Ashadegreener

Neilcaldwell_2

Hello,

My sister has had "Rent a roof" free solar panels from a Shade Greener fitted some 12 years ago. She doesn't believe she is seeing any gain and has had Octopus engineers check meters etc. and nobody can say that all is OK. Comparing her electric bill to the bigger family next door (hers is roughly the same if not slightly larger, which I would not expect).

So the question is - How do you know if you are getting any "Free" electricity. Or how can I prove is she is paying for it all and ASG is getting all the feed in from everything being generated?

In theory she should be able to benefit from sunny days and use the washing machine say for free. I mean without trying in the Summer months I would expect her to be getting something out of the deal, yet she tells me she perceives she's getting nowt!

Any advice on this would be really welcomed, is there some kind of meter I can see how much she's getting? She can log in to ASG web portal and see how much is being generated on any 1 given day, but the perception is 100% of that is being exported and they are getting everything - and she's not able to use any of it.

Baldytyke88

Does she have a smart meter and when was it fitted? I understand that the meter will have reading from how much is generated.

I have 8 solar panels and I don't notice a cheaper bill, but I do get £200+ per year back in FIT payments.

Google says an average electricity bill would be £1000+, my yearly bill for last year was £723 or 2,141kwh, so maybe my panels are working correctly.

How much electricity did she use/cost for 2025?

QrizB

Or how can I prove is she is paying for it all and ASG is getting all the feed in from everything being generated?

If any electricity is being generated, ASG will get the FIT payments. That's part of the deal.

ASG don't benefit directly from exported electricity, so even if the could monopolise it (and they can't) there would be no point doing so.

Any advice on this would be really welcomed, is there some kind of meter I can see how much she's getting?

Sort of, but it'll need some arithmetic.

Does she have a smart meter? If so, what model? The smart meter should have an export register which measures how much electricity is exported.

ASG will have a generation meter, which measures how much electricity has been generated by the panels.

Someone (you, her, the postie) needs to read both ASG's generation meter and the export register on her smart meter. Make a note of the readings. Then, after some days/weeks/months (depending on how patient you are), read them both again.

Then comes the arithmetic.

Calculate how much ASG's generation meter has increased by over that period. Calculate how much the export register has increased by over the same period. It should be less than the increase in ASG's meter.

Then subtract the export register increase from ASG's generation meter increase. This is how much electricity has been generated by the panels but has not been exported, and that is the number you're looking for - how much solar electricity your sister's household has used during the period.

born_again

Comparing her electric bill to the bigger family next door (hers is roughly the same if not slightly larger, 

Would only be of any use if both are on the same tariff at the same company. Even then it at best would be a guide, as they may be very thrifity, compared to your sister.

debitcardmayhem

Does she have an IHD ? , on a sunny day with no heavy load on e.g. kettle,oven, heating the IHD should show zero or very little use. Quick and dirty of course….

Reed_Richards

I have never known how these rent-a-roof schemes determine how much solar energy has been generated. Presumably they can obtain remote readings from a generation meter but how is that done? Sorry, this is a bit off topic but it might just be relevant.

QrizB

I have never known how these rent-a-roof schemes determine how much solar energy has been generated. Presumably they can obtain remote readings from a generation meter but how is that done?

I've never seen one in the wild but the ones I've seen photos of all had generation meters with cellular data modems attached. A bit like a SMETS1 smart meter, but reporting to the rent-a-roof company's own (most likely contracted) data service.

The same sort of system that "landlord meters" use for sub-meteing a shared supply, but measuring export.

This type of thing:

https://www.topupmeters.co.uk/shop

Reed_Richards

So "A Shade Greener" can monitor the generation remotely. Presumably somewhere there is a generation meter with a display that the OP's sister can read and check that it goes up from one (sunny) day to the next. And if the system went wrong and stopped generating, would we expect "A Shade Greener" to take action to fix it or might that not be cost-effective?

QrizB

So "A Shade Greener" can monitor the generation remotely.

Yes, that's how they get paid their FITs.

Presumably somewhere there is a generation meter with a display that the OP's sister can read and check that it goes up from one (sunny) day to the next.

Yes, that should be possible. If the OP or his sister can share a photo of the generation meter, we can probably help them read it (if they need any help).

And if the system went wrong and stopped generating, would we expect "A Shade Greener" to take action to fix it or might that not be cost-effective?

A FIT from 2014 (12 years ago) could be paying almost 29p/kWh generated, depending on exactly what date the system was commissioned. For a typical 4kWp system in a good location, that's ~£1000/yr and it will remain payable & CPI-indexed for another 8 years. I would have thought it would be in ASG's best commercial interests to fix any faults that might arise.

But, until someone checks the meter readings and does the necessary arithmetic, the only people who know if it's working or not are ASG.

_Sam_

Does she have an IHD ? , on a sunny day with no heavy load on e.g. kettle,oven, heating the IHD should show zero or very little use. Quick and dirty of course….

As above, IHD for quick and dirty method. For proper monitoring a CT clamp - something like this (just a first result from google, but you can do some research as to which monitor would be best): https://amzn.eu/d/0cE8DXoC