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From Sunlight to Savings: How Do Solar Systems Work?

Big Y Southwick, MA solar project

Solar energy is a clean and renewable energy source that harnesses the power of the sun. While the process of turning the sun’s rays into usable energy happens almost instantaneously in a photovoltaic system, the process is complex.

How do Solar Panels Work?

Most solar panels (or solar modules) are made up of silicon photovoltaic cells. Once the sunlight hits the panels, the energy contained in light particles (otherwise known as photons) knocks electrons away from the silicon nucleus. Freeing the electrons is the first step in creating an electrical current. The second step is getting the electrons to flow.  

Silicon’s electrons are tightly configured in a geometric pattern, and the free electrons will not flow uniformly. Electrons, however, flow freely when there is a higher concentration of electrons in one area than in an adjacent area, and when they have a pathway to flow. To promote this kind of flow in photovoltaic cells, a small amount of impurities is introduced to the silicon to change the overall number of electrons in the material. This process is called “doping.” A portion of the cell will have more electrons based on the impurities added (typically phosphorous), and some will have fewer electrons based on a different impurity (typically boron). On the side with fewer electrons, there will now be “holes” where electrons are lacking in comparison to the other side. 

With the imbalance of electrons on either side, a small electric field is created, and the free electrons on the side with more will rush to fill in the holes on the other side. This flow can be captured by metal contacts on the front and back of the silicon, and the released electrons form a current. Typically, a silicon solar cell is 6” by 6”. Each solar cell is connected in series to form a module of 60 or 72 cells, and these modules are wired together to increase the total power output of the system. While this is not the only solar cell configuration, it is the most common one in conventional photovoltaic systems.

The Brains of the System: The Inverter

In most systems, each solar module will be connected to approximately 15 to 20 other modules in series. The energy that is created by the solar modules is known as DC (direct current) energy; however, conventional household and electric transmission grids use alternating current, or AC power, because it is easier to transport and manipulate. In order to convert the solar energy, the modules are connected to a device called an inverter, and the inverter converts the DC energy into AC energy.

Inverters are robust pieces of equipment, and they provide many other important functions for a reliable solar PV system. Inverters can optimize their output by adjusting the voltage and current coming into the inverter through the modules. They can also adjust their output based on the conditions of the grid. However, one of the most crucial functions of inverters is that they connect to a data acquisition system (or DAS), allowing you and your solar provider to remotely monitor what is happening on site and how much energy is produced.

Bringing it All Together: The Interconnection

After all the solar panels are connected to an inverter, the AC power is gradually combined until it is ready to connect to your business through a single point. This can happen in two ways: for residences and businesses in smaller facilities, the solar system will most likely be connected to the existing electrical equipment in a breaker. For larger facilities, this is typically done in the switchgear on the other side of the main switch for your building. In either case, the electrons produced by the solar system have now made it to the electrical system of a building, and your business can now reap the benefits of clean electricity from the sun.

If you’re interested in learning more about solar, and how it can benefit your company’s bottom line, please call us at 888-225-0270, or email us at info@entersolar.com.

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This entry was posted in Solar Basics, Solar Energy, Solar by Babatunde Woodard-James

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