Important Facts about Home Solar Panels
Solar panels for homes and commercial buildings are widely considered a reliable standard in environmentally smart energy solutions, in communities and cities around the world. For many of us those standard deep blue solar panels just seem like a good idea. We know they create electrical energy from the sun, are an environmental choice we can live with, and that we’ll be spending far less on energy to maintain our habitable spaces by using them.
Learning more about how solar panels work and how they are rated provides valuable insights for anyone considering a solar installation. In understanding a few basics you’ll be prepared to evaluate solar panels and systems, so that you can develop a realistic cost framework for doing a solar installation. You’ll also learn how to choose a reputable solar panel installation company such as Sandbar Solar, and what questions to ask prior to ordering.
How Solar Panels Create Electricity
So how does a solar panel create electricity? The answer requires an understanding of the action sunlight has on a substance used widely in solar panel manufacturing today. Derived from silicon dioxide, silicon – the second most common element in the earth’s crust – is a chemical element found abundantly as silica sand and in the rock quartzite. The electronics industry depends on the monocrystalline form, used as a semiconductor in everything from iPhones to laptops. In the manufacturing of solar panels silicon is heated to a melted state and is either poured, molded or layered on sheets of thin metal backing. Three categories of solar cells are created, they include Monocrystalline – single crystal cells, Polycrystalline – multi crystal cells and Amorphous – thin film silicon. When sunlight hits silicon solar cells of a solar panel it literally bumps electrons loose from the silicon atoms. These free agent electrons are then captured and conducted through metal contacts on the front of each solar cell and through wiring that carefully connects all the cells and panels in a solar system. The electrical energy released and captured by a solar system is called direct current, or DC. North Americans however, rely on alternating current or AC power. To resolve this, solar systems use what’s called an Inverter that converts the flow of electricity from DC to AC. Now let’s look at how solar panels are rated in industry terms, to better understand their varying capacities.
How Solar Panels are Rated
Solar panels naturally are valued for their capacity to produce electrical energy. Today silicon solar panels are used widely around the world for homes, businesses and in large solar parks. Monocrystalline panels remain the most energy efficient within manufacturing cost ratios, and Polysilicon panels come in second. Thin film panels tend to be the least energy efficient, but due to comparatively lower manufacturing costs, thin film panels are the first choice for solar park development. The solar industry uses three primary means of qualifying solar panels which include module efficiency, rated power, and power per square foot.
Solar panel manufacturers use a percentile range typically between 6 to 15 percent to ascribe a value to a solar panel’s energy efficiency. That may seem like a low percentile range, but for today’s solar industry the seer reliability of the technology means homeowners and businesses alike can predict that a newly installed solar system will last them a good 20 to 25 years. Efficiency is then a measurement of the ratio of output power from a solar panel in watts, to input power or watts from direct sunlight. This is easily the most commonly referred to percentile rating given to solar panels today.
Rated power is another useful measurement to keep in mind. This is the output wattage a solar panel produces under standard test conditions (STC). When shopping for solar systems this STC rating means the wattage a panel is able to create when exposed to 1000 watts of light per square meter, which is the same as direct sunlight. Solar panel manufacturers conduct panel tests using this method and assign a rated power value. When considering this value it can be helpful to realize that STC is demonstrating wattage output of a panel under optimal sunny conditions.
Lastly, the industry measures solar modules by power per square foot, also referred to as power output per square foot. When planning a solar installation for a residential home, just knowing the power per square foot of a module can make the planning process that much easier, given your available roof space. If you have limited roof space, ask solar professionals in your area about ground mounting. Based on your location, your ground space and the solar capacity you would like, this could be an alternate option to doing a roof installation. The results with a ground mounted system are the same, only if nothing obstructs the path of the sun’s light to the solar array throughout the day.
If you are having professionals develop a solar system design for your home, you can now rest a little easier knowing you have sufficient knowledge on how solar panels work, so that you can discuss available options and make informed decisions. Solar energy is a wise investment in your home and in your future, so take your time to evaluate quality solar panels on the market, and you’ll be ready to make the best decision for your home.