The next step on Adrian’s Wood Lane Net Zero journey was to install solar panels on his house roof. Typically a fabric first approach would be the logical next step through installation of loft insulation, draught exclusion etc. But there’s nothing to stop you installing solar panels at any point in your net zero journey.
The Solar panels were installed through the Zero Chippenham Community Solar scheme. At the time of installation (2019) the solar panels installation cost Adrian £4300 through the Zero Chippenham scheme with an estimated 5 year payback period, saving 0.9t CO2 per year. At the time of installation the cost of batteries still made them prohibitive, so for solar panels alone the payback period is determined by how much of that daytime free electricity can be used. Scheduling the dishwasher or washing machine for midday becomes something of a ritual when you’re generating your own electricity.
At the time of writing (November 2023) the cost of a similar solar installation is broadly similar, but could come in at typically £5500 for an installation like this with a battery ready hybrid inverter, or £10,000 complete with battery storage. One of the changes over the last three years is the ready availability of hybrid inverters. That is an inverter that can connect to your solar panels and a battery at the same time. This offers a VAT advantage at 0% if solar and battery are installed together, and saves space with only one inverter. The cost of batteries has fallen and the cost of grid electricity increased such that batteries now offer viable payback. This is further helped by the number of flexible tariffs now on offer or the ability to buy and sell electricity dynamically.
If you have a hot water cylinder it’s still more cost effective and environmentally friendly to install a device such as the MyEnergi Eddie to divert excess solar electricity to heat your hot water rather than use a battery. If you have an electric car, though vehicle to grid is still in its trial stage, you can use chargers such as the MyEnergi Zappi to divert excess solar to charge your car. After all your car is essentially a house battery on wheels.
The amount of solar generated does vary significantly between summer and winter, and bright and overcast days.
Please see more of our case studies on the Community Solar scheme page.