When you are ready to purchase a photovoltaic (PV) solar electrical system ( for example: GOAL ZERO NOMAD 7 PLUS ), thoroughly check out the various packages that companies offer to ensure that you get the best solar electric panels. Be sure to explore tax incentives that are available. Between loan programs that solar power installation companies may offer and the tax credits and incentives available at both federal and state levels, you may be able to reduce the cost of a PV power system by many
thousands of dollars.
For example, photovoltaic solar panel systems that provide electricity for a home and that meet applicable fire and electrical code requirements are eligible for a federal tax credit of 30% of the cost up to $500 per .5 kW of power capacity. This program is for principal residences only (not rentals or second homes) and expires Dec. 31, 2016.
In California, the Go Solar California program was launched in 2006 with a goal to install 1 million solar panels on homes in 10 years. This $3.3 billion program hopes to reduce the demand for energy during peak times while reducing the cost of electricity.
When you go shopping for the photovoltaic cell system that is right for your home, keep these considerations in mind: OutputHow much juice does your home need? If your power bill breaks down the amount of electricity you use on a 24-hour basis, you can easily determine how many watts your PV array will have to generate in order to satisfy your home’s needs. During peak hours of the day, when the sun is highest in the sky and the PV cells can operate the most efficiently, output can range from 40 watts all the way up to 200 watts. The difference generally is in the technology, size, and price of the cells.
Dollars Per Watt
Another way to gauge the cost of purchasing PV cells is to look at the dollars-per-watt cost ratio. A rough estimate would be to shop for modules that are priced in the $4- to $5-per-watt range. This means that if the module has a maximum output of 100 watts it would cost $400 to $500. Using this method of calculation, you can roughly determine how much you would need to spend to power your home.Insolation
Insolation is the term used to measure the amount of direct sunshine that falls on a square meter per day. It is rated in kilowatts and will help you determine how much energy you can expect your PV array to produce.
Mounting a Solar Array
In North America, a solar array must have direct southern exposure and the proper tilt to ensure maximum efficiency. There are several kinds of solar array mounting systems for the home, and picking the right one is critical to getting the most out of your investment. Directly installing the PV modules flat on your roof may be the most aesthetically pleasing approach, but it will reduce the amount of power generated during low-light, cloudy, and rainy days (yes, PV cells even work in the rain, they just generate less electricity.)
Mounting on a stand may be more practical, especially if your home has a flat or unusual roof. Some module mounting stands come with sensors and motors to automatically turn and tilt the PV cells to follow the sun across the sky and capture the most energy possible.
There are several kinds of solar collection technologies on the market today, but the primary one that catches homeowners’ attention is photovoltaic (PV). Most industrial or commercial solar energy power plants use reflective mirrors to focus the rays of the sun to super-heat fluids that in turn heat water to make steam for traditional steam-powered turbines. PV cells are different because they directly convert energy from the sun into electricity without needing a generator or any moving mechanical parts.
Scientists discovered the process of capturing solar energy through photovoltaic cells in the 1950s. By the late 1960s, the U.S. space program powered electronic equipment on satellites in orbit with solar technology. Although manufactures develop many new styles of PV cells, two distinct kinds are appropriate for home use:
Crystalline Silicon Solar Cells
Silicon, the second most common material on Earth, is abundantly found in sand. Manufactured silicon crystals are sliced to about 300 micrometers (a micrometer is 1/1,000,000 meter) thick and coated to work as a semiconductor to capture the sun’s energy. Solar radiation (sunshine) lands on a PV cell, and, as the energy is absorbed, electrons are freed and channeled off. The flow of electrons is basic electricity. Silicon PV cells remain the dominant style of PV cell on the market but require more materials and labor to produce than polycrystalline PV cells.
“Thin-film” (Polycrystalline) PV Cells
Thin-film PV cells use either an alternative to silicon as a semiconductor or amorphous silicon. Thin-film PV cells have the advantage that the modules can be relatively flexible or bendable, mass produced, and engineered to directly cover building materials such as shingles and siding. Though thin-film PV cells generate less electricity than the standard crystalline silicon cells, they can operate more efficiently in low light and cloudy conditions.
PV Cell Output
Regardless of the type of PV cell, the amount of electrical output is measured in watts. Each PV cell may be as small as 3 inches square and generate only a few watts of electricity. In order to gather a useful amount of power, cells are linked together to create modules that are the recognizable “solar panels.” A series of modules linked together is called an “array.” An array could have two or a thousand modules, depending on how much electricity is trying to be created.