Appletree Cottage, Fifehead Magdalen, Gillingham

 Near the end of 2018 we moved into an ordinary-looking house in a pretty village in North Dorset. We chose the house because of the lovely view across the Blackmore Vale, and because the house was south facing and wasn't thatched! We discovered that it had cavity wall insulation (so an expense we didn't have to budget for) and thick loft insulation, so it was already cheaper to run than most houses of the same size. And it has the benefit of a glazed extension (conservatory is too grand a word!) which warms up very nicely, even in winter sun. 

 

However, it had an oil boiler which was smelly and pumping out CO2 at a rate of knots, so we embarked on our plan to reduce our carbon footprint, which we'd been wanting to do for years but never had the roof space nor the southerly aspect. Four months after moving in we had 15 solar panels installed, giving 4+kwh at peak, and a month or so after that, the 13 kwh Tesla Powerwall was installed to store the solar-generated electricity. We just managed to qualify for the last of the FIT grants, albeit at the lowest rate of about 4.5p a unit, and estimate the solar will pay for itself in about 12-15 years. 

 

In November of 2019 the Air Source heating was installed. This involved an upgrade of all the radiators because of the lower water temperature in the system. We quickly learned that because of the slowness of heating the house, unlike oil or gas heating, switching everything off overnight in winter is not an option! We now just keep it ticking over all the time. With the RHI payments we'll recoup about 3/4 of our outlay in 7 years. 

 

We originally had an Economy 7 meter so used off peak electricity to charge the Tesla overnight, and output during the day. This worked well, but in April 2021 we enrolled with Octopus on the Tesla Energy Plan, where our import cost per unit is the same as the output cost per unit, and Tesla control the charging of the Powerwall, with the aim that with many setups like ours, Tesla have a "virtual power station" to send stored electricity to the grid at peak times. We like this idea very much of using battery storage to save up low CO2 electricity such as wind or solar, and allowing the country to benefit, so we will continue for as long as Tesla and Octopus want to run with it.