Solar Water Heaters

If you listen to the mechanical engineers in the Solar Energy Laboratory at the University of Wisconsin, they’ll tell you that an average four-person household using an electric water heater needs somewhere in the vicinity of 6,400 kilowatt hours of electricity each year in order to consistently heat their water. If you assume that the electricity is generated by a traditional power plant with an efficiency of about 30% (a modest estimate), that would mean that the average electric water heater accounts for approximately eight tons of carbon dioxide each year, which is nearly double what is emitted by a modern motor vehicle. That very same family of four that is using either an oil-fired or natural gas water heater will personally contribute about two whole tons of CO2 emissions each year, simply by heating their water.

Though it may come as a shock to many, expert analysts have concluded that residential water heaters all throughout North America produce a total amount of annual CO2 roughly equaling that which is produced by every single car and light truck in operation throughout the entire continent. To further put things into perspective, if merely half of all those households switched to using solar powered water heaters, the subsequent reduction in CO2 emissions would be equal to the effect of doubling the fuel-efficiency of all the cars on the road.

The concept of having half of those aforementioned households switch to solar water heaters might not be as far fetched as you might think. According to a recent report by the Environmental and Energy Study Institute (EESI), there are approximately 1.5 million solar water heaters already implemented in homes and businesses across the United States. Solar water heaters are incredibly versatile and can function in any climate. The EESI estimates that about 40% of all U.S. residences have adequate access to sunlight. They believe that roughly 29 million homes are capable of making the switch to solar water heaters today.

One of the most popular reasons to switch to solar is the savings. While the initial cost of solar water heaters is relatively high, between $1,500-$3,500, the energy savings are huge. Due to the significant amount of money that can be saved from utilities, most solar water heaters will pay for themselves usually within four to eight years. On top of that, solar water heaters on average last between 15 and as much as 40 years, which is roughly the same lifespan of the traditional systems.

As if all that weren’t compelling enough, in 2005 the United States began offering tax credits of up to 30% for homeowners to cover the cost of installing a solar water heater in their home. It is important to note, however, that this credit isn’t available for hot tub or swimming pool heaters, and that the installed system needs to be certified by the Solar Rating and Certification Corporation.

Another important factor to note is that in many cities a building permit is required to legally install a solar water heater into an existing house. Check with your local municipalities to determine what steps you might need to take to safely install a solar water heater in your home.