Solar Panel & Battery Calculator
Estimate roof panel capacity, annual solar generation, battery impact, export income and indicative electricity savings.
Typical use: Early-stage UK solar PV feasibility, roof capacity, electricity usage, tariff savings and battery sizing scenarios
Using this calculator
Open the interactive calculator to enter your project measurements and adjust the available settings. Review the calculated quantity and buying units before ordering materials. Check product coverage, pack sizes and installation guidance with the manufacturer or supplier.
Planning and practical guidance
Solar Panels, Batteries & Inverters Explained
Understand the main parts of a home solar system, including panels, string and hybrid inverters, batteries, optimisers and export.
- Solar panels generate DC electricity when daylight reaches the cells; the amount produced varies with array size, orientation, pitch, shading and weather.
- An inverter converts the panels’ DC electricity into AC electricity that normal household circuits and appliances can use.
- A standard solar inverter manages the PV array, while a hybrid inverter can also manage a compatible battery within the same system architecture.
- A battery stores surplus energy for later use. Its headline capacity and usable capacity are not always identical, so compare usable kWh when assessing storage.
How Smart Solar, Batteries & EV Charging Work Together
A plain-English guide to solar priorities, battery charging, grid import, export and smart EV charging schedules.
- Most home energy systems monitor power flowing between the solar array, house, battery and electricity grid.
- A common priority is to supply current household demand from solar first, reducing electricity imported from the grid.
- When solar generation exceeds household demand, compatible systems can charge the home battery before exporting remaining surplus.
- Later in the day the battery can discharge to support household demand, reducing the amount bought from the grid.
Solar Panels & Batteries for Rental Properties: Landlord Considerations
Assess solar and battery storage for a rental property with ownership, metering, tariffs, roof condition, tenant benefit and maintenance responsibilities in mind.
- Check the roof condition and remaining service life before adding solar; removing and reinstalling panels for an imminent reroof can undermine the economics.
- Understand who pays the electricity bill and who would receive any export income under the intended metering/tariff arrangement.
- Assess annual electricity use and likely daytime occupancy because tenant usage patterns affect self-consumption and the value of a battery.
- Clarify ownership of the PV/battery equipment, warranties, monitoring accounts and who is responsible for faults or app access between tenancies.