Do I need to tell the electricity network operator about solar panels in Luton?

Yes. Luton Borough Council's EV chargepoint strategy draws on UK Power Networks forecasts for the town and describes UK Power Networks as owning and maintaining electricity cables across London, the South East and East of England. Under G98, a system up to and including 16A per phase (3.68kW on a single-phase supply, 11.04kW three-phase) is notified within 28 days after commissioning. Above that, G99 applies and the network operator must be applied to before installation. MCS says adding a battery to solar is likely to exceed 16A per phase, so plan a solar and battery system with that step in mind.