Finally finished my 2020 heat pump performance and home energy review. We achieved an average heat pump COP for the year of 3.91, a heating cost of £208 and a unit cost for heat of 2.73 p/kWh. The new blog post is available here https://trystanlea.org.uk/heatpump2020 

The average space heating COP was 4.2, average water heating COP 3.83 and combined space heating, water heating and standby COP 3.91

Here's the monthly electricity input into the heat pump separated out by space heating (orange), hot water (yellow) and standby (grey)

Separating out the standby consumption was a new element of the analysis this year, the average COP for space heating and hot water without standby was 4.11. The standby consumption mainly in summer dragged it down to 3.91

In comparison with mains gas with a 80% efficient boiler I calculate that our heat pump was 43% cheaper and reduced CO2 emissions by 82% (including standing charge and cost and emissions associated with gas boiler electricity consumption)

Our total electricity cost for the year was £589 on @octopus_energy Agile. Our average unit rate for the whole house was 9.8 p/kWh (inc VAT), heat pump: 10.7 p/kWh and EV: 7.6 p/kWh, lighting & app 11.1 p/kWh. The following chart shows the monthly breakdown by component

I also looked at carbon emissions based on half hourly co2 intensity data from https://carbonintensity.org.uk . Heat pump 192 gCO2/kWh for the electric (49 gCO2/kWh heat), EV 167 gCO2/kWh (44 gCO2/mile), lighting & appliances 196 gCO2/kWh.

Finally the blog looks at a comparison between the energy assessment I did on the house and our actual in use heating energy use, we used 14% more heating energy in 2020 than 2019, partly due to increased comfort and partly just increased occupancy, but still 38% less than SAP..

For the more detailed discussion see the blog post here https://trystanlea.org.uk/heatpump2020  and for an overview of the heat pump see the video I put together last year on the system here thanks all for reading & watching! :)

I've written a blog post on the @Openenergymon monitoring system behind the above analysis here https://trystanlea.org.uk/monitoring