On 24/11/11 09:51, Chris Green wrote:
I don't think our usage is that regular! :-)
Well I'm sure mine isn't either!
I also suspect that the bulk of our electricity consumption is overnight as we try and do all of our washing, dishwashing, tumble-drying (when it's not dry outside) and water heating on economy7. Since the meter already tells us what we used overnight I can't see what further another meter is going to tell us.
It depends what you want to know. If you want the information, and if your appliances have timers, it would be fairly trivial to set the washing machine to start at midnight, the dishwasher at 2am, and so on, then look at how they compared. Or, for that matter, unless you do the same every night, comparing trends from one day to another will tell you a lot too (albeit you could do that with just the meter, but having the data collected for you so you only have to check it when you want to, rather than having to take meter readings manually every night).
During peak rates I think it's quite likely lighting that consumes most but as that's very random according to who is sitting where I can't really see what a 'spot' reading is going to tell us.
A spot reading won't tell you anything, but a sequence of spot readings should. For example, if you have some sudden spikes that'll tell you something different from a pretty much flatline trend. It might indeed just confirm what you already suspect, or it might give you some surprises.
In the grand scheme of things I don't see it saving us any real money; the cost of the kit might be covered by savings we can make by changing our usage or fixing some problems we didn't know we had, but if we get anything more than that back it's unlikey to be a good return on the time taken to investigate it. If I'm honest, my motivation is more curiosity and playing with the data on my Linux box than it is cost or environmental savings. But who knows? Making some fairly simple efforts to reduce water usage actually made a substantial difference to our bills, so the same is probably true here too.