Case Study #4

       Mark Schimmoeller and Jennifer Lindbergh live on a hilly, partially forested homestead in the northern part of Franklin County. In January 2001 they moved into their 288 square foot post-and-beam cabin, which they had been building for the previous 18 months. Their cabin is off the grid and has no utility connections- neither water nor gas nor phone.

       The cabin was sited and designed to make optimum use of the sun’s energy. Two 75-watt solar panels were installed on the roof before they moved into the house. The long south face of the house has windows carefully located to provide passive solar heating during the cold months, while the overhang was designed to prevent unwanted solar heat gain during the warm season. Open space in the yard around the cabin hosts both a solar cooker and a solar water heater, both of which are used on a regular basis from March through October.

      Since moving into their cedar cabin, Mark and Jennifer have built an addition onto the south and east portions of the house. The addition has doubled the area of the house (not counting a new root cellar beneath the addition). To accommodate additional electrical needs in the addition, another 75-watt PV panel was added to the roof, along with a new battery bank. The addition has enhanced the original passive solar design, by including thermal mass in the form of a Solar Slab, a concrete slab designed to circulate solar-heated air around the cabin.

       The couple installed a third solar electric system to service a small (10’x16’) guest cabin on their land. This 100-watt array provides electric lighting, can run small appliances like a radio or laptop computer, and operates a telephone answering machine (the guest cabin also serves as a phone booth)

      The initial 150-watt solar array installed on the cabin powers a small, super-efficient DC refrigerator and two compact fluorescent lights, which can each be used for about 4 hours per day. They also have a stereo CD player which they occasionally use. (They have a radio with a built-in solar panel and battery which works very well). The cabin is wired for 12-Volt DC power and they have a battery back-up.

      Jennifer and Mark have been very happy with the performance of their solar electric system. It has never run low on power, even in the dead of winter and the refrigerator, while small, meets their needs. “Honestly, I’ve been surprised at how well the solar system works,” commented Jennifer. “Before we moved into the house I had thought that relying on solar energy would require some kind of sacrifice- and I was ok with that. But the reality has been that we have all the electricity we need, there’s very little maintenance required (although I must confess, Mark does the maintenance), and the system just works really well.”

      The PV system at the guest cabin has also functioned well. The one problem they had was finding an answering machine that would operate on 12V DC at the proper amperage. They use a cigarette lighter adapter to plug the answering machine directly into the 12V power supply.
      The cabin also has a solar attic fan with its own small PV panel that powers the fan whenever the sun is shining. A switch enables them to run the fan at night from the batteries.

      Mark and Jennifer’s family has been using solar cookers on a regular basis for over ten yeas. Mark built the solar cooker that he and Jennifer use, based on a design he helped create during a work project in Peru. This multi-reflector solar box cooker is insulated with cardboard and newspaper, has a glass lid, and a door in the rear panel. Four reflectors made from plywood and aluminum foil concentrate the sun’s energy inside the box, cooking the food.
      The solar cooker is a mainstay in Mark and Jennifer’s home from March through October. On nearly every day that’s at least partly sunny, a main portion or their whole dinner is cooked outside with the sun’s energy. Some of the foods they most commonly cook in the solar cooker are beans, rice, potatoes, and other vegetables. Mark is a writer and works from home, which makes it convenient for him to put food in the cooker at mid-morning and to reposition the cooker a couple of times during the day. They find that the solar cooker is a time-saver, because they can do other things while their main dishes are cooking outside. When the evening comes, they bring in the pots from the solar cooker and maybe add a few final touches to their meal. This helps them to get dinner prepared more quickly.
       Mark’s mother, sister, and some friends also use solar cookers on a regular basis. The dishes they prepare include casseroles, omelets, lasagna, pasta, tomato sauce, breads, cakes, cookies, granola, soups, pizza, and fruit canning. Mark’s family-members are mostly vegetarian so they do not cook meat dishes, but the solar cooker does cook meat without any trouble. During his work in Peru, meat was commonly cooked in the solar cookers he built with Peruvian families.
      Mark and Jennifer use a solar water heater that is a variation on the solar cooker, utilizing a large insulated box covered with glass but lacking reflectors. Since Mark and Jennifer do not have running water, they heat their water in a large pot inside the water heater, then carry the pot into the house for washing and bathing. (In the winter time they just keep the pot on the wood stove.) Mark’s family also uses a solar food dryer, which he built for drying vegetables and herbs.