@jeff no, it was 21 with a set back. Probably to 18, I can't remember exactly

@jeff just checked and it was 2.44p/kw for gas and we spent about £140 for it. At our current gas tariff of 4p it would be £230 so that's my comparison target (for the heat pump).

Electricity wise, we used 416kw last December without a HP at a price of 14p/kw - Approx £58. Dual fuel we had a higher electricity tariff as we used so little in a year. Only 1.4MW due to our solar and batteries. This year so far we've purchased 2.7MW and we didn't have the heat pump at the start of the year.

I've finally received my bill for the 21st of November to the 20th of January. Why they billed two months together I have no idea.

Long and the short of it £423 for the two months.

3481kw @ 11.33p once the tariffs were blended plus standing.

1214kw at 5p - £57

2267kw at 15p - £336

Octopus Go and batteries seem to be keeping me in business for the moment

News update from me. The scaffold next door is finally coming down and my solar panels are now back in the sun... after 3 months. At least it was the darkest time of the year that it was up. Hopefully now the solar can start to make a dent into our costs now the full 8.4kw is available to us again.

looks like today might be somewhat of a landmark day for the year. If things continue I think we may well avoid buying any significant "peak power"

Current battery status is 84% so another 3kwh of storage left to fill. It'll be interesting to see if this gets us to 00:30 when the off peak rates kick back in!

I was so close - died just before midnight

@batalto Hi batalto, newbie here (so cant DM you) - wondered if u could advise please....We're being offered a 8kW Midea that can be installed in time to catch the last of the RHI. Our home is much smaller than yours but just wondered how you're finding your Midea? Do you have an on/off thermostat (lots of voices on here saying it shouldn't have one) or do you just use the controller? I'm looking at your helpful COP tracker spreadie and just checking i'm reading it right - e.g. 25/1 : total power in 69kWh, power delivered 179kWh when ambient was ave 4degs with a COP of 2.59? Thanks for any feedback.

@ianjrw I guess I find it fine. The app is a bit crappy and buggy, for example at the moment its not logging data for some reason - no idea why. House is plenty warm now we have the weather compensation nailed. 

On your questions, I am using a nest thermostat. If I was to install again I would use the controller. I will swap to the controller at some point, but its a job that's a bit of a hassle so I'll get round to it at some point.

Yes I think you are correct - its worth remembering that ambient is an average of the whole days temperature. So it would have had a terrible COP overnight when its very cold and a much better one during the day hours. Better to look at the analysis tab which will show the "spread" of power and COPs for every temperature

@batalto thanks, thats great. So no combined COP under 2.5. Any idea why somedays you get better COP on the water, other days on the heating?

@ianjrw it can only be due to ambient temperatures when we are using the heat pump. I imagine there is a bit of an error bar in there too (in terms of measuring power used and heat delivered). However it will be broadly correct.

@batalto nice. I see you have set up your Current weather compensation: 50@-3 and 25@17. Is that easy to do with the Midea - a curve or straight line?

@ianjrw it's just in the installer menu, takes about 30 seconds to change