The use of solar energy technology is expanding rapidly following the increased need for clean, renewable or alternative energy to save Planet Earth. Predicted to become the world's largest source of electricity by 2050, solar energy is an inexhaustible resource that can meet the energy needs of the entire world.
Fig. 1: Ensuring a greener world – A solar-powered sewage treatment plant
What is solar energy?
Solar energy is the conversion of radiant light and heat into electricity using constantly evolving technologies. To produce energy from solar resources, active solar power technology can be grouped into two categories: (i) photovoltaic (PV) technology (ii) solar thermal power or concentrating solar power (CSP).
Solar energy from photovoltaic cells is used for commercial power generation, road signs, calculators, satellites and in many other applications.
CSP is mainly used in very large power plants. In this system, mirrors are deployed to reflect and concentrate sunlight onto receivers that collect solar energy. This energy is converted into heat and harnessed into thermal energy to produce electricity to be used in various domestic and commercial applications, such as drying, heating, cooling, cooking, etc.
The N-type and P-type semiconductor material in solar panels absorb sunlight which allows electrons to flow through the material to produce electricity. In this process, most of the visible light spectrum and about half of the ultraviolet and infrared light spectrum are converted into usable solar energy.
The amount of energy generated by a solar energy system in a given location depends on how much of the solar energy reaches it and also on the size of the system itself.
Current Status of the Solar Industry
Currently, the solar industry is developing steadily around the world. It has become a tool to improve the economic situation of developing countries. Significantly, the International Solar Alliance (ISA), initiated by India, has brought together the nations of the world for a shared solution to make solar technology an economically and technically viable proposition. It presents a dream opportunity for engineers to be part of the solar technology revolution that ISA has unleashed on the world.
Solar power production in India increased from 2.63 GW in 2014 to 22 GW in 2018, an eight-fold increase. It currently represents 16 percent of the country's installed electricity generation capacity. Solar energy can very effectively supplement the electricity supply from an electricity transmission network when electricity demand peaks in summer.
Without a doubt, India will continue to be the brightest spot in this regard as it is expected to have the largest solar power installed capacity base in the coming years. Pertinently, India has set a target of producing 175 GW of renewable energy capacity by 2022, which includes 100 GW of solar energy. There is also a need to strengthen storage technology to balance the trajectory of massive use of this energy.
The government has planned to provide financing of 210 billion rupees ($3.1 billion) to the solar panel manufacturing industry to increase its photovoltaic capacity. As India is expected to become the largest solar energy market, foreign companies are planning to set up solar power plants through joint ventures.
Types of Solar Devices
There are several solar powered devices available today, some of which are as follows:
Solar panels
A solar panel consists of a connected and packaged array of photovoltaic solar cells typically 6x10. The electricity generated in this system is supplied for commercial and residential applications. Wafer-based crystalline silicon cells or thin-film cells are used in most modules and must be protected from mechanical damage and moisture.
Fig. 2: Taking advantage of the Sun – Installation of Solar Panels in Progress
A photovoltaic junction box fixed to the back of the solar panel is its output interface. Externally, MC4 connectors are used to facilitate weatherproof connections to the rest of the system. At the same time, photovoltaic modules can also have USB power interface.
To achieve a desired output voltage or in parallel to provide a desired current capacity (amps), the module's electrical connections are made in series. Silver, copper, or other non-magnetic conductive transition metals are used in the lead wires that draw current from the modules.
Electric car
Solar-powered vehicles promise to significantly reduce the consumption of fossil fuels. Solar vehicles provide substantial savings over gasoline/diesel costs. Solar electricity is not only cheaper, but also offers a green energy option, which can help us with environmental conservation.
Fig. 3: Driving the Future – A Solar Powered Car
Inverters on the grid
Solar photovoltaic systems employ on-grid systems to generate energy when the utility's electrical grid is available. They need to be connected to the network to work. The advantage is that they can send excess energy generated back to the grid in case of excess production, so that this energy can be used later.
Off-Grid Inverters
You can also store solar energy in batteries which come in handy when the power grid goes down or if your system is not connected to the grid. But you should be aware that although off-grid systems provide power for emergencies when the electrical grid is down, they cannot sustain all loads given limitations in battery volume. Furthermore, there is a higher cost involved in purchasing specialized equipment for off-grid systems and greater complexity in installing their components.
Rooftop solar installations
To convert solar energy into electricity, solar panels are placed on the roof. Significantly, in India around 250-300 days are exposed to the sun, due to which there is a huge potential for solar energy production in the country. Rooftop solar plants range in capacity from one kilowatt to five hundred kilowatts.
solar water pumps
Solar pumps, also called photovoltaic solar water pumping systems, have been recognized as the cheapest source of water supply. The pump is fully automated at sunrise and sunset and requires no supervision. This is an ideal high-tech green energy product that integrates economy, reliability and environmental benefits.
Fig. 4: Pumping energy – Solar water pump in a field
The solar pump system uses the energy generated by solar cells to drive DC, permanent magnet, brushes and position sensors through maximum power point tracking, shifting and control devices.
Garden and street lights
Solar powered garden and street lights are very economical and useful. These lights turn on for 5 to 6 hours at night after being charged all day.
Solar Cooker
Leave the solar cooker exposed to the sun in the morning before going to work. You will heat it enough to cook after you return.
Fig. 5: A viable solution – Solar cooker working well in a mountainous area
Solar Geyser
The solar geyser contains a light tube that heats the water. The water in the solar geyser is hotter than in the water heating system.
Solar Inverter
Nowadays, the solar inverter is also supported by the grid, and can be charged from grid power even when solar energy is not available.
Solar Lantern
There are many types of solar lanterns available in the market, which provide 5 to 6 hours of battery backup to charge solar energy all day long.
Growing Demand for Solar Engineers
The infinite potential of solar energy has fueled the need for solar engineers, who bring their experience in designing, developing, planning and implementing solar technology projects for cities, businesses and homeowners. They manage everything from a few rooftop residential installations to large-scale solar power plants that provide cleaner energy to grid-connected customers.
According to a report from the Solar Energy Industries Association (SEIA), solar energy is now one of the fastest growing sectors in the world. There is a growing demand for solar engineers equipped with diverse skills in the field of solar energy such as systems design and engineering; installation of solar systems; device manufacturing and characterization; Quality control and reliability tests; customer consultancy, site assessment, financial assessment, project management and consultancy as well as (technical) sales.
Solar engineers are generally employed by renewable energy companies, companies specializing in solar engineering, leading consulting firms, oil and gas companies preparing to transition to renewable energy, and non-profit organizations.
Professionals from diverse engineering disciplines are employed in diverse facets of this industry. Materials engineers are involved to develop, process and test the materials used in the solar industry, such as metals, plastics, glass and semiconductors. Electrical engineers are involved in designing electrical circuits for solar panels, inverters, wiring systems, and other supporting devices. Mechanical engineers deal with the mechanical devices employed in capturing and transferring solar electricity. Industrial engineers help coordinate the global implementation of solar energy systems in buildings and communities. These engineers work with contractors to ensure that a system is designed as efficiently as possible to meet people's maximum needs.
Conclusion
Thus, solar energy can ensure energy security through dependence on an indigenous resource, in addition to increasing sustainability, reducing pollution and mitigating global warming. The sheer magnitude of available solar energy makes it a highly viable source of electricity. These advantages are leading to further development of the solar technology sector, offering rewarding career prospects for engineers.