Best tariff or strategy for solar/battery 16 May 2022 at 1:43PM in Green & ethical MoneySaving 15 replies 1.3K views

1961Nick

random321 said:

I'm just having a 5kW system installed with 4.8kWh battery and am also wondering which tariff to choose. I'm thinking Octopus Go as we do have an EV so especially over winter months will charge the solar batteries and car between 12.30am - 4.30am, and also program dishwasher/washing machine etc to run during the same time.

If you do manage to move onto Octopus Go, it may be worth considering increasing your battery storage closer to the amount of power you can harvest during the Go period (assuming that's still under your daily consumption?).

A Pylontech 2.4kWh battery working with Octopus Go will save between £155 & £190 pa after taking account of round trip losses (based on 1 cycle per day, 28.5p/7.5p/kWh, 20% loss). ROI should be 4.5 - 6 years but may improve in October when the price cap is updated.

Alnat1

Any clue on how much the Pylontechs cost now and if there's much availability?

We had our system fitted in March with 2 x 2.4kw and I realised that we could do with another battery. Some reasons, when we're GMT you cook after dark so 4.8 doesn't last until morning, if we get a decent day in the shoulder months we could store more and use next day if weather wasn't so good, also installing company never mentioned that the battery discharge rate would only be 2.4 with the 2 pylonteachs despite a 3.6 Lux, 3 batteries would give us the 3.6 we had assumed.

1961Nick

Alnat1 said:

Any clue on how much the Pylontechs cost now and if there's much availability?

We had our system fitted in March with 2 x 2.4kw and I realised that we could do with another battery. Some reasons, when we're GMT you cook after dark so 4.8 doesn't last until morning, if we get a decent day in the shoulder months we could store more and use next day if weather wasn't so good, also installing company never mentioned that the battery discharge rate would only be 2.4 with the 2 pylonteachs despite a 3.6 Lux, 3 batteries would give us the 3.6 we had assumed.

Midsummer wholesale have some US2000B in stock for £873.60 inc vat. The US2000C seems to be well over £1000 assuming you can find anyone with stock.

Alnat1

Thanks Nick 

ispookie666

For us it was 

• Battery should be able to power the house outside the Economy 7 rate -  Mainly useful during the winter months when the solar production will be very low (often less than 1 O) 
• Battery to be big enough to soak up enough solar PV generation  
• Emergency backup power when grid goes down.  
• Reduce reliance on oil heating 
• Maximise solar generation - we went with micro inverters due to panels on multiple roofs and significant shading.  

Solar has been up and running since end of Jan and the batteries installed a week ago.  I have left 15% of the battery for emergency backup.  
Currently on Eon Next Nextflex Economy 7 tariff.