The Energy Audit: Part One

I’m auditing myself to figure out what my environmental footprint is.  Part of this analysis needs to look at the energy that I consume. 

To keep this initial energy audit simple, I’m going to just look at electricity.  I have a natural gas water heater, that I’ll look into later.  Also, I’m going to leave out the gas that I use in my car, and the gas required to get food and goods to me.  For now, what I want a clear picture of is how much electricity I am using, primarily in my home. 

Like with my water provider, there are some great online tools that make this pretty easy to figure out. Puget Sound Energy provides my electricity usage over the last two years.  The last billing statement I got says that I used 553 kilowatt hours of power.

Um…what is a kilowatt hour?
Kilowatt hours (abbreviated as kWh) are the unit used by power companies in the US to bill against.  It’s based on the watt, which we should all be familiar with from light bulbs. 1 kilowatt hour = 1,000 watt hours. So, a 100 watt light bulb running for one hour would use 100 watts of power, or .1 kilowatt.

A good way to visualize a kilowatt hour is to think of some of the following examples.  It’s enough power that you could:

• Run 10 lamps with 100 watt bulbs for one hour
• Run your vacuum cleaner for one hour
• Run your hair dryer or microwave oven for one hour
• Watch TV for 10 hours.

Now we’re prepared to look at our power consumption in terms of kWh.

So -- how much power am I using?

Our average power consumption over the last 6 months was 474 kWH. 

Now, notice the big dip from two summers ago?  We have a cooling/heating system in our condo that works by blowing air over hot or cool water.  About a year ago, it started leaking like crazy into our bedroom whenever it ran.  We haven’t gotten it fixed yet.  What’s remarkable about this, is that when we were using it regularly (just during early morning and evening hours), we were using 2.5 times more power per month. 

We survived this summer pretty easily without A/C.  But now it is winter and I’m working from home.  As I type this, I’m sitting in a chair with sweatshirt, hat, socks, gloves, and a huge blanket and still have to stop typing every few minutes to blow into my hands. I am FREEZING. It’s not comfortable, and I’m going to have to fix it.  The trick will be how to do it in an energy-efficient way.  There’s no way we’re going back to the old system – it is a ridiculous power sink.

How are we doing compared to the rest of America?
According to the Department of Energy, the average household in America consumes 10,656 kWh per year.  According to my averages, with our heating/cooling system broken, we consume 6348 kWh/year or 60% of the national average. Which makes sense. We're a relatively smaller household with no children, so our power needs are going to be more in control.

However, with our heating/cooling systems working, however, we consume 37% OVER the national average.  Just goes to show how one small change can make sure a huge difference.

The next step for the energy audit was to understand which devices were using the most power.  Click here to read the next article in the series: Which household appliances draw the most power?