Solar Hot Water Units

Solar Hot Water Systems

The sun's heat has been used for decades to heat water for homes and businesses. At the turn of the 20th century, solar heated water systems were common in Southern California. Some countries have made their use mandatory. For example, all homes in Israel have solar hot water systems.

More than one-half million solar hot water systems have been installed in the United States, mostly on single-family homes. The majority of these systems are used to heat swimming pools.

Typically, a homeowner relying on electricity to heat water could save up to $500 in the first year of operation by installing a solar water heating system. The savings over time increases due to increasing electricity rates. The average solar heating system pays for itself in four to seven years.

After heating and cooling, water heating is the largest consumer of energy in U.S. residences, accounting for approximately 15% of electricity usage and 25% of gas usage. In general, factors impacting water heater energy consumption can be separated into two categories; factors affecting the amount of hot water used and those affecting the efficiency of the water heating system.

Factors impacting water usage are the use of water for bathing, showering, shaving, and other purposes as well as the use of clothes washers and dishwashers. The largest impact on water heating energy consumption is typically showering habits.


After heating and cooling, the next-largest use of energy in most homes is heating water. In the average home, heating water for cooking, bathing and other purposes accounts for about 15 percent of energy use. That's why taking steps to make more efficient use of hot water can have a significant effect on energy bills.

One of the most important steps is ensuring that your water heater is the right size for your family's needs. A water heater that's too small will constantly have to heat more incoming water. One that's too large will waste money keeping unneeded water in its tank warm. Newer water heaters tend to be better-insulated with foam. Keeping your water heater maintained - such as draining some water every month or two to flush out scale - can extend its life and improve its efficiency.

A newer technology considered by some homeowners is the tankless water heater. Unlike traditional water heaters that store hot water, tankless heaters instantly warm water as it travels to the faucet. The concept is that you pay to heat only the water you're using. However, many tankless water heaters can only handle a limited amount of water, so they may not be able to provide enough hot water for two users at the same time. In addition, they use a tremendous amount of power when heating water. Some models place such a great demand on the home's wiring and panel, a separate 60- to 150-amp circuit may need to be installed for safe operation. Also, because of use of better foam insulation in tank models, "stand-by losses" are virtually eliminated.