How To Harness The Power Of The Sun: Beginner’s Guide To Solar Energy.
“I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait until oil and coal run out before we tackle that”. Thomas Edison (1931)
The sun is one of the renewable energy obtained from natural resources which can be replenished but cannot be diminished. They don’t emit harmful substances such as greenhouse gases, and are environmentally-friendly energy source of energy.
The sun is the main source of energy as well as the source of life .The power of the sun which is called solar energy can be used to generate electricity through the use of solar panels.The sun supplies energy in the form of radiation and we have 3 Types of Radiation:
- Direct Radiation (GB) – Is the radiation that reaches the earth’s surface directly without scattering or reflecting.
- Diffuse Radiation (GD) – Is the radiation that has scattered before reaching the earth.
- Reflected Radiation (GR) – Is the radiation touching the earth surface after reflecting on objects such as clouds.
Note : Direct solar radiation produces more power than the diffused and reflected solar radiation when it strikes on the PV modules due to its intensity of power.
In cloudy weather conditions, diffuse solar radiation will also produce current when it strikes on PV modules but the amount of current will be less.
The Total Global Radiation (G) = GB + GD + GR
The Amount of Solar Radiation depends on four factors which include:
- Location (Latitude)
- Time of the year
- Local weather
- Time of the day.
Four Common Instruments For Measuring Solar Radiation are:
- Pyranometer
- Pyrheliometer
- Campell-Stokes Recorder
- Photovoltaic Sensor.
The Photovoltaic Principle:
Photovoltaic systems generate electricity directly from sunlight based on Photovoltaic effect. The Photovoltaic effect occurs when sunlight strikes a photovoltaic cell, electrons are excited and generate electric current that is carried through wires within the cell to an electrical circuit.
A PV module is an assembly of photovoltaic cells that are arranged in series and parallel to form the desired voltage and current. PV modules are rated in Watts and are available in different sizes ranging from 10 watts to 550 watts.
The PV modules also called Solar Panels absorb sunlight or the power of the sun and convert it to electricity in the form of direct current to charge batteries and electrical loads.
The PV array is a combination of two or more PV modules arranged either in series or parallel mounted on rooftops, or existing structures. The PV modules have the ability to generate electricity as long as sunlight strikes on it, and have a lifespan of 25 years.
There are 3 types of Solar PV Modules which are: Monocrystalline PV modules, Polycrystalline PV modules and Amorphous PV modules. The most widely used PV modules in Nigeria is the Monocrystalline PV modules.
Stay tuned for the more on PV modules……
