While we all know that solar photovoltaic panels convert sunlight into electricity, few people understand the science behind it. We will be diving into the science of solar this week. Although it can seem complex, the photovoltaic phenomenon is the ability of matter and light to emit electrons.
Let’s first look at the fundamental flow of electric generator before we move on to the molecular levels.
How do solar panels work?
- The Basic Steps of Solar Energy Generation and Transmission
- The solar panels are illuminated by sunlight, which creates an electrical field.
- The electricity generated flows towards the edge of the panel and into a conductor wire.
The conductive wire carries the electricity to an inverter. It transforms DC electricity into AC electricity, which can be used to power buildings. Another wire transports AC electricity from inverter to property’s electric panel (also known as a breaker box), which then distributes it throughout the building according to its needs. Any electricity that is not required upon generation flows through the utility meters and into the utility electric grid. The electricity flowing through the meter causes it to go backwards. This credit your property for excess generation. We now have an understanding of how solar electricity is generated and flows. Let’s dive deeper into the science behind the solar PV panel.
Solar PV Cells: The Science Behind It
Photovoltaic panels are made up of small photovoltaic cells. They can convert sunlight into electricity. Semi-conductive materials are used in these cells, which include silicon. This semi-conductive material can conduct electricity and maintain the necessary electrical imbalance to create an electric field. How Panels Works When sunlight strikes the semiconductor in a solar PV cell (step 1, in our high-level review), the energy of the light in the form photons is absorbed. This causes electrons to drift free in the cell. For a visual, the solar cell has a combination of positively and negatively charged semiconductors that are arranged together to create an electrical field. (See the image to left).
The electric field causes the electrons to drift in one direction, towards the metal plates. This current is called an energy current. The strength of the current determines the amount of electricity each cell can produce. The current is directed into wires once the electrons have reached metal plates. This allows the electrons flow as they would in other sources of electric generation (step 2, in our process). The solar panel produces an electric current. This energy is then passed through a series wires to an inverter (see Step 3). Although solar panels can generate direct current electricity (DC), most electricity consumers require alternating current electricity (AC) to power their homes. The inverter is responsible for turning the electricity from DC into AC, making it available for daily use. Once the electricity has been converted into usable power (AC power), it’s sent from the inverter through the electrical panel (also known as a breaker box and distributed throughout the building according to its needs. Now, the electricity can be used to power appliances and lights.
The utility meter is the last step in the process. It sends any electricity not used via the breaker boxes to the utility grid. The utility meter measures electricity flow from the grid to your home and vice versa. This meter is reversed if your solar energy system produces more electricity than you use on site. You are then credited for any excess electricity generated by net metering. This meter is used to pull additional electricity from the grid when you use more electricity than your solar panel is producing. Unless your storage solution has enabled you to go completely off-grid, you will still need to draw energy from the grid at night when your solar array isn’t producing. This grid energy can be offset by the solar energy you produce throughout the day, and during periods of low usage. Although solar is complex in its details, the benefits it can bring to property owners and businesses is obvious. A professional solar developer will be able to walk you through the benefits and help you decide if solar is right for you.