In 2005, Matt and Adam Farrell, Cornell graduates and owners of Ithaca, New York-based Silicon Solar, made the transition into solar thermal water heating. In doing so, the brothers invented their own version of evacuated tube solar collectors and have now landed at least one major solar water heating project.

The brothers will be installing a solar water heating system at the Wallkill Correctional Facility in the Hudson Valley. Silicon Solar’s collectors consist of heating tubes made from two layers of borosilicate glass separated by a vacuum. An anti-freeze solution runs through the collectors, where it is heated by the sun. From the collectors, the fluid is sent to the hot water system, where it transfers its heat to the water supply. (more…)

Solar water heaters are the most inexpensive and cost-effective way to go solar. These solar thermal systems may be used in any climate to great effect. While initially more expensive than conventional water heaters, solar hot water systems take advantage of free solar energy to save money over time. Federal, state and local incentives and rebates also cut down on those initial costs by at least 30 percent.

Types of solar water heaters

There are two general types of domestic solar hot water systems. Active systems have electronic controls and circulating pumps to move water throughout the system. Passive systems do not have any mechanical components and use convection, gravity or other natural forces to draw hot water through the system.

There are two types of active systems as well: indirect and direct flow systems. Direct systems circulate water through the collectors (described below) and into the home in a continuous cycle. Indirect systems utilize a medium, or heat transfer fluid, which runs through the collectors, absorbs solar heat, and then passes through a heat exchanger (typically within close proximity to the storage tank to prevent heat loss as the heated water travels), where that heat is transferred to the water supply.

Photo Credit: r_neches

Water heater components

A solar water heater consists of two main components: the collector and the storage tank (add pumps and controls for active systems). There are three types of solar thermal collectors in residential use. The most popular of these is the flat plate collector, which are large, flat and contain a metal absorber plate that collects and transfers solar heat to water flowing through tubes attached to the absorber. (more…)

Photo credit: Snap

Along with photovoltaics, solar thermal hot water heaters are growing more fashionable and marketable every year. Solar hot water heaters are more expensive than conventional models, although energy savings over time and increasing federal and state financial incentives narrow that gap considerably. After your new solar water heater is installed there is typically very little maintenance required — a big selling point for manufacturers and installers.

Very little, however, does not mean zero maintenance — just very rare maintenance. For active systems, pumps and other electrical components may need repair or replacement, but usually not for at least 10 years (quality solar thermal systems come with at least a 10-year warranty).

Yet another good maintenance question comes in regard to the water or fluid flowing through the system and/or solar thermal collectors.

Water

The water in solar thermal systems rarely needs to be replaced, even for systems with a storage tank. According to the federal government, the average person uses 15-20 gallons of water per day. That is why the average family of four’s water tank will be about 80 gallons in size. Remember that reducing your water usage will save even more money and reduce the size of your system, saving on initial costs as well.

Because the system is sized to provide enough water for daily use, the water within the system is not allowed to grow stagnant — the only real reason why the water would need to be replaced. Speak with your solar thermal installer about any further considerations that may arise based on your location, lifestyle, and type of system. (more…)