It all started in 2014 when he was considering buying a car to commute to York, about 20 miles from where he was living at the time. He decided to try a pure EV and obtained a Nissan Leaf through a lease just as a trial. The first thing he noticed was that the monthly cost of the lease was less than what he had been previously paying in petrol, so a very worthwhile way of commuting! He was very impressed with the performance, although range was a bit of an issue at the time so he made the decision to purchase a replacement once a high-spec electric SUV came onto the market. In 2017 Jaguar announced the i-Pace so he paid the deposit and has enjoyed high performance petrol-free motoring ever since.
However, the story does not end there. From Day 1 he was keen to find a way of powering the car from an alternate, sustainable source. He then turned to solar power. He could not install roof panels on the house – ideal as south facing and above the tree line – as the house is Grade II listed. He opted instead to go big and installed 26 panels of 355 kW capacity each in the field next door, a total of 9.23 kW. This is just within the planning consent limit for a private PV system of 10kW. He also installed a battery bank with an equivalent capacity of 30 kWh.
The panels are south facing (obviously) and inclined at 35° – the optimum for that latitude. Since installation at the end of January to the end of June it has produced, on average, about 40 kWh per day. On a sunny July day it produces in excess of 60 kWh per day, where on average he uses about 20 kWh per day. The car consumes 7 kW (a total capacity of 90 kWh and consumption rate of 34 kWh per 100 miles) and his wife – who is a potter – has a kiln which consumes about 9 kW for about 8 hrs when firing (about once per month). Batteries are probably a luxury as he notes feeding back into the grid is probably a more attractive option than storage, but they do provide a sense of security. Batteries provide power at night and on very dismal days, which are common in Yorkshire! The grid essentially acts as a seasonal battery. If you are going to experience any shade at any time he says “optimisers” are essential as they allow the best panels to still perform well, which is something most suppliers fail to mention. He also installed a 900W wind turbine and harnessed that to the battery as well just in case!
Finally, given the excess energy now being produced he has replaced his old gas boiler with an electric boiler – which also only heats when excess energy is available. Its still early days but he notes he is still putting energy back into the grid even after the conversion…
Doing a cost benefit analysis – as engineers do – he calculates he is getting a 15% IRR assuming a life of 10 years with a payback period of <5 years. This can only get better with energy costs increasing as they are right now. So, what started out as an in-principle project to “go green” at any cost has become economically attractive.
In conclusion, solar panels, despite the UK’s profusion of cloudy days, seem to make economic sense, where a substantial household, including electric boiler, potters kiln and electric SUV can be run sustainably from the PV installation. Well done for leading the way, Pat!