Thought it would be good to start a thread about what people’s ASHPs actually consumed in electricity. Obviously lots of variables, but good to have some hard data, especially now it’s winter time.
Here’s my whole house readings for 7 Dec 2021 to 6 Jan 2022:
For a 13kW Grant Aerona3 in a 125m2 semi detached chalet bungalow (with a very draughty loft conversion) in Cambridgeshire. Base load of other electrical appliances probably 12-14kWh depending on use of the tumble dryer.
The first week may be slightly too high as things weren’t set up right, but otherwise the ASHP is taking maybe 3kWh on a mild day and 25-30kWh on a freezing one.
Same dates. 160m2 bungalow Lincolnshire. 14kW Mitsubishi. 21C throughout. This is just heating. Dec 25 onwards about 25% high because I wasn't using weather compensation. 10kWh mild and 40kWh cold.
Same kind of time period for 105m2 bungalow in rural Surrey.
105 m2 bungalow in South East England
Mitsubishi Ecodan 8.5 kW air source heat pump
18 x 360W solar panels
1 x 6 kW GroWatt battery and inverter
Raised beds for home-grown veg and chickens for eggs
Same kind of time period for 105m2 bungalow in rural Surrey.
I should add that the energy usage is not a like for like representation of our costs, though. Our solar panels are offsetting the demand and the battery, when not being recharged from the panels, is recharging overnight so most of the remaining demand from the ASHP is actually night time rate energy.
Previously we had an oil fired boiler and got through about 2,000 litres a year. Mid November a 1,000 litre delivery from the most competitive supplier was £605. Mid December it was £672. By my calculations if we had a year with twelve Decembers we’ll save about £400 over the oil costs, and without the solar pv we’d probably just about see parity.
105 m2 bungalow in South East England
Mitsubishi Ecodan 8.5 kW air source heat pump
18 x 360W solar panels
1 x 6 kW GroWatt battery and inverter
Raised beds for home-grown veg and chickens for eggs
We consumed 963.52 kWh of power in December (2021), importing 862.07 kWh because our solar PV generated 101.46 kWh.
So the 862.07 kWh equates to £190 on our tariff which may sound reasonable, but it's not because our heat pump is not working all the time as the HVO in the oil boiler is doing the difficult heating work.
As a comparison, and this is the scary bit, in December 2020 when the heat pump was running solo we imported 2.39 MWh of power. Back then, it cost us £262 – if we'd repeated that kind of consumption this December it would have cost us a staggering £526. It's crazy.
We used 1211kWh total electric in December for a 210m2 bungalow
This includes electric to run the house and both EVs. This equals about £160 on my current tariff (a guess because of the day/night split)
Daikin Altherma 3H HT 18kW ASHP with Mixergy h/w cylinder; 4kW solar PV with Solic 200 electric diverter; Honda e and Hyundai Ioniq 5 P45 electric vehicles with Myenergi Zappi mk1 charger
@luke this is very impressive Luke! Thanks for sharing. Did you fit the room sensor yourself or get electrician in? Presume just order from NIBE?
The room sensor was installed with the heat pump. I'm sure your heating engineer could come back and fit it.
The sensor is recommended for radiator installs as the building responds quicker to heat input changes so I would have thought you'd benefit from it to prevent overshoot as it works with the WC curve to help adjust the required flow temperature.
