Solar panels

QrizB

Yes, that's basically correct.

Also, never talk to cold callers.

I think that same chances have called me now and again. They've got hold of a list of folk with solar panels and are trying to separate them from their money.

MeganByers

We installed ours March last year. Been paying £100 a month direct debit for gas and electric since installation and still £900 in credit now as we sold a lot back in summer so have dropped our payments to £25 a month from next month. Our direct debit before was £250 a month. Reckon they will pay for themselves in about 8 years. We have 11 panels and a 15kw battery. Cost was 14k installed. About 9k of that was batteries.

Telegraph_Sam

I suspect that it's vastly more economical to go for (11) panels from the start rather than upgrade mid term.  Similarly you have to be a relatively heavy consumer for the saving from investing in a (15 kW) battery to make sense IMHO. Re-assess as costs  (incl. tariffs on Chinese imports) come down.

doodling

Hi,

Solar power is limited by the surface area you have available on which to put panels (which in turn is, on average, proportional to the area of land that you own).  The angle is a secondary issue - you only need to care about it if you want to optimise the amount of power you get per panel but panels are sufficiently cheap that optimising the per panel output is usually a waste of time.

Telegraph_Sam

Hi
Bear in mind that my panels are 13 years old, bought at a time when prices were not what they are today (whilst labour is not either, but in the opposite direction).  Given the physical limitations (and I can remember getting  into very deep water in the solar forum over the technicalities) I would  indeed like to optimise the power per panel but which I am not convinced can be improved on short of starting from scratch. Or the power per the total installation. All along provided that it makes economic as well as technical sense.  If it is doable to add 2 - 4 panels, why then did the original installer with a green field to go on chose to specify only 8. I can no longer rely on the inverter having a limitless life either so need to mentally budget for shelling out for a replacement.
All told not a simple Q & A.
As an aside I have never properly cleaned them down since installation since I was assured that they were self-cleaning
PS Largish south facing bungalow located in the North East, rural location, reasonably clear of tree shadow for most of the day.

doodling

Hi,

What is sensible to install depends on many parameters including:
1. The cost of the panels.
2. The cost of the associated inverter.
3. The labour cost of install.
4. Whether you have batteries as well (and their size).
5. The cost of mains electricity.
6. The price at which you sell excess electricity.
7.  How much electricity you use.
8. The size of the inverter you are permitted to fit (which in turn depends on the capability of the DNO's local network).
9. Whether you have a productive use for "spare" electricity (e.g. off setting the use of more expensive fuels).
10. The regulatory environment at the time.
11. What you want to achieve (I.e. there may be drivers in addition to financial ones).
12. The space you have available to install panels.

All of those parameters change over time.  What might have been the right choice some years ago may not be the right choice now.  It is also possible that the install was suboptimal.from the start - not all installers correctly take all of the above into account.

One important point is that sunk costs are largely irrelevant.  It doesn't matter that you paid a lot of money for the panels years ago, panels are cheap and 8 panels is well under £800 worth (excluding installation) no matter how much they cost new. Depending on the factors above, it is likely that more panels would be a better bet than trying to optimise the use of the existing ones.

Qyburn

Telegraph_Sam said:

Hi
Bear in mind that my panels are 13 years old, bought at a time when prices were not what they are today 

If I remember correctly you receive FIT generation payments, and it sounds like you're going to do so for quite a few more years. You need to make sure any upgrade or addition doesn't disqualify you.

Telegraph_Sam

Tks I'll bear that in mind. Unaware that this danger existed other than if I was to switch out of Octopus wholesale

QrizB

Telegraph_Sam said:

Tks I'll bear that in mind. Unaware that this danger existed other than if I was to switch out of Octopus wholesale

There are quite strict rules re. changes to a FIT-accredited system, and if you break them you can lose your payments.

On the other hand you can switch FIT suppliers quite easily without any deleterious effect.

Telegraph_Sam

doodling said:

Hi,

What is sensible to install depends on many parameters including:
1. The cost of the panels.
2. The cost of the associated inverter.
3. The labour cost of install.
4. Whether you have batteries as well (and their size).
5. The cost of mains electricity.
6. The price at which you sell excess electricity.
7.  How much electricity you use.
8. The size of the inverter you are permitted to fit (which in turn depends on the capability of the DNO's local network).
9. Whether you have a productive use for "spare" electricity (e.g. off setting the use of more expensive fuels).
10. The regulatory environment at the time.
11. What you want to achieve (I.e. there may be drivers in addition to financial ones).
12. The space you have available to install panels.

All of those parameters change over time.  What might have been the right choice some years ago may not be the right choice now.  It is also possible that the install was suboptimal.from the start - not all installers correctly take all of the above into account.

One important point is that sunk costs are largely irrelevant.  It doesn't matter that you paid a lot of money for the panels years ago, panels are cheap and 8 panels is well under £800 worth (excluding installation) no matter how much they cost new. Depending on the factors above, it is likely that more panels would be a better bet than trying to optimise the use of the existing ones.

@doodling: Tks for the lowdown. The topic is obviously vastly more complex than I had anticipated and it would take a lot of unbiased expertise to come to a balanced decision. Facts are that I have a setup that seems to be working as is. Whilst to change to a 2 - 4 panel upgrade or replacement would incur significant outlay without being able to forecast the (net) return. All change of course if the present system fails

I have been trying to reply but the text has served to lock myself out of the forum!