In recent decades, the search for alternative energy resources has grown increasingly urgent. Pollutants emitted by fossil fuels pose a threat to our global ecosystem, and even as we make attempts to minimize the adverse effects of those harmful byproducts, we are faced with the futility of continuing to rely primarily on nonrenewable resources. Experts from all walks of science have begun looking toward infinite elements for reliable sources of energy. With its life-sustaining properties and crucial role in our universe, the Sun has quickly become a formidable candidate as a potential energy source—and modern innovation has presented a means of harvesting that potential for practical use.
Solar panels, which were first introduced onto space crafts in order to provide electricity while traveling, are tools comprised of smaller cells, all of which are able to convert light energy from the Sun into electrical energy able to power homes. These panels take advantage of the photovoltaic effect, the creation of an electric current with a semiconducting material and exposure to a light source. Often dubbed PV cells because of this, the cells are constructed most usually out of the semiconductor silicon, which absorbs a portion of the light that strikes the panel. Since the silicon is also outfitted with an electric field, negative on one side and positive on the other, the electrons that are knocked loose after absorption are forced to move in a single direction. This creates a direct current of electrons, which must then be transformed into an alternating current by a device called an inverter, after which the energy is readily usable within our communities.
PV cells convert roughly ten to fifteen percent of the light that happens to strike them. This may seem to be a dismally minuscule amount, but solar energy is a source of such a high quality that our needs could be met using merely two hours’ worth of the sunlight that reaches the Earth. Some photovoltaic systems additionally employ a complex arrangement of lenses and mirrors in order to direct more sunlight toward the panels and, consequentially, generate more electricity. While this makes for a pricier set-up, as opposed to not concentrating sunlight at all, the benefits in terms of energy collection are arguably worth the larger start-up costs.
Moreover, solar energy can feasibly be stored, so that we do not find ourselves powerless during the night or inclement weather. Batteries can be constructed to store solar energy as electrochemical potential, to be used at a later time, and solar energy can be implemented as a means of creating nontoxic generators called fuel cells. In the end, cost, not efficiency, is what makes solar energy a challenge to universally employ.