If you already live a greener lifestyle by doing some of the simpler things like insulating your home, replacing old appliances with more efficient ones, driving less, and buying locally, then what is the next step? Maybe you can lower your greenhouse gas emissions by installing a solar water heater. Solar water heating is one of the least publicized but most cost-effective renewable energy options. According to Windy Dankoff of Conergy, solar water heaters capture six times more energy than solar electric at a third the cost. This is why solar water heating offers excellent economics.
Quick History of Solar Water Heat
If you wanted hot water a hundred years ago, you had to put a pot of water on a fire. When Clarence Kemp patented the first solar water heater in 1891, the process became as automatic as the rising sun. The first solar water heaters became popular in California and Florida, increasing in popularity in these states for a number of decades. By the 1940s, natural gas became widespread, and the industry dried up.
However, the oil embargo of 1973 revived interest. President Jimmy Carter installed solar hot water and electric systems on the White House roof. Unfortunately, Ronald Reagan had these systems removed in 1981 and worked to eliminate energy efficiency tax credits. Today, energy insecurity along with environmental concerns, and 30% tax rebates are taking solar off of life support.
Solar Water Heaters
In a solar hot water system, water or antifreeze moves through various pipes, which are attached to black absorber plates. The fluid heats up and transfers its heat into a solar storage tank. The heated tank warms domestic hot water, living spaces, pools, spas, and even the ice on some driveways.
A standard gas or electric water heater draws cold water from the municipal supply (which is usually about 45-55 degrees). When our gas water heater draws water from the solar storage tank, the water can be hotter than the 120 degree setting. On these days, no natural gas is used to heat our baths, faucets, or washing machines.
When we have plenty of sun and need heat in our living spaces, a radiant floor system delivers heat from the solar storage tank to the floor under our first story. Instead of our floors being cold, they’re the warmest part of the room. This eases the load on our furnace and saves us money.
Not only does our solar hot water heater reduce home heating bills, it makes the temperature in each room more uniform since the floor delivery prevents heat from immediately rising to the ceiling and up the stairs. Before, Goldilocks would only stay on our warm second floor. Now, solar heating makes all three levels of the house “just right” and saves us about $500 per year (with a 120 square foot array). If natural gas prices increase by 6% every year (a conservative estimate), our savings will double in 13 years. Our solar heating system should pay for itself in less than 10 years, something our furnace will never do. Our solar water heater eliminates about a ton of carbon emissions each year. It is doing the work of about an acre of trees!
If you want to reduce your carbon footprint, first do the easy stuff. Then, consider solar water heating.
Solar Water Heating, by Ramlow, Bob and Benjamin Nusz., New Society Publishers, 2006.
Best Power International
St. Paul, MN