What are solar panels?

Learn more about solar panels

Solar Panels are a form of active solar power, a term that describes how solar panels make use of the sun's 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 covert it into electricity.

What are solar panels made of?

Solar panels are typically constructed with cystalline 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 Earth's atmospheric interference, terran solar panels will never perform as well as solar panels exposed directly to the sun's rays. (see space-based solar power.)

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 earth's 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.