New Mexico homeowners and businesses now have until February 15 to apply for 2007 state tax credits for solar energy systems installed during this past year.

My Day in the Sun

Our life is frittered away by detail. Simplify, simplify.

-- Henry David Thoreau

hen I first moved into my house, an oddly elegant renovated miner’s cabin in Madrid, the woman who fixed it up, Shannon, told me she used to build and paint furniture in what’s now my dining room. With four floor-to-ceiling south-facing windows, that room is so cozily toasty even on a bitter February day, thanks to all that concentrated sunlight, that Shannon bragged, "I used to work in here totally naked!"

Unfortunately, the heat doesn’t radiate out to the rest of the house after the sun goes down -- it evaporates -- and when I moved in, the original heating system was two ineffectual little propane-burning wall units, one in the dining room and one in the living room. Needless to say, it was pretty cold in there from fall through early spring, not to mention expensive to try to heat. So when it became apparent that oil prices were only going to continue rising, we unhooked the heaters and put a woodstove in the living room, and now it’s much warmer in there.

But wood’s not exactly cheap, either, nor available in endless quantities. So what about all this solar heat in the next room? Is there any way to take better advantage of that? It’s great till the sun drops down over the mesa and the nighttime big winter chill descends over our valley, then we’re back to huddling around the stove.

Can I make my solar dining room work for me without spending thousands of dollars? There are ways we can all retrofit our houses to take advantage of our sunny Southwest heritage. Knowing as we do that climate change on a global scale is already taking place, and knowing as well that the only way we have the thread of a chance of saving some semblance of this beautiful planet is to quit burning fossil fuels now, it’s nevertheless pretty easy to become "future shocked," or overwhelmed. Which is why it’s so imperative to choose something -- anything -- and begin to make the changes in our way of life that will quickly lead away from our continuing to produce CO₂. And since the sun has the potential to create not only heat for our homes but is also a viable alternative source for heating our water and our ovens, as well as creating our electricity, all-things-solar seems like a good place to start.

And, in case you haven’t been keeping up with solar tax credit developments, here’s some additional news that may just motivate you to hop that solar bandwagon now rather than later: New Mexico homeowners and businesses now have until February 15 to apply for 2007 state tax credits for solar energy systems installed during this past year. New Mexico provides a tax credit of up to $9,000 for a solar energy system installed between January 1, 2006, and December 31, 2015, in addition to the federal tax credit of up to $2,000. If two separate systems are installed, such as solar photovoltaic electric and solar thermal heating, state tax credits can be claimed for both systems, up to a total of $18,000. In order to qualify for the tax credits, a homeowner or business must first have the solar system certified by the state Energy, Minerals and Natural Resources Department. For more information, visit www.CleanEnergyNM.org, or to file an application, call the agency at (505) 476-3310.

We’ve all been hearing about the concept of solar-energy harvesting for decades now. Passive systems, having far fewer parts and requiring far less know-how, are easiest to install and are also the least expensive, so for this limited space, we’ll concentrate on the passive variety. The most common passive solar system works with what’s called "direct gain," referring to the sunlight entering a building through its windows and warming the interior. This heat is captured during the day by various thermal mass techniques and then slowly radiates out into the space beyond sunset. Designing a direct gain system includes calculating how much window area and how much thermal mass are required to provide the desired quantity of heat for the space. In general, total direct gain glass area should be at least 7 percent, but not exceed 12 percent of the house’s floor area.

Taking my house as an example, what sorts of solar renovations and retrofits could I implement right now, this winter, that would drastically lower both my heating bills and my carbon footprint? The first and most obvious problem to address is the worst source of heat loss: drafts. (Remember when your mom and dad would yell, "Shut the door! We’re heating up the whole front yard"? Well, they were right.) Weather stripping can be placed around leaking window and door frames (most experts consider the foam type to be the most effective), and cloth can be stuffed in places that over time have warped, become misaligned or were poorly constructed in the first place.

When Shannon worked on my house starting back in the 1980s, she installed what were at the time state-of-the-art skylights. Jump ahead 20 years, and the very best money can now buy, in the categories of both skylights and regular windows, is the dual-pane wood-frame variety. The rest of my windows are dual pane, but the skylights are all single, so since going out and replacing those is going to have to wait a year, what we’ve done instead is cover them with shrink-wrapped plastic. By the way, for anyone whose house still has those old-style New Mexico tried-and-true aluminum window frames, those are not your friends. ("Horrible!" exclaims a solar-expert friend of mine when describing windows of the aluminum dinosaur kind. "If you took a picture of one of those from the outside with a thermal camera, the whole area would be bright red, it’s leaking so much heat from inside!")

Now on to my sunroom, the one where Shannon used to work naked. There are actually several ideas I could employ in there to increase my thermal mass and make it act like a big heat sink. It’s already got the requisite virtual wall of south-facing glass; we just want to make it not so hot at noon and not so frigid in the nether hours. The first, and easiest, idea is to cover all the glass windows and doors once the sun goes down. Insulating or waffle shades are a good bet. However, they’re also a bit steep on the budget when you’ve got as much glass area as I’ve got to cover, so I’ve been using flannel sheets instead, which still make a considerable difference.

Another solution is to cover the wood floor. The thermal storage capabilities of a given material depend on the material’s thermal conductivity, specific heat and density. Conductivity tends to increase with increasing density so that, generally, the higher the density of the material, the better. Effective materials for floors include painted, colored or acid-etched concrete, brick or any kind of quarried tile, such as slate and dark ceramic tile. One-half inch of slate tiles, for example, which amounts to about a half a ton of rock to cover my entire dining room floor, would take both time and energy to heat up (especially the darker slate, although darkness isn’t a prerequisite), allowing for the perfect balance, in solar terms, of slow absorption of the sun’s rays during the day and then the equally slow releasing of this stored heat back into the house again throughout the night.

Thermal mass can be collected elsewhere than in the floor -- it can be incorporated into a building design in the form of trombe walls, fireplaces or bancos, too. Plus, the sun doesn’t need to hit these surfaces directly in order to store the heat. Take the idea of heating by water storage. For my room, I’d need five or six 55-gallon drums painted black. After setting each one on wheels, filling them with water and capping them, I’d tip each one on its side for maximum exposure of surface to the sun. The water acts as a collector, slowly releasing its heat as the sun retreats. There are lots of variations for solar heating by water storage on the Internet.

Trombe walls, another south-facing idea I’d like to try, are constructed out of thermal-mass material. For my room, the southmost-facing wall is already spoken for with all that window coverage. I’d open a portion of the south-facing wall that separates the dining room from the living room, take out the insulation material and insert either adobe or stone, then cover and seal it with a pane of glass positioned about 2 inches from its surface, creating an "air pocket." Sunlight enters, the heat is trapped by the glass, and then it’s absorbed by the thermal-mass wall. Heat radiates from the wall into the interior of the room in the evening and throughout the night.

In keeping with the passive solar concept, trombe walls don’t require ventilation because the idea is not to circulate warm air but to allow the walls themselves to radiate heat. They can be combined with direct gain windows in the same wall, and furniture can be placed up against a trombe wall without hurting the effectiveness of its solar gain.

These thermal-energy harvesting techniques have the most practical application for my own particular quirky house. But other solar-energy ideas, of course, literally abound.

The new Modified Trickle Down solar heating system, or MTD, which heats water directly, is a case in point. It’s a trickle-down open-loop system similar to Harry E. Thompson’s original "Trickle Down Solar Roof." The latter’s panels, however, took up an entire corrugated metal roof’s surface area, whereas an MTD system harvests heat through individual collectors pressed together to form the solar roof, and the heat is transferred directly to the water held in place by a Trickle Down Bed. Instead of using a heavy, fragile and expensive piece of glass, the MTD system uses long-lasting and inexpensive polycarbonate material as its exterior glazing method and a thin, inner polypropylene film to conserve heat.

There’s lots more to explore in this vast solar field of possibility -- we haven’t even scratched the surface here in home solar-electricity systems, for example. Or hot water heaters. Surf the Internet for further details on all the ideas mentioned here plus the strategic use of greenhouses for thermal gain, solar-heated ovens and, by the time this comes out in print, who knows how many new solar items. Japan, Germany and especially China, as well as California, are way ahead of us in the solar field.

What I’m especially enamored of about solar technology is that its catalog, so to speak, of ideas and products, once affordable only to the upper middle class and beyond, is now so open-ended, with everything from easy and cheap on up. And the sun itself? Free as the day is long. And no CO₂ emissions. I like all that in an alternative energy source. Elegantly simple.




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	New Mexico homeowners and businesses now have until February 15 to apply for 2007 state tax credits for solar energy systems installed during this past year. My Day in the Sun Our life is frittered away by detail. Simplify, simplify. -- Henry David Thoreau hen I first moved into my house, an oddly elegant renovated miner’s cabin in Madrid, the woman who fixed it up, Shannon, told me she used to build and paint furniture in what’s now my dining room. With four floor-to-ceiling south-facing windows, that room is so cozily toasty even on a bitter February day, thanks to all that concentrated sunlight, that Shannon bragged, "I used to work in here totally naked!" Unfortunately, the heat doesn’t radiate out to the rest of the house after the sun goes down -- it evaporates -- and when I moved in, the original heating system was two ineffectual little propane-burning wall units, one in the dining room and one in the living room. Needless to say, it was pretty cold in there from fall through early spring, not to mention expensive to try to heat. So when it became apparent that oil prices were only going to continue rising, we unhooked the heaters and put a woodstove in the living room, and now it’s much warmer in there. But wood’s not exactly cheap, either, nor available in endless quantities. So what about all this solar heat in the next room? Is there any way to take better advantage of that? It’s great till the sun drops down over the mesa and the nighttime big winter chill descends over our valley, then we’re back to huddling around the stove. Can I make my solar dining room work for me without spending thousands of dollars? There are ways we can all retrofit our houses to take advantage of our sunny Southwest heritage. Knowing as we do that climate change on a global scale is already taking place, and knowing as well that the only way we have the thread of a chance of saving some semblance of this beautiful planet is to quit burning fossil fuels now, it’s nevertheless pretty easy to become "future shocked," or overwhelmed. Which is why it’s so imperative to choose something -- anything -- and begin to make the changes in our way of life that will quickly lead away from our continuing to produce CO₂. And since the sun has the potential to create not only heat for our homes but is also a viable alternative source for heating our water and our ovens, as well as creating our electricity, all-things-solar seems like a good place to start. And, in case you haven’t been keeping up with solar tax credit developments, here’s some additional news that may just motivate you to hop that solar bandwagon now rather than later: New Mexico homeowners and businesses now have until February 15 to apply for 2007 state tax credits for solar energy systems installed during this past year. New Mexico provides a tax credit of up to $9,000 for a solar energy system installed between January 1, 2006, and December 31, 2015, in addition to the federal tax credit of up to $2,000. If two separate systems are installed, such as solar photovoltaic electric and solar thermal heating, state tax credits can be claimed for both systems, up to a total of $18,000. In order to qualify for the tax credits, a homeowner or business must first have the solar system certified by the state Energy, Minerals and Natural Resources Department. For more information, visit www.CleanEnergyNM.org, or to file an application, call the agency at (505) 476-3310. We’ve all been hearing about the concept of solar-energy harvesting for decades now. Passive systems, having far fewer parts and requiring far less know-how, are easiest to install and are also the least expensive, so for this limited space, we’ll concentrate on the passive variety. The most common passive solar system works with what’s called "direct gain," referring to the sunlight entering a building through its windows and warming the interior. This heat is captured during the day by various thermal mass techniques and then slowly radiates out into the space beyond sunset. Designing a direct gain system includes calculating how much window area and how much thermal mass are required to provide the desired quantity of heat for the space. In general, total direct gain glass area should be at least 7 percent, but not exceed 12 percent of the house’s floor area. Taking my house as an example, what sorts of solar renovations and retrofits could I implement right now, this winter, that would drastically lower both my heating bills and my carbon footprint? The first and most obvious problem to address is the worst source of heat loss: drafts. (Remember when your mom and dad would yell, "Shut the door! We’re heating up the whole front yard"? Well, they were right.) Weather stripping can be placed around leaking window and door frames (most experts consider the foam type to be the most effective), and cloth can be stuffed in places that over time have warped, become misaligned or were poorly constructed in the first place. When Shannon worked on my house starting back in the 1980s, she installed what were at the time state-of-the-art skylights. Jump ahead 20 years, and the very best money can now buy, in the categories of both skylights and regular windows, is the dual-pane wood-frame variety. The rest of my windows are dual pane, but the skylights are all single, so since going out and replacing those is going to have to wait a year, what we’ve done instead is cover them with shrink-wrapped plastic. By the way, for anyone whose house still has those old-style New Mexico tried-and-true aluminum window frames, those are not your friends. ("Horrible!" exclaims a solar-expert friend of mine when describing windows of the aluminum dinosaur kind. "If you took a picture of one of those from the outside with a thermal camera, the whole area would be bright red, it’s leaking so much heat from inside!") Now on to my sunroom, the one where Shannon used to work naked. There are actually several ideas I could employ in there to increase my thermal mass and make it act like a big heat sink. It’s already got the requisite virtual wall of south-facing glass; we just want to make it not so hot at noon and not so frigid in the nether hours. The first, and easiest, idea is to cover all the glass windows and doors once the sun goes down. Insulating or waffle shades are a good bet. However, they’re also a bit steep on the budget when you’ve got as much glass area as I’ve got to cover, so I’ve been using flannel sheets instead, which still make a considerable difference. Another solution is to cover the wood floor. The thermal storage capabilities of a given material depend on the material’s thermal conductivity, specific heat and density. Conductivity tends to increase with increasing density so that, generally, the higher the density of the material, the better. Effective materials for floors include painted, colored or acid-etched concrete, brick or any kind of quarried tile, such as slate and dark ceramic tile. One-half inch of slate tiles, for example, which amounts to about a half a ton of rock to cover my entire dining room floor, would take both time and energy to heat up (especially the darker slate, although darkness isn’t a prerequisite), allowing for the perfect balance, in solar terms, of slow absorption of the sun’s rays during the day and then the equally slow releasing of this stored heat back into the house again throughout the night. Thermal mass can be collected elsewhere than in the floor -- it can be incorporated into a building design in the form of trombe walls, fireplaces or bancos, too. Plus, the sun doesn’t need to hit these surfaces directly in order to store the heat. Take the idea of heating by water storage. For my room, I’d need five or six 55-gallon drums painted black. After setting each one on wheels, filling them with water and capping them, I’d tip each one on its side for maximum exposure of surface to the sun. The water acts as a collector, slowly releasing its heat as the sun retreats. There are lots of variations for solar heating by water storage on the Internet. Trombe walls, another south-facing idea I’d like to try, are constructed out of thermal-mass material. For my room, the southmost-facing wall is already spoken for with all that window coverage. I’d open a portion of the south-facing wall that separates the dining room from the living room, take out the insulation material and insert either adobe or stone, then cover and seal it with a pane of glass positioned about 2 inches from its surface, creating an "air pocket." Sunlight enters, the heat is trapped by the glass, and then it’s absorbed by the thermal-mass wall. Heat radiates from the wall into the interior of the room in the evening and throughout the night. In keeping with the passive solar concept, trombe walls don’t require ventilation because the idea is not to circulate warm air but to allow the walls themselves to radiate heat. They can be combined with direct gain windows in the same wall, and furniture can be placed up against a trombe wall without hurting the effectiveness of its solar gain. These thermal-energy harvesting techniques have the most practical application for my own particular quirky house. But other solar-energy ideas, of course, literally abound. The new Modified Trickle Down solar heating system, or MTD, which heats water directly, is a case in point. It’s a trickle-down open-loop system similar to Harry E. Thompson’s original "Trickle Down Solar Roof." The latter’s panels, however, took up an entire corrugated metal roof’s surface area, whereas an MTD system harvests heat through individual collectors pressed together to form the solar roof, and the heat is transferred directly to the water held in place by a Trickle Down Bed. Instead of using a heavy, fragile and expensive piece of glass, the MTD system uses long-lasting and inexpensive polycarbonate material as its exterior glazing method and a thin, inner polypropylene film to conserve heat. There’s lots more to explore in this vast solar field of possibility -- we haven’t even scratched the surface here in home solar-electricity systems, for example. Or hot water heaters. Surf the Internet for further details on all the ideas mentioned here plus the strategic use of greenhouses for thermal gain, solar-heated ovens and, by the time this comes out in print, who knows how many new solar items. Japan, Germany and especially China, as well as California, are way ahead of us in the solar field. What I’m especially enamored of about solar technology is that its catalog, so to speak, of ideas and products, once affordable only to the upper middle class and beyond, is now so open-ended, with everything from easy and cheap on up. And the sun itself? Free as the day is long. And no CO₂ emissions. I like all that in an alternative energy source. Elegantly simple.