Our family started on a journey to de-carbonise our house about 8 years ago. When we redid the roof, we put in 12 solar panels. We were just in time to be part of the feed in tariff (FIT) a guaranteed level of income for the power we generated. From this we generate around £200 a year. It’s now no longer available, though the market to buy renewal energy is much more competitive now.
3 years ago we added 2 x 8kwh hour batteries to our system so we could use the electricity we generated by day, at night. In the winter we could top up our batteries at the cheap nighttime rate (7p per kwh) and use it during the day. 18 months ago we got rid of our oil boiler and switched to an air source heat pump. So our house is now carbon free in its energy, and we have one electric and one petrol car.
Our electricity bills for the whole of 2024 was £831 and this includes the cost of running our electric car for about 4000 miles a year.
Things we have learnt
1. the installation disruption isn’t too bad
It wasn’t a big disruption to do all this. The solar panels were a few days of scaffolding and while we were reroofing anyway. We had to replace all the downstairs radiators and the pipes to make them wider bore as heat pumps work at a lower temperature so need to circulate more. The electric works for the car charger, heat pump and panels is considerable but mainly in the area around the electric meter. Indeed our solar panel installer has had to get electrical qualifications to put in the batteries and car charger - so much of renewables is centred around electrics.
2. the capital cost has been high.
We paid around £5k for the panels, £10k for the batteries and car charger and £17k for the heat pump (less the £5k grant, which is now £7.5k). We have just added an extra battery to make our total battery capacity 26kwh, another £3.5k.
3. but the running costs are low.
Our highest monthly energy (ie electric) bill in 2024 for our detached 4 bed house was £148 and our lowest £26. The total cost for the year for 2024 was £831 and this is before our new battery but a full year of heat pump. We have a wood burner, and we keep a low house temperature in winter.
2. It’s a change in daily habits and monitoring energy use.
There are now three apps that my wife looks at to see if the system is working. We can turn the heat up for the cat when we are holiday. We can see how much the panels are generating, when we are using expensive electricity, and more. We plug the car in on sunny days. We run the dishwasher in the middle of the night. Gone are the days when we thought about energy every 3 months when the bills came in.
5. The combination of panels, batteries and a heat pump is key
Looking back just having solar panels barely changed our lives at all. It’s the combination of solar panels and batteries that made a big difference because we could use our own electric and stop the idiocy of exporting by day to earn 12 p per unit and then buy electricity in the evening for 25p a unit.
6. The decarbonising journey goes on
We have a 9 year old electric Nissan Leaf it does for most local journeys but in practice our range anxiety stops us going more than 50 miles in it. The new EVs go much further now - 250 or 300 miles - and make long-distance journeys possible with minimal charging stops. When our very old prius gives us the ghost we will move over and worry about charging two electric car on one Zappi charger!
It would be easy to simply believe that we have spent a lot of money just to decarbonise our house and that is true. But our bills have come down overall and we have a much better, more energy efficient system. Not everybody can afford it, but we could, and every little helps when
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