Power Diverter for Existing Solar Panels

robbsafc

Does anyone have experience of having had a Power Diverter fitted to their solar panels? If so are you noticing a saving on heating your water? I have been quoted £400 + vat to have an Eddi fitted. I am just looking to maximise the amount of solar energy I am using rather than exporting back to the grid.For example today as I am the only one at home I am at times exporting around 2kw when the sun is out. This is energy I would rather use rather than export, not the the export rate is that good anyway.

So please share your experiences if you could so I can make an informed decision.

Rob.

Verdigris

The economics are marginal, in most cases. See this thread:

https://forums.moneysavingexpert.com/discussion/6338037/spare-solar-solic-200-or-solar-iboost-thoughts#latest

QrizB

robbsafc said:

This is energy I would rather use rather than export, not the the export rate is that good anyway.

Who is your export with? FIT or SEG?

Octopus Outgoing Agile is paying 25p/kWh (or more) today. Even the Outgoing Fixed rate of 7.5p/kWh is slighlty more than the April price of gas.

Petriix

The economics are different depending on when your panels were installed. If you're on deemed exports then you don't lose the payment for what you don't export whereas on SEG you miss out on the 5.5p or whatever. 

QrizB

I see from this thread:

https://forums.moneysavingexpert.com/discussion/4031309/change-who-pays-my-fit-payments

If they haven't moved house in the meantime, it seems the OP has 2011- or 2012-era FITs and so probably has deemed export, a good generation payment but the lower rate per kWh.

[Deleted User]

I have an EDDI and it is a solid and dependable piece of kit with excellent UK support. Is it saving me money: the answer is yes. I can heat all the hot water that I need from March though until October via diverted solar, and for the few months when solar isn’t available, I boost via EDDI using cheap electricity from Go.

Will it pay for itself: who knows?

robbsafc

Hi thanks for the replies, much appreciated. Yes my solar panels are on the highest tariff, as they were installed in December 2011. So from the Ofgem website I can see that from April 2022 I shall be getting 60.23 p/Kw and an export rate of 4.25p/Kw. There are times when no-one is home during the day so whatever the panels are generating would be wasted as it is at the moment. I have looked at heat source pumps, but they are too expensive for me at the moment (also don't have sufficient funds). But if I could spend a few hundred on a power diverter and gain from that by reducing my gas useage surely it's a winning situation. Is the saving by reducing my gas useage by using a diverter to heat my water a worthwhile investment? Is there any way to calculate how much this would save me or to calculate how long it would take to recoup my investment?

Verdigris

Is the saving by reducing my gas useage by using a diverter to heat my water a worthwhile investment?

From April 1st a kWh of gas will costs 7p. How many 7ps will it take to pay for the diverter? Well over 2000 hours at 2kW, by my mental arithmetic.

robbsafc

At the moment my tariff for Gas is 3.167 p/Kwh and I am on a fixed Tariff until May 2023. The standing charge is 13.968 p per day which I can't do anything about.

Verdigris

So that's doubled the payback time, at your current rate.

I'd have thought batteries, to time-shift the surplus to the evening, might give a better ROI. Especially when the 50p kWh is upon us.

Sterlingtimes

For me, it has been worthless for 8 years. For the winter, export is close to zero with nothing to divert. For the summer, it has always been cheaper to burn gas and then get paid for the export. This summer might be promising: with the price of gas at 7.367p per kWh and a summer boiler efficiency of 80%, the effective price of gas is 9.208p per kWh whereas my price of export will be about 6p per kWh. But the marginal benefit is still very small given that I use 60% of my generated electricity.