Off-Grid · Tools
What size power station do you actually need?
A honest UK sizing tool: what a portable power station will run in an outage. And what it flatly won't. Built on UK 13 A socket limits and energy-label maths, not US guesswork.
What do you need to keep running?
Add each appliance, its wattage (check the plate on the back), and how long you need it over the outage. For a fridge or freezer, tick the box and enter the yearly kWh from its energy label. It's far more accurate than the plate wattage.
What this tool assumes
The kettle problem. A UK 13 A socket delivers at most about 2,990 W (230 V × 13 A). A typical kettle draws close to 3,000 W, right at that ceiling, and above the continuous output of essentially every portable power station sold. If the tool tells you it can't run something, that's why, and it's the honest answer whatever the battery size.
Fridges and freezers. Their plate wattage (~100–150 W) is misleading. The compressor only cycles on part of the time. We size them from the yearly kWh figure on the UK/EU energy label instead, which is far more accurate than multiplying plate watts by hours (the mistake most US calculators make).
Battery capacity is a range. A station's headline Wh is its battery; what reaches the socket is less, after inverter and conversion losses (roughly 85–90% efficient. A manufacturer estimate we'll firm up as we test units). So we give a sensible range, not a single false-precise number.
Surge. Two motor loads (say a fridge and a freezer) can kick in together during an outage, so we size the surge rating for the two largest coinciding, not just one. Sizing for one is a common shortcut that undersizes the station.