The New Independent Home
by Michael Potts
from chapter 5 :
Mapping Home Energy
Up to this point, although other energy forms have been mentioned in passing, the emphasis has been on electricity. Now is the time to get serious about all the other energy uses in a home, and what will be required to achieve independence. How does your home life fit into the larger planetary energy budget?|
We all consume fossil energy. In the last century North Americans have learned to use up phenomenal volumes. In one year, the average North American is responsible for reducing the sum of global stored energy by more than ten 18th Century North Americans used in their whole lifetimes, a five-hundredfold increase. Of course, these heritage fuels cannot be replaced in millions of years. There is much written about this subject which we do not want to duplicate here.
For the most part, we are unconscious of the energy we squander. Our vehicle addiction is beyond reason. At home, we throw away one out of every two units of energy we buy. Our appliances are inefficient, we use too many of them, and we use the wrong kind of energy in most of our activities. For example, using electricity for heat (in electric water heaters, stoves, or ovens) wastes up to 80% of the original energy. The all-electric dream home of the 1970s has turned into a costly energy-hog nightmare in the 1990s. Many of us seem to be incapable of having fun unless we are wasting energy with leaf-blowers, set-skis, hot tubs, and a million unsustainable pursuits.
You are here invited to participate in two exercises needed to make a sensible energy budget. In the first exercise you are asked to make a drawing of the south elevation of your home, and a map of the space you inhabit extending out about 100 paces in every direction. In my work, I am constantly astonished by the degree to which homes (and most other structures) built since 1920 turn their backs on the free energy around them -- sunlight, wind, and running water. To start using this energy well, you must first understand where it is, and this exercise provides an instrument for finding it. Your job is to map your home site's energy opportunities, or potential income, as well as the liabilities inherent in the site.
Although site is all-important when building a new house, I am often amazed at how much energy can be found and used in the ambient of existing houses. My students systematically find a quarter to a third of the energy they need to run their homes just "lying around" the site.
The south side of a house is the business end from an energy perspective, although all exposed surfaces, even the one exposed to the earth, plays a part. Who would have thought that a roof's slope had any but aesthetic importance? But if we want to get the best performance from expensive photovoltaic modules, they should be pointed to within ten degrees of perpendicular to the sun. One of the most anguished moments for "tree huggers" -- city-bred back-to-the-landers -- is when they understand that not all trees should be kept. In a net heating environment, where heating degree-days exceed cooling degree-days, trees that shade the house or energy harvesting equipment are ready for conversion into firewood and building materials, and we gratefully replace them with lower-growing, more thoughtfully chosen flora.
|A well-organized storm hurled itself at Caspar on February 5th, 1998,|
dropping as much as a quarter of an inch of rain an hour.
About the time the satellite photo was taken, the power failed.
One of the most interesting and curious discoveries for me, as I became accustomed to my land, was the patterns of weather. Hard to miss that the cold, sharp winds dominating our clear weather come from the northwest off the Gulf of Alaska. Storms, which had seemed a random and chaotic phenomenon, attack my house with greatest fury from the southwest here on the northern California coast. In lucky poverty, I chose not to build a driveway to my house . . . and now I am glad that cars must stay a hundred meters away. I recommend this separation to anyone who cares for a sweet-smelling, peaceful place to live. I am quite sure the map I would have drawn during the first year I lived on my land would have missed significant influences, and I am still learning. When I finally acquired a computerized weather monitor and started graphing weather, I discovered that a significant early morning wind blows from the east, the "quiet" side of the house, about a hundred mornings a year. During the winter of 1997-98, which was exceedingly wet thanks to El Niņo, vernal pools and swamps appeared that we had never seen before. A wise neighbor told me when I moved here thirty years ago, "You won't even start to know your land until you've lived here seven years." Thirty-two years later, I begin to think it will take more like seven times seven. How long will it take to learn the land if the climate is truly changing dramatically?|
It will take most people at least a year to complete this mapping process well enough to use it seriously. Elsewhere in this book, wise homesteaders advise that you not build on a property until you have lived a circle of seasons on it. And you will need to be superlatively attentive to nuances during that year. Often, when trying to do this exercise with old-timers, I fail to get good answers about where winter storms originate. "The sky," the more perspicacious hazard. In summer I have been told by old-timers that there are no winter storms in places known for harsh winters. When I insist that the blizzards for which the region is famous must come from somewhere, I often get a blank stare, and the grudging admission, "I don't rightly remember." Civilization disconnects us from the influences of nature, and it takes a conscious effort to reconnect. This is your invitation.
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