I'll have to look around for degree day data in my area, and think about how to use it. I once stumbled across a chart with avg degree days, but I haven't found anything more detailed yet. I wonder if I can find a local meteo station, or will I have to do with data for the whole city. I live 20km from the city center, next to a forest, so it's always a few degrees colder here than in the "city" (even though I'm still within city limits).
I don't note prices. Maybe because they are misleading? I invested in insulating my Grandma's attic, claiming it will reduce heating costs. I could feel the difference, as since then the upstairs temperature never falls below 18°C, before it would be 16°C. But when the gas bill for the winter came, it was higher than in the previous years, so Grandma claimed it didn't work. I explained that
- The winter was longer and colder than in previous years,
- Gas prices went up 30% in the last year.
Even though we
used less, we still
paid more. Without insulation the bill would have been even higher. She still said it didn't work since the bill was higher.
Prices are tricky, as even if you record them to be able to see how they change over time, you should also record yearly inflation, etc.