Solar Power: Here Comes the Sun

Passive Solar Design Passive solar means no mechanical or electric devices are being used with the system. Installing passive solar at your current cabin or incorporating it into plans for new construction or renovation is not a daunting task. You probably are already using it to some extent. The DOE defines passive solar design as using your windows, walls and floors to collect, store and distribute solar energy in the form of heat in cooler weather, and reject solar heat when it’s warm. Skylights can also be part of a passive solar design. South-facing windows with overhangs, awnings and glazing can control solar heat gain and loss. Federal standards have been developed for windows and skylights for new and existing construction based on your climate. Visit www.efficientwindows.org. Thermal mass (material that stores heat) is another component of passive solar design. Concrete, stone, brick and tile are commonly used to store the heat from the incoming sunlight. New construction allows for a designated sunspace, which collects heat, but can be closed off from the rest of your retreat by doors or windows. Warm air collected by the sunspace can be vented into adjacent rooms or circulated with fans. An alternative for existing cabins is to locate a thermal mass wall, also called a trombe wall, on the south-facing side. A layer of glass is mounted about an inch in front of the outside of a dark-painted exterior masonry wall. This wall absorbs solar heat during the day and releases it slowly into the living space. As the indoor temperature drops, heat from the trombe wall radiates into the adjacent room. Landscaping and insulation are also passive solar measures. Well-planned landscaping can cut heating and cooling costs by protecting your cabin from hot summer sun and cold winter winds. Low shrubs will keep your southern facing solar-access areas open to the sun’s energy. Locate large shade trees to screen your east, west and north walls from cold winds. Insulation in your cabin’s exterior walls will help keep it cooler in the summer and warmer in the winter. Heat flows naturally from a warmer to a cooler place. Insulating the ceiling and crawl space will keep the solar heat from transferring from the roof to the cabin interior. Solar Hot Water Remember that hose you left on the deck last summer and had to let the hot water run out before you could even touch it? Hot water is one of the oldest and most common applications of solar energy. Recognizing this, California recently passed the Solar Hot Water and Efficiency Act of 2007, which set a goal of 200,000 hot water solar heating systems in the state. The legislation provides rebates of up to $1,500 for purchasing solar hot water systems that replace conventional hot water systems that use natural gas. This includes vacation home owners. It is limited to natural gas customers because it will be funded by a surcharge on natural gas. State lawmakers expect the increased demand for new solar hot water systems will also bring down the cost of installing replacement solar hot water heating systems (which currently runs between $3,000 and $6,000). This new program took effect Jan. 1, 2008. Whether your place is in California or not, the sun can be harnessed to heat water for direct use or to heat water to supplement an existing hot water system. These types of systems require a roof-mounted solar collector to heat the water and a well-insulated storage tank. Water is pumped through the solar collector – a row of parallel metal or glass tubes in an insulated glass-covered collection panel – and is heated by the sun. Then the water goes into the storage tank in the cabin for direct use, or it can be piped into the existing hot water heater. Where freezing is a problem, the system must be drained for the winter. Active Solar Heating Active solar heating uses technology similar to solar hot water systems, though it requires a larger solar energy collection area (more panels). The two systems can also be combined to provide both indoor heat and domestic hot water. The water is pumped through the solar collectors then into a hot water storage tank. The heat is distributed through hot-water baseboards, radiators or pipes imbedded in a thin concrete slab floor. Solar Electricity Photovoltaic panels, known as PVs, use solar cells to convert sunlight into electricity. Various sized PVs are used to power most solar devices – from small PVs on solar patio lights or solar calculators to large PVs for commercial uses. The solar power system can be sized to meet your cabin’s electrical needs. It can be an independent off-the-grid system with storage batteries or used to supplement your existing service. While PVs have traditionally been black panels, users are asking for a new look. In response, the industry has innovated with solar cells that double as roofing shingles and tiles, building facades and glazing for skylights. If your roof is not in the shade and has southern exposure, your cabin is a good candidate for using solar energy. And if your roof is unsuitable, solar panels or collectors can be installed on the ground. While the optimum orientation is true south, solar collectors can actually face up to 90 degrees east of south or west of south without affecting performance. Going solar, like any significant home renovation, means checking local building codes and property association rules. And you’ll want to find a reliable installer, since installation can involve plumbing, electrical and other construction skills. Where the Sun Shines The bottom line: If you’re going solar to save on your power bill and help the environment, a quick pre-solar check list is in order. The nonprofit Alliance To Save Energy offers a comprehensive home energy checkup at www.ase.org. According to the DOE, taking steps to make your current cabin as energy efficient as possible might actually save more on your power bill than supplementing with solar energy would. PV-generated electricity is more expensive than utility-supplied electricity in terms of the initial home owner investment required and the payback in energy savings over the life of the system. However, some homeowners favor solar energy systems for other reasons – such as environmental benefits and energy independence. And the new technology is a great benefit to cabin owners who are off-the-grid. The career of journalist Pat Faherty has taken him across the U.S. Currently, he resides in Florida – the Sunshine State, of course.