Roof Mounted Solar Panels
On fine days the sun shines over the expanse of a building's roof, making it an ideal place for collecting solar energy. If we can harness that energy and convert it into usable power, then we can reduce the amount of carbon dioxide being released into the atmosphere, and at the same time our electricity bills, making our houses more energy independent. We can do this by placing photovoltaic cells, or PVs, on the roof tops, though the extent to which we can do this is dictacted by the building's load bearing capacity.
Basics of PVs
Photosensitive materials produce energy when exposed to light. A thin layer of one of these is inside solar cells, and the free electrons within increase in energy when placed in sunlight, detaching from the molecules when their energy level is high enough, which causes electron flow.
Identifying a suitable roof
Solar cells must be exposed to direct sunlight to work efficiently. As the sun moves across the sky, the solar panels need to have a motorized tracking facility so that they will always be facing the sun. Some roofs are not suitable for this, in which case panels should be mounted facing south and unobstructed. Increased exposure to the sun can also be achieved in some cases by elevating the panels.
If a roof cannot take the weight of larger panels, it can be re-built using a product called solar shingles, which have PV cells in them.
In high temperatures, PV cells become much less efficient, so in some areas wind power is likely to be a more practical choice. In warmer states like Florida and California, this problem has been solved by solar power generators which distribute their power through the grid, which is a more economical and efficient system than homes having their own PV cells.
The components of a roof mounted solar panel system
Household electrical systems use alternating current, whereas the current generated by PV cells is direct current, so inverters are required to convert it. Householders can reduce power costs through solar energy, and if they have a large system, can even be totally independent and possibly sell their excess to the grid. Householder and power company both gain from this, and it could even prevent power outages in times of peak demand.
Cost of PV systems
Roof panels cost between $6,000 and $30,000, and over the life of the solar panel, this works out at a cost around 25 cents per unit of electricity, which is higher than most power companies charge. However, many state governments have incentive schemes to encourage solar energy use and this would reduce the cost per unit.
Installing your own solar energy source also protects you from things like rate increases, inflation and deregulation; in addition it is environmentally friendly, and reduces emissions caused by use of fossil fuels.
Overall, we should all be turning to solar energy in our homes, from both economic and environmental perspectives.
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