System designer
Answer a few questions and we will size the array, battery and inverter, then show you the actual parts we stock and what they cost. No account, no phone call, nothing hidden. Send it to our engineers at the end if you want it checked.
This sets the voltage, the kind of inverter you need and how we size for winter. You can change everything afterwards.
This is the single number that decides the size of everything else. A rough figure is fine.
Most people know their bill but not their kWh. We convert it using the unit rate below.
Prefilled with the Ofgem price cap for July to September 2026. Change it to your own rate for a truer figure.
Add what you actually run. We will total it up and fill in the figure above.
Sunlight in Britain varies by a third from the south coast to northern Scotland, and a roof pointing the wrong way loses more again. Both change the array size.
December in Britain gives under one hour of useful sun a day. Sizing for it honestly means a much larger array, which is why most year-round off-grid setups also keep a generator or a hookup for the darkest weeks.
Find the building, then trace the roof face you want panels on. We will measure it and make sure the design actually fits. Skip it if you would rather just answer the questions.
This sizes the inverter. It is about the biggest simultaneous draw, not how much you use over a day. A kettle is about 2000W, a microwave 900W, a fridge 150W.
Most homes are single phase. Farms, workshops and larger units are often three phase, which needs a different inverter. Check the main fuse or ask us if you are not sure.
More days means a bigger battery bank. Two is the usual starting point.
Optional. Your design is already on screen and you can order the parts yourself. Send it over if you want a person to sanity check it, adjust it, or quote you for the whole lot.
The designer needs JavaScript. Send us the details instead and an engineer will size it for you and reply with a written quote.
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