Back in December 2017 we installed a SolarEdge 5.7kWp solar PV system on our average 1930s semi. Incorporated with the system was the ability to divert excess solar generated electricity to the immersion heater in our hot water cylinder. Initially there were a few problems with the controller for the hot water which wasn’t fully rectified until March 2018. From mid April until late October 2018 we switched off our gas central heating system and relied solely on the PV to heat our water.
Below is a graphic generated from the SolarEdge app which shows in 2018 our PV generated 5.25 MWh of electricity. Over the year we consumed 4.59 MWh of electricity. As you will see from the graphic we immediately consumed 42% (2.2 MWh) of the electricity our PV generated with the remaining 58% (3.05 MWh) flowing back into the National Grid.
While it’s really pleasing to see our PV system performing well I’m disappointed that we were not able to use more of the generated electricity ourselves, meaning we still need to buy 2.38MWh electricity from the Grid in the evenings often at peak periods. Currently I believe the best option is to install a large battery such as a Tesla Powerwall 2 which will store excess solar generated electricity which we can then use when the sun is not shining. We hope to install a battery in the first quarter of 2019 and I am eager to see the self-consumption percentage rise.