Renewable Energy: Ground-source heat pumps (GSHP)

Lately, I've been talking to a new vegetarian acquaintance -- a physicist with a keen interest in renewable energy -- about geothermal heat pumps, or ground-source heat pumps, to be even more specific (i.e. to distinguish them from air-source heat pumps). I'd mentioned to him my recent visit to an off-grid solar-powered house in the Knowlesville area of NB and he brought up some figures on the cost effectiveness of different types of renewable (and non-renewable) energy in Eastern Canada. Apparently, solar doesn't hold a lotta water for him, mostly because of installation costs and also because of the relatively low amount of sun we get in this colder climate. I did some investigating and am now really intrigued by this type of heating system. Various articles about these ground-source heat pump systems (e.g. this one), claim that by using them, you can lower your heating / cooling costs anywhere from 30-70%. Also, although the initial installation costs are several times higher than installing conventional heating systems, those costs can be recouped within 5-10 years.

Essentially, what happens is that when you dig far enough down into the ground, say, 3 or more metres, you reach a point where the temperature of the earth is constant year-round, varying according to latitude. So the ground source heat pump, using a small amount of electricity and a compressor, extracts heat from the ground to heat your home in the winter, and then in the summer it extracts heat from your home and pumps it back into the ground.

Mother Earth News has a much more detailed (and average-joe-reader-friendly) article on these pumps here. I hope to share more about this type of system as I learn more, myself.

Eliot Coleman and The New Organic Grower

I first heard of Eliot Coleman when a friend of mine -- an enthusiastic hands-on student of organic farming practices -- mentioned a book of Coleman's that he'd just picked up a while back. He insisted that it was a must-read for anyone serious about organic gardening or farming. The book was The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener (A Gardener's Supply Book). I've since picked up my own copy, and not only has it left me looking forward to spring when I can get my backyard garden going again, but it's made me excited about the prospect of someday obtaining my own parcel of land and getting out of the city for good.

First published in 1989, then revised in 1995, the book discusses the various methods and techniques which Coleman has gradually developed during his own (more than a) quarter of a century of smallish-scale organic farming on his own land, on others' farms, as well as in more experimental / educational settings. The information in the book is geared towards maximizing productivity and efficiency (e.g. through techniques such as effective crop rotation), without compromising quality or sustainability. Coleman focuses on ways to ''build'' the soil to improve its fertility, and by extension, to improve plant health without falling back on commercial fertilizers (which ultimately ruin the soil) and toxic pesticides. Of particular interest to me (as I gaze out the window at the fresh heap of snow dumped on my small city these past days) is how Coleman, whose small farm is located in Maine, has learned to extend short growing seasons using unheated and (or mostly unheated) mobile greenhouses (amongst other things) so that even an organic farm exposed to harsh New England winters can operate year-round, and do so with with little or no reliance on fossil fuels or expensive machinery.

His book is regarded as the organic farming guide and the information in it is as useful to the urban backyard gardener as it is to the homesteading market farmer with a 1-5 acre farm. He has a ''small is better'' attitude, asserting that 2.5 acres per person is more than enough land to handle and that those 2.5 acres are sufficient to grow a plentiful variety of vegetables capable of feeding up to 100 people for a year! Throughout the book, he describes a farmer's most valuable tools as those of observation and common sense -- to take notice of what works or what doesn't, and while not being afraid to think outside the box, to always, always learn from your mistakes and then use those mistakes to improve your methods. While farming, Coleman would document everything from seeding and harvesting dates to the daily weather and refer to those notes in later years, for instance. For a sneak peak at the book, here's the table of contents (with links to some excerpts) that he features on his Four Season Farm website.

So I've been curious about what led Eliot Coleman to become the organic farmer's organic farmer. Wikipedia offers up some data about him. Other internet explorations led me to find out that it was reading Scott and Helen Nearing's back-to-the-land homesteading classic Living the Good Life in his mid-twenties that triggered his initial interest in growing food. In 1968, he purchased 60 acres of land from them in Harborside, Maine (then selling 20 of those acres at the same price he'd paid for it them). He and his first wife Sue settled in to a simple life of homesteading, clearing the land and using the Nearings' methods as a starting point. The typical daily routine of their first few years there with their young daughter are discussed in this 1971 Mother Earth News article.

The rest of Coleman's life up until the 1990s involved a lot of travel and a variety of pursuits, mostly centered around the practice and politics of organic farming, and some of which I'll likely write about at a later date. For now, I'm looking forward to finishing up this amazing book and putting in a seed order so that I can start planning my own little garden, incorporating some of his methods.