The solar energy is the most valuable chapter in renewable energy now a day. The ultimate source of energy means we all know that the sun and sunlight are the largest energy received by the Earth. How solar energy is harnessed from the sun with the help of different solar panels, let’s explore!
Solar energy plays a vital role in the recent era, due to pollution or lack of sources of non-renewable energies. There is a drastic increase in solar energy uses in this modern era. It is really open up a new chapter in energy because:
Let’s, explore the details of solar energy!
The sun undergoes some fusion process and produces huge energy. A small amount of that energy is reached to the earth.
A huge energy is released by the sun. This energy is in the form of light and radiation.
Sun power or Solar power is simply the conversion of energy when sunlight converts into electricity.
When it comes to the earth, some portions are lost due to reflection, absorption, etc.
However, this energy seems less i.e., 51%, but it is huge in comparison with the world’s requirements.
Refer to the above image, how the radiation or absorption happens in the earth.
This solar radiation can be converted into thermal energy or electricity to use as clean energy in our daily requirements.
Solar energy is the most abundant energy resource on Earth. The energy which we received from the sun is called solar energy. This is one of the best renewable energy sources on earth.
Solar energy is different types:
In this method, we use solar power without any device. Like daylight, passive solar heating & cooling, etc.
In this method, mechanical or electrical equipment is used to increase system efficiency.
This is the heat energy that is produced from solar power using solar heating panels.
In the current environmental pollution problem across the globe, the demand for solar thermal energy is increasing day by day.
Photovoltaic energy is produced from the incident solar energy by using photovoltaic solar cells.
Concentrated solar power is produced from the mirrors or reflectors mainly for large scale power productions.
Example: Solar power plants
Solar panels are the main device to produce solar energy. This device or panel converts sun rays into electricity.
There are a few parts of a solar panel. Normally a standard solar panel has six components, these are namely, as follows:
There are mainly three kinds of solar panels, generally used.
Normally, solar panels are made in the following steps:
Silicon is produced from sand in an arc furnace.
Silicon is collected as solid
Melt the silicon rock and make cylindrical shape or ingots
Silicon ingot is sliced into thin films. This thin slice is called as wafers. Pure silicon is very shiny and it reflects the sunlight.
Anti-reflective coating is used for silicon wafer to reduce the sunlight losses.
Step#7 – Making Solar cells
Wafers are well treated. Once treatment is done, metal conductors are added on each surface and made a grid-like matrix on the surface. This matrix is nothing but solar cell and it converts solar energy into electricity.
Step#8 – Solar Panel
All solar cells are bonded together by metal connectors and create a link between cells. This structure forms a solar panel.
When the solar panel is ready, it is tested to check the performance of solar cells, and certify for ready to use.
Energy from the sun is renewable or usable energy received from the sun in the form of electric or thermal energy. Now a day, the use of solar power is very common for;
There are various ways to capture solar energy and convert it into usable energy.
There are a few ways to harness solar power:
Photovoltaic is a very common way of converting solar energy into usable electricity. This electricity can be used immediately based on requirements. Else, it can also be sent to the electric grids or stored in a solar battery as well.
Solar energy captured in solar panels or solar modules. This solar panel consists of:
How Does Photovoltaic Cell Works?
Silicon is a widely used nonmetal and it has very good conductive properties. It absorbs the sunlight and converts it into usable electricity.
Working principle of photovoltaic cells, step by step:
Step-1: Light strikes the semiconductor that is silicon cells,
Step-2: Light rays have photons and these photons hit the solar cell,
Step-3: Due to the hitting of photons, electrons present in the silicon cell becomes loose from the atoms,
Step-4: Loose means, these electrons get motion
Step-5: The motion of electron means, electricity generates,
Step-6: Conductors are attached to the positive and negative sides of a cell, & form an electrical circuit.
Step-7: Electric wiring is attached to the positive and negative sides to capture the electricity.
Solar panels are produced by multiple cells and multiple solar panels are wired to fulfill higher demands.
This entire process complete with light hits the silicon cell, losing electrons from the silicon cells, and providing motion on it. This is known as the “photovoltaic effect,”
Now, the generated current is known as direct current (DC) electricity and it is necessary to convert it into alternating current (AC) electricity for most household electric appliances.
Solar thermal means directly capture solar radiation and use many ways.
Solar thermal energy, normally three kinds:
Low-temperature solar thermal energy uses to heat and cool the air to control the temperature.
For example: In passive solar building design, the sun rays directly heat the space in the building. If heating is not required, simply block the light.
Mid-temperature solar thermal energy systems for heating water etc.
For Example: Here, heat from the sun is captured by collectors on your rooftop and then transferred to the water running through your home’s piping.
It has replaced all traditional water heaters.
High-temperature, Large scale electricity generation, high-temperature solar thermal energy systems are widely used.
This type of technology is known as CSP or concentrated solar power.
Let’s try to understand CSP.
Concentrated solar power or CSP plants employ concentrating or focusing, collectors or reflectors or mirrors to concentrate sunlight. This sunlight received in a wide surface area.
The working principle of concentrated solar power, as follows:
There are so many CSP in the world.
The flat-plate collectors are widely used panels to capture solar power and convert it to thermal energy. These are mainly used for solar heating applications.
Flat-plate collectors consist of glass sheets and blackened metal plate,
Refer the below image for a typical flat plate collector,
Diagram of typical solar ponds are as follows,
It’s a pond filled with salty water to collect solar power. This pond receives solar power through insulation. Later on, this heat is trapped and the water splitting into three layers.
Uppermost layer: fresh air with low salinity since salt settled at the bottom
Middle layer: Insulating layer, salinity is more than the top layer
Bottom layer: Lowest layer and where solar power is stored and extraction is possible.
Importance of Solar Ponds
Solar panels produce a direct current or DC electricity. We use AC current in our home appliances. Hence, it is necessary to convert this DC to AC. The solar inverter is mainly used to convert DC current into AC.
Normally, three kinds of solar inverters are used,
Here, solar panels are connected by “strings”, and that is why it is known as string inverters. Multiple strings of panels can be connected to a single inverter,
Power output at the string level is only optimized at string inverters, without the individual panel level.
Microinverters are installed on each individual panel,
No separate central inverter is required,
These are normally mounted onto the back of the solar panel
The power production of each individual panel can be easily monitored by micro inverters.
Power optimizer systems
These are located at each panel. It doesn’t convert DC to AC at the panel site, it conditions the DC and sends it to a string inverter.
The power production of each individual panel can be easily monitored by power optimizer systems.
Summary of the benefits of Solar power,
In 2019, the total solar power installed in the world is 6,27,000 MW. India has installed a total of 42,800 MW solar power. It is comparatively less with respect to the thermal power plant of nuclear power plants, however, the world is now a day looking for renewable energy like solar.
There are few important standards used in the solar industries,
Code and Standards
ISO 9050; Glass in the building
Code and Standards
ISO 10217: Solar Energy -Water Heating
In recent time, there are so many organizations are making solar panels due to continuous demands.
A few of them are listed below,
Hence, we have got a basic idea about solar power, solar energy as well as solar panels. Any questions, please write in the comment box.