What is solar energy and how is it created?

The rays of the sun contain enough energy to power the appliances in our homes and the energy produced from the sun, called solar energy has become a more sustainable alternative worldwide. As seasons change throughout the year, sunlight received at different geographic locations vary which coincides with the amount of solar power created. This is also influenced by time of day, the local landscape, and season, and local weather. ^[1]  There are two kinds of solar energy – one which is produced by photovoltaic cells (commonly known as solar cells)  which is the most typical and used by solar panels and concentrating power which is used in large power plants. ^[2] You most likely have seen solar panels on a home or perhaps even a solar energy farm. But how is this energy produced? First the sun’s rays are “converted from sunlight to direct current energy”. ^[3] Then, the “inverter converts direct current into alternating current.”^[3] After all of this, the power is sent to the appliances and lights inside the home. What makes this power source sustainable is that any extra energy produced can be fed back to the energy grid – or even the rest of the neighborhood. It is common for homeowners to sell leftover energy back to energy companies as well. The video below provided  illustrates  how photovoltaic material converts sunlight into energy. As you will see, each device is just a small “cell” connected together to form the large panels that we are familiar with.^[2]

As mentioned previously, the second most common source of solar energy is concentrating solar power. It is produced by using mirrors to convert the received sunlight into heat. As a result, the thermal energy collected by a receiver which “spins a turbine to power an engine that drives a generator.” You will not see concentrating solar power plants in residential areas, but rather used for larger projects. ^[2]

Morocco’s Solar Power Plant in the Sahara 

Near the town of Ouarzazate, Morocco which is on the edge of the Sahara desert the new Noor I power plant that is capable producing “160 megawatts of power” of providing renewable energy to millions of Moroccans. This, just the first phase of a multi-phase project is a massive development and once finished will be the largest solar power development in the world. ^[4] 

These plants are powered by concentrating solar power which uses the sun’s energy to convert into thermal energy to then convert water into steam that can power turbines.^[4]  A unique feature of this technology is that the time of day or cloud coverage will not affect the amount of electricity produced out of the plants because “heat from the fluid [in the solar plant’s pipeline] can be stored in a tank of molten salts.” according NASA’s Kathryn Hansen. This system does not stop production once it is met with nightfall, cloud coverage, or weather changes but it is meant to produce energy for 20 hours a day.

The benefits that this development will provide for the Moroccan people is a reduction in carbon emissions and an overall better quality of life for the nation since electricity is essential to households. According to World Bank, Morocco receives “97 percent of its energy” from imported sources and the ability to produce their own energy will make the country as a whole more efficient. ^[4]

India’s Solution to Space Scarcity 

     It is commonly known that India is one of the most overpopulated countries in the world and with little space and poor infrastructure, much of the growing population has been left without housing and little to no access to electricity. As a result, it has become difficult for the country to develop its industry and for the government to provide for people’s most basic needs. 

A solution to the energy crisis was created by a scientist at the  Central Engineering Research Institute in India by Dr. Harsh Vardhan. One solar tree takes up a mere “4 square feet and produces up to 3 kilowatts of power. This is enough to power five households.” ^[5] To put this into perspective, typical solar panel layouts which are those seen in the United States can require 400 square feet of land. It is composed of a series of panels that are arranged in a tree-like formation and unlike Morocco’s solar power plant, these trees are powered by photovoltaic cells, by arranging the panels at a height, it can harness between “10-15 percent more energy “than panels on the ground.^[5] After nightfall, these trees can provide energy for up to two hours. To address the issues that dust can cause when covering solar panels, the tops of solar trees have sprinklers that make them self-cleaning. Not only will this make life easier for millions of people but meeting a high demand for renewable energy will greatly improve the daily lives of so many.

As you can see from each of these innovations, solar energy has the potential to harness the creativity of scientists into creating more sustainable sources of energies in developing nations. As the world becomes more aware of the detriments of carbon emissions, particularly in developed nations like the United States, the push toward solar energy is just one way to make your footprint smaller.

Sources:

1.  Solar Radiation Basics. Energy.gov (2013). Available at: https://energy.gov/eere/solar/articles/solar-radiation-basics. (Accessed: 22nd February 2018)
2. Solar Energy Technology Basics. Energy.gov (2013). Available at: https://energy.gov/eere/solar/articles/solar-energy-technology-basics. (Accessed: 22nd February 2018)
3. How sunshine becomes solar energy. Solar City Available at: http://www.solarcity.com/residential/how-does-solar-power-work. (Accessed: 22nd February 2018)
4. Domonoske, C. Morocco Unveils A Massive Solar Power Plant In The Sahara. NPR (2016). Available at: https://www.npr.org/sections/thetwo-way/2016/02/04/465568055/morocco-unveils-a-massive-solar-power-plant-in-the-sahara. (Accessed: 22nd February 2018)
5. Plant solar trees to solve space issue. Smart Cities Council India (2017). Available at: https://india.smartcitiescouncil.com/article/plant-solar-trees-solve-space-issue. (Accessed: 22nd February 2018)