Understanding Energy Conservation

Living with renewable energy is fundamentally about energy conservation. However, in the context of discussions about energy usage, conservation can have different meanings depending on the perspective taken.

A woman mentioned to me recently that she and her husband thought they could retrofit their grid home with renewable energy because the house was already "energy efficient" and incorporated many "energy conserving" appliances.

The problem with that idea is that she was defining energy conservation in utility company terms, not in renewable energy terms. Utility companies have made a big push in the last few years for energy conservation. They have done this because they have discovered that slowing the demand for electricity means they don't have to construct new generating plants costing hundreds of millions of dollars with millions more needed to operate them.

A utility company that preaches energy conservation tends to promote appliances and lighting systems that will reduce your energy usage 10-20%, relative to less efficient appliances that do the same job.

It is important to understand the distinction between the utility company's view of energy conservation and the energy conservation inherent in renewable energy. If you replace your existing appliances with more efficient ones and reduce your energy consumption by, say, 15% you won't really make much of an impact in your monthly bill. It might go down about 5 bucks a month or so. A whopping 60 bucks a year.

However, for the utility company that 15% is significant. It means they don't have to build those new generating facilities and can sell you electricity generated by existing less expensive facilities. That improves their bottom line and keeps their stockholders happy.

Now, don't get me wrong, I'm not at all suggesting that is a bad thing. Energy conservation in any form can only help us all in the long run. But that kind of energy conservation is significantly different from the conservation built in to a renewable energy home.

I'll use our home as a comparison. Say a person who wanted to convert his grid home to renewable energy has a monthly bill that averages $35. Using IREA's current rate of 8 cents/kWh (kilowatt hour) he is using 437.5 kWh/month. If his energy conservation techniques reduced that bill by 15% he would be paying $29.75/month for 372 kWh.

Our home turns those conservation figures completely around. We use about 60 kWh/month, a reduction of more than 85% from his original usage. That equates to a utility bill of $4.80/month. It certainly wouldn't be in a utility company's best interest to encourage that kind of conservation. Their revenue would drop considerably if they did. If everyone with utility grid connected homes practiced that kind of energy conservation the utilities would be scrambling to do whatever they could to increase electricity usage (anyone remember Ronald Reagan advertising the GE all-electric home of the fifties?). Or worse, they would just raise the rates to compensate (which would really make renewable energy affordable).

So, as you can see, it doesn't make much sense to convert a typical grid-connected "energy efficient" home to renewable energy because the efficiencies involved are of a different scale. It would take a very large renewable energy system to power even a modest "energy efficient" grid connected home. Far larger than even the system I talked about in the last column.

Conversely, it would require a considerable redesign of a grid connected home to reduce its energy consumption to the point where renewable energy would be affordable, and that redesign would, itself, be expensive.

I had to tell the woman I spoke to that she and her husband would be better off learning as much as they can now about renewable energy and incorporating it into the new home they hope to build in the near future. The last time I talked to her she reported that were both excited about renewable energy and were working on plans for a renewable energy home.

All Contents © 1997
Wagonmaker Press
Thomas W. Elliot


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