Solar power systems absorb sunlight and produce electricity. Solar power is also known as green energy. Green energy resources are renewable. We are close to the first quarter of the 21st century. Solar systems have become inexpensive and are recognised as the most prevalent type of renewable energy. This ohmic blueprint provides all important points which you should know about Solar Power Systems.
List of Components
- Solar Panel
- Battery Regulator
Schematic Diagram of Solar Power System
The solar panel is a combination of solar cells. Solar cells are also known as photovoltaic cells (PV cell). The size of single cell ranges between 6-6.5 (square inches). The thickness of the whole cell is same as a page.
Note: The working principle of solar cells is a part of technical scientific knowledge and you can simply skip this part if you’re more concerned with physical knowledge and working.
Working Principle of Solar Panel
The PV cell has two regions, namely the p and n regions. A pn junction is formed between them. The n region is very thin and allows sunlight to penetrate through it. Whenever sunlight photons penetrate any region (n or p), it strikes the atoms near pn junction and knocks an electron out of valence shell.
The electron leaves the atom, creating a hole behind. Finally, the electron-hole pairs are generated.
After formation of electron-hole pairs, the free electrons in p region move towards n region under the action of electric field and holes in the n region move towards p region.
On connecting load with the panel, these electrons start moving from negative terminal towards the load and then back to the positive terminal. From there, these again pass through pn junction and back to n region. Meanwhile, the sunlight creates new electron-hole pairs and the process continues.
The Insight of Solar Cell Features
Typically the size of solar cell ranges between 6-6.5 square inches. A single cell can approximately produce 0.5V. The terminal voltage is slightly dependent on sunlight. Change in sunlight’s intensity has a mere change on output voltages.
However the amount of current depends on the intensity of sunlight.
Formation of Solar Panels
A single cell provides 0.5V on output. Due to this reason, a single cell is impractical. A combination of multiple solar cells in series can solve our problem.
Solar panels are available in 12V, 24V, 36V, 48V, 96V and 120V. One can also get a custom made panel depending on his specific applications.
A battery regulator controls the rate of electric current flowing to the battery. It is also known as charge controller/charge regulator. A charge controller takes the output from the panel and ensures that battery is properly getting a charge. In simple words, a regulator acts as a safety device against over charge.
A solar panel generates DC voltage. Batteries also store this DC voltage. On the other hand, electrical components and devices at our homes require ac voltage. An inverter changes stored DC to ac. For example a standard inverter converts 12V DC to 12V AC.
A transformer steps up the 12 Vac to 120Vac. Usually, transformers and inverter circuit is assembled inside the same box.
Solar panels require deep cycle Lead acid batteries. A deep cycle battery is deeply discharged whilst by using most of its capacity. Moreover, these batteries can be recharged thousands of times and are also available at lower cost.
For the same ratings lithium-ion battery costs double than a Lead acid battery.