Solar panels are hardware panels made to extract energy from the sun's rays in order to generate electricity of heating. The most common solar panel technology deployed today to generate electricity is solar photovoltaics (PV). Each solar PV module is made up of a collection of solar cells, 95% of which are made of silicon, an element commonly found in sand. Modules are classified by their maximum power output and can range from 100 watts to over 350 watts. A solar PV system usually includes an array of multiple PV modules, as well as an inverter, and interconnection wiring. The price of solar panels has decreased dramatically over the last decade, making solar a great investment for homeowners looking to saving money.
Solar Panel Technology
Solar panels create electricity by using the energy in sunlight to excite electrons and cause them to move in an electric current. Solar PV technology can trace its origins back to Bell Telephone, where in 1954 scientists discovered that silicon crystals could create a flow of electrons when exposed to the energy of the sun. Usually when sunlight hits an object, the energy in the sunlight is converted to heat. However, when sunlight hits some materials, the energy in the sunlight creates an electric current instead of creating heat. This insight led to the development of silicon solar cells, which use sunlight to create an electric current. Future research into solar cells has enabled us to take that electric current and harness it for power.
Most PV panels today can be classified as mono-crystalline or poly-crystalline. The main difference between the two is purity. Poly-crystalline solar panels have a lower silicon purity and thus are less efficient and don’t last as long as mono-crystalline panels. However, it is expensive to purify silicon, making mono-crystalline panels more expensive. Most PowerScout partners use mono-crystalline panels because the increased efficiency and durability overcome the additional costs. Thin film PV technology has taken off in recent years. However, despite being relatively inexpensive, thin film PV requires significantly more space and does not last nearly as long. Thin film technology is rarely used for residential purposes.
Solar Panel System
A solar panel system is made up of more than just the solar panels, and many parts are required to convert sunlight into usage energy and transport than energy throughout the grid and to your home. First, sunlight transmits energy to the solar cells, which causes an electric current called a direct current (DC). In direct current, the electrons all move in the same direction. However, most places in the US use alternating current (AC) in order to move electricity long distances. This is where a device called an inverter comes in handy. An inverter converts the DC electricity that is created in the panels to AC electricity that can be used by homes and businesses. Inverters also help monitor your solar panel systems.
From there, electricity can be sent to your home to power your appliances and lights, or it can be sent onto the electric grid. Even with a solar system, it still makes sense to be connected to the grid. Each home and business have an electric meter that keeps track of how much electricity you use from the grid and how much electricity you send back onto the grid. If your solar panel system produces more electricity than you use in a month, your meter can actually run in reverse. In this case, the utility could actually owe you money for the excess energy your system is producing. However, you can only sell back to the utility at the wholesale rate, which can be 50% lower than the retail electricity rate. Installers should size your solar system to maximize savings, which usually means designing a system that produces up to as much as you consume.
Solar Panels for Homes
Most homeowners install solar panels on their roof, though, ground mounts are an attractive option if solar doesn’t work for your roof and you have land available to install solar panels. Shading, roof orientation, and the amount of sunlight in your region determine the feasibility of solar for your home. An ideal roof has no shading from trees or other obstructions, faces south, and receives a lot of sunlight throughout the year. To find out if your roof is suitable for solar, it’s important to talk to several installers. They will come to your home and design a system that works for you and your home. The ideal number of panels for your home depends on the rated wattage of the panels and your annual consumption. Ideally, you want your solar system to produce exactly as much energy as you consume each year. PowerScout strongly suggests getting quotes from multiple installers to compare quotes and find the best deal.
Before solar panels can get installed on your roof, you have to choose a financing option. While paying for a system upfront usually leads to the greatest savings, buying a solar panel system is not an inexpensive purchase. Luckily, there are many ways to go solar beside paying for the system upfront. There are a number of loan options available, as well as options to lease the panels through a Purchase Power Agreement (PPA). We’ve put together a guide to help you decide which option is best for you. After you’ve chosen an installer, they will take care of the permitting and installation. The installation process can take about three months from the time you sign with an installer until your system is operational. Once your system is installed, you can start saving with clean solar energy!