A compact home battery could charge on a cheap tariff and support the house when electricity costs more. That does not make today’s plug-in solar rules a battery permission.
The solar framework excludes storage
The interim product specification for plug-in solar does not cover an electrical energy storage system. There is no confirmed date for a matching plug-in battery route.
Manufacturers are signalling interest. Octopus Energy has announced a small battery range for 2027. Product announcements do not settle installation rules.
Tariff spread creates the opportunity
If a 2.5kWh battery delivers 2.2kWh after losses, a 20p tariff spread is worth about 44p per full useful cycle. Across 300 cycles, that is roughly £132 before other costs.
Battery wear, standby use, missed cycles and control behaviour reduce the result. Solar charging can change the calculation again.
Questions a credible product must answer
How does it prevent unsafe islanding? Which circuits and protective devices support it? How does it coordinate with solar? What registration is required? Who carries the warranty and recall obligation?
Until those answers are backed by the final framework and product evidence, our battery tool remains a planner rather than a buying recommendation.