Passive Systems

A passive water heater consists of a water tank integrated into or located above a solar collector. These systems are suitable only for warm climates where there is no risk of freezing.

In a passive system where the storage is separate from the collector, as water in the collector warms, water flows by natural convection through the collector to the storage tank. Water gets hotter as it progresses up through the copper tubes, and then to the tank. This pre-heated water feeding the tank causes the electricity to not need to turn on.

Why Use a Solar Water Heater?

Solar water heaters provide you with several benefits over conventional water heaters. You will reduce your hot water heating costs. You will also be directly reducing greenhouse gas emissions (carbon dioxide, CO2, released into the atmosphere), thereby contributing to a healthier environment.

The energy you can expect to save by switching to a solar water heater depends on several factors such as the size of the collectors and storage tank, appliance efficiency, amount of sunlight in your region and, very importantly, the amount of water you use. A typical solar hot water system will reduce annual energy costs by 40 to 50 percent. You can expect that a solar water heater will provide you with 1500 to 3000 kWh of energy per year, depending on your hot water usage and regional climate.

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