Views: 1025 Author: Site Editor Publish Time: 2022-08-18 Origin: Site
Inside a solar cell
The workhorses of solar energy are cells stacked with five layers of glass, an anti-reflection material, a metal conduction grid plate, two layers of semiconductors, and a metal conduction plate.
The top glass layer is for protection, keeping out dust, dirt, and bugs, and makes the cells easy to clean.
The anti-reflective material under the glass allows light to pass through, but not reflect on the internal metal parts and back out into the environment. That ensures the panels are collecting as much sunlight as possible.
The metal plates and semiconductors make a sort of electricity sandwich. Metal plates on the top and bottom of the semiconductors allow current to move through them, acting as street signs to direct the current.
But the power generation comes from the semiconductors.
Two semiconductor layers sit on top of one another, one made of silicon and phosphorus, the other of silicon and boron. When light hits the cell, it excites electrons in the phosphorus, known as valence electrons, with enough energy that they break free from their element, and go on the search for an element close by that has fewer electrons, like boron. The free-floating electrons bond to boron in the other semiconductor layer, creating a migration of electrons between layers. When the electrons move, they create energy in the form of a current.
It’s the current that’s harnessed by the metal plates and collected as voltage.
Enel’s arrays are unique because they can collect solar power on both sides of the module.
Getting power on the grid
The next step is getting the voltage from the cells onto the grid, a process that requires the power to be transformed to the right voltage.
To do this, the electricity from solar panels flows along feeder transmission lines, bringing the power to a conversion unit. There, the power is “cleaned,” meaning DC waves are chopped up to create AC waves, and sent to a transformer box. In the transformer, the power enters on the low side and is “stepped up” to a high side so the voltage matches that of the grid.
All the electricity comes together at the substation where it is prepared to enter the ERCOT system.
At the substation, the electricity goes through batteries, where it could be stored indefinitely.
[Solar] panels provide the solar power to the substation, which then goes from the substation to the transformers in the [battery storage] yard and then to the power conversion systems and then to the batteries themselves, at which point they are charged, We have the ability to then discharge those batteries as needed or as necessary back onto the grid.
From the batteries, electricity flows to a Rayburn Electric substation and onto the grid.
Unlike a natural gas plant, solar fields have built in downtime at night. Its staff completes maintenance at night when the sun isn’t shining so the system can stay online during the most productive parts of the day.
By keeping up on maintenance every day, technicians are able to catch potential issues long before they lead to a bigger problem.
Note: Reprinted from Finger Lakes Times