Energy usage

I've been taking meter readings from both the gas & electricity meters on a regular basis since our last full supplier change in July 2008. The interval between each reading has been between 1 and 24 days after the previous (generally about once a week) and at a consistant(-ish) time of between 11pm and midnight. The time is less important for long durations reads but more important to avoid skews on 1- or 2-day intervals.

The resulting charting shows our peak daily usage at the very start of January and again a little later the same month:

(I think I need to sort out the time axis)

Surprisingly the peak is not during the "big freeze" with the snow at the start of February. This is most likely because by then we'd identified that due to have a stupidly undersized "compact" radiator in our large loft room. For the baby twins we are keeping this room at a constant temperature through the night and we found the heating in this room was staying on most of the night. Not the time to have the heating off to add another radiator - a project for the spring - so since mid January we've had a 2kw electric heater on a timer* to supplement the radiator. This seems to be resulting in a lot less boiler firing & gas usage (this is also shown by looking at the cortex logs).

Next to do is to add the electricity usage to the chart (which will show a slight increase when the 2kw heater starts to be used) then finally a chart showing total electricity+gas kwh/day. (watch this space)

So what's the point of all this? The point is to get a better understanding of how much energy we're using, mostly because it's getting ever more expensive. And understanding how much & when allows us to see if there are specific problems (like the undersized radiator) or "quick wins" (like using the electric heater to compensate till we have a permanent solution). Plus it gives us more of an idea of the likely cost of that post-winter gas bill....

* ideally the heater would be hooked into cortex as this would nicely fit as a 'secondary heat source' but we don't have the necessary idratek module and at short notice before I went away a simple timer was a good solution