Solar hot water heaters are contraptions that can turn sun rays into savings.
There are several types of systems, some more popular in warmer climates and remote, off-grid areas. But the tech is becoming more sensible for wider application, providing a way for you to cut utility costs at home.
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How does a solar water heater work?
There are two main types of systems: active and passive. Both use solar collectors — tubes, flat plates, or other types, which are designed to trap heat from the sun — and storage tanks, according to the U.S. Department of Energy.
In active-direct systems, pumps circulate heated water through collectors to the home. Active-indirect systems warm a non-freezing fluid first. A heat exchanger transfers the heat energy to the water, using a pump to move the liquids. This system is better for regions that have freezing temperatures.
Passive systems also have two types: integral collector-storage and thermosyphon, which typically don't use pumps. They "transfer heat by natural circulation as a result of buoyancy," ScienceDirect explains. These systems are reliable and have a long life but are not as efficient, according to the DOE.
Integral collector-storage systems use a storage tank that is covered with a clear material so the sun can heat the water, which travels to the home's backup water heater. This system is better for warmer climates, as the outdoor plumbing could freeze.
Thermosyphon units heat water in a collector on the roof. The water runs through the plumbing when someone turns on a faucet below it, and there is typically a 40-gallon storage capacity.
These solar systems can be used to preheat water before it enters a traditional heater, or used in tandem with tankless heaters, all per the DOE.
Why are solar water heaters getting attention?
Simply heating water can burn through 14-18% of your household utility budget, according to the DOE. CNET reported that Americans dole out, on average, up to $70 each month to use electric water heaters. The solar systems offer a solution as we consider more cost-efficient utility alternatives, using renewable energy.
"The overall result is a lot less energy used for water heating," climate journalist Michael Thomas says in a video clip shared by Canary Media.
While sunlight is a necessity, Thomas says in the clip that insulated tanks help to keep water warm during cloudy days and at night. Backup systems help create a stable warm water supply.
Still, less than 1% of U.S. homes use a solar water heater. The usage abroad is higher, and not just in sun-heavy regions. For example, Austria is high on the list, per capita, according to Thomas.
How will the systems impact me?
The perks are clear (and sunny). The systems provide planet-friendly energy that can save you money via a unit that lasts for decades, per CNET.
The upfront cost with installation is between $3,000 and $8,000. The units also take up space, often on rooftops, for the sun-catching tech and storage. Design details depend on the type of system you choose, all according to CNET.
The impact, however, is immediate.
"Homeowners see savings of $781 on energy costs each year and a 100% return on their investment in just a few years. From then on, the sun produces free hot water," per a Forbes report.
Take it to the next level
You can also take some steps after heating water to lower your energy bills even more. Switching to efficient faucets, and even using your dishwasher more (versus hand-washing), can cut costs while maximizing your solar-heated hot water, per the DOE.
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