Reroofing, replace old PV?

[Andehh]

We are refurbing & extending a bungalow, the previous owners install 21 x PV panels back in 2012 ish when the feed in tariff was at its highest. 

 

Everything still works fine, and on the best bet day we can hit approx 3kWh. Mixture of low roof angle, some shade & I'm guessing 10 year old panels mean we will never hit the full 4kWh which I believe ours are paper spec's as. 

 

 

As part of the reroofing, I am debating replacing them all with a lower quantity of newer panels in the hope of achieving some extra output! 

 

Has anyone ever gone down this route before? Is it fairly straightforward to replace old with new? 

 

Is there a risk this could impact our very good FIT? 

 

Thanks 

[SteamyTea]

18 minutes ago, Andehh said:

Everything still works fine, and on the best bet day we can hit approx 3kWh. Mixture of low roof angle, some shade & I'm guessing 10 year old panels mean we will never hit the full 4kWh which I believe ours are paper spec's as. 

Think you mean 3 and 4 kW (installed capacity). kWh is energy, kW is power. Power times time is energy.

18 minutes ago, Andehh said:

am debating replacing them all with a lower quantity of newer panels in the hope of achieving some extra output!

It may affect the FiT payment, but you can replace them. Give MCS a call and ask. Then let us all know.

 

Have you thought of going roof integrated PV. Probably similar price to reproofing, and looks better. You could fit more modules and have a separate circuit dedicated to DHW heating. That is the cheapest energy storage there is. Alternatively, or as well as, battery storage to reduce imports.

Really comes down to how much you want to spend overall.

Edited August 29, 2021 by SteamyTea

[Andehh]

Thanks will do, MCS wasn't fussed, but wasn't sure who might be. For £2k a year, we want to be sure.

 

I have emailed British Gas to ask them (our FiT provider), and will report back when I know more

[SteamyTea]

25 minutes ago, Andehh said:

report back when I know more

Good on you, we like definitive answers on here.

There is still some confusion about I stalled capacity and limited capacity AFAIK.

[Ferdinand]

Interesting.

 

I thought you could be moved onto the current system.

 

Moving my panels is one thing I have in my plan for them, and the strings are .done to facilitate that. 

 

I think you need to make sure it is like-for-like. ie No noticeable increase in power generation.

[Andehh]

The challenge we have is the capacity is 3.99kwh limit (I think) but the panels are from 2011.

 

Our plans involve a mono pitch roof, which would have the solar panels angled away from the south facing they currently enjoy. 

 

Desire is to replace the panels with new ones, and do so such that we can 'over compensate' with quantity/quality, to cancel out the loss from the negative angle. 

Edited September 12, 2021 by Andehh

[SteamyTea]

7 minutes ago, Andehh said:

Desire is to replace the panels with new ones, and do so such that we can 'over compensate' with quantity/quality, to cancel out the loss from the negative angle. 

I got a £270 speeding fine for overcompensating the times I have been stuck in traffic.

It don't work like that.

[Andehh]

...its works if you don't get caught!

 

I might just have to wait to hear back from British Gas, but it depends on what they use to authorise the system surely? Do they limit you on Sheer size of system or maximum power output allowed? 

 

Could you elaborate please SteamTea?

[TonyT]

The FiT registration states the equipment installed, so apart from a like for like repair that doesn’t alter the potential output  you aren’t to change components.

 

Unless you want the fit payment stopped and at 55p a unit generated that would be daft.

[SteamyTea]

21 minutes ago, TonyT said:

The FiT registration states the equipment installed, so apart from a like for like repair that doesn’t alter the potential output  you aren’t to change components.

That is my understanding, but it is over a decade since I was involved in it.

[Andehh]

Thanks very much guys, that makes sense! I remember seeing the serial numbers on the paperwork now that you mention it. 

 

I'll just have to accept a lift & refit, annoying as the new roof orientation will put them slightly off pitch.

 

 

Edit to add:

 

For others in a similar situation, the below will 'help', but I may need too still reach out to them. Removal & refit for roof change, but maintaining existing equipment I hope to maintains our eligibility. It isn't definitively clear in my mind though? 

 

https://www.ofgem.gov.uk/publications/consultation-fit-replacement-generating-equipment

Edited September 13, 2021 by Andehh

[SteamyTea]

42 minutes ago, Andehh said:

For others in a similar situation, the below will 'help', but I may need too still reach out to them. Removal & refit for roof change, but maintaining existing equipment I hope to maintains our eligibility. It isn't definitively clear in my mind though? 

 

https://www.ofgem.gov.uk/publications/consultation-fit-replacement-generating-equipment

That will be worth following.

[TonyT]

Don’t tell anyone then, and it will be fine!

[Andehh]

Just to update, speaking 'hypothetically' with British Gas (my FiT provider) & OFGEM...there seems to be a relatively 'common sense' approach to this, though always take this with a pinch of salt.

 

If you are removing the system for building work, just let us know....when you reinstall it let us know..if system isn't being changed no issues at all. If you change any aspect of the system let us know & provide justification for it/invoices for replacement parts. Replacing 95% of the system with new components (as I was wondering above) would 'probably' class as a new installation & loss of Fit...but if you are replacing some panels due to breakage, that should be fine. 

 

There is a slight vagueness overall, ie not cut & dry...just a contact us with a good reason & you will probably be OK.