Greener living. Reducing carbon footprint. Eco-friendly. Such terms are bandied about a lot these days, and are associated with trying to reduce the damage we do to our planet. In many cases, the most ecologically sound way of doing something is also the most expensive and we have to make a choice: save money or help the environment?
In the case of home solar panels, both are possible. Admittedly, the cost of solar panels is not negligible. They require quite a large investment for installation and possible changes to hot water systems or for electricity generation, but in the long run they will reduce the cost of energy in the home – and they have a tiny carbon footprint. They’ll also add value to a property, particularly with the possibility of an energy crisis in the future.
Home solar panels can be installed to heat water or to produce electricity. There is a common misconception that solar power can be used to run the central heating system of a house, but in nearly all cases this is inaccurate: the heating is separate from the hot water system. While solar power can provide abundant hot water, it’s very unlikely it can heat your house, especially in winter when there’s less sunlight around! For those people who are lucky enough to have an outdoor swimming pool, however, there are pool-heating panel kits available.
Hot water systems generally use one of two types of solar panel: the easily-recognized flat panel or the less well-known solar tube. Flat panels usually consist of thousands of little cells designed to trap and contain solar energy: the cells are usually pyramidal in shape so that they have a bigger surface area to catch sunlight. The panels are covered by a sheet of glass, though often even the covering is made to a special formula to help improve the passage of sunlight, instead of dissipating useful energy into the glass and losing it.
Solar tubes are more efficient than the basic flat panels. They’re built like big thermos flasks: the central area is “evacuated” – in other words, it’s almost a vacuum – and the tubes are lined up into a square, much like the flat panel. The advantage of the tube design is that the glass is not flat or pyramidal: the tube shape means that there’s 360 degrees being heated by the sun, throughout the day. That’s a lot more surface area. Once the surface is heated and the central, evacuated area warms up, the tubes act like that thermos flask, trapping the heat inside so that it can be used.
Both flat panels and evacuated tubes are used for hot water systems. To generate electricity (and sell the surplus to the energy companies!), “PV” panels are required. “PV” stands for “photovoltaic” - these solar panels capture sunlight in similar ways, but are built to convert that energy into electricity instead of using it to heat water pipes.
All solar systems have certain requirements and will give varying results. They have to be installed on a south-facing roof, at an angle of between 20 and 50 degrees, so that they capture sunlight for as long as possible during the day. They can be installed on a flat roof as well, but part of the installation will be to prop the panels up at the appropriate angle.
The return on the initial investment depends very much on a house’s “microclimate”. In the UK, for example, there is less powerful sunlight than near the equator – about 55% as much. In the more northern states of North America, figures are similar, whereas down in the south there’s a great deal more heat. In general, though, solar water heating can provide hot water on demand for an average family throughout the year with very little – if any – backup required from a boiler system.
In any case, it’s worth getting quotes on prices and possible returns from a professional, even if you eventually decide to do the installation yourself or build the solar panels yourself.
Find more information about solar panels on Home Solar Panels blog. Also read my post: Home Solar Power as an Investment in the Future, where I talk about cost of solar panels.
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