Solar panels (leased) can I install batteries?

Rambolicks

I have leased solar panels (a shade greener). They regularly have a surplus going back to the grid in the hours of 10am to 3pm. Does anyone know if installing something like a powerwall battery pack is forbidden. I think there may be alternative battery setups that will make it economically viable now energy prices are going up. 

Thanks in advance. 

MattMattMattUK

Rambolicks said:

I have leased solar panels (a shade greener). They regularly have a surplus going back to the grid in the hours of 10am to 3pm. Does anyone know if installing something like a powerwall battery pack is forbidden. I think there may be alternative battery setups that will make it economically viable now energy prices are going up. 

Thanks in advance. 

Usually you are not allowed to as they make their money from a cut (or all) of the FiT, younger to read your contract.

wrf12345

You can charge a "battery" but presumably not have it connected permanently into the wiring but once the battery is charged you can connect an inverter to it and run things off an extension lead or completely separate circuit. If you have an eBike for instance you are allowed to charge this and then use the battery with an inverter in the house on its own circuit but not allowed to connect anything to the leased inverter (usually in the attic). I used to run a cheap 3kW electric heater on sunny winter days rather than the ch when I had a house with a leased system (the heater connected to a relay that switched on when a small solar panel generated enough current, to roughly match the amount of sun the pv array was getting).

[Deleted User]

Rambolicks said:

I have leased solar panels (a shade greener). They regularly have a surplus going back to the grid in the hours of 10am to 3pm. Does anyone know if installing something like a powerwall battery pack is forbidden. I think there may be alternative battery setups that will make it economically viable now energy prices are going up. 

Thanks in advance. 

All battery installations require DNO approval as batteries are treated as potential generators to the Grid. The DNO may also impose a site export limit which could, potentially, require some adjustment to or a change of solar inverter. 

The DNO also has to be satisfied that in the event of a Grid failure both the solar and the battery will isolate themselves from the Grid or that your property will go into islanding mode via, for example, a PW2 Gateway. As what you are proposing will involve changes to your existing solar wiring then you might find yourself in breach of any terms and conditions attached to your solar panel lease.

DNO applications have to be paid for. SPEN charged me £350 a year or so ago to approve my solar PV/battery installation. I was also on the hook for a potential witness testing visit again at cost to me.

I have no idea what your daily consumption of electricity is nor do I know your annual output but ,on a small sized array, the RoI on a battery isn’t good. I have a 7kWp array and I am only totally off Grid for about 9 months of the year but I still export 20% of my total output. On a few poor days in December with total daily outputs in the region of 250Whs then I was still importing over 95% of my daily energy from the Grid. Finally, when doing your ‘man maths’ you need to take into account the 10% round trip loss from solar to battery to home.

PS Don’t forget VAT in your cost calculations.

Petriix

There's no reason why an AC coupled battery system would impact the FIT solar panels and they wouldn't notice any difference. As long as everything new is installed house side of the existing generation meter then you'll be fine.

Rambolicks

Thanks everyone sounds like it's not viable with them being leased and a relatively small array (3kw). Good to know the ins and outs tho. Maybe when global warming gives us a bit more sun it might be worth revisiting. 

ProDave

Your best bet to maximise self usage is fit one of the solar PV diverter devices to automatically send surplus PV power to your immersion heater to heat hot water.

MWT

ProDave said:

Your best bet to maximise self usage is fit one of the solar PV diverter devices to automatically send surplus PV power to your immersion heater to heat hot water.

They are not cheap though so always do the calculations on the difference between what you would be paid for the export vs normal cost of heating the water (gas/low rate electric).

QrizB

MWT said:

ProDave said:

Your best bet to maximise self usage is fit one of the solar PV diverter devices to automatically send surplus PV power to your immersion heater to heat hot water.

They are not cheap though so always do the calculations on the difference between what you would be paid for the export vs normal cost of heating the water (gas/low rate electric).

In the OP's case he probably isn't paid for export as the panels are leased. However the price of an iBoost (£280) or Immersun (£500) would buy quite a lot of gas.

MWT

QrizB said:

MWT said:

ProDave said:

Your best bet to maximise self usage is fit one of the solar PV diverter devices to automatically send surplus PV power to your immersion heater to heat hot water.

They are not cheap though so always do the calculations on the difference between what you would be paid for the export vs normal cost of heating the water (gas/low rate electric).

In the OP's case he probably isn't paid for export as the panels are leased...

Agreed, but zero is still a number    ... and the warning, like the promotion of the diverter as a solution will be read by many other people.

_Sam_

We have similar situation with leased panels in the new house. To me personally the main drawback of being tied to the lease for the next 15 or so years is not being able to replace the panels for more efficient version. From doing a bit of research the current panels are either 185 or 210 watts (there are 16 of them). 

I'm thinking of the best way to squeeze the most out of what we have, getting a battery looks attractive to catch the leftover electricity when we are not at home (otherwise I'd keep the car plugged in). We would also be able to charge the battery with the EV night time low tariff if necessary, to use it then during the day.

I've checked the lease and it doesn't look like there is a restriction for as long as we don't alter the already installed system which is the property of the company, and from what I understood installing an AC coupled battery would not require an alteration? The relevant bits from the lease say:

Tenant (the company) covenants to permit the Landlord (us) to use such of the electricity generated as required for domestic use. Landlord (us) covenants not to damage or alter or remove the whole or any part of the system, and not to sell any of the generated electricity.