Energy Diet

The assignment in this second week of the 360 Energy Diet is to tally our stats for how much water, electricity, natural gas and gasoline we use every year by checking our monthly bills. Also, we must decide on one thing to track numerically over eight weeks. “This could be one of the items above; how much meat you consume in ounces or grams; how many bottles of water or soda you drink; or something else that you think could have an impact,”  diet coach Christina Nunez said in an email. (Check out how Christina did in the first round of the 360 Energy diet.)

I spent a few hours today tracking down utility bills. Because I don’t keep the old bills, I was obliged to register online with the various service providers. As a result, I will from now on be paying natural gas and electricity bills online–which is another nail in the business model of the U.S. Post Office, but surely better for the environment in the form of less paper and energy consumption to power mail delivery vehicles.

Going online to access my accounts also provided something I hadn’t expected: Both Washington Gas and Dominion Virginia Power provide links to advice and assistance to reduce energy consumption.

Dominion states on its website that the utility is committed to helping Virginia meet its energy goal –and  that’s why it’s offering energy conservation programs to help customers conserve energy and maximize savings. The company is running a number of energy efficiency and peak-shaving programs  “designed to meet the needs of our customers and move us towards meeting the state’s 10 percent voluntary energy conservation goal enacted by the Virginia General Assembly and the governor in 2007. It provides environmental benefits in a cost-effective manner that translates into very real financial savings for our customers.”

So I enrolled in the Smart Cooling Rewards program that pays U.S.$40 for letting Dominion cycle on and off our air-conditioner or heat pump system during periods of high demand.  “You’ll be helping your wallet and the environment,” Dominion promised.

Next I studied the electronic records of our natural gas and electricity consumption. The table on the right is extracted from our electricity bills of the past 18 months, courtesy of Dominion. The important number, in my view, is the average daily consumption of kilowatt hours (kWh). I have marked the peak months — the dreaded Northern Virginia summer when the air-conditioner cranks to keep the house tolerable. It’s in these months when the Smart Cooling program is supposed to kick in by turning the air-con off for up to four hours at a time. I’m expecting a meaningful reduction in our energy consumption this summer and will keep you posted.

While both utilities provide a record of how many therms and kilowatt hours we consumed every month, Dominion also has a neat function that allows its customers to really drill down into consumption and understand where and how they can make a difference. Look at this example of our most recent electricity account: (Click on the image to enlarge it to a readable size.)

What I am looking at here is a comparison of our electricity consumption in May 2011 vs. that of April 2011 and also May 2010. I was struck by how complicated the energy savings game can be. There are a lot of factors to be considered, not least average external temperatures and the variable prices of energy. But notice from the table at the top of this post that in May this year we used less kWh than any other month of the past 18 months. If I recall correctly, we used less energy primarily because April was a particularly pleasant month and we did not use the air-con at all.

For the sake of completeness, I am also including our natural gas consumption records here. You will see the peak months are winter, when the furnace that powers the central heating cranks up.

It’s pleasing to note that total therms consumed in  the 12 months to April 2011 were 759, down from 842 we used in the year before that.

The 360 Energy Diet obliged me to take careful note of our domestic energy consumption and I have learned a lot. I have enrolled in the Dominion program to save electricity this summer — and earn $40. Perhaps we can use that toward investing in something else that will conserve energy in our home.

We have elected to track electricity consumption during the next eight weeks. I will let you know how much energy we “lose.”


  1. Chad Lipton
    June 10, 2011, 2:34 pm

    Great data, David. Your decrease in nat gas can probably be explained by the severe winter of 2010 where it snowed 30+ inches. The average temperature was colder, therefore you would have used more gas heat. At any rate, there are mindful things you can do that are in your control for this coming winter. Hopefully we can uncover some things during the energy diet.

    If I correctly understand Dominion’s summer AC program–based on familiarity of BGE and Pepco programs–Dominion is not necessarily going to turn down the AC on a regular basis. They retain the right to reduce a home’s AC if they face a potential black out or brown out in the region. Over the course of the summer it is possible that they will only exercise that power a handful of times.

    Your best bet to capitalize on similar savings is to use a programmable thermostat. There are four settings: wake, leave, return and sleep. Instead of explaining everything in this blog response, I’ll refer to a website. It is worth the review: