Solar: The Large And Small Scale
The sun has become one of the leading sources of clean and renewable energy in the US. More specifically, during the third quarter of 2014, panels that generate 1,354 MW of solar were installed in various parts of the country, which represents a 41% increase in solar power generating capability in comparison to the same period in 2013. While total solar output in the U.S. is still low, new technology, subsidies and the creation of sizable solar farms show that solar is continuing to advance and will remain an important employment avenue for future engineers.
To learn more solar, checkout the infographic below created by the New Jersey Institute of Technology’s Online Masters in Electrical Engineering degree program..
How A Solar Panel Works
A solar panel consists of many silicon wafer cells. When exposed to direct sunlight, the electrons in the cell material get excited and as a result, they leave their atoms and flow through a solar panel as direct current (DC). In order to power typical home appliances, the DC energy has to undergo conversion to alternating current (AC).
The History of the Solar Panel
The technology and intention to harness energy from the sun dates back to 1954 when Gerald Pearson, Daryl Chapin, and Calvin Fuller developed a photovoltaic cell at Bell Labs. In 1959, Hoffman Electronics improved PV cell technology to achieve energy conversion efficiency of 10%. However, at $100 per watt, solar power generation at this point was costly. Dr. Elliot reduced this cost to $20 a watt in 1970 with help from Exxon Corporation.
The first amorphous silicon PC cell was introduced in 1976 by Christopher Wronski and David Carlson, both employees of RCA Laboratories at the time. Research in this field continued until the University of South Florida produced a thin-film photovoltaic cell with energy efficiency of 15.9% in 1992. In 1994, the National Renewable Energy Laboratory used a combination of gallium compounds to make a PV cell with energy conversion efficiency exceeding 30%.
The National Renewable Energy Laboratory and Spectrolab, Inc. followed suit in 1999 with a PV cell that converted 32.3% of the sunlight hitting its surface into electricity. In 2000, BP Solarex unveiled two thin-film solar modules: the 0.5-square-meter module and the 0.9-square-meter module. The former module had an energy conversion efficiency of 10.8%, the best for such a module at that time, while the latter module had an energy conversion efficiency of 10.6%. In 2007, the University of Delaware unveiled PV cells with a conversion efficiency of 42.8%.
The Benefits of Using Solar Panels
One of the biggest benefits of using solar power at home is the energy savings. For instance, installing a five-panel solar unit can lower your annual electricity bill by as much as $1,000, which translates to $25,000 over a period of 25 years. Secondly, you can earn money selling excess energy to utility companies. Thirdly, you would qualify for tax credits. At the state level, households that invest in solar energy panels can earn money by selling State Renewable Energy Credits (SRECs) on the open market. The government also runs a solar rebates program where one receives money for investing in solar energy. Finally, net metering programs where utility companies credit the accounts of property owners who feed clean energy into the grid make it easy to lower energy spending.
Solar Panel Ownership versus Leasing
If you live in a rented property, leasing makes sense although energy bill savings will be lower in comparison to a homeowner. A tenant can save anywhere from 15% to 30% while the energy bill of a homeowner can fall by up to 50%. By installing a single solar panel, a homeowner can expect to save about $6,200 over a 30-year period. In comparison, the homeowner would be able to save about $4,000 over the same period by going with the leasing option.
Some companies have set up solar farms where tens or even hundreds of solar panels generate peak output of more than 1MW. However, instead of selling this energy directly to consumers, solar farms sell it to utility companies. For example, the Ivanpah Solar Electric Generating farm in the Mojave Desert, California that generates enough energy to power more than 140,000 households. The Japanese boast of a floating solar farm that can generate 1.7MW of electricity. Unlike land-based farms, floating farms generate more energy due to the cooling effect of water.
The Pros of Solar Energy
To start with, the sun is a free and environmentally friendly energy resource that virtually anyone can tap. Moreover, solar panels are easy to expand and require little maintenance because they have no moving parts. Moreover, manufacturers of solar panels have come up with solar units that suit a wide range of applications. Finally, one can use a solar unit for distributed or centralized power generation.
The Cons of Solar Energy
Compared to traditional energy sources, the cost of installing solar units is still relatively high. Furthermore, the sunlight that reaches the surface of the earth typically fluctuates depending on factors such as cloud cover, time of day, and time of year. Another negative is the use of toxic chemicals that are harmful to the environment. Examples of such chemicals include hydrofluoric acid during manufacture of PV cells. Additionally, the manufacturing process is very energy intensive. Currently, there are no commercial initiatives targeting the recycling of silicon material in discarded PV cells.
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