An exampleYouve probably seencalculators with solar cells-- devices that never needbatteries and, in somecases, dont even have anoff button. As long astheres enough light, theyseem to work forever. Youmay also have seen largersolar panels, perhaps onemergency road signs, callboxes, buoys, and even inparking lots to power thelights. That is Photovoltaicenergy at work.
Photovoltaic energyPhotovoltaic energy isthe direct conversion oflight into electricity at theatomic level. Somematerials exhibit aproperty known as thephotoelectric effect thatcauses them to absorbphotons of light andrelease electrons. Whenthese free electrons arecaptured, an electriccurrent results that canbe used as electricity.
Cells to Panels to an ArrayA number of solar cells electricallyconnected to each other andmounted in a support structure orframe is called a photovoltaicmodule. Panels are designed tosupply electricity at a certainvoltage, such as a common 12volts system. The currentproduced is directly dependent onhow much light strikes the panel.Multiple panels can be wiredtogether to form an array. Ingeneral, the larger the area of apanel or array, the more electricitythat will be produced.
Solar PanelsSo you saw the way a panel, or an array, is "pieced" together. Solarcells convert sunlight into electricity through a process where lightenergy in the form of a photon strikes the solar cell, creating a smallamount of electricity, as you already know.However to collect energy from the sun, solar panels need a fewmaterials under the glass to harness the sun. Here are a few ofdifferent types of thin film coatings:Amorphous silicon (a-Si), cadmium telluride (CdTe), Copper-IndiumSelenide (CuInSe2), Gallium Arsenide (GaAs) Multi-junction Cells,Dye-Sensitized Thin Film Solar Cells(DSSC), and Organic/PolymerThin Film Solar Cells.All these coatings are used to absorb sunlight and form into energy.Which can be used to power your home, however there are a couplemore steps before your running your toaster off solar.
The InverterThis energy generated by the panel, in the form of directcurrent (DC), is transmitted to the inverter. The job of theinverter is to convert the DC power the solar panel hasgenerated to alternating current (AC) that is transmitted on thegrid.The inverter converts DC to AC by using two switches whichconvert the positive only DC power to an alternating positive tonegative AC power. The inverter will then step up the voltagefrom 12 volts to 120 volts, which is the voltage used throughoutthe US electrical grid. This conversion of voltage is what allowsa 12 volt DC solar polar to be tied into a 120 volt AC grid.
The Utility MeterThe meter takes the amount of 120 volt AC energy your cellshave created and measures it in the form of kilowatts (kW), witheach kilowatt being equal to 1,000 watts of energy. Tounderstand how much energy is within a kilowatt, to generateone kilowatt, a 200 watt solar system would have to operate atpeak efficiency for five hours.As the electricity is transferred from the inverter to the grid, theutility meter measures the amount and at the end of the monththe power company compares the amount of electricity you useagainst the amount you added to the electrical grid.
Grid-tied SolarGrid tied solar means that your solar array is directly connectedto your utilities grid. Your array acts like a generator andproduces energy that is first used by you and any extra is soldto your electric utility. If youre generating enough electricity tosupport yourself then your electric bill is considerably lower.However if you use more energy then your solar arraygenerates, your utility will bill you for the difference (net).
Off the grid solarOff the grid solar is when you installa system and are no longer "attached"to an electrical company. They dontmeter you and if you cant generateenough solar to support your home,you either have a generator or youreliving in the dark till the sun comes outand can recharge your system.The energy you receive from yoursolar array, feeds a charge controller, the charge controllermonitors the attached battery bank to maintain fully chargedhealthy batteries. The inverter draws DC power from thebattery bank and creates 120 volt AC to feed the electricalloads from your home.
Global Green Energy Corp.Global Green Energy Corp. designs, manufactures, markets, and installsinnovative renewable energy solutions for the residential and commercial USmarkets.We accomplish this mission by:1. Using sustainable business practices,2. Providing local employment,3. Creating local and regional alliances with the public and private sectors,and,4. Building a local manufacturing and installation model that can be replicatedon a national scale.Our core environmental and socially responsible values include three basicprinciples:• Educate ourselves and empower others.• Use less, create more.• Invest locally.For more information visit www.ggec.co or ask one of our representatives.