Modelling load profiles
I’ve been trying to figure out how to model load profiles for different appliances. There are a few different approaches but the most sensible approach begins by assuming that, for an appliance to be used:
- the household needs to be occupied (i.e. somebody’s home)
- the household occupant wants to use the appliance (a desired activity)
- the activity requires a certain appliance
There are some different ways to allocate the precise timing but I think I’m going to simplify this approach. I’ll test it and then if that doesn’t work I’ll try something different.
CodeZoo
I just came across CodeZoo, which is a recently launched site with free libraries for a whole bunch of standard tasks. It looks like it should be really useful – just a quick browse brings up all sorts of things that I might want to use.
Fancy math
I came across another interesting article on simulating load profiles and this one suggests using principal components analysis and some regression. I had a go with it yesterday and managed to get a pretty good approximation using one year of electricity demand data at hourly interval. Running princomp in R, I picked three components out of 24 and that covers 98% of the variance. Check it out (click for bigger):
The next step is to add some exogenous variables and see if I can generate new curves given likely temperatures, days of the week, holidays and so on. I’ll have to brush up on my matrix math a bit first though.
New mail!
I ordered a copy of Java in a Nutshell a couple months ago and it finally arrived today. It looks pretty good but as my office mates pointed out, what size nutshell are they referring to? The thing weighs in at over 1200 pages!