Solar panels - no clue at all

ASA201

Hi everyone.   I’ll start with a be gentle plea.  I would say I’m a relatively switched on guy but my goodness I cannot for the life of me get my head around any of this solar stuff.   

Some context…. We moved into a new house (to us, built in 1997) which has solar panels on the roof.    We’ve no prior experience with them.  

There was a form waiting for us from Octopus to transfer the Feed in Tariff from the previous homeowners to ourselves which we duly filled in.  

From the paperwork my solicitor sent me the panels have been in situ since 2013 so 11 years old.   Prior to Octopus the agreement was with First Utility.    I have MCS certificate and a range of info as to the estimated annual generation, the net capacity - none of which means anything to me.   

So anyway, Octopus are taking a while to do anything with the change of ownership forms but once they deal with it what can I expect?

Are 10+ year old panels any use?   What will I be earning in terms of rates per measurement of electricity on the 2013 feed in tariff system?   Should I change to Octopus Export.  

Help!! 

Reed_Richards

What you can expect is that quarterly Octopus will contact you and ask for the reading from your generation meter.  A short while afterwards you will get a statement and a payment made into your bank account.  If you have a smart meter and Octopus is your electricity supplier then it might be to your financial benefit to change from a payment entirely based on what you generate to a payment based on both generation and actual export.  But you can do some sums when you get your first statement. 

Keep_pedalling

11 year old panels are very worth having, you will get another 14 years of index linked feed in tariffs which will pay you handsomely for every KWh they produce. I had 6 panels of similar age earning around £800pa at the house we recently sold. 

Martyn1981

Keep_pedalling said:

11 year old panels are very worth having, you will get another 14 years of index linked feed in tariffs which will pay you handsomely for every KWh they produce. I had 6 panels of similar age earning around £800pa at the house we recently sold. 

Totally agree, the panels will still be working great.

Sorry for the pedantry, but just to say, if the install was in 2013, then the FiT period would have been for 20yrs, so probably 8/9 years left. The 25yr FiT deals ran till the end of July 2012. Then a new 20yr rate came into force on 1st August. [My second system on the WNW roof was installed on the 28th July 2012 ... phew!]

Magnitio

It's worth noting that, as well as the panels, you will have an inverter that converts DC from the panels to AC. These don't last as long as the panels, so it is worth checking that it still works. Do you have a smart meter at the property? If so, then when (if) the sun comes out and you don't have any major consumers on in the house, you should see that you are exporting electricity.

Martyn1981

ASA201 said:

Hi everyone.   I’ll start with a be gentle plea.  I would say I’m a relatively switched on guy but my goodness I cannot for the life of me get my head around any of this solar stuff.   

From the paperwork my solicitor sent me the panels have been in situ since 2013 so 11 years old.   Prior to Octopus the agreement was with First Utility.    I have MCS certificate and a range of info as to the estimated annual generation, the net capacity - none of which means anything to me.   

Are 10+ year old panels any use?   What will I be earning in terms of rates per measurement of electricity on the 2013 feed in tariff system?   Should I change to Octopus Export.  

Help!! 

Hiya, it's really hard to guess at a figure as the FiT subsidy rates were being changed almost quarterly from late 2012, so hard to know what rate the install got. And (good news) FiT rates are index linked, so it would have grown steadily since.

You can probably find the details (somewhere? perhaps on the forms from Octopus?) or wait till your first submission, and see what the rate on the payment is.

Only a wild, wild guess, but it may be in the mid 20p's per kWh* generated now. So for instance if you have a 3kWp** system facing south and working well, maybe 3,000kWh pa, so £750.

Or, perhaps a 2kWp system, facing west with lots of shading, so maybe 1,500kWh's pa, so around £375.

If you post the specs, system size and estimated annual generation, then we may be able to estimate a bit better, but the crucial info will be the FiT rate you are now on. BTW that rate will go up in Apr with index linking.

*Just to complicate things a little more, there are actually two payments. The first is simply a subsidy for generating clean electricity, that's the feed in tariff. The second is a payment for export (exporting excess not used by the house), and is typically simply estimated to be 50% of what you generate. However, you can give up the deemed export part, and have it paid on actual export if you have a smart meter. I don't know if the previous owners have done this, the paperwork you have may give us clues.

Again, total wild guess just for the purposes of responding, so don't think these numbers are accurate, but you may be on a FiT rate of say 22p/kWh and a deemed export of 6p/kWh, giving a grand total of 25p/kWh (20p + (6p/2)). If you can see any numbers/info in these regions it would help.

**PV systems are sized on the ratings of the panels x the number of panels. So for instance you might have 10x 250Wp panels giving a system size of 2,500Wp or 2.5kWp. That means that at the rated temp, in good sunshine, when lined up with the sun, they could generate 250W each. The p is for peak, as generation will vary. Panel performance drops off as temps get high, but can actually out perform the peak when it's really cold.

ASA201

Thanks everyone.    Really appreciate the replies so far.  Few points for me to come back on.   

@Reed_Richards thanks for clarifying the process.   As far as I can work out I have one additional meter, which says Single Phase Watt Hour Meter on it and has a sticker reading Photovoltaic System.   This is next to my other meters and CU. 

I do have a smart meter for both gas and electric both of which are with octopus and I guess I’m not sure how I work out whether to stay with the existing setup or move the solar side of things to octopus for generation and export as you say? 

@Keep_pedalling and @martyn1981 thanks

@Magnitio the inverter is in the loft space in the garage, below the solar panels and as far as I can tell it’s working - no faults shown on it.    The meter I referenced above I have seen ticking upwards in terms of digits.   Not at a great rate of knots mind you.   As said I do have a smart meter for my electricity but I’m not sure how from looking at this I could tell whether I’m exporting or not. 

@martyn1981 estimated annual generation says 1768kw, declared net capacity is 2.0, I have 8 individual solar PV panels, with individual panel wattage of 250 returning that total installed capacity of 2.0.    Is the drop to the 1768kw based on the position and/or compass angle of the panels?  Is that something that would have been shown on the paperwork?  

Reed_Richards

First get your basic FIT payments sorted.  And find and record the export reading on your smart electricity meter.

After a year read your export again and see how much of the electricity you generated was exported.  If it's more than about 25% then you should be better off switching to being paid for your actual export (at 15p per kWh) rather then being paid less per kWh for a deemed export figure (which is the norm under the FIT scheme).

Keep_pedalling

Martyn1981 said:

Keep_pedalling said:

11 year old panels are very worth having, you will get another 14 years of index linked feed in tariffs which will pay you handsomely for every KWh they produce. I had 6 panels of similar age earning around £800pa at the house we recently sold. 

Totally agree, the panels will still be working great.

Sorry for the pedantry, but just to say, if the install was in 2013, then the FiT period would have been for 20yrs, so probably 8/9 years left. The 25yr FiT deals ran till the end of July 2012. Then a new 20yr rate came into force on 1st August. [My second system on the WNW roof was installed on the 28th July 2012 ... phew!]

Whoops! Sorry, ours were actually from 2012. The ones in our new place are only 6 years old so previous owners were getting very low FIT, we have moved to SEG payments.

Martyn1981

ASA201 said:

@martyn1981 estimated annual generation says 1768kw, declared net capacity is 2.0, I have 8 individual solar PV panels, with individual panel wattage of 250 returning that total installed capacity of 2.0.    Is the drop to the 1768kw based on the position and/or compass angle of the panels?  Is that something that would have been shown on the paperwork?  

Hi. That answers a lot. So, in the UK a good system can get about 1,000kWh per 1kWp of panels per year. Some can do a bit better, especially if further south, and maybe coastal cooling (for example). My east and west panels will get around 800kWh/kWp, as they see very little low sun in the winter months.

So 1,768kWh pa from 2kWp is perfectly reasonable, assuming it's not perfectly south facing, and also the generation estimates from a decade ago tended to be a bit low. In fact the earliest 2010+ were based on Sheffield, and even took into account estimated panel degradation, so were long term averages. [Just to say I expected 1% to 2% panel degradation pa, but have seen next to nothing after 13yrs, certainly not 10-20%.]

Doh! Just thought, have a lot at your PV meter (proper name is TGM, total generation meter, only mention this so you can better follow chats/comments), and see what it says. Assuming it hasn't been replaced, then you can divide by 11yrs, to give a rough average of what you generate. Fingers crossed it's around or better than 1,768kWh.


You could have a read (if you're really desperate) of the PV FAQ's (see my auto sig for link), but they are quite out of date now, but may give you some simple background info and explanations of abbreviations.

Ectophile

250W panels are now obsolete.  But still better than mine, which are older and only 190W.  You can now get 450W panels.

But if you replace the panels with better ones, you'll probably need a new inverter to handle the extra power.  So that's a substantial cost.  And you will no longer be eligible for FIT payments as it's a new system.  Given that FIT is free money, with no tax on it, I wouldn't rush to replace the panels.