Solar power is quickly becoming not only one of the trendiest, but also one of the most effective and groundbreaking renewable power sources on the market. Because of the continued decrease in cost and simultaneous rise in photovoltaic efficiency, solar panels are now one of the most popular methods of offsetting or replacing traditional electricity generation in both commercial and residential applications. Across America small businesses, private homeowners and even government entities are all beginning to find a host of reasons to go green, go off-grid and go solar.
Utilizing the power of the sun is highly appealing for off-grid living applications for several reasons. For one, the price of solar panels has dropped dramatically over the last several decades since the introduction of the solar panel to the market in the late 1970s. Since 1977 costs have dropped from $76.67 per watt to $0.36 per watt in 2014 (Swanson’s Law). The cost of implementing rooftop solar power can be further offset in many markets by selling excess electricity back to the grid. In many cases, this rooftop solar-produced electricity can be sold back to the grid at a higher price than consumers pay for it, a mechanism known as a feed-in tariff.
Aside from their affordability and obvious ecological and efficiency benefits, modern solar panels are remarkably long-lived and reliable. Many companies guarantee their solar panels at a lifespan of 25 years or more with retention of 80% of the rated power output. This, coupled with the ease at which the modern consumer can obtain, set-up, and scale-up their own solar energy system, makes solar panels the ideal method of electricity production for those considering an off-grid lifestyle.
How Do Solar Panels Work?
Solar panels are composed of numerous smaller components called solar cells, or photovoltaic cells. The term photovoltaics (PV) describes the process by which solar energy is converted into electrical energy. Photovoltaic solar cells employ photodiodes, or devices that convert light into direct-current (DC) electricity. This conversion is achieved by means of the photovoltaic effect, which describes the excitation of electrons as a result of their interaction with light photons.
Most solar cells use photodiodes that are composed of the semiconductor silicon, which absorbs solar light photons. The silicon semiconductor is usually present in two layers; each coated with either boron or phosphorus in order to create an electric field that captures electrons liberated from the silicon. Each solar cell is electrically connected to the rest of the module by wires composed of gold, silver copper or other nonmagnetic conductor. Free electrons are transmitted via direct current through these conductors to an inverter, which converts the DC current to an alternating current (AC) for household consumption or storage in a deep-cycle battery.
Types of Solar Panels
As far as residential and off-grid solar electric power production goes, there are two primary types of photovoltaic cell (and therefore solar panel type) that are most appropriate for consideration. These types, known as monocrystalline and polycrystalline silicon, are currently the cheapest, most efficient, and most residential-appropriate solar panels on the market. Other types, including building-integrated photovoltaics (BIPV) and thin-film solar cells (TFSC), are more commonly applied to larger scale commercial power generation operations.
Monocrystalline and polycrystalline silicon solar cells are both, as their names suggest, composed of crystalline silicon. The difference in the two lies primarily in silicon grade (purity), energy and space efficiency, and cost. Monocrystalline silicon cells are composed of a higher-purity silicon, and are therefore more efficient in terms of power output and space consumption. For these reasons, monocrystalline silicon solar panels are more expensive to consumers than polycrystalline silicon solar panels, which take up more space and are generally less efficient.
Solar Panel Installation
Numerous companies across the U.S. now offer solar photovoltaic installation services in many local and regional markets. Solar City, for example, is beginning to dominate the solar-panel installation markets in the western U.S. Countless local and regional companies also continue to appear and compete in this quickly-growing market as well.
For the more technically minded and hands-on types, there are countless books, guides, and starter kits available on the market that can make the process of DIY solar installation safe and fairly simple.