calculating monthly usage gas+elec

bigleblowski

Hi MSE peeps.


Long time reader, first time poster. I was wanting to know if anybody has any idea how I could calculate a projected average monthly usage figure for both gas and electric? I'll explain a bit. I have moved in to a new property and have started to record my monthly usage in an attempt to roughly predict what my expenditure will be (vs actual when figures received). I only have a months results so far ;-). Given that we are in December and it's a little bit chilly/dark outside I fully expect the bills will be a bit more at the moment than e.g. July. Does anybody have any idea roughly what percentage less a double glazed, reasonably energy efficient one floor apartment with two occupants uses in summer months compared to winter? I realise this is a highly subjective and specialised question but I'm only looking to get a decent estimate so I can be sure to pick the best tariff. Thanks in advance for any light you may be able to shed on this.

Robwiz

How long is a piece of string? It depends so much on your lifestyle. The biggest consumers of power will be heating and hot water. Much depends on your set temperature and the hours you run your heating and the number of showers/baths taken. After that, cooking, washing and dishwashing are all significant uses – but if you eat out a lot or buy in takeaways your energy use will be lower than if you cook from raw ingredients, bake your own bread and cakes, etc.

That said, we find that our usage during the winter months is around twice our summer usage and the spring/autumn shoulders are approximately half way in between.

You'll get more of an idea of what influences your consumption if you take meter readings more frequently. I switched to weekly and still wasn't able to make sense of the variations so now read them daily. It's possible then to correlate consumption with outdoor temperature and our lifestyle.

ilikecookies

Welcome bigleblowski!

As Robwiz says it's really hard to advise because they are just so many variables in play. Any estimates/comparisons will be so rough-and-ready that I'm not sure they will be of much use to be honest.

It's a case of collecting the data religiously and then analysing it once you have enough months of data. I take electricity meter readings each month (and also submit them each month to generate a bill so I know what those readings equate to in pounds and pence). As we are off-grid I also measure how much oil we have in the tank each month too.

In our circumstances (5-bed house, double-glazed but still strangely drafty and cold) we spend about £35/mth on electricity in the winter (we're on Economy 7) and as little as £15-20/mth in the spring/summer (I blame the tumble dryer and lights!). In terms of oil we can use up to 400 litres/month in coldest winters (when the central heating is on) but just 50 litres/month in the spring/summer when we only use it for hot water. So as you'll see our winter usage is dramatically higher than spring/summer so we save up on that basis.

It's quite eye-opening when you have the data. The old adage "what gets measured gets managed" definitely applies in this house!

Good luck. If you need any more specific advise let us know!

bigleblowski

Thanks for the replies. I know there are a lot of variables to account for. I think if I work on the basis that usage will be approx. 30-40% less in the summer then I can be reasonably confident that I'm not over estimating by too much. Have started work on a spread sheet that calculates the data for me, so I know what my bill will be before I receive it. Intend to harvest a lot more data over the next few weeks/months. Hopefully should start to build up a pretty accurate picture by then. It's almost fun, in a weird way :-)


Thanks again