What savings can I expect in Luton?

It depends on your roof and how much of the electricity you use at home. PVGIS estimates that a 4kWp south-facing array in Luton makes about 4,095kWh a year, or about 3,274kWh facing east. At Ofgem's October to December 2026 average unit rate of 26.32p per kWh, 4,095kWh used at home would be worth about £1,078; exported at Outgoing Octopus's 12p per kWh it would earn about £491. If you use some and export the rest at those rates, the value falls between the two. A battery can raise the share you use yourself, and Smart Export Guarantee payments require an MCS-certified installation.