Solar Hot Water

Solar hot water (SHW) systems convert sunlight into heat energy and transfer that heat to a fluid circulating through a solar collector.  The circulating fluid carries the heat to the hot water system in your house or business. 

By reducing the amount of energy your current hot water system uses, you save money - from 60% to 80% of your annual cost to produce hot water for your house can be saved with a SHW system.

With most current hot water systems, every time hot water is used the system brings in cold water to replace the water taken from the hot water tank.  With a SHW system, when you use hot water the heated water is coming from the solar storage tank.  As a result, your hot water heater doesn't turn on and use energy - gas or electric - to heat water.  You save money!

In addition, with a SHW system you have more hot water readily available for use and won't run out during a shower!  A SHW system can be designed to provide all the hot water you need daily for bathing, laundry, and more.

A SHW system provides the best dollar value for using the energy provided by the sun to produce your hot water.  It's much cheaper to heat water directly from the sun rather than use solar generated electricity to run your electric water heater.

Let's look at a few terms used in discussing SHW systems and how these may apply to you:

DHW - This means Domestic Hot Water and simply refers to the system in your house that produces potable hot water for bathing, laundry, and more.  In homes (or businesses) without a SHW system, a gas or electric water heater usually produces hot water.  In some cases a boiler system produces the hot water.

Space heating (SH) - This refers to a system that heats the space in which you live or work.  There are several ways to accomplish this task.  Some systems heat air and some water.  Some systems store the heat, while some deliver the heat directly to a living space without any storage. 

Solar space heating systems are more complicated to design and install than the SHW system alone, and they cost more.  These systems require more space for the additional solar collectors and additional or larger storage tanks.

Solar space heating and solar hot water heating are an ideal mix for a solar energy system in your home because both use water heated in the "low heat" range - up to 160 degrees F. 

Closed-loop antifreeze system - Often referred to as a "glycol mix" system, this pressurized heat collection system operates within a specific pressure range.  Typically, the system uses a 50-50 mixture of water and food-grade, non-toxic propylene glycol liquid to indirectly heat the water used in the DHW system in your house. 

The glycol mixture circulates through the collector, picks up heat produced by the sun, and carries it back to the SHW system storage tank.  Using a metal heat exchanger, the heat from the storage tank is transferred to the potable water circulating in the DHW system.  This system of heat collection can be used in both SHW systems and solar space heating systems.

Drain-Back system - This is a heat collection system design that can use either a glycol-mix or mineral-free water as the collection and transfer fluid.  This system is not pressurized.  In this design, when the SHW system pump shuts off the circulating fluid will immediately drain from the collectors - and external piping - into a small storage tank located in an interior space. 

During winter months, this system provides protection against system component damage from freezing in the event of a power failure.  During summer months, this system provides protection against system component damage due to overheating. 

Recirculation loop system - This type of heat collection system is used primarily in commercial applications.  It works well in most climates and is expecially useful in businesses with large amounts of hot water being used daily - hotels, hospitals, dormitories, indoor swimming pools, and more.  The solar collectors are mounted on the roof and the hot water produced feeds directly into the recirculation loop found in commercial building boiler heat and hot water systems.  In most cases, no additional storage tanks are added.

Yes ... you can heat your hot tub with solar!

Sorry, spa and pool heating with solar energy systems don't qualify for the Federal tax credit or State rebate.