About Solar Power
Why solar? It’s time to reduce your monthly electric bills with clean solar power. Electric rates are skyrocketing, but clean solar energy is abundant and free to harness. Thanks to new technologies and a wealth of solar rebates and solar incentives, there has never been a better time to invest in clean solar energy. Home solar panels provide energy independence and protect homeowners from costly utility rate hikes. Solar panels increase home value from the moment of installation, last a lifetime and require very little maintenance. Should you decide to sell your home, a home powered by clean solar energy sells at a premium compared to one without. Save money and reduce your carbon footprint with clean, renewable solar power.
How do Solar Panels Work?
Solar photovoltaic (PV) technology produces electricity from sunlight, using solid-state materials with no moving parts. It’s a mature technology, first invented by Alexandre-Edmond Becquerel in 1839 and initially commercialized at Bell Labs in the 1950s. For residential application, solar power falls into two main categories. First is grid-tied solar power, where the home generates its own electricity but can also draw power from the utility company at night. The second type of solar energy for homes is off-grid solar power, where the home is located too far from an electrical utility cable and the home must generate its own power, storing energy in batteries for use at night.
A basic home solar panel system consists of solar PV cells connected and packaged together in weather-protected modules, which are fastened side-by-side on a racking system to form an array. The solar panel modules produce direct current (DC), which in a grid-tied system flows to a grid- interactive inverter. An inverter changes DC voltage to the alternating current (AC) for the household electric circuit powering wall outlets and all AC appliances. Excess solar power from the inverter may flow out of the house through the utility company’s electric meter and into the city-wide grid. When this occurs, the meter may run backward, and the utility will credit the out flowing solar electricity against electricity purchased from the grid at other times, like at night. This process is called net-metering.
In an off-grid solar power system, DC power flows from the modules through a charge controller (also called a regulator), which is an electronic device that produces a smooth flow of current at the desired voltage. From the charge controller, the solar power can go to a set of storage batteries and then on to the inverter, as needed.
Today’s Commercially Available Solar Panels Come in Three (3) Versions:
Single-crystal (or monocrystalline) modules are currently the most efficient — that is, one square meter produces the most electric power. These solar panels must be mounted in a rigid frame. Monocrystalline solar PV panels are useful when there isn’t much room for mounting or for homeowners who wish to keep their solar panel installations small.
Multicrystalline (or polycrystalline) modules are made of cells cut from multiple crystals, grown together in an ingot. This type of solar photovoltaic panel is slightly less efficient than a single- crystal solar panel, but is cheaper to produce and cheaper to buy.
Thin-film solar cell modules (or amorphous solar modules) are made by depositing thin layers of materials on glass, metal or plastic substrates. These solar panels are less efficient than silicon solar panels and more space may be required to generate the same amount of solar energy. Thin film solar cells are known to perform well in low light conditions. Not to mention, they are less expensive, durable, and their flexibility enables the solar PV panels to bend to fit the most unique roof shapes.
What are Solar Photovoltaic Cells Made of? How are Solar Panel Cells Made?
Crystalline photovoltaic solar cells are comprised of silicon, a little bit of boron, and phosphorus. These solar energy cells contain anti-reflection materials, a screen printing of electrically conductive grid lines on the top, as well as a coating of aluminum on the bottom to collect the electrons. The solar cells are made by liquefying the silicon (derived from pure sand) at high temperatures, and then slowly cooling the material in a way that creates large crystals. For single crystal solar panels, a cylindrical boule is very slowly pulled from the molten silicon. Polycrystals are cooled in a block that is formed by quartz glass, making the grains of crystals as large as possible. The solid materials are sawed into very thin wafers to produce the individual solar panel cells.
Thin-film solar panel modules are made from very thin layers deposited on an electrical conducting surface. These materials may originate as silane gas for amorphous silicon, cadmium and tellurium for CdTe, or copper, indium, gallium and selenium for CIGS. The deposition techniques may include sputtering, co-evaporation in a vacuum, electro- deposition, sintering or other techniques. Many variations of thin-film solar panel materials are being investigated for low-cost manufacturing and higher solar-to-electrical efficiencies.
How much Solar Power do I Need for My Home?
Electric power is measured in watts. A kilowatt (Kw) is 1,000 watts and a megawatt (Mw) is one million watts. You buy electricity in kilowatt- hours (Kwh) (which is energy as opposed to power). For instance, if you run a 100 watt light bulb for an hour, you’ve used 100 watt-hours of energy. If you run it for 10 hours, you’ve used 1 Kwh, for which the average household would be billed 14 cents (at $0.14/Kwh). A 1-Kw PV array can produce 1-Kw in direct sun. If sunlight falls on it five hours a day, it may produce 5-Kwh that day.
Know your load. If your family uses 600 kWh of electricity each month, that works out to about 20 kWh per day. If you get an average of five hours of direct sunlight daily, you’d balance your electric use with about 4 kW of net-metered solar photovoltaic power. A 2-kW system would offset about 50 percent of your bill.
What about Solar Panel Installation? Where and How Should I Install Solar Panels to Ensure Top Performance?
Solar panel installation location is critical to solar panel performance. Solar panels should face the sun. This usually means due south, though if you have a heavy air-conditioning load in the late afternoon you may want to point the array southwest. The solar array should not be shaded during any part of its productive day. Solar panels should be tilted upward at the correct angle to optimize seasonal exposure — typically at the angle of your latitude so it gets sunlight at a right angle at the spring and fall equinoxes. Some solar panel arrays can be made adjustable for varying the angle at different seasons. If the solar panels need to be elevated above the roof surface, it places additional uplifting loads on the roof structure during wind storms. If the roof doesn’t offer a suitable structural surface for solar panel installation, consider a ground-mounted solar array in the yard.
How Much Maintenance Does a Solar PV System Require?
Solar PV is considered a low-maintenance system – there are no moving parts and mother nature keeps them clean. We have a web based monitoring system that you and SolarMax Inc can see what your system is doing to keep track of your power production. So, if there is any issues you will be notified by email from your solar system automatically.
What is a Microinverter?
Some newer grid-tied systems replace a large central inverter with several microinverters, individually attached to the back of each PV module. Power coming off the module/inverter combination is 240 volts AC and can tie directly to the household service panel. A major advantage is that if one module is shaded or broken, performance of the rest of the system is unaffected. You can monitor the performance of each individual panel, on a home computer or your smart phone.