We are often asked, “How much money will I save with a solar hot water heater?”

According to the U.S. ENERGY STAR website, installing an ENERGY STAR-certified solar hot water system will save the typical family 50 percent or more annually on their water heating bill. (Saving up to 80 percent is quite possible, according to another government site, energy.gov.)

Exactly how much money you will save depends on a number of factors. Let’s take a look at each in turn.

Your household size: In general, the more people living in a household, the more hot water you will use and the greater the savings.

Type and cost of backup fuel: Because the sun doesn’t always shine, almost every solar water heating system includes a backup water heater to pick up the slack at night or during prolonged cloudy spells, so you can enjoy an uninterrupted supply of hot water.

Usually, your existing hot water heater can be used for backup. For most households, this runs on either electricity or natural gas. When calculating your savings, we factor in the average energy rates for your area. ENERGY STAR estimates a conservative savings of $140 per year for natural gas backup, or a $2,900 lifetime savings. Double that for electric.

Solar energy factor: A system’s solar energy factor (SEF) is the amount of energy the system produces from the sun divided by the amount of backup energy used. In other words, it measures the efficiency of the system. Your system efficiency depends on the components and insulation used for the system, as well as collector orientation and latitude. When you purchase an ENERGY STAR-certified solar water heater, you can be assured that the system meets approved efficiency standards.

Your hot water usage patterns: You can save even more with your solar water heater by adjusting your usage patterns. Using more hot water when it is available, and delaying hot water use during cloudy spells, can help minimize your reliance on backup fossil fuel. For instance, showering at night allows you to take advantage of the heated water produced that day. Doing laundry on sunny days also lets you maximize the percentage of solar heat you use.

Your solar water heater’s lifespan: The average life expectancy of a solar water heater is 20 years, although some last 30 years or more. We prefer and use Kingspan Thermomax solar thermal collectors, which are designed to last at least 25 years providing long-lasting value for your home.

Our solar agents are experts at quickly and easily determining the solar thermal setup that will get you the most savings and fastest payback. To find out more about solar water heaters, or to get a free assessment for your home, please request an estimate. One of our qualified solar experts will be happy to assist.