Energy Solutions

Last week we examined the amount of energy it takes to transport and treat water — and how we can conserve energy by using less water. This week, we’ll look at the inverse of that: how much water it takes to produce energy and how our energy conservation efforts reduce water use.

The water intensity of energy

It takes a lot of energy to transport and treat water in this country, and it takes a lot of water to produce the energy we use. To put this a different way: when we save water we save energy, and when we save energy we save water.

Last week, I touched on some of the strategies coming out of the “hypermiling” movement to boost automobile fuel economy. Here are a few more:

1. Lighten the load. The more weight we haul around in our cars or trucks, the more energy we use. If you keep sandbags in the bed of your pick-up for winter traction, remove them in the summer. Empty your trunk of those unneeded items you’ve been hauling around.

In this column I usually focus on how to save energy in our homes and businesses, but for many of us, getting around is our largest energy consumer—particularly in the summer months when we’re not heating our houses. Some of us are lucky enough to have hybrid cars, and this gives us a head start in saving transportation energy. I just calculated that the 2003 Honda Civic Hybrid we own, which averages about 40 miles per gallon (mpg) year-round, has saved us about 2,800 gallons of gas over the 146,000 miles we’ve driven it (compared with a car getting the U.S.

I had the good fortune last week to spend a few hours touring the Bensonwood offices and factory in Walpole, New Hampshire. I’ve known Tedd Benson for perhaps 20 years, and knew of him a lot longer than that through his writings. He pretty-much created the modern timber-framing profession, starting back in the early 1970s when he set out to reinvent the craft of timber-frame construction that our New England ancestors used centuries ago.

Last week, after reviewing a little physics regarding condensation and latent heat, I described how air conditioners remove unwanted humidity. This week I’ll examine how dehumidifiers work in removing moisture and when it makes sense to use them.

Last week, I addressed strategies for controlling moisture sources in homes during the summer — one of the contributors to discomfort during hot humid summers. This week, I’ll examine how to remove unwanted humidity using air conditioning equipment, starting with some fundamentals.

To understand moisture removal, it’s important to brush up on a bit of physics. Air is able to hold only a finite amount of water vapor, and that amount is governed by the temperature of the air.

High relative humidity is a significant problem in many regions of the country during the summer months. In hot weather, the higher the humidity, the less comfortable we are--partly because moisture does not evaporate from our skin as readily. More worrisome over the long haul, high humidity levels in the air and high moisture content of materials in our homes can result in mold growth, which, in turn, can cause allergies and other health problems (as well as damage the building itself).

We’re into those hot days of summer--really hot--with temperatures predicted in the mid- to upper-90s, even in Vermont, this week. In this column I’ll provide some simple tips for keeping (reasonably) cool in hot weather or, if you use air conditioning, operating that air conditioning equipment most efficiently.

Keep the sun out

One of Vermont’s longest and most treasured covered bridges now has the newest, most environmentally responsible lighting. This past weekend, the 267-foot West Dummerston Covered Bridge (the longest operating covered bridge fully within Vermont), built in 1872 by Caleb Lamsom and listed in the National Register of Historic Places, was fitted with state-of-the-art LED lighting.