After installing all these technologies, we received not just the EPC A rating we desired, but also a very warm, comfortable home and drastically reduced energy bills.
Based on December 2023 energy rates, we are looking at savings of £1,210 annually.
We are very happy that the house's carbon footprint is down from 2.7 tCO2e in 2020 to 0.6 tCO2e in 2022 and our running costs are only £350/year (plus £100/year gas standing charges for the gas hob).
General Learning Points
- Ensured we had a well-insulated draughtproof house before installing the heat pump – invested £10k over the years on insulation and £16k on new windows.
- Probably wouldn’t install solar thermal – PV generation through a heat pump can efficiently generate hot water.
- Current inverter can only produce 2.5kW from battery – made changes to how we use the kitchen ie a 3kW kettle changed to 1.5kW kettle (takes longer to boil) / don’t put the kettle and toaster on simultaneously
- Heat pump pulls 3kW on startup so cannot run 100% from battery.
- Participated in demand response periods – the utility company pays us for not using electricity at certain peak times in winter (heating setpoint lowered during period to ensure heat pump not operating / ensure battery full beforehand) – rates for saving electricity / discharging the battery to the grid can be over 400p/kWh.
- Still have gas installed for cooking hob but will probably change to induction saving £100/yr.
- Would now change wood burning stove to 3kW direct (external) air supply stove and seal up the floor vents.
Also see this information on the Energy Saving Trust Green Homes Network site:
Eco Retrofit - you want to eco retrofit your house but don't know how?
Cumbria Action for Sustainability https://cafs.org.uk/retrofit-made-easy/ are doing great work and have a lot of resources. Although they only operate in Cumbria, their on-line videos etc are still very helpful: www.youtube.com/@CumbriaActionForSustainability/videos Especially look at the 4 EcoRetrofit for Householders videos which are recorded webinars by experts.
General heating and heat pump design ideas:
We have found the Heat Geek very interesting in how to design and operate a heating system for our house. His site is: https://www.heatgeek.com/ and he has accredited a range of Heat Geek approved contractors around the country. If you like "how to" videos, his channel is www.youtube.com/@HeatGeek
Heat Pump consultancy:
For Fife and the Scottish central belt, if you have already addressed the draughts, insulation and windows in your house and are now looking to get a heat pump installed, then for a fee, Keith at www.theheatpumpguide.co.uk/ could survey your house, calculate your heat loads, work out the correct size heat pump, get contractors quotes, and support you through the install.
Weather compensation - if you want to learn more then look at Heat Geek videos above, but there is interesting data on https://energy-stats.uk/vaillant-arotherm-weather-curve-information/