I’ve just renewed our domestic energy contract for another year. While checking the bills I noted all the information that the government now requires energy companies to include in consumer bills in an effort to persuade the majority of UK consumers who are on expensive standard variable tariffs to switch to more competitive limited-term tariffs and/or smaller suppliers. I’m guessing that many of those people are on a standard tariff because they switched to a fixed price, limited term tariff at some time in the past and didn’t take action when it came to an end. I’ve diarised the need to investigate the market again in 11 months’ time, shortly before the current fixed term deal comes to an end.
My latest bill gives the typical annual domestic consumption figures in the UK: 3,100kWh electricity and 12,000kWh gas. We buy about 1,550 kWh of electricity and 9,000 kWh of gas and consume additionally an unknown portion of the 3,400 kWh or so of electricity generated by the photovoltaic (PV) panels on the roof. We don’t have an export meter, so the actual amount of self-generated electricity that we use can’t be measured, but it’s estimated at 50% for feed-in tariff purposes. I think we probably export a lot more than 50%, because our annual electricity consumption only fell by about 500 kWh when the PV panels were installed. Adding that figure to our current mains consumption gives a total annual electricity consumption of 2,050 kWh.
There’s just the two of us in the house, but it’s a 100-year-old, 3 bedroom, detached property and we both work from home, meaning it’s occupied pretty much all day, every day. So how is our energy consumption so much lower than the typical figures? Put simply, we’re thrifty. When buying any electrical appliance, whether it’s a lawnmower or a light bulb, its energy performance comes into the evaluation process. We switch off everything that’s not in use at the wall switch and we don’t use an electrical appliance if there’s an alternative – clothes are only tumble dried when the weather is bad for several days in a row, for example, and we don’t even own a dishwasher. We changed over to compact fluorescent bulbs when they first became available some 35 years ago, and now the fluorescents are being replaced with LEDs as they fail.
Ever since the PV panels were installed, we take care to use the larger electrical loads, as much as possible, during daylight hours and one at a time. That helps because then the immersion heater, washing machine, vacuum cleaner or whatever is consuming (at least in part) the “free” self-generated electricity, saving 13.7p/kWh on our new tariff. If we ever do get an export meter fitted then each self-generated unit we use will mean one fewer exported unit, for which we currently receive about 3.8p, but there’ll still be a worthwhile saving. Of course, it’s only a saving if the “free” energy we consume during the day would otherwise come from the mains and have to be paid for, there’s no saving to be made by excessive, unnecessary consumption, even if it is when the sun is shining brightly.
Although the UK’s feed-in tariff for PV generation is no longer available for new installations, the cost of a domestic PV installation has also fallen dramatically. It’s still an investment worth considering for anyone with a suitable roof who isn’t planning to move any time soon.
Our gas consumption fell markedly when we had solid wall insulation installed in 2013. Now, our cottage is cosy in winter; it warms up quickly when the heating comes on, and if there’s any sun during the daytime, even in January, we don’t need the heating on until dusk. The house stays warm enough for radiators in unused rooms to stay off without risk of condensation or freezing in all but the coldest weather. Our previous boiler, replaced in summer 2018, was nearly 23 years old and, according to the official website that provides data for domestic energy assessors, its annual efficiency was only about 76%. In fact, it was almost certainly less than that, because the reduction in the house’s heat demand meant that it was oversized.
The new condensing boiler has a thermal efficiency of over 90%, but changing it before the existing one died wasn’t worthwhile because our annual gas bill was only about £350, and that includes the oven, hob and a gas fire. We’ve reduced our gas consumption by 14%, worth £50, in the 12 months since we got the new boiler, which is certainly welcome but not enough to justify replacing the old one had it still been working.
One of the other ways we’ve reduced our heating costs is by installing a simple wood-burning stove I made out of a gas cylinder. We mostly use it on cold days at the weekend – having to keep getting up to put logs in is just too distracting when working – and our small garden produces just about enough fuel for that. We’ve also got the attic very well insulated and have taken steps to stop draughts throughout the house. Draught-proofing is probably the most cost-effective energy saving measure of all. Whenever it’s blowing a gale I feel around skirting boards, cornices, the holes where heating pipes come up through the floor, window frames and doors with the back of my hand, or use a lighted candle, to detect air ingress and then I seal the gaps straightaway, while I remember.
When I advise my commercial and industrial clients how to save energy, I always recommend starting with the no cost and low cost measures – the low hanging fruit. The savings realised by attention to such things as switching off unused equipment, insulation and draught-proofing can then be used to invest in the slightly more expensive measures, and so on. Often it’s not cost effective to go very far down this route, because the energy consumption will by then be so much lower than it was to start with.
The same process works equally well at a domestic scale. Recently a friend asked me to have a look at his house because he was shocked to learn that our electricity consumption was less than half his, even allowing for our self-generation. I realised why as soon as I stepped through his front door; the hallway was lit by several wall-mounted and ceiling-mounted flush light fittings, each of which contained a pair of 60W candle bulbs. In total the hall lighting was consuming 600W, and my friend left the lights on all evening. The rest of the house was much the same. Replacing these power-hungry bulbs with LED ones was an easy win.