Case Study – Solar PV owner adds a battery and cuts his bills to 30 pence per day!

Brief: Hafod Installed a 4 Kw south facing solar PV system in the Winter of 2015 for Mr and Mrs Johnson’s home in Denbigh.

In the winter of 2016, One year after installation, Mr Johnson took a generation meter reading which was 3940 kwh. This was a remarkable year of generation and the solar panels actually generated more electricity than the house consumed. Unfortunately, due to the timings of generation, they were still paying £35 / month in electricity. They wanted to explore ways of using as much of the solar pv generated as possible.

Execution: Hafod researched the different battery storage options available and after consulting with the client designed a Tesla Powerwall home battery system with a 6.4kwh storage. This was deemed perfect for the property as the average daily usage was around 10kwh (4kwh evening / night usage)

A SolarEdge control technology was installed along-side the Tesla battery. The system was AC coupled meaning we did not need to take out the old inverter which was barely one year old. The system was installed in one day with no disruption to the home and the benefits of the battery were felt after day one!

Full monitoring platform of the battery system was provided for the client.

  • Technologies installed

    • Wall mounted Tesla Powerwall 1 Lithium ion battery technology 4kwh storage 100% depth of discharge.
    • Storedge control system and AC coupled solaredge inverter 3.3kw peak output.
    • Full monitoring of solar generation, self-consumption and export via cloud based app.

  • Customer benefits

    • Increase own use from the solar pv system from 25 % to 85% (rather than exporting back to the grid).
    • Saving an extra £400 per year in electricity bills.
    • Energy security and the possibility of charging the battery on low peak tariffs in the future as the country undergoes the smart meter roll out.