Generating electricity from the sun
In 2022, I decided to investigate solar PV and battery. After extensive online research, I got four quotes from different suppliers, and chose EVi, a small, Fife-based installer, who I would recommend. The installation took two days, cost £10,000, and included the following:
10 Trina Vortex S 400W panels with Tigo optimisers totalling 4 kWp.
In 2022, I decided to investigate solar PV and battery. After extensive online research, I got four quotes from different suppliers, and chose EVi, a small, Fife-based installer, who I would recommend. The installation took two days, cost £10,000, and included the following:
10 Trina Vortex S 400W panels with Tigo optimisers totalling 4 kWp.
GivEnergy 3.6kW hybrid inverter installed in combe space.
GivEnergy 8.2kWh LiFePO4 battery storage system (maximum size single battery available from GivEnergy at time of install).
The battery is 94% efficient in charge / discharge cycle
GivEnergy 8.2kWh LiFePO4 battery storage system (maximum size single battery available from GivEnergy at time of install).
The battery is 94% efficient in charge / discharge cycle
The solar PV hybrid inverter produces up to 3.6kW of electricity, but the battery can only discharge at 2.5kW. In summer, the solar powers the house and charges the battery for use after the sun goes down. In winter, the battery is charged on cheap-rate electricity and used to run the house during the day.
- Initially daily look at graphs / now just content all works.
- Operation changes winter / summer and with tariff
- Now on Octopus Cosy but have been on Flux and an EV tariff – in winter charge both EV and battery fully between 4-7am @16.1p/kWh
- In summer the battery stores PV generation during the day for use overnight, so electricity bills show only export to grid
When system was installed export rate was 4.5p/kWh, so ran system to maximise self use of PV, but now getting 15p/kWh for export, so cheaper to charge EV at night than charge off PV during day even in summer.
We assumed we would get “island mode” capability (running building off the battery in event of power failure) – would now insist on external earth during install (retrofit very expensive).
Would now install at least a 13.5kWh battery and inverter capable of delivering up to 6.5kW & island mode, to maximise use of solar generation in spring and autumn, and to take better advantage of variable time of day tariffs.
The software can also predict the solar generation three days in advanced based on weather forecasts which could allow for different battery charging regimes. Differences can be due to local clouds or shading.
Summary
- 4kWp Solar PV (10 panels)
- 3.6kW hybrid inverter & 8kWh battery installed in combe space
- Sized to maximise renewable energy use.
- Easy to change charging / discharge strategy in App and website.