourly export tariffs with Octopus (this is not pie in the sky, some people are already doing it), and in the more distant future possibilities like vehicle to grid and vehicle to home. Already in use are contracts where an energy supplier pays to be able to use your home battery for grid stabilisation, again discussed in detail on this forum although generally not well received.

And then there's also the possibility of high energy usage customers such as EV owners using preferential overnight rates to charge their cars and therefore in theory making less savings from solar panels. But conversely, the possibility of using solar diverters to displace gas (or other) heating. And the effects on the financial benefits of this caused by whether export payments are made based on deemed export or metered export. Again, all of this discussed in detail in this forum.

And then we have the sky-high prices of solar panel installations right now compared to five years ago, and we have the knowledge that solar panels generally last far longer than predicted but inverters do not.

And then there's the actual practicalities of how much of the generated power you're actually using, what proportion of that is really a saving, and how to maximise that. Which is very much something you learn by actually doing it, not by saying "the industry standard is to estimate 50%" and then plugging that into a spreadsheet and producing a "payback time in years is X" answer.

All of that is before we even get started on home batteries, with or without islanding capability, with or without special hourly import rates designed for them, and what their current cost is today or six months from now. And whether the electrification of heating and transport, and the need for air conditioning as the climate warms, means that household energy demands will be so much higher in future.

So there are a lot of variables, not just some payback-in-years number that someone came up with in 2014 based on a finger-in-the-air quote for a "typically sized system". (For example - I paid much less per kWp installed capacity by installing a larger system.)

Many people on this forum are making solar panels "work for them", some of them in fact appear to be making colossal profits due to being early adopters. Some of those people are re-investing those profits in things like home battery systems which might not have a worthwhile ROI, but they find it interesting (or ethical) to try. There's one regular poster here who began a couple of years ago by wondering if an 8 year ROI was possible for a solar panel install, I believe we told him that it wasn't possible. His initial data after the install suggested that we were right, but now that energy prices have gone through the roof, that might not be the case any more.

"do they even last that long" and "can take up to a minimum of" and "too early to really know" is the dangerous and misleading thinking.

When is the best time to plant a fruit tree? 20 years ago. When is the second best time to plant a fruit tree? Today.

Similar applies to solar panels, the best time to buy them was just over ten years ago because of the huge profits from FiT ... the second best time to buy solar panels is still today. (Although, given the lateness of the hour, you could probably wait till Monday.)

A rather long and unnecessarily blinkered response - although perhaps for understandable reasons.    I suggest you do a little research on confirmation bias.  The OP was not asking whether it made sense 10 years ago to install solar panels, or indeed whether some people can make the numbers work for them today.  He was asking does it make sense for the average person today to install them.

The answer is it is complex and you need to do extensive research involving data from lots of different sources.  If once doing this research the payback period is greated than 10 years, then it is likely that greater invesment returns can be obtained from other sources.

One of the key issues as an investor in solar panels (rather than somone who installs solar panels for ethical/security reasons) is that once the investment is made you cannot back out of it.  As such is it very tempting to only read materials that support your initial decision and to discount any data source that seem to suggest that solar panel investment is becoming more marginal.

Of greater interest is not whether the 3% of people who have installed solar panels think that it is a good investment, but why the 97% of people who haven't, continue to think that is the best decision for them.

How is the response blinkered. I thought Hexane took extraordinary care to stress over and over (throughout) that there are many variables that need to be considered. That would seem to be the exact opposite of blinkered.

If you are interested in getting PV, then ask away on here, there are loads of folk who give you advice, including telling you outright that PV won't work for you, if that's the case.

Personally, (and keep this between you and me), now might not be the best time to get PV as there's a rush on, and all sorts of global issues, especially regarding transport costs, so things are pretty crazy. It might be that it only gets worse in the short term, but hopefully things will settle down in a year or two, and component costs will fall again.

For your information, my sister got a 10.3kWp system installed last Autumn for ~£8k, but she did already have scaffolding in place. Now, less than a year later, busy solar firms seem to be pricing far smaller installs for almost as much.

jamesmorgan

Martyn1981 said:

jamesmorgan said:

Hexane said:

jamesmorgan said:

Hexane said:

jamesmorgan said:

In the same way as early energy saving lightbulbs were sold on the basis of extremely long lives, in real world conditions many turned out not to last as long as was originally assumed.  

wait what? I bought a bunch of early energy saving lightbulbs about 20 years ago, most of them are still occupying spots in less-used rooms (frequently used rooms now have LED instead).

as for "too early to know", you do realise that many solar PV systems owned by people on this forum have been in use for more than ten years? Do you imagine that they will suddenly start exploding once they reach 15 years old, like human teenagers?

jamesmorgan said:

If I had a spare £5-10K sitting around and wanted to invest it for optimum payback, solar panels wouldn't be very close to the top of the list. 

Really??? I have a large sum in global multi-asset funds through an ISA, and even larger sums in pension schemes that mainly invest in things like the FTSE100, but the only reason I wouldn't have invested more money in solar panels on my roof, is that my roof is only so big and I would eventually run into official opposition as the installed power passed 10kWp. Your investment priorities seem out of whack.

jamesmorgan said:

My broad thoughts are that energy generation is much better when economies of scale are used to drive efficiency.  Solar farms are a much better long term option than the cottage industry of having a generator on everyone's house.

That's exactly why I bought solar panels when I could buy 315W panels cheaply, instead of similar-sized 200W panels for a lot more. Unfortunately for me - fortunately for some others - the government took the opposite view and subsidised people who bought the 200W panels. Still a topic for merry debates to this day, but both sets of people made the right decision.

You can buy a share in a solar farm if you want to. But you might be better off signing up to Ripple Energy.

Understanding failure rates of systems is a complex area.

Thank you for pointing that out. It's good that we have someone with your level of insight and expertise to explain it to us.

Hexane said:

jamesmorgan said:

In the same way as early energy saving lightbulbs were sold on the basis of extremely long lives, in real world conditions many turned out not to last as long as was originally assumed.  

wait what? I bought a bunch of early energy saving lightbulbs about 20 years ago, most of them are still occupying spots in less-used rooms (frequently used rooms now have LED instead).

as for "too early to know", you do realise that many solar PV systems owned by people on this forum have been in use for more than ten years? Do you imagine that they will suddenly start exploding once they reach 15 years old, like human teenagers?

jamesmorgan said:

If I had a spare £5-10K sitting around and wanted to invest it for optimum payback, solar panels wouldn't be very close to the top of the list. 

Really??? I have a large sum in global multi-asset funds through an ISA, and even larger sums in pension schemes that mainly invest in things like the FTSE100, but the only reason I wouldn't have invested more money in solar panels on my roof, is that my roof is only so big and I would eventually run into official opposition as the installed power passed 10kWp. Your investment priorities seem out of whack.

jamesmorgan said:

My broad thoughts are that energy generation is much better when economies of scale are used to drive efficiency.  Solar farms are a much better long term option than the cottage industry of having a generator on everyone's house.

That's exactly why I bought solar panels when I could buy 315W panels cheaply, instead of similar-sized 200W panels for a lot more. Unfortunately for me - fortunately for some others - the government took the opposite view and subsidised people who bought the 200W panels. Still a topic for merry debates to this day, but both sets of people made the right decision.

You can buy a share in a solar farm if you want to. But you might be better off signing up to Ripple Energy.

Trusting sources with a vested interest (eg suppliers) for expected lifespans of their products can be dangerous. 

That's true, but not relevant to anything that I said, because I did not recommend doing so.

Your "too early to really know" assumption is equally dangerous, solar panels have been around a long time and there is a wealth of data which shows that in general panel performance holds up better than originally predicted. Panels now routinely come with 20 or 25 year warranties for output.

The person who started this thread began with the unsourced and bizarrely worded claim "Apparently it can take a minimum of 14 years to break even" (either that's a minimum or it can take that long, do you see the problem with the wording?) and then followed that with "do they even last that long?" The answer of course is yes they do, and to even ask something so basic in such a skewed way, leads to wondering about the motivation for the post. A post which you then jumped on with information about LED light bulb failure rates and an old article from 2014.

It should be obvious why an article from 2014 is worse than useless for answering "are solar panels pointless" in 2022, but if not then just compare the price you were paying per kWh of electricity in 2014 (or 2013 if that's when the data for that article was collected) with the price you will be paying per kWh of electricity in October 2022.

Things change fast, and people on this forum are well aware of the different variables involved. No, payback time in years is not the only variable, that's just the end result that people (like the OP) tend to grab some figure from some source of greater or lesser reliability, and then tout it as "the answer" as to whether solar panels are worth it or not. Without understanding how that figure was arrived at or why the calculations might have changed in the last six months (never mind the last eight years).

So on this forum people are aware of the removal of FiT payments and the introduction of SEG payments. They're aware of the controversially high FiT payment rates for early adopters (many of which agreements are still in place to this day), and of the benefits of FiT payment rates being inflation-linked in an era of suddenly sky high inflation. They're aware of the possibility of receiving much higher rates than the common SEG ones by signing up to hourly export tariffs with Octopus (this is not pie in the sky, some people are already doing it), and in the more distant future possibilities like vehicle to grid and vehicle to home. Already in use are contracts where an energy supplier pays to be able to use your home battery for grid stabilisation, again discussed in detail on this forum although generally not well received.

And then there's also the possibility of high energy usage customers such as EV owners using preferential overnight rates to charge their cars and therefore in theory making less savings from solar panels. But conversely, the possibility of using solar diverters to displace gas (or other) heating. And the effects on the financial benefits of this caused by whether export payments are made based on deemed export or metered export. Again, all of this discussed in detail in this forum.

And then we have the sky-high prices of solar panel installations right now compared to five years ago, and we have the knowledge that solar panels generally last far longer than predicted but inverters do not.

And then there's the actual practicalities of how much of the generated power you're actually using, what proportion of that is really a saving, and how to maximise that. Which is very much something you learn by actually doing it, not by saying "the industry standard is to estimate 50%" and then plugging that into a spreadsheet and producing a "payback time in years is X" answer.

All of that is before we even get started on home batteries, with or without islanding capability, with or without special hourly import rates designed for them, and what their current cost is today or six months from now. And whether the electrification of heating and transport, and the need for air conditioning as the climate warms, means that household energy demands will be so much higher in future.

So there are a lot of variables, not just some payback-in-years number that someone came up with in 2014 based on a finger-in-the-air quote for a "typically sized system". (For example - I paid much less per kWp installed capacity by installing a larger system.)

Many people on this forum are making solar panels "work for them", some of them in fact appear to be making colossal profits due to being early adopters. Some of those people are re-investing those profits in things like home battery systems which might not have a worthwhile ROI, but they find it interesting (or ethical) to try. There's one regular poster here who began a couple of years ago by wondering if an 8 year ROI was possible for a solar panel install, I believe we told him that it wasn't possible. His initial data after the install suggested that we were right, but now that energy prices have gone through the roof, that might not be the case any more.

"do they even last that long" and "can take up to a minimum of" and "too early to really know" is the dangerous and misleading thinking.

When is the best time to plant a fruit tree? 20 years ago. When is the second best time to plant a fruit tree? Today.

Similar applies to solar panels, the best time to buy them was just over ten years ago because of the huge profits from FiT ... the second best time to buy solar panels is still today. (Although, given the lateness of the hour, you could probably wait till Monday.)

A rather long and unnecessarily blinkered response - although perhaps for understandable reasons.    I suggest you do a little research on confirmation bias.  The OP was not asking whether it made sense 10 years ago to install solar panels, or indeed whether some people can make the numbers work for them today.  He was asking does it make sense for the average person today to install them.

The answer is it is complex and you need to do extensive research involving data from lots of different sources.  If once doing this research the payback period is greated than 10 years, then it is likely that greater invesment returns can be obtained from other sources.

One of the key issues as an investor in solar panels (rather than somone who installs solar panels for ethical/security reasons) is that once the investment is made you cannot back out of it.  As such is it very tempting to only read materials that support your initial decision and to discount any data source that seem to suggest that solar panel investment is becoming more marginal.

Of greater interest is not whether the 3% of people who have installed solar panels think that it is a good investment, but why the 97% of people who haven't, continue to think that is the best decision for them.

How is the response blinkered. I thought Hexane took extraordinary care to stress over and over (throughout) that there are many variables that need to be considered. That would seem to be the exact opposite of blinkered.

If you are interested in getting PV, then ask away on here, there are loads of folk who give you advice, including telling you outright that PV won't work for you, if that's the case.

Personally, (and keep this between you and me), now might not be the best time to get PV as there's a rush on, and all sorts of global issues, especially regarding transport costs, so things are pretty crazy. It might be that it only gets worse in the short term, but hopefully things will settle down in a year or two, and component costs will fall again.

For your information, my sister got a 10.3kWp system installed last Autumn for ~£8k, but she did already have scaffolding in place. Now, less than a year later, busy solar firms seem to be pricing far smaller installs for almost as much.

It is blinkered because he immediately discounts any information from websites that don't fit into his world view.  I chose 2 webites at random to illustrate a point.  I could easily have chosen 10 others that say similar things.  It is very apparent that there is a very wide range of estimates for pay back periods from many organisations actively promoting solar panels.  This is an indication that it is a complex area and much depends on a variety of assumptions.  For this reason it is critical to obtain data from a wide range of sources and then aggregate the data before coming to a decision.  

I'm not considering PV at the moment.  I looked at them around 10 years ago.  The sums didn't work for me then (both at the time and with a retrospective analysis).  I have also looked recently and as you rightly say the sums look worse now.

I have no vested interest either way in this - although do suggest to anyone considering it that they look into it carefully and not get too swayed by anyone with a vested interest.

ABrass

jamesmorgan said:

Martyn1981 said:

jamesmorgan said:

Hexane said:

jamesmorgan said:

Hexane said:

jamesmorgan said:

In the same way as early energy saving lightbulbs were sold on the basis of extremely long lives, in real world conditions many turned out not to last as long as was originally assumed.  

wait what? I bought a bunch of early energy saving lightbulbs about 20 years ago, most of them are still occupying spots in less-used rooms (frequently used rooms now have LED instead).

as for "too early to know", you do realise that many solar PV systems owned by people on this forum have been in use for more than ten years? Do you imagine that they will suddenly start exploding once they reach 15 years old, like human teenagers?

jamesmorgan said:

If I had a spare £5-10K sitting around and wanted to invest it for optimum payback, solar panels wouldn't be very close to the top of the list. 

Really??? I have a large sum in global multi-asset funds through an ISA, and even larger sums in pension schemes that mainly invest in things like the FTSE100, but the only reason I wouldn't have invested more money in solar panels on my roof, is that my roof is only so big and I would eventually run into official opposition as the installed power passed 10kWp. Your investment priorities seem out of whack.

jamesmorgan said:

My broad thoughts are that energy generation is much better when economies of scale are used to drive efficiency.  Solar farms are a much better long term option than the cottage industry of having a generator on everyone's house.

That's exactly why I bought solar panels when I could buy 315W panels cheaply, instead of similar-sized 200W panels for a lot more. Unfortunately for me - fortunately for some others - the government took the opposite view and subsidised people who bought the 200W panels. Still a topic for merry debates to this day, but both sets of people made the right decision.

You can buy a share in a solar farm if you want to. But you might be better off signing up to Ripple Energy.

Understanding failure rates of systems is a complex area.

Thank you for pointing that out. It's good that we have someone with your level of insight and expertise to explain it to us.

Hexane said:

jamesmorgan said:

In the same way as early energy saving lightbulbs were sold on the basis of extremely long lives, in real world conditions many turned out not to last as long as was originally assumed.  

wait what? I bought a bunch of early energy saving lightbulbs about 20 years ago, most of them are still occupying spots in less-used rooms (frequently used rooms now have LED instead).

as for "too early to know", you do realise that many solar PV systems owned by people on this forum have been in use for more than ten years? Do you imagine that they will suddenly start exploding once they reach 15 years old, like human teenagers?

jamesmorgan said:

If I had a spare £5-10K sitting around and wanted to invest it for optimum payback, solar panels wouldn't be very close to the top of the list. 

Really??? I have a large sum in global multi-asset funds through an ISA, and even larger sums in pension schemes that mainly invest in things like the FTSE100, but the only reason I wouldn't have invested more money in solar panels on my roof, is that my roof is only so big and I would eventually run into official opposition as the installed power passed 10kWp. Your investment priorities seem out of whack.

jamesmorgan said:

My broad thoughts are that energy generation is much better when economies of scale are used to drive efficiency.  Solar farms are a much better long term option than the cottage industry of having a generator on everyone's house.

That's exactly why I bought solar panels when I could buy 315W panels cheaply, instead of similar-sized 200W panels for a lot more. Unfortunately for me - fortunately for some others - the government took the opposite view and subsidised people who bought the 200W panels. Still a topic for merry debates to this day, but both sets of people made the right decision.

You can buy a share in a solar farm if you want to. But you might be better off signing up to Ripple Energy.

Trusting sources with a vested interest (eg suppliers) for expected lifespans of their products can be dangerous. 

That's true, but not relevant to anything that I said, because I did not recommend doing so.

Your "too early to really know" assumption is equally dangerous, solar panels have been around a long time and there is a wealth of data which shows that in general panel performance holds up better than originally predicted. Panels now routinely come with 20 or 25 year warranties for output.

The person who started this thread began with the unsourced and bizarrely worded claim "Apparently it can take a minimum of 14 years to break even" (either that's a minimum or it can take that long, do you see the problem with the wording?) and then followed that with "do they even last that long?" The answer of course is yes they do, and to even ask something so basic in such a skewed way, leads to wondering about the motivation for the post. A post which you then jumped on with information about LED light bulb failure rates and an old article from 2014.

It should be obvious why an article from 2014 is worse than useless for answering "are solar panels pointless" in 2022, but if not then just compare the price you were paying per kWh of electricity in 2014 (or 2013 if that's when the data for that article was collected) with the price you will be paying per kWh of electricity in October 2022.

Things change fast, and people on this forum are well aware of the different variables involved. No, payback time in years is not the only variable, that's just the end result that people (like the OP) tend to grab some figure from some source of greater or lesser reliability, and then tout it as "the answer" as to whether solar panels are worth it or not. Without understanding how that figure was arrived at or why the calculations might have changed in the last six months (never mind the last eight years).

So on this forum people are aware of the removal of FiT payments and the introduction of SEG payments. They're aware of the controversially high FiT payment rates for early adopters (many of which agreements are still in place to this day), and of the benefits of FiT payment rates being inflation-linked in an era of suddenly sky high inflation. They're aware of the possibility of receiving much higher rates than the common SEG ones by signing up to hourly export tariffs with Octopus (this is not pie in the sky, some people are already doing it), and in the more distant future possibilities like vehicle to grid and vehicle to home. Already in use are contracts where an energy supplier pays to be able to use your home battery for grid stabilisation, again discussed in detail on this forum although generally not well received.

And then there's also the possibility of high energy usage customers such as EV owners using preferential overnight rates to charge their cars and therefore in theory making less savings from solar panels. But conversely, the possibility of using solar diverters to displace gas (or other) heating. And the effects on the financial benefits of this caused by whether export payments are made based on deemed export or metered export. Again, all of this discussed in detail in this forum.

And then we have the sky-high prices of solar panel installations right now compared to five years ago, and we have the knowledge that solar panels generally last far longer than predicted but inverters do not.

And then there's the actual practicalities of how much of the generated power you're actually using, what proportion of that is really a saving, and how to maximise that. Which is very much something you learn by actually doing it, not by saying "the industry standard is to estimate 50%" and then plugging that into a spreadsheet and producing a "payback time in years is X" answer.

All of that is before we even get started on home batteries, with or without islanding capability, with or without special hourly import rates designed for them, and what their current cost is today or six months from now. And whether the electrification of heating and transport, and the need for air conditioning as the climate warms, means that household energy demands will be so much higher in future.

So there are a lot of variables, not just some payback-in-years number that someone came up with in 2014 based on a finger-in-the-air quote for a "typically sized system". (For example - I paid much less per kWp installed capacity by installing a larger system.)

Many people on this forum are making solar panels "work for them", some of them in fact appear to be making colossal profits due to being early adopters. Some of those people are re-investing those profits in things like home battery systems which might not have a worthwhile ROI, but they find it interesting (or ethical) to try. There's one regular poster here who began a couple of years ago by wondering if an 8 year ROI was possible for a solar panel install, I believe we told him that it wasn't possible. His initial data after the install suggested that we were right, but now that energy prices have gone through the roof, that might not be the case any more.

"do they even last that long" and "can take up to a minimum of" and "too early to really know" is the dangerous and misleading thinking.

When is the best time to plant a fruit tree? 20 years ago. When is the second best time to plant a fruit tree? Today.

Similar applies to solar panels, the best time to buy them was just over ten years ago because of the huge profits from FiT ... the second best time to buy solar panels is still today. (Although, given the lateness of the hour, you could probably wait till Monday.)

A rather long and unnecessarily blinkered response - although perhaps for understandable reasons.    I suggest you do a little research on confirmation bias.  The OP was not asking whether it made sense 10 years ago to install solar panels, or indeed whether some people can make the numbers work for them today.  He was asking does it make sense for the average person today to install them.

The answer is it is complex and you need to do extensive research involving data from lots of different sources.  If once doing this research the payback period is greated than 10 years, then it is likely that greater invesment returns can be obtained from other sources.

One of the key issues as an investor in solar panels (rather than somone who installs solar panels for ethical/security reasons) is that once the investment is made you cannot back out of it.  As such is it very tempting to only read materials that support your initial decision and to discount any data source that seem to suggest that solar panel investment is becoming more marginal.

Of greater interest is not whether the 3% of people who have installed solar panels think that it is a good investment, but why the 97% of people who haven't, continue to think that is the best decision for them.

How is the response blinkered. I thought Hexane took extraordinary care to stress over and over (throughout) that there are many variables that need to be considered. That would seem to be the exact opposite of blinkered.

If you are interested in getting PV, then ask away on here, there are loads of folk who give you advice, including telling you outright that PV won't work for you, if that's the case.

Personally, (and keep this between you and me), now might not be the best time to get PV as there's a rush on, and all sorts of global issues, especially regarding transport costs, so things are pretty crazy. It might be that it only gets worse in the short term, but hopefully things will settle down in a year or two, and component costs will fall again.

For your information, my sister got a 10.3kWp system installed last Autumn for ~£8k, but she did already have scaffolding in place. Now, less than a year later, busy solar firms seem to be pricing far smaller installs for almost as much.

It is blinkered because he immediately discounts any information from websites that don't fit into his world view.  I chose 2 webites at random to illustrate a point.  I could easily have chosen 10 others that say similar things.  It is very apparent that there is a very wide range of estimates for pay back periods from many organisations actively promoting solar panels.  This is an indication that it is a complex area and much depends on a variety of assumptions.  For this reason it is critical to obtain data from a wide range of sources and then aggregate the data before coming to a decision.  

I'm not considering PV at the moment.  I looked at them around 10 years ago.  The sums didn't work for me then (both at the time and with a retrospective analysis).  I have also looked recently and as you rightly say the sums look worse now.

I have no vested interest either way in this - although do suggest to anyone considering it that they look into it carefully and not get too swayed by anyone with a vested interest.

Choose your websites.more carefully then. Because the numbers you linked to were rubbish. Even the same website didn't agree with them.

silverwhistle

jamesmorgan said:

  It is very apparent that there is a very wide range of estimates for pay back periods from many organisations actively promoting solar panels.  This is an indication that it is a complex area and much depends on a variety of assumptions.  For this reason it is critical to obtain data from a wide range of sources and then aggregate the data before coming to a decision. 

Please.. perhaps you don't appreciate exactly how patronising this sounds, but Hexane was pointing out the complexity and the number of variables for payback; with a background of personal experience, not as an organisation promoting solar panels.

Of course one needs to research these matters but,as ABrass has pointed out, you need to choose and assess your sources, as the ones you have selected "at random" as evidence for your views have flaws.

jamesmorgan

silverwhistle said:

jamesmorgan said:

  It is very apparent that there is a very wide range of estimates for pay back periods from many organisations actively promoting solar panels.  This is an indication that it is a complex area and much depends on a variety of assumptions.  For this reason it is critical to obtain data from a wide range of sources and then aggregate the data before coming to a decision. 

Please.. perhaps you don't appreciate exactly how patronising this sounds, but Hexane was pointing out the complexity and the number of variables for payback; with a background of personal experience, not as an organisation promoting solar panels.

Of course one needs to research these matters but,as ABrass has pointed out, you need to choose and assess your sources, as the ones you have selected "at random" as evidence for your views have flaws.

OK - last post on this as I suspect progressing further is not going to be very beneficial.  I've simply chosen the first 10 websites on suggested payback for solar panels in the UK.  Most of the sites suggested a payback of around 12-18 years with 10 years being the lowest from one website (but only for certain areas in east anglia). None of the sites indicated anything like the paybacks of well under 10 years that some people have been suggesting.

My point which I stick by is that anyone considering installed solar panels needs to take feedback from early adopters with a pinch of salt and do some proper research.  I'm not attempting to influence anyone who has already bought into the technology - you have already committed to the decision and it is what it is for you.

 https://www.renewableenergyhub.co.uk/main/solar-panels/return-on-investment-for-pv-return-on-investment-for-solar-panels-roi-for-pv-solar-panels-pay-back/
https://solartogether.co.uk/blog/how-long-until-solar-panels-pay-for-themselves
https://www.greenmatch.co.uk/blog/2014/06/solar-panels-are-they-worth-it
https://www.solarguide.co.uk/solar-panel-payback-time#/
https://www.moneysavingexpert.com/utilities/free-solar-panels/
https://uk.renogy.com/blog/what-is-the-average-payback-period-for-solar-panels-in-the-uk/
https://greenbusinesswatch.co.uk/uk-domestic-solar-panel-costs-and-returns-2019
https://blog.spiritenergy.co.uk/homeowner/solar-panel-payback
https://www.theweek.co.uk/business/personal-finance/956333/solar-panels-are-they-worth-the-investment
https://www.realhomes.com/advice/how-much-do-solar-panels-cost

Spies

When I was trying to justify the cost, I did my own research, I worked out what the panels would generate on both elevations by obtaining accurate data and feeding it into PVGIS, I then used a realistic estimate of how much of that generation I could use each month, it varies from 60% in the winter months to as little as 36% in the summer months, I then took that self use and offset it against what I would be paying for the electricity had I not been generating my own, that was multiplied by a 30p unit rate, any excess I was then multiplying by a modest 15p.

With all that data I came to the conclusion that it would take me roughly 7 years for the panels to pay for themselves.

Now in October the unit rates will obviously increase but similarly the price I get paid for export will also go up, so the payback period may be even less, it all depends how long energy prices remain high.

ed110220

jamesmorgan said:

silverwhistle said:

jamesmorgan said:

  It is very apparent that there is a very wide range of estimates for pay back periods from many organisations actively promoting solar panels.  This is an indication that it is a complex area and much depends on a variety of assumptions.  For this reason it is critical to obtain data from a wide range of sources and then aggregate the data before coming to a decision. 

Please.. perhaps you don't appreciate exactly how patronising this sounds, but Hexane was pointing out the complexity and the number of variables for payback; with a background of personal experience, not as an organisation promoting solar panels.

Of course one needs to research these matters but,as ABrass has pointed out, you need to choose and assess your sources, as the ones you have selected "at random" as evidence for your views have flaws.

OK - last post on this as I suspect progressing further is not going to be very beneficial.  I've simply chosen the first 10 websites on suggested payback for solar panels in the UK.  Most of the sites suggested a payback of around 12-18 years with 10 years being the lowest from one website (but only for certain areas in east anglia). None of the sites indicated anything like the paybacks of well under 10 years that some people have been suggesting.

My point which I stick by is that anyone considering installed solar panels needs to take feedback from early adopters with a pinch of salt and do some proper research.  I'm not attempting to influence anyone who has already bought into the technology - you have already committed to the decision and it is what it is for you.

 https://www.renewableenergyhub.co.uk/main/solar-panels/return-on-investment-for-pv-return-on-investment-for-solar-panels-roi-for-pv-solar-panels-pay-back/
https://solartogether.co.uk/blog/how-long-until-solar-panels-pay-for-themselves
https://www.greenmatch.co.uk/blog/2014/06/solar-panels-are-they-worth-it
https://www.solarguide.co.uk/solar-panel-payback-time#/
https://www.moneysavingexpert.com/utilities/free-solar-panels/
https://uk.renogy.com/blog/what-is-the-average-payback-period-for-solar-panels-in-the-uk/
https://greenbusinesswatch.co.uk/uk-domestic-solar-panel-costs-and-returns-2019
https://blog.spiritenergy.co.uk/homeowner/solar-panel-payback
https://www.theweek.co.uk/business/personal-finance/956333/solar-panels-are-they-worth-the-investment
https://www.realhomes.com/advice/how-much-do-solar-panels-cost

Sorry, taking the first 10 Google results is such a poor method as to be practically useless. You're really getting into garbage in - garbage out territory. One of them even has 2014 in the URL which is prehistoric in terms of electricity prices and not so much better for PV prices. I was paying about 11p/kWh until a few years ago. 

The only reasonably rigorous way to estimate savings will be with:-

a) Price of PV system (+ batteries if using)
b) Estimating generation, which is straightforward if you know the wattage of the proposed system, its location and bearing from south.
c) Your electricity consumption, during the day especially if not using batteries (more difficult without analysing smart meter data).
d) Your electricity cost

Taking estimates from random websites is going to be about as useful as a chocolate teapot, or worse horribly misleading.

For example I had a 4.8 kW system with 6.5 kWh of batteries installed for less than the price that one of those sites suggested was typical for just the PV. We don't use an unusual amount of electricity and have saved £120 in 49 days since install.