by Jim Yvene Cadion || Photo credit: Energy Department of the US
There is something crucial, yet inconspicuous, about the sun.
It is behind the fame of the world’s dominating energy sources, such as fossil fuels and hydroelectric power. Both the chemical potential energy in fossil fuels and the kinetic energy used by hydroelectric power is essentially derived from solar energy through a series of energy transformations. With the advent of new technologies, solar energy can be utilized more directly through the use of solar panels.
We sometimes stare at solar panels with no idea how they work. Using these to generate electricity seems like creating energy out of thin air. How is this possible? How could light be converted to electricity almost instantly?
The answer is that it is made possible through the atomic enigmas of photovoltaics.
Photovoltaics is the direct conversion of energy carried by electromagnetic radiation into electrical energy at the atomic level. This phenomenon, called the photovoltaic effect, was first observed by the French physicist Alexandre-Edmond Becquerel in 1839. It is based on the photoelectric effect, a phenomenon first explained by Albert Einstein wherein photons or particles of light carrying sufficient energy are able to knock and release electrons from atoms. When electrons are released, they are able to move more freely but are typically tricked to our advantage into flowing through electrical circuits. This movement of electrons is the electric current, which is what the process aims to generate.
Utilizing photovoltaic technology becomes advantageous as the earth intercepts an astronomical amount of solar power— a total of 173,000 terawatts, a magnitude more than 10,000 times the world’s total energy consumption, according to Washington Taylor, a physics professor at the Massachusetts Institute of Technology (MIT). This makes its generation of energy sustainable, unlike fossil fuels— which are estimated to be depleted by 2060, according to the Millennium Alliance for Humanity and Biosphere.
In addition, its generation of energy does not emit harmful greenhouse gases in comparison to fossil fuels, which account for the emission of billions of metric tons of carbon dioxide annually. This consequently makes photovoltaic technology exceptionally beneficial in alleviating climate change.
Given its clean and sustainable features, photovoltaic technology appears to be a better option than fossil fuels, especially now that we are dealing with fossil fuel depletion and climate change. However, there is more to this than meets the eye.
Solar panels provide an inconsistent energy supply for most areas of high energy demand since it only works during the daytime and in favorable weather conditions. Making this energy source consistent requires efficient storage of energy and efficient power grids that could distribute electricity from areas with prolific sunlight to areas under the shade. However, with current technology, this would mean large price tags and uselessness, as more energy dissipates when longer transmission lines are used.
Another challenge that photovoltaic technology faces are its inefficiency. According to the United States Solar Energy Technologies Office, most commercial solar panels have mean efficiencies of 15-20%— percentages far lower than fossil fuels’ mean efficiencies, which range from 35-45%.
Although the sun imparts a great amount of energy, present-day photovoltaic technology could only harness less than a speck of it. Principal dependence on this technology remains not completely feasible.
With further innovations, however, this may be possible in the future. Priorities on tackling related challenges, such as climate change and energy resource depletion, depending on the perceived opportunity costs and the specific assumptions we have to make when trying to solve such multifaceted problems.
But, the transition towards direct capture of solar energy is a mere walk in the Labyrinth filled with hedges of technology, economics, and politics.