Home Solar Electricity Generation
In order to generate usable electricity directly from sunlight we need to use commercially produced photo voltaic (PV) cells. These PV cells convert the light from the sun directly into usable electricity, albeit at a low voltage.
These PV cells are composed of two layers of semi-conducting material. When the sun shines on a PV cell it creates a voltage difference across the two layers of the cell. This voltage differential produces electricity which can then be stored in a battery for later use or used directly. The higher the light intensity, the greater the electric current flowing. PV cells are linked together serially to provide a usable voltage. Often they are produced in panels to provide sufficient power to charge a 12v lad-acid battery.
Are PV cells realistic for home home solar power?
Well… maybe!
PV cells and panels are readily available and many companies will be happy to install you a working home solar power system. This will generate some electricity during the day, even when it’s cloudy. The problem is the cost of the installation. Typical installation prices are around $10,000 (USA) for a 2.5KWp system. This may generate half of your annual electricity if your location gets a lot of sunshine. Perhaps a third if you get some cloudy days. Even if we assume that you live in an area with very high electricity prices, this will save you at most $500 a year. This gives you a payback period of 20 years assuming no maintenance is required during the first 20 years. This is a realistic assumption for PV cells, barring physical damage. Battery technology, however, cannot provide this sort of no-maintenance or replacement time frame. Realistically, heavily used batteries will need to be replaced every five years or so increasing your maintenance costs. If you live in an area with low energy costs, or a lot of cloud these figures are ever worse.
These high initial costs, and battery maintenance, must be reduced substantially for home home solar power electricity generation to be cost-effective. There are some DIY solutions than can be installed for as little as $200, which will reduce this payback period dramatically. I’m going to cover these low-cost home solar power projects in a later post.
Photo by Tiggs07
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