Many homeowners recognize the value of solar energy technologies but have been leery of the highly visible collectors on their roofs. Although the term "solar power" may be synonymous with environmental-friendliness and freedom from fossil fuel dependence, some types of solar systems have been avoided because of their unattractive (or unique) appearance from the curb. For this reason, photovoltaic (PV) modules,, which convert sunlight directly into electricity, have been integrated into roofing or other building materials as an alternative to traditional PV modules that are mounted above the roof on racks. The result is a photovoltaic system that is less noticeable but has benefits that are hard to miss. Once installed, BIPV components not only protect the home from storms and rainy weather but produce free electricity for use in the home. The residential industry most often uses building-integrated photovoltaic roofing products; however PV systems can also be integrated into façade materials, awnings, and covered walkways.

The many types of photovoltaic roofing products compliment many different roofing materials including asphalt shingles, standing seam metal roofing, and slate or concrete tiles. BIPV roofing products are produced by manufacturers whose products are designed to serve both functions -- as a roofing material to protect the home and as an electrical device to produce electricity. PV systems can be sized on a small scale to produce a limited amount of energy or be large enough to power an entire home and send excess electricity to the utility.

Most residential BIPV systems are used in conjunction with utility-supplied power. In addition to the PV-active roofing, an inverter, located near the electrical panel, converts the PV produced electricity into utility compatible alternating current (AC) electricity for the home. PV systems that utilize battery storage can produce electricity for the home even when the utility power is disconnected or when the sun is not shining.

Utility-provided electricity is used when the house demand is greater than can be supplied by the photovoltaic roofing. .PV systems can be sized on a small scale to produce a limited amount of energy or be large enough to power an entire home and send excess power produced during daylight hours back into the utility's lines. Typical residential PV systems commonly have a peak power production of between 1,200 and 5,000 watts, AC - requiring 150 to over 1000 square feet of roof area depending on the efficiency of the PV technology used.

(Lightning): PV systems reduce the amount of electricity purchased from the utility.

(Leaf): Electricity produced using the sun’s energy reduces the amount of energy used from non-renewable resources such as coal, gas, oil and nuclear, and energy is not wasted as transmission losses. In addition, there are significant environmental benefits resulting from reductions in air pollution from burning fossil fuels, reductions in water and land use from central generation plants, reductions in the storage of waste byproducts. In addition, the solar technologies produce energy with little noise and few moving parts.

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Harnessing energy from the sun to heat water is nothing new. Solar water heaters have been commercially available since the 1800s. What's new is how solar water heaters look these days. Most modern solar water heaters mount flush with a home's roof and resemble skylights. Solar water heaters are an environmentally sound way to reduce energy bills.

Solar energy can meet part or all of a home's domestic hot water needs. Geographic location, system design, collector orientation, and collector size will determine how much energy can be provided for domestic hot water heating. Solar water heaters come in a variety of configurations. Each differs in design, cost, performance, and level of complexity. Most systems have back-up water heating such as electricity or gas. A solar water heating system usually consists of a hot water storage tank, a solar collector that absorbs solar energy, a back-up energy source, and (for forced circulation systems) a pump and controls.

There are two main types of systems: passive and forced circulation. Within each type, there are several configurations. A passive water heater consists of a water tank integrated into or located above a solar collector. In an integrated collector storage (ICS) system, also called batch water heater, the water is heated and stored inside the collector. These systems are suitable only for warm climates where there is no risk of freezing. In a passive system where the storage is separate from the collector, as water in the collector warms, water flows by natural convection through the collector to the storage tank. A forced circulation system requires a pump to move water from the storage tank to the collector. Most solar water heaters in the United States are the forced circulation type.

There are several types of solar collectors. Most consist of a flat copper plate, painted black, that has water tubes attached to the absorber plate. As solar energy falls on the copper plate and is absorbed, the energy is transferred to water flowing in the tubes. The absorber plate is mounted in a casing that has a clear covering and insulation to protect the absorber plate from heat loss. Other collectors include an integrated collector and storage system and the evacuated tube collector. Integral collector and storage systems combine the function of hot water storage and solar energy collection into one unit. Evacuated tube collectors produce higher temperature water and are more complex than flat plate collectors. Evacuated tube collectors consist of a series of tubes that contain a heat pipe to absorb solar energy and transfer it to a liquid medium. The tubes are evacuated (vacuum) so that there is very little heat loss from the tube. Most solar collectors are roof-mounted. Solar water heaters are used for domestic hot water, pool heating and space heating needs.

(Lightning): Solar water heaters can help save on water heating costs by reducing the amount of gas and electricity needed to heat water.

(Leaf): By using sunlight to heat water instead of a combustible source or power plant-produced electricity, less pollutants are being introduced into the environment.

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