Solar domestic water heating is one of the fastest payback renewable energy applications available, for two reasons:
- Most hot water systems are pretty efficient to begin with. Unlike home heating, there aren’t a whole lot of measures you can take to minimize heat loss in your water heating system(aside from insulating your tank and pipes, which is not usually hugely expensive). So the solar heat you gain to heat your water gets used pretty efficiently to your benefit.
- Domestic hot water is in demand all year round. There’s very little seasonal fluctuation in your need for hot water. No matter what temperature it is outside, you still need hot water to wash your dishes, do your laundry, take showers and perform other cleaning tasks. With a solar hot water system, what that means is that you’re able to make use of your solar heat not only in the winter when there’s less available sunlight, but also in the summer when you have more hours of sunlight to take advantage of.
If there is a problem with solar water heating, it is that most households only have a limited need for hot water. Once that need is met, and they want to continue to build their solar profile, they need to move on to less-efficient means of harnessing solar energy, such as solar thermal space heating or photovoltaics. (Not that these measures aren’t worthy and effective, but they don’t come close to providing the bang for the buck that a solar water heater will.)
Commercial use – the perfect solar water heating application
Enter the commercial solar water heating application. In many ways commercial water heating is the area where solar hot water can most brightly shine. Businesses that use a lot of hot water, such as hotels, motels, restaurants, breweries, laundromats and some manufacturers often use substantial amounts of hot water on a year-round basis. In addition, many of these enterprises use most or all of their hot water during the day and early evening, when solar heat is most readily available.
Businesses such as these often see substantial savings from solar thermal water heating. Although it is a big upfront investment, current incentives allow eligible businesses to acquire solar water heating for as little as 20 cents on the dollar. Payback on these systems can happen in just a few short years, and after that, the investment just keeps paying back in free hot water year after year.