IntelEfficient

The feeling of fresh, warm water on your face in the morning shower is soothing, refreshing and invigorating.  The feeling of sunshine on your shoulders is equally therapeutic – in modest doses of course.  Imagine combining these two to naturally warm water with sunshine, and you have a match made in heaven.

 We’ve actually been doing this for years – at least in the summer and in warmer climates.  Some of the earliest versions of solar water heaters were simply metal tanks sitting out in the sun in the southwestern United States.  The Climax brand solar water heater was first marketed in California in 1890.  By the 1950’s, half of the homes built in south Florida had a solar water heating system.  But when the utilities started promoting cheap energy, the systems were no longer cost-effective.

These original systems were only practical in the warmer climates, because the thermo-siphon systems can’t survive a hard freeze.  So, rather than heating the water directly, a separate heat transfer fluid (typically glycol) is used to capture the warmth from the sun and circulate that through a heat exchanger in the hot water storage tank.  This closed-loop system is the most common way of heating water with solar energy.

Solar water heating systems used to be practical but not pretty.  In earlier models, both the tanks and collector panels were mounted on a south-facing roof.  These systems tended to be clunky and visually unappealing.  As the closed-loop systems became more common, insulated storage tanks were installed indoors.  The most efficient collector panel is made of evacuated tubes, which have a vacuum seal and virtually no heat loss.  These work better in colder climates and on overcast days, and are well suited for commercial or heavy-duty applications. Read the rest of this entry »

Sarah Heyman and her family have always been conservative when it comes to consumption.  They are far from the ordinary family: Sarah rides her bike to work, and since they live near bus and MetroLink stops, they often use mass transit to get around.  As a result, they have made a critical choice to live with a single car, which they use whenever necessary or convenient.  “I’ve been doing this kind of thing my whole life – it’s a great way to live!” says Sarah.

When their water heater began to fail last year, Sarah and her husband Michael wanted to explore alternatives to the traditional hot water tank.  They considered a tankless option, which only heats water on demand so you don’t have to maintain a body of heated water that you may or may not need.  They also looked at heating their water with solar energy, because these systems typically reduce the energy needed to heat water by 50 to 80 percent.  While it’s often difficult to accurately determine how much money is spent heating water, in the average home typically 20% of the total energy consumed is used to heat water.  Read the rest of this entry »