Solar Energy

Climate change is a problem that presents many challenges and will require many different solutions. One solution is to use multiple renewable energy sources, which would cut down on greenhouse gas emissions. Renewable energy sources include solar energy, wind energy, nuclear energy, etc. Solar energy has many benefits and downsides that are important to understand. Solar energy is a major clean energy source that could be important to combating climate change.

Solar energy is a clean energy source that uses the sun to power technology such as cars, lights, electronic devices, etc. Solar energy involves converting sunlight into thermal or electrical energy, which makes it one of the cleanest and most abundant renewable energy sources (Solar Energy Industries Association). The sun is a resource that will not be depleted except on cloudy days, so it is an important renewable energy to explore. The Solar Energy Industries Association says the four types of solar energy are photovoltaic, solar heating and cooling systems, concentrating solar power, and passive solar.

Solar photovoltaic involves changing sunlight into electricity with a device or solar cells (EIA.gov). This is a simple process that just requires a device or cell and sunlight, which would be easy to use in place of fossil fuels. The Energy Information Administration states, “Small PV cells can power calculators, watches, and other small electronic devices” and many cells or panels can create enough electricity to power homes. Another problem is PV devices require open land in sunny areas to power homes (EIA.gov). Using photovoltaic devices can be useful for providing electricity to homes but it needs a large enough space with a lot of sunlight. PV materials can be expensive, but they are becoming cost effective because devices only need a small amount of it (EIA.gov). This limits what parts of the United States and the world that can use photovoltaic devices as an energy source, but it would be beneficial for those areas.

Concentrating solar power is power plants that use the sun to create electricity. The National Renewable Energy Laboratory states, “any power plants today use fossil fuels as a heat source to boil water. The steam from the boiling water spins a large turbine, which drives a generator to produce electricity”. There are new power plants that use sunlight to heat up the water that powers the turbines. The three types are linear concentrator, dish/engine, and power tower systems (NREL). Solar energy can replace fossil fuels in power plants eventually and there are multiple choices for solar power plants. Linear concentrator systems use mirrors to focus sunlight on tubes to heat the water, dish/engine systems use mirrored dishes to concentrate sunlight onto thermal receivers, and power towers use mirrors to concentrate sunlight to a receiver on a tower (NREL). All three types of concentrating solar power plants use mirrors in different configurations to direct sunlight to one area with the purpose of heating water to create electricity. These kind of power plants would be useful because they can replace power plants that use fossil fuels, but this would take years to accomplish.

Solar heating and cooling systems use the sun to heat and cool buildings. The EPA says this form of solar energy involves technologies that absorbs heat from the sun to heat buildings or water. Unglazed solar collectors use heat-conducting materials with no glass to transfer the heat from sunlight to fluid under the materials to heat water (epa.gov). This can be useful because it can provide heat without glass, which could be cheaper and safer. Transpired solar air collectors use perforated metal on the south side of a building with fans pumping the heated air throughout the building (epa.gov). It is another alternative that can provide heat to buildings and it does not require the use of fossil fuels. Flat-plate solar collectors use heat-absorbing materials on a panel to heat water or the air with a heat exchange system (epa.gov). Evacuated tube solar collectors use clear vacuum-sealed tubes filled with fluid that can heat up (epa.gov). These four types of heating and cooling systems provide different options than traditional energy sources. This would be safe for the environment because they are built onto the buildings and they do not create emissions. Solar heating and cooling systems may not be cost effective for buildings that do not have these alternatives built on or they may not be effective for areas with limited sunlight.

Passive solar involves making a home or building energy efficient with solar technology. According to the Department of Energy, “passive solar design takes advantage of a building’s site, climate, and materials to minimize energy use”. This involves reducing the energy loads required for heating and cooling by using energy-efficiency strategies (energy.gov). It requires windows or devices to have access to the sun, shaded windows during cooling seasons, a building made of material that can absorb heat, a way to distribute the heat, and ways to control heat such as fans or shutters (energy.gov). One or more of the different solar heating and cooling systems can be used as well to reduce the use of traditional energy sources. Solar panels can be added to a building so solar energy is used for every aspect of energy consumption. There are many variables in determining whether buildings are suitable for passive solar energy. It is one of the more complicated types of solar energy and can be costly if a building is not built for it already.

Solar energy has benefits and limitations that should be considered much like any other energy source. The Energy Information Administration states the benefits to solar energy are no air pollutants or carbon dioxide are emitted and it has “minimal effects on the environment”. These are significant benefits to solar energy when compared to fossil fuels. This would help combat climate change because solar energy does not emit greenhouse gases. Sunlight varies based on the climate, season, time of day, and weather (eia.gov). Using solar energy may not be feasible for locations that have limited sunlight. Another limitation would be that “the amount of sunlight reaching a square foot of the earth's surface is relatively small, so a large surface area is necessary to absorb or collect a useful amount of energy” (eia.gov).

Solar panels need a large enough space to provide energy to millions of people, which would need to be an uninhabited areas such as a desert. Photovoltaic cells are made with some toxic materials or chemicals and the fluid used for transferring heat in some solar thermal system can be hazardous (eia.gov). A solution to this is having laws or regulations on the disposal of potentially dangerous chemicals. There are downsides to solar power plants much like other power plants, which are “long-term effects on habitat areas for native plants and animals” (eia.gov). According to the EIA, this is due to the construction of a power plant and ecosystems being affected due to using large amounts of water for cleaning off materials. Solar power towers can kill birds and insect due to them flying into the beam of light created from solar power towers,

Solar energy can be a useful energy source and it is an industry that is growing every year. The SEIA states the solar industry has had an annual growth rate of 68% since 2006. This has increased the yearly installed solar capacity from about 200 megawatts (MW) in 2006 to about 15,000 MW in 2016 (seia.gov). This is a significant increase in just ten years, which could continue in the years to come. The solar Investment Tax Credit (ITC) is a 30 percent tax credit on making solar systems, which goes down to 0% for residential use and 10% for commercial use after 2021 (seia.org). The tax credit has helped the solar industry to grow and become competitive with more companies entering the industry. The solar tax credit may not be as necessary by 2021 because the solar industry has become as big as some traditional energy industries.

Utility generation of solar energy went from 508 MW in 2006 to 54,866 MW in 2016. In the same time frame, petroleum went down from 64,166 MW to 24,205 MW and coal went down from 1.99 million MW to 1.2 million MW (eia.gov). Solar energy has grown at a fast pace and has exceeded petroleum as a utility energy source. It is far away from coal, but it could catch up years from now as the industry continues to grow and become more competitive. The solar industry also employs 374,000 people in the United States with more than 260,000 spending most of their time on solar compared to 1.1 million employed by coal, oil, and gas. The solar industry provides jobs to thousands of Americans and it is a fourth of jobs provided by the three big traditional fuel sources combined. If the solar energy industry continues to grow, then it could potentially replace the jobs provided by the fossil fuel industries.

Solar energy continues to grow as a fuel source, which uses the sun to create energy for electricity. Photovoltaic, solar heating and cooling systems, concentrating solar power, and passive solar are the four types of solar energy. There are positives and negatives to solar energy that should be considered, much like any other energy source. Solar energy is a growing industry that provides utility power and jobs for thousands of Americans. Solar energy is one of many clean energy sources that are growing and it will be important to combating climate change.

References

https://www.eia.gov/energyexplained/index.cfm?page=solar_home

https://www.energy.gov/downloads/2017-us-energy-and-employment-reporthttps://www.nrel.gov/workingwithus/re-csp.html

https://www.energy.gov/energysaver/energy-efficient-home-design/passive-solar-home-design

https://www.nrel.gov/workingwithus/re-photovoltaics.html

https://www.power-technology.com/projects/solana-solar-power-generating-arizona-us/

https://www.seia.org/initiatives/about-solar-energy

https://www.seia.org/solar-industry-data