A solar photovoltaic power plant is a regular power plant that converts solar energy into electricity through the photovoltaic effect. This effect occurs when sunlight photons bump into a specific material and displace an electron, which generates a direct current.
The acronym PV is commonly used to refer to photovoltaics.
A photovoltaic plant is made up of PV modules and an inverter. Photovoltaic panels are responsible for transforming solar radiation. In turn, the inverter converts direct current into alternating current with characteristics similar to the electrical grid.
A solar array is a collection of multiple solar panels that generate electricity as a system. In a solar array, all the electricity generated is injected into the electrical distribution network. In this way, the performance is better because all the energy generated is used.
The largest solar PV power plant in the world is the Bhadla Solar Park in India. It has an installed capacity of 2,245 MW. The total cost of the installation was 1200 million euros.
Photovoltaics (PV) is renewable energy and clean energy because it does not generate polluting gases.
Parts of a solar photovoltaic power plant
Solar PV power plants are made up of different components, of which we cite the main ones:
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Solar modules: they are made up of photovoltaic cells. A PV cell is made of a material called silicon that is prone to suffer the photovoltaic effect. Commonly, they are systems for tracking the Sun.
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Meteorological tower: it is the place where the different climatic conditions are analyzed.
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Direct current (DC) cabinet: It receives the electricity generated by the PV cells.
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Investor: it converts the generated electricity from direct current (DC) to alternating current (AC).
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Alternating current (AC) cabinet: It receives the electricity that the inverter has transformed into AC.
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Transformation center: in this place, the energy adapts to the conditions of intensity and voltage suitable to be transported.
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Transportation lines: They are the lines that allow electricity to be transported to the consumption centers.
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The control room in which the operators can supervise the operation of all the plant’s elements.
How does a PV power plant work?
The operation of all the equipment in the plant is supervised from the control room. In addition, information is received from the tower, the inverter, the power cabinets, the transformation centers, etc.
The process to transform solar energy into electricity is as follows:
1.- Conversion of solar energy into direct current
Photovoltaic cells are the essential elements of a photovoltaic system. These are grouped in photovoltaic panels.
Solar cells capture the Sun’s radiation and convert it into electrical energy. In general, they are composed of silicon which is a semiconductor material that facilitates the photoelectric effect.
When a photon collides with a solar cell, an electron is released. With the sum of many free electrons, electricity is generated in the form of direct current.
The electricity generation capacity will depend on meteorology (radiation, humidity, temperature, etc.). Therefore, depending on the weather of each moment, the solar radiation that the photovoltaic cells will receive will be variable. For this reason, the tower is built in the solar plant.
2.- Transformation of direct current to alternating current
Photovoltaic panels generate direct current. However, the electrical energy that circulates through the transmission network does so in alternating current. For this reason, direct current (DC) must be transformed to alternating current (AC).
First, the direct current from the solar panels is led to a direct current cabinet. In this cabinet, the current is molded into alternating current through a current inverter. The electricity is then sent to an alternating current cabinet.
3.- Transport and supply of electricity
The current that reaches the AC cabinet is not yet ready to be supplied to the electricity grid.
For this reason, the electrical energy produced passes through a transformation center. This center adapts the intensity and voltage to be the best conditions for the transmission lines.
Large PV plants face the additional challenge of needing to achieve favorable grid connections.
Types of photovoltaic plants
There are several types of photovoltaic plants, which vary according to their size, configuration and application. Here are some of the most common types:
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Large-Scale Photovoltaic Power Plants: These are large solar power generation facilities designed to produce a significant amount of electricity. They can occupy large areas, such as solar parks on the ground or on elevated structures. These plants typically have a capacity of several megawatts (MW) or even gigawatts (GW).
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Floating photovoltaic plants: These plants are installed on bodies of water, such as reservoirs, lakes or ponds. Photovoltaic panels float on the surface of the water, which helps reduce water evaporation and improves the efficiency of the panels due to the natural cooling provided by the water.
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Rooftop photovoltaic plants: This type of installation involves the placement of photovoltaic panels on the roofs of residential, commercial or industrial buildings. These installations can be on a small or medium scale, and are usually intended to supply energy directly to the buildings themselves.
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Distributed photovoltaic systems: These systems are made up of multiple photovoltaic panels installed in homes, businesses or smaller industrial facilities. The electricity generated is used to meet the energy demand in the place where the installation is located, and the excess energy can be injected into the electrical network.
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Solar Tracking Plants: These plants use solar tracking systems to automatically adjust the orientation of the panels throughout the day to follow the path of the sun. This allows a greater capture of sunlight and, consequently, a greater production of electricity compared to fixed systems.
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Hybrid photovoltaic systems: These systems combine photovoltaic panels with other energy sources, such as wind turbines or diesel generators. The integration of various sources allows for a more stable and reliable supply of electricity, especially in places where the availability of sun can vary or be limited.
The 5 largest solar plants in the world
Below is a table with the five most important photovoltaic plants in the world:
|
No. |
Plant Name |
Location |
Capacity (MW) |
|
1 |
Bhadla, Rajasthan, India |
2,245 |
|
|
2 |
Parque Solar Tengger Desert |
Mongolia Interior, China |
1,547 |
|
3 |
Pavada Solar Park |
Pavagada, Karnataka, India |
2,050 |
|
4 |
Parque Solar Noor Abu Dhabi |
Abu Dhabi, United Arab Emirates |
1,177 |
|
5 |
Parque Solar Kurnool |
Kurnool, Andhra Pradesh, India |
1,000 |
Impact and Affectation on the environment
Photovoltaic plants are a form of renewable energy generation and generally have a lower environmental impact compared to power plants based on fossil fuels.
However, they are not completely impact free and can affect the environment in different ways. Here are some things to consider:
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Land use : Large-scale plants require a considerable amount of space to house the solar panels. The installation of these plants may imply deforestation or the alteration of natural habitats, which may have an impact on local biodiversity.
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Water use : Some cooling systems may require water to maintain the efficiency of the solar panels.
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Manufacturing and materials : The production of photovoltaic panels requires the use of materials and energy, and their manufacture can generate emissions of greenhouse gases and other pollutants. Also, some materials used in the panels, such as silicon, come from minerals that require intensive extraction processes.
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Waste and Recycling : Solar panels have a limited lifespan, and at the end of their useful life, they can become electronic waste.
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Impact on fauna : Some photovoltaic installations, especially large installations on the ground, imply a modification of the landscape and vegetation that can represent risks for local fauna.