Solar PV has the greatest potential to meet the world’s growing electricity needs when compared to other renewable energy sources. The energy from 1 hour of sunlight on the earth’s surface is sufficient to meet annual global energy consumption.
Governments and regulators are able to facilitate the implementation of renewable energy. The development of solar PV has been, and to a large extent continues to be, driven by targeted policies and incentives, such as feed-in-tariffs or green certificates, that trigger developments in different market segments. These may range from solar PV residential building mounts to non‐residential and utility‐scale PV developments. This will change dramatically as the cost of PV‐generated electricity drops to parity with other generation sources, and economic decisions will dominate.
However, while targeted policies continue to be important, a key market driver of solar PV development is the concept of “grid parity”. Grid parity is said to occur when the levelized cost of solar power reaches the same level as that of conventional power. This phenomenon is both location‐specific and end‐use application specific. The goal for solar photovoltaic energy production is to achieve “grid parity” i.e. to be cost competitive with the current energy generation. This can only be achieved by reducing the cost per watt of the solar cells/modules produced and increasing their efficiency.
Today “grid parity” is an approaching target for distributed solar power, and in some countries it is already reality as grid connected systems are now at or very near to grid parity where the cost of electricity produced from privately-owned rooftop PV systems or utility-scale PV plants is equal to, or less than, the cost that the consumer would be paying for electricity from the grid.
Principle of solar energy: The Photovoltaic effect
Photovoltaic (PV) effect is the conversion of sunlight energy into electricity.
In a PV system, the PV cells exercise this effect. Semi-conducting materials in the PV cell are doped to form P-N structure as an internal electric field. The p-type (positive) silicon has the tendency to give up electrons and acquire holes while the n-type (negative) silicon accepts electrons. When sunlight hit the cell, the photons in light excite some of the electrons in the semiconductors to become electron-hole (negative-positive) pairs. Since there is an internal electric field, these pairs are induced to separate. As a consequence, the electrons move to the negative electrode while the holes move to the positive electrode. A conducting wire connects the negative electrode, the load, and the positive electrode in series to form a circuit. As a result, an electric current is generated to supply the external load. This is how PV effect works in a solar cell.
Solar PV Power represents a high-yield investment for the next 20-25 years. The production of energy from renewable sources contributes to the development of a clean and sustainable planet and People all over the world are increasingly aware of both the environmental and economic benefits of generating clean energy.
Energy from sun is free and the sun will continue to shine for billions of years to come. While the solar energy is inexhaustible and renewable, its irradiance is environment-friendly. The solar power system does not emit CO2 or any green-house gas, which is environmentally damaging. In addition, silicon, the raw material in making solar cells, is the second most abundant element in the earth’s crust. Since the solar industry has been developing and the technology is maturing, the PV power systems are efficient for both commercial and residential use.
In contrast, fossil fuels, as our main sources of energy, are depleting. Our high dependence on fossil fuels is inevitably going to push up their prices continuously until they are used up. Fossil fuels are nonrenewable and environmentally damaging. Recent climate change is in part a consequence from the increased CO2 concentration in the atmosphere caused by burning fossil fuels.
Therefore, it is essential for us to seek alternative renewable energy resources for guaranteed energy supply and environmental protection. Solar is the answer.