800W is the maximum rated AC output in the legal definition. It is not necessarily the combined panel rating, or a promise of continuous generation.
Two ratings with different jobs
The panel rating is measured under standard test conditions. The inverter’s AC rating describes its output to the home. Keep these in separate columns when comparing kits.
The law refers to maximum rated AC output of 800W. The specification caps apparent power at 800VA too. These related quantities are not interchangeable in every electrical context.
Can panels add up to more than 800W?
Extra panel capacity can improve output below ideal conditions while the inverter limits its output. That does not mean arbitrary panel additions are allowed.
The complete kit must respect the manufacturer’s limits and UK specification. The IPS advises considering professional electrical assessment above 960W total PV module capacity.
Power is not energy
800W is 0.8kW. Producing that for one hour gives 0.8kWh. Actual output varies and panels produce nothing at night.
Compare annual kWh and likely self-consumption, not just the headline wattage. A good location and matching electricity demand make the difference.
A practical example
If the home needs 1,500W and solar contributes 600W, roughly 900W comes from the grid. If it needs 200W and solar contributes 600W, roughly 400W is surplus, before considering any compatible installed equipment.
Our calculator assumes no income from that surplus. Confirm any eligible export arrangement separately.
Prepared from the linked sources. This is guidance, not a product certification or an assessment of your home. Tell us about a correction.