Solar photovoltaic panels make electricity from light. An inverter turns their output into electricity your home can use.
Follow the energy
Panels produce direct current. The inverter converts it to alternating current for household circuits. When generation exceeds simultaneous demand, the surplus can flow to a battery or the grid, depending on the system. When it falls short, your home usually imports the difference.
Separate power from energy
Panel capacity is commonly stated in kilowatts peak (kWp), a rated output under test conditions. Production over time is measured in kilowatt-hours (kWh). Two roofs with the same rated capacity can have different annual output because their surroundings and orientations differ.
Look beyond the panel count
A proposal should explain the mounting, inverter, cabling, monitoring and connection work as well as the panels. Ask who handles access, roof condition and aftercare. Treat a system as a complete installation rather than a shopping list of modules.
Read the system at one moment
Suppose the panels are producing 2 kW and the house needs 0.7 kW. Without storage, about 1.3 kW is available for export before any system limits. Switch on another 2 kW load and demand becomes 2.7 kW: the grid supplies the missing 0.7 kW. These instantaneous flows change continually. Adding up a whole day’s production cannot show whether the home imported electricity at breakfast or exported it at lunchtime.
Know what the monitoring screen measures
Look for separate readings for solar generation, household demand, grid import and grid export. An inverter-only display may show generation without knowing the home’s total consumption. Ask which meters or sensors provide each figure and whether the dashboard estimates any values. Keep access to your account and downloadable history at handover so you can compare your electricity bills with the system’s records.
Follow the installation beyond commissioning
Keep the equipment schedule, electrical documentation, warranty information and a simple layout drawing together. Record a normal day’s dashboard readings once the system is working. A change in the graph may be weather-related, but an unexplained loss of reporting deserves investigation. Establish who provides remote support and what information they need before arranging a visit; a blank app does not itself prove the panels have stopped generating.
Your planning checklist
- Panel and inverter models with rated power clearly labelled.
- A diagram showing where generation and consumption are measured.
- Owner access to monitoring and an explanation of each reading.
- A named contact for equipment faults and reporting problems.
Common questions
Does a 4 kWp system produce 4 kWh every hour?
No. kWp is the array’s rated power under standard test conditions. Actual output changes with light and operating conditions. Energy in kWh is the power accumulated over time; 2 kW maintained for one hour equals 2 kWh.
Is solar electricity the same as solar hot water?
No. Photovoltaic panels produce electricity. Solar thermal equipment collects heat for uses such as water heating. Quotes, plumbing requirements and financial calculations need to identify which technology is being proposed.