Inverter Load
Simulator
Your battery and solar can only supply as much as your inverter allows. Switch things on and see when the grid takes over, or when a backup would trip in a power cut.
How is the solar connected?
A hybrid shares one inverter between solar and battery.
Battery
An empty battery can’t help, whatever its size.
Main fuse
On the black cutout box by your meter. Not sure? Pick 60A, the lowest.
The grid
In a power cut there’s nothing to top up from.
Always on: fridge, router and standby, about 0.3 kW.
Same job, less energy. A microwave reheats for a fraction of an oven, a heat pump dryer uses about a third of the power, and induction gets to temperature faster.
Start-up surges aren’t shown. Depending on the appliance and your system, some things draw a brief surge as they start. Many inverters and batteries have short-term tolerance to handle it, so check your datasheet.
- Appliance loads
- Typical UK figures
- Base load
- 0.3 kW, always on
- Start-up surges
- Not modelled
- Backup output
- Same as the inverter
- Cost
- Grid kW × your peak rate
- Main fuse
- Amps × 230V
- 1Hybrid: supply = the lower of the inverter rating and solar + battery discharge. Separate solar inverter: solar adds on top of the battery inverter.
- 2Load above that supply comes from the grid, at whatever you pay at that moment. Only the grid part goes through the main fuse, so the fuse markers sit at your supply plus the fuse rating.
- 3In a power cut there’s no grid, so a load above the supply trips the backup. Separate solar inverters usually shut down in a cut.
- Battery discharge rateOften lower than the inverter, and the real limit on a dark evening. Check the datasheet: it’s often per module.
- Levi’s HiOneEach 8 kWh HiOne-8B-G3 gives 4 kW continuous (6 kW for 10 seconds). Three give 12 kW, matching the 12 kW controller.
- Start-up surgeSome motors and compressors spike for a moment as they start. Whether your system rides it out depends on its short-term rating.
- Backup circuitsMany systems only back up essential circuits, often at a lower power than normal.
- Main fuse60A, 80A or 100A in most homes: about 13.8, 18.4 or 23 kW. It belongs to your network operator: call 105 if it blows.
- Circuit breakersEach circuit has its own, like 32A for a ring main (about 7.4 kW) or 40 to 45A for a shower. This looks at the whole house, not single circuits.
- Electric showersAt 8.5 to 10.5 kW, one shower outruns most home batteries on its own.