A typical water heater costs $ 300 to $ 400 per year to operate. These costs will continue to increase over time with the rising costs of fuel. . A solar water heater, when properly sized, could eliminate 60 to 90 % of these costs. Burning oil or gas in a water heater produces Carbon Doixide (CO2) which contributes to global warming. Shifting solar thermal hot water greatly reduces the CO2 released.
These systems collect the heat energy from the sun and use that heat directly to heat water for swimming pools, domestic hot water, heating systems and even cooling systems. You are probably familiar with the hot water, which comes out of an out garden hose when it is first turned on.. This same heat from the sun can heat water to 160 to 180 degrees F. There are several types of solar collectors and systems depending on the applications.
Solar Thermal Collectors – The heat collecting panels are either a flat plate design or evacuated tube style. The flat plate collectors heat the water directly in a series of tubes, which are located in the panel itself. In evacuated tube panels, the sun heats an element in the vacuum tube and the heat is transferred to a single tube of water at the end of the panel.
Direct / Indirect systems –One basic type of solar thermal system is the direct system where the water in the heating tubes is potable or drinkable. An indirect system uses a glycol mixture in the heating tubes, which then transfers the heat to the domestic hot water tank via a heat exchanger. The indirect systems are used in colder climates where the water in the heating tubes may freeze during winter months.
Residential / Commercial – Both systems are available. The residential system would have one to four solar collector panels mounted on a homeowner’s roof and the system is used to heat water for showers etc. The commercial systems are much larger and they are designed for preheating water for large boilers or even used in absorbing chillers to produce air conditioning for the building. Commercial systems would have 20 to several hundred solar collectors depending on the amount of hot water needed for the application.
Rebates / Incentives – The state rebates are limited for solar water heaters. State and Federal tax incentives are available. Since these incentives change, consult a tax advisor for more details. The US EPA does offer a program for Five Star Energy Efficient homes. This program help homeowners to qualify with more favorable terms on mortgages and possibly on refinancing.
