I started experimenting with solar in the early 1970s with the construction of a Trombe wall, possibly the first in New Mexico. A Trombe wall is essentially a very thin greenhouse with glazing applied vertically to a stone or adobe wall. The glazing can be in the form of clear fiberglass, polycarbonate or glass, with a two- to six-inch air space between glazing and wall surface, which is painted black to absorb heat. Heat migrates through the mass of the wall in the course of the day and radiates into the living space throughout the night. Being vertical, Trombe walls collect solar radiation only in the winter, not in the summer when the sun is high overhead.
Next came an attached solar greenhouse inspired by the work of solar pioneers Bill and Susan Yanda; it consisted of an 8-by-30-foot structure attached to the bedroom wing of our south-facing, homemade adobe house. The Yanda design called for the glazing to be sloped at 45 degrees. We started out with polyethylene sheeting because it was cheap, replacing it soon with Lascolite, semirigid clear fiberglass panels. But the 45-degree angle presented several problems. As you approached the south wall, headroom decreased, limiting easily usable indoor space. And the greenhouse overheated in late spring, summer and early fall.
The greenhouse has since gone through several iterations. In version two, we tore down the 45-degree-angle framing and replaced it with vertical framing and double-glazed, glass patio-door inserts. Four feet of the roof was sheathed with double-wall polycarbonate panels and four feet of insulated roofing, which eliminated the overheating problem. But the greenhouse space, which opened into the bedrooms via two sets of French doors and into the kitchen via double windows, was too narrow for multiple uses. In the springtime, we started 10,000 plants for the farm. In the fall, we cured some 50 bushels of winter squash. In both cases, there was little room for anything else. And, throughout the winter, much of the space was taken up by large pots of tomatoes.
Twenty years later, in the fall of 2013, we completed version three, expanded to 14 by 36 feet, with an insulated concrete floor replacing uninsulated cement floor tiles. We were able to reuse the double-glazed window panels. The added space allowed us to install a ping-pong table, which doubles as a dinner table for large parties, and a stock-tank fish pond to maintain mosquito fish or gambusia to replenish the pond of our outdoors-constructed wetlands, which is our own little sewage-treatment plant. And we still have room for spring vegetable starts, a dozen large potted tomato plants, a fig tree and a Meyer lemon, and room in the fall for 20 bushels of winter squash.
But the attached greenhouse is not our only season-extending tool. About six years ago, we had a 14-by-30-foot unheated hoophouse built. For the first years, we used it to grow tomatoes. Our farm is in a cold spot in the Embudo Valley, and we can have light frosts into early June and frost on the lawn in mid-August. The hoophouse added a month at both ends of the growing season for tomatoes and gave us a much better harvest. But there is quickly a glut of tomatoes each season at the Santa Fe Farmers’ Market, where we sell most of our produce. So, last fall, Scott Moore, who manages the farm now, tightened up the hoophouse and planted various greens and several types of lettuce, which have thrived through the winter.
In spring 2013, SolLuna Solar, based in Dixon, installed a 3.65 kW photovoltaic (PV) system atop our guesthouse, a net-metering system that, at the time, generated almost enough electricity to satisfy all our needs. This and the new greenhouse expansion led inadvertently to a solution of the problem of solar hot water in the main house, in the form of a heat-pump water heater. Heat pumps work like refrigerators, extracting heat—or cold—from the atmosphere. Our heat-pump water heater pulls heat from the greenhouse air and turns it into hot water, a simple and elegant solution to the hot-water problem. Within a year, savings in propane use have essentially paid for it. By contrast, solar hot-water systems are complex and expensive in northern latitudes where freezing is an issue, though our heat-pump water heater is fed by two simple solar tanks on the roof. Rebuilt 1984 Cornell batch heaters, they are made up of two 30-gallon tanks enclosed in insulated, reflective cabinets with triple glazing.
In the course of rebuilding the greenhouse in 2012, I had a 240-volt line installed across the roof, to the end of adding an outlet in the garage for a plug-in hybrid or electric car. This we acquired last fall, a 2012 Chevy Volt, which has a 30- to 40-mile range on battery power alone, shifting to gas-powered electricity generation thereafter. On a recent trip from Dixon to Española and back, the car ran at 199 miles per gallon. A Dixon-Taos round trip yields up to 160 miles per gallon, and Santa Fe and back, with four hours of recharging in the Railyard public garage, about 85 miles per gallon.
All of this does not entirely free us from big oil or big coal, upon which everyone will always be somewhat dependent, if only for the energy needed to manufacture equipment for generating renewable energy (RE) such as solar panels and windmills. We need a few more PV panels to completely cover our electricity usage, but most of our space-heating needs and all of our hot water are provided by our attached greenhouse. More than half of our northern New Mexico driving is powered by the electricity we ourselves generate. Propane still serves for cooking and for a small, efficient space heater in our bedroom. We still use diesel for our tractor at the rate of about 30 gallons a year and gasoline for the farm pickup, which averages 20 miles per gallon.
On the farm, we pay self-employment tax but little or no income tax and, thus, have been unable to benefit from various RE tax credits. For the PV system, these amount to about 30 percent of the cost of the system. For a new Chevy Volt or other electric car, the tax credit is $7,500. This leads me to wonder why so many middle-class people fail to take advantage of these subsidies, to the end of reducing their carbon footprints and having a positive effect on global climate change. Inertia? Apathy? Ignorance of new technologies?
An old argument is this: “Why pay all of your electricity 15 or 20 years in advance by investing in a PV system?” To which an obvious answer is, why not radically reduce your carbon footprint while you can? Or, instead of installing PV, are you willing to continue to add to carbon pollution these next 15 or 20 years?
Another argument is, “It will take a major catastrophe to change things,” which is the litany of those who believe that it will take a major catastrophe to change things. Another couple of Katrinas or Sandys, the failure of the Atlantic Gulfstream, the permanent flooding of Miami and New York, the drying up of Sao Paolo or Los Angeles. This ignores the fact that we ourselves are already that catastrophe, in the millions of gallons of petroleum and tons of coal we have used up over our lifetimes for heating, cooling, lighting, transportation and consumer goods. The operative term here is “it”—referring to out there, the forces of good and evil, the political system, the oil and coal companies. What’s missing is “me” and “you.” What? I can’t change without being driven by a major catastrophe? You can’t?
In my lifetime, we have gone from gas-guzzlers to relatively fuel-efficient vehicles, from the typewriter to the computer, from the wall phone to the smart phone, from ocean liners to jumbo jets, from fountain pens to ballpoint pens, from paper maps to GPSs, from hot air balloons to drones. None of these technological changes have been purely positive, but the shift away from largely fossil-fuel sources of energy to largely renewable sources requires little more personal adjustment than some of the technological changes of the past 75 years. With, however, one caveat: the future of the human project is now at stake. If we wish to see our children and grandchildren live in a world not driven by extremes of climate change and resultant civil and international strife, then change we must—and fast.
In the present political and environmental climate, doing nothing is not an option. As drivers of cars and consumers of food and fossil fuels, we are living lives that we cannot morally or intellectually defend in a world of gross inequality and unprecedented human-induced habitat destruction and species extinction.
Going solar—as much as you can—may not save the world, but it is doing something positive. It’s setting an example, and, who knows, if widely enough followed, it may well end up helping save the world in the long run.
Stanley Crawford has farmed and written in the Embudo Valley of New Mexico since 1969.