thanks Ashley, I've just seen this - that is very helpful. Do you know what the numbers are showing - the 'Usage Now' is 3.26 kW and the cost is £0.00/hr - I assumed originally that meant I was exporting 3.26 kW but on speaking to Bulb, they said that 3.26 was what the household was using and presumably the export figure is the small difference between what was showing on the inverter and the 3.26. However, I now have similar figures (and the sun is blazing) and I have turned off everything in the house so I can't see how that is a household usage figure - very confusing...… also my export meter is showing something completely different and the supplier can't explain.... gaahh!!!
The figure is what you’re exporting.
If you consider the location of the smart meter within your local circuit, what Bulb have said can’t possibly be right (not unexpected). It’s impossible for your import/export meter to know your actual household usage because it just can’t see it. When your import/export meter reads 3kW export, it has no way of knowing whether your solar array is generating 3kW with 0kW local usage, or 5kW with 2kW local usage, because all the generation and local usage happens before the import/export meter. To see your actual local usage, you need to take the value at the inverter minus the value being exported according to your IHD.
To be more mathematically rigorous, it’s better to consider the value shown on the IHD with the pylon symbol to be negative usage. That way you can just add the two number together to get your local usage. i.e.,
2kW (inverter) + 1kW (import) = 3kW household usage.
2kW (inverter) + -1kW (export) = 1kW household usage.
I just want to know if I have enough export atm to install a megaflow boiler with iboost to replace my central heating boiler. The experts are not proving very helpful.
I’m sure I don’t need to say this, but remember that your central heating will be needed in the winter when then sun isn’t blazing, so working out the maths today isn’t going to be representative of the performance you need.