Healthy home · home energy
Measure the household before buying the hardware
Solar, battery and portable-power comparisons become more useful when they start with when your home uses electricity—not only the annual total on a bill.
A seven-day demand diary
Overnight base load
Record the lowest steady demand. Investigate always-on equipment before sizing generation around avoidable use.
Morning and evening peaks
Note kettles, cooking, showers, heating equipment and EV charging. Power peaks and daily energy are different decisions.
Daytime occupancy
Solar is easiest to use directly when electricity demand overlaps daylight. Record working-from-home and weekend differences.
Flexible loads
List appliances that can move to sunny or off-peak periods without disrupting family life.
Essential outage loads
Separately list what genuinely needs backup, its watts and required running time. A normal grid-tied solar system may shut down in a power cut.
Information to request from an installer
- Generation assumptions, shading and orientation used in the proposal.
- Estimated direct use, export and battery cycling—not just total generation.
- Tariff assumptions and whether savings include future price estimates.
- Equipment, usable battery capacity, warranties, monitoring access and replacement responsibilities.
- What happens during an outage and which circuits, if any, are backed up.
Evidence boundary
Energy Saving Trust explains that suitability and savings vary with roof, shading, system size and household use. Treat quoted payback as a model with assumptions, not a guarantee.
Read Energy Saving Trust’s solar guidance →