A typical Solar pv electrical principles is described to refresh our basic electrical knowledge. This knowledge will allow us to be comfortable with the compose of our pv solar principles and have trust that it is not over or under designed.
The pv Solar power System: A pv Solar principles has the four major components.
Pure Sine Inverters
1) The Solar Panel: This is the component that receives photons from the sun and converts the photon power into electricity. The panels are rated in Watts.
2) payment Controller: This component insures that the warehouse batteries are not overcharged and damaged.
3) warehouse Batteries: The batteries store our collected electricity until we use the power to power our appliance. Our electricity is store as the potential power rated in Volts.
4) Inverter: This component changes the current from our batteries, which is stored in direct current (Dc), to an alternating current (Ac) which is compatible with our household appliance.
Conversion of Sunlight to Electricity: Photovoltaic power is the conversion of sunlight into electricity through a photovoltaic (pv) cell, commonly called a solar cell. A photovoltaic cell is a non mechanical gadget usually made from silicon alloys.
Sunlight is composed of photons or particles of solar energy. These photons consist of varied amounts of power corresponding to the distinct wavelengths of the solar spectrum. When photons attack a photovoltaic cell, they may be reflected, pass right through, or be absorbed. Only the absorbed photons furnish power to generate electricity. When sufficient sunlight (energy) is absorbed by the material (a semiconductor), electrons are dislodged from the material's atoms. Extra treatment of the material covering during manufacturing makes the front covering of the cell more receptive to free electrons, so the electrons simply migrate to the surface.
The production of a solar panel is usually stated in watts, and the wattage is determined by multiplying the rated voltage by the rated amperage. The formula for wattage is Volts times Amps equal Watts. So for our example, a 12 volt - 60 watt solar panel measuring about 20 X 44 inches has a rated voltage of 17.1 and 3.5 amps .
V X A = W
17.1 volts times 3.5 amps equals 60 watts.
Our solar panel rated as 60 watts exposed to 6 hours of peak sun will produce 360 watt hours of power per day. An typical; home will need 4000 watts of Dc generating power to produce sufficient kwh to cover each year electrical consumption. This equates to 67 - 20 X 44 inches solar panels from the example above.
Wiring the System:
Solar panels can be wired in series or parallel to growth voltage or amperage respectively, and they can be wired both in series and in parallel to growth both volts and amps. Series wiring refers connecting a safe bet terminal of one panel to the negative terminal of an adjacent panel. This relationship will produce voltage as the sum of the two panels and the amperage will remain the same as the production panel. Two 12 volt and 3.5 amp panels wired in series will produce 24 volts at 3.5 amps.
Solar panels can be wired in parallel by connecting safe bet terminals to safe bet terminals and negative terminals to negative terminals. Two 12 volts and 3.5 amps panels wired in parallel will produce 12 volts and 7 amps.
A series/parallel wired principles refers to doing both to the above. This wiring task would produce 24 volts and 7 amps from our two 12 volt and 3.5 amps panels.
Inverter:
An inverter is a gadget which changes Dc power stored in a battery bank to accepted 110 / 240 volts Ac. Nearly all our lighting, appliances and motors are designed to use Ac power. Inverters come in sine wave and modified sine wave output. Most 11o volts devices can use the modified sine wave output. However, Extra devices that use lasers or silicon controlled rectifiers will need the pure sine inverter which is more expensive.
Auto change switching is a coarse internal feature which enables switching from one Ac source to someone else and / or from utility power to inverter power for designated loads. Battery climatic characteristic compensation, internal relays to operate loads, automated remote generator beginning and stopping and many other programmable features are available.
Charge Controller:
A payment controller monitors the battery's state of payment to insure that when the batteries need current when required and also insure that the batteries are not overcharged. Connecting a solar panel to the batteries without a payment controller seriously risks damaging the batteries and potentially causing a security concern.
Charge controllers are rated based on the number of amperage they can produce from a solar array. If a controller is rated at 20 amps you can connect up to 20 amps of solar panel current output. Industrialized payment controllers utilize Pulse-Width-Modulation which insures the most efficient battery charging and extends the life of the batteries. Even more Industrialized controllers can consist of Maximum Power Point Tracking which maximizes the number of current going to the batteries by lowering the panel's production voltage.
Many Industrialized payment controllers offer Low Voltage Disconnect and Battery climatic characteristic compensation as elective features. The Low Voltage Disconnect allows the terminals to be voltage sensitive. If the battery voltage drops too far the panels are disconnected thus preventing damage to the batteries. The Battery climatic characteristic compensation adjusts the payment rate based on the climatic characteristic of the battery since batteries are sensitive to climatic characteristic variations above and below about 75 F degrees.
Batteries:
The batteries for our principles should be Deep Cycle units which are designed to be discharged and then re=charged hundreds or thousands of times. Batteries are rated in Amp Hours (ah) and are usually rated at 20 or 100 hours. Amps hours refer to the number of current which can be supplied by the battery over the periods of hours. An example would ne a 350 ah battery could furnish 17.5 continuous amps over a 20 hour period.
Like solar panels, batteries are wired in series and/or parallel to growth voltage to the desired level and growth amp hours.The capacity of the battery amp hour capacity requires meticulous sizing for the conditions under consideration. Longest periods of no sun or cloudy conditions, availability of generator or grid backup or a standby generator with battery charger are among the conditions for consideration. The size of the battery bank will depend on the warehouse capacity required, the maximum extraction rate, the maxium payment rate, and the minimum climatic characteristic at which the batteries will be used.
Overall Design:
As with all electrical systems there are voltage losses as the electricity is carried over the wires, batteries and inverters and these losses are dependent on the efficiency of each component. These efficiency losses vary from component to component, and from principles and can be as high as 25 percent. A trained technician will be required to fine tune the principles for efficiency.
summary of a Pv Solar energy ideas