The Saving Power of Active Solar Water Heaters

Conventional (natural gas, oil or mains current electricity) hot water heaters for your home account for a significant portion of every monthly utility bill. This single appliance can be responsible for 16% to 20% of monthly charges. Over the ten year life of a water heater, an average homeowner spends $10,000.00 operating it. Solar water heaters on the other hand, are powered by a free, renewable energy source - the sun. Their life time cost is about 1/10th of that typical $10,000.00 and their life span is approximately 25% greater.

Solar water heaters come in two types active and passive. Active solar water heaters have thermostats and pumps while passive solar water heaters do not. A passive system relies on the principals of thermodynamics and the natural tendency of hot water to rise above cold, while an active system uses thermostatic controls, holding tanks and pumps for distribution of the hot water.

Active systems are further divided into open looped and closed looped systems (or direct systems and indirect systems). In either application, geography and climate are the largest factors in determining which type of system is selected. An open looped system is typically installed in a residential application with a single water demand. A colder climate requires a closed loop system because of the increase chance of freezing.

An indirect (or closed looped) active system will use heat transfer methods to maintain the hot water temperature. The solar collectors heat a carrier fluid of glycol/water/antifreeze mixture. That fluid heats a tank that then heats and holds the hot water. The system is very efficient in either temperate or extreme climates but requires more maintenance including fluid changes every 3 to 5 years.

With any active solar water heater you can expect between 50% and 100% of your production needs to be met, while enjoying tremendous energy savings.