If you are feeling the urge to "go green” or simply want to save money, you may want to look at photovoltaic arrays options. The science of photovoltaic power is expanding exponentially and rapidly. There are currently four basic photovoltaic arrays for thehomeowner to choose from. A photovoltaic array can be made up of a number of materials, some of which have been improved upon over time. In this overview of photovoltaic arrays, I will also give you an idea of the costs and benefits of their use.
What is a Photovoltaic Array?
A photovoltaic array is a grouping of specialized cells, often made of silicon, which converts solar radiation into direct current electricity. The first question you need to answer before investing is, "How much electricity does my household use in a day?" You should easily be able to get a good idea of how many kilowatt hours you use by going over a year’s worth of electric bills, or by monitoring your power. When choosing photovoltaic arrays to generate electricity, here is a simple formula – number of kilowatt hours divided by four. So if you use eight kilowatt hours per day, you will need a two kilowatt system. Cost and type of photovoltaic array will also depend on how your house issituated. There is also no relationship to the size of your house with the cost. Also note photovoltaic arrays are for electricity, not to be confused with solar converters for uses such as hot water.
Though all photovoltaic arrays tend to look somewhat alike, cell groupings, size of panel, and materials vary. Here is what they look like:
Amorphous panels are one of the earlier technologies and are the least likely choice for a homeowner. All photovoltaic arrays are guaranteed to work for 25 years, but all types will degrade to some degree over that time period. The degradation never falls below 80 percent, which is also part of the warranty. An amorphous panel will degrade quicker than other choices, according to Greenfield Solar Store owner Mark Skinder. "The glass coating can get scratched and yellowed over time," said Skinder. Amorphous panels also tend to be harderto install.
Monocrystalline Panels or Modules
Skinder describes the creation of a monocrystalline panel as "a big molten silicon sausage-shaped object that gets sliced into extremely thin slices." The thin slices are used to convert the solar energy in panels. However, Skinder says that monocrystalline panels,while highly efficient, are also very expensive and "more resource intensive."
Multicrystalline Panels or Modules
By 2007, multicrystalline photovoltaic arrays became the next big thing in solar power. Multicrystalline panels are what you are most likely to come across when you are in the market for solar power. Multicrystalline panels are less expensive to make and the technology is simpler. "It is the lowest embedded energy technology," said Skinder. Multicrystalline cells are also noted to be efficiently used in any climate.
Hybrid Panels or Modules
The latest technology embraces two of the earlier concepts in photovoltaic arrays. A hybrid, also widely available, is a marriage of monocrystalline and amorphous arrays, layered to generate an even greater efficacy of solar energy into electricity. Skindersaid that the hybrid panels have shown an improvement over other photovoltaic arrays by approximately 15 percent.
Why Install a Photovoltaic Array?
Costs associated with purchase and installation of a photovoltaic array range from $7 to $8 per kilowatt, depending on the panel you choose. If your home does not have good exposure for a photovoltaic array, you can also have panels placed on posts. The cost is higher for post installation by approximately a dollar more per kilowatt.
Homeowners can not only reap the benefits of lower cost electricity, but sometimeseven earn money for the unused portion of the electricity generated. Installing photovoltaic arrays may seem expensive at first, but various federal and state incentives can largely offset the cost.
Cris Carl is a freelance journalist who lives in Greenfield, MA. She enjoys manyoutdoor activities and taking care of her home. She is president of the Native American non-profit Friends of Wissatinnewag.