Solar Panels Usability
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Solar panels (arrays of photovoltaic cells) make use of renewable energy from the sun, and are a clean and environmentally sound means of collecting solar energy.
The solar revolution of the last two decades has made solar energy an increasingly powerful force in the energy arena. Solar Panels use arrays of solar photovoltaic cells to convert photons into usable electricity. With solar panels, we are provided with clean, renewable energy from the sun.
WHAT ARE SOLAR PANELS?
Solar Panels are a form of active solar power, a term that describes how solar panels make use of the suns energy: solar panels harvest sunlight and actively convert it to electricity. Solar Cells, or photovoltaic cells, are arranged in a grid-like pattern on the surface of the solar panel. These solar voltaic cells collect sunlight during the daylight hours and convert it into electricity.
WHAT ARE SOLAR PANELS MADE OF?
Solar panels are typically constructed with crystalline silicon, which is used in other industries (such as the microprocessor industry), and the more expensive gallium arsenide, which is produced exclusively for use in photovoltaic (solar) cells.
Other, more efficient solar panels are assembled by depositing amorphous silicon alloy in a continuous roll-to-roll process. The solar cells created from this process are called Amorphous Silicon Solar Cells, or A-si. Solar Panels constructed using amorphous silicon technology are more durable, efficient, and thinner than their crystalline counterparts.
For very important solar projects, such as space probes that have to rely on solar energy, very-high efficiency solar cells are constructed from gallium arsenide by a process called molecular beam epitaxy. Solar cells constructed by this process have several p-n junction diodes, each designed to be maximally efficient at absorbing a given part of the solar spectrum. This solar panels are much more efficient than conventional types, but the process and materials involved make them far too expensive for everyday applications.
The newest solar panels function on the molecular or quantum level, and represent an exciting new technology coming into play. These solar panels are created by implanting carbon nanotubes or quantum dots into a treated plastic. Unlike silicon-based solar panels, these solar panels do not have to be constructed in a clean room, and therefore production costs are somewhat dimished.
For continued instruction in the manufacture of solar panels, see How solar panels are made.
The practical applications of solar panels constructed from plastics are staggering – they could be overlayed onto a laptop screen to provide continous power, or provide supplemental power to any number of outdoor appliances. The primary hurdle for this new technology is efficiency, and these plastic solar panels have an operational efficiency of about .11% of their silicon-based counterparts. The only short-term solution to this energy problem is for these plastic solar panels to generate electricity from light outside the visible spectrum of light. Some highly-experimental plastic solar panels have been made to absorb infrared energy, and if a solar panel is made that can absorb both infrared energy and light from the visible spectrum, the operational efficiency could increase up to thirty percent.
HOW MUCH POWER DO SOLAR PANELS PRODUCE?
In direct sunlight at the surface of the equator, a maximally efficient photovoltaic cell about 1/5m in diameter creates a current of approximately 2 amps at 2 volts, however, due to the Earths atmospheric interference, terran solar panels will never perform as well as solar panels exposed directly to the suns rays.
Years of overheating and physical wear can, however, reduce the operation efficiency of the photovoltaic unit. Solar cells become less efficient over time, and excess energy is released into its thermally conductive substrate as infrared heat.
The amount of power solar panels produce is influenced by the quality of the solar panel, the materials and technology used in making the solar panel, and the amount of time the solar panel has been in use. When purchasing solar panels, it is therefore wise to look beyond size and look at the dollars/watt ratio.
WHERE DOES SOLAR ENERGY COME FROM?
Solar energy originates in the depths of our sun. The sun endures a continuous stream of thermonuclear explosions as hydrogen atoms are fused into helium atoms. We encounter the resultant energy as radiation that strikes the surface of the earth. Solar panels convert this solar radiation into useful electrical energy and store them in batteries for our use. Enough solar radiation strikes the earth every day to meet earths energy needs for an entire year. Solar panels help us harvest this energy and convert it into usable energy to meet the everyday needs of modern life.
LEARN HOW SOLAR PANELS CONVERT SUNLIGHT INTO ELECTRICITY
Solar panels collect solar radiation from the sun and actively convert that energy to electricity. Solar panels are comprised of several individual solar cells. These solar cells function similarly to large semiconductors and utilize a large-area p-n junction diode. When the solar cells are exposed to sunlight, the p-n junction diodes convert the energy from sunlight into usable electrical energy. The energy generated from photons striking the surface of the solar panel allows electrons to be knocked out of their orbits and released, and electric fields in the solar cells pull these free electrons in a directional current, from which metal contacts in the solar cell can generate electricity. The more solar cells in a solar panel and the higher the quality of the solar cells, the more total electrical output the solar panel can produce. The conversion of sunlight to usable electrical energy has been dubbed the Photovoltaic Effect.
The photovoltaic effect arises from the properties of the p-n junction diode, as such there are no moving parts in a solar panel.
SOLAR INSOLATION AND SOLAR PANEL EFFICIENCY
Solar Insolation is a measure of how much solar radiation a given solar panel or surface recieves. The greater the insolation, the more solar energy can be converted to electricity by the solar panel. Click to learn more about solar insolation.
Other factors that affect the output of solar panels are weather conditions, shade caused by obstructions to direct sunlight, and the angle and position at which the solar panel is installed. Solar panels function the best when placed in direct sunlight,