It’s a common misconception that one solar panel can do it all. While technically it is possible for solar electric panels to create electricity and to heat water using electricity, this is terribly inefficient. Any time energy changes forms, there is an efficiency loss, and in the case of heating water with electricity, the losses are tremendous. That’s why we have solar photovoltaic modules for electricity and solar thermal modules for heating water.
Solar photovoltaic modules produce electricity and are approximately 15% efficient using today’s technology. That means for the amount of surface area they consume on your roof, only 15% of the sun’s energy can be converted to electricity. While that may sound low, it is effective at creating energy for powering appliances in your home that have no solar thermal or other solar alternative.
Solar thermal modules that heat water do not create electricity. They take the energy of the sun and transfer it directly to water running inside the panels. This is a simple process. Anyone who has left a garden hose coiled up in the sun realizes how hot water can become in a rubber hose. This same concept, along with purposeful design and material technology, is used to make solar pool heating panels. Because electricity is not involved, the efficiency of solar pool heating panels is fantastic – around 5 times that of solar photovoltaic modules. Of course, solar thermal panels can’t do some things, like charge your iPod or run your television.
Both technologies have their place and their purpose. What is key is understanding your energy use and determining a cost effective and purposeful plan to reduce your dependence on utility electricity while maintaining or increasing your standard of living. Your solar dealer can point you in the right direction!