Calculating energy costs with solar/EDDI diverter and Economy 7

worlestone

I'm trying to find out whether there is an online calculator for energy costs, I know there are lots of variables, but something as a start point. I'll explain why...

We have a 4 bed house in a rural area on Economy 7, no gas in the village, we run storage heaters and an immersion tank through Octopus Snug using 11,000kWh a year. We are having solar panels installed at the end of January as part of the HUG2 grant and have the option of an EDDI diverter (heating hot water) and a Tesla battery both of which we would need to pay for.

I don't think it would be cost effective for us to install a battery (no plans for an electric vehicle and cost estimate @ £7,700), but the EDDI might make sense, though it's cheap enough for us to heat water with off peak at 9p/kWh.

The solar is 5.28kWp on roof solar with Solis 3.6kW inverter with 4066kWh per year output... whatever that means.

I have no idea and want to make the best use of what we'll have access too, whether to sell any excess to Octopus or divert to the immersion, hence looking for some way of calculating this.

Thanks in advance

Qyburn

worlestone said:

the EDDI might make sense, though it's cheap enough for us to heat water with off peak at 9p/kWh.

You should be able to get 15p/kWh for your export, so if you can get all or most of your water heating at 9p then your better off doing that.

QrizB

Qyburn said:

worlestone said:

the EDDI might make sense, though it's cheap enough for us to heat water with off peak at 9p/kWh.

You should be able to get 15p/kWh for your export, so if you can get all or most of your water heating at 9p then your better off doing that.

Exactly this. Solar diverters currently make no sense for most people.