Powering Down

A couple months ago, Maggie talked me into giving a presentation at the Simply Living Fair about our 3-kWh Challenge (which has more details, if the presentation is too high-level for you). The presentation went very well and has some more information (and hard numbers) about our electrical use since January. In my challenge post, I clocked us in at just under 80 kWh, but the official number from Duke Energy was just 71 kWh! The difference is just because we started and stopped measuring at different times, but it still sounds good.

My presentation slides are embedded below, but I’ll add some explanation underneath to replace some of the bits where I talked.

On the graph of our electrical usage, I included one line for each year plus a bar graph series at the bottom that represents our kWh usage per day based on my readings. There’s a LOT of variation, mostly due to hot water heating, the furnace, or A/C. When we stopped using all of those things in June, everything calmed down a lot.

In the end, we used 28% of the electricity we used last year, which is a tiny 14% of the electricity used by the average house our size!

We ended up using 115 kWh in September and are on track to stay under 120 kWh in October, so we’ve been able to maintain usage at 50% of last year’s numbers.

Just looking at electricity, we’ve saved about $175 so far this year and reduced our CO2 emissions by almost 2.5 tons (coal is not a very clean source of electricity)!

We’re incredibly happy with what we’ve done so far and plan to continue trimming as we head into the heating season! We knocked out some insulation projects today that will hopefully help and we’ll certainly keep you updated about the solar furnace!

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2 Responses so far »

  1. 1

    Andy said,

    December 24, 2010 @ 2:06 pm

    Neat presentation, lots of great info.

    I’m not sure the building size directly correlates with the usage though. If I lived in a 1500 sq ft home instead of my ~450 sq ft apartment, the heating/cooling would go up, but cooking, computers, washing clothes, etc. all stay the same.

  2. 2

    Will said,

    December 24, 2010 @ 2:58 pm

    Thanks, Andy!

    You’re right that it’s a rule of thumb rather than a real correlation. Since heating and cooling costs are high enough for most people to drown out other use, it’s a reasonably good approximation, especially since there are a million other variables in play as well (gas vs. electric appliances, ranch-style versus multiple floor housing, outdoor pools, etc).

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