Mr CM owner of the property had an annual consumption of 6000 units per year and spending approximately £2400 on electricity (excluding Gas used for heating, cooking, and hot water costs). The mix use was approximately 25% pre 4pm and 75% after 4pm. Mr CM was using approximately 16kwh per day. His demand profile had a high use of tumble drier in Winter and air conditioning in the summer months. He also planned to purchase an electric vehicle in the summer of 2023 that will push his load demand substantially higher. Our installed solution was 4kva of solar panels on south/east facing roofs and a 10kwh/3.68kv Zhyphen energy storage system. The storage enables Mr CM to contract to a dual tariff energy supply and charge the battery at a reduced rate between 9pm and 7am. Projected savings have been calculated on an average of 3 kwh stored overnight and discharged between 7am and 4pm when is energy use is lower.
The solar generated during daytime hours will be prioritised for charging the battery to enable 10kwh to be charged in summer months. In the winter months this will be circa 3 to 4 kwh of charging. During the winter months the overnight cheap rate electricity will be charged at a higher volume providing at least 6 kwh into battery for discharge at peak times. The combination of solar and cheaper off-peak rate electricity is predicted to achieve a 50% reduction in electricity bills costs. This is anticipated to result in a saving of around £1200 per year and a substantial reduction in CO2 emissions.
A similar domestic installation with solar PV in Derry/Londonderry where the Zhyphen energy storage system was installed in the loft to save space (as seen in image 3 of the slideshow).