How solar panel cells work

You’ve probably seen solar panels on rooftops all around your neighborhood, but do you know how they actually work to generate electricity? Here we’ll take a look at solar photovoltaic cells – and why we think costs keep dropping while efficiency keeps improving.



Solar panels are made up of photovoltaic cells

A solar panel is made up of six different components, but arguably the most important one is the photovoltaic (PV) cell, which actually generates electricity. The conversion of sunlight into electrical energy by a solar cell is called the photovoltaic effect, and that’s why we refer to solar cells as “photovoltaic.”

There are many photovoltaic cells within a single solar panel. A standard panel used in a rooftop residential system will have 60 cells linked together, and commercial solar installations often use larger panels with 72 or more photovoltaic cells.



How does a photovoltaic solar panel generate electricity?

Photovoltaic cells, through the photovoltaic effect, absorb sunlight and generate flowing electricity. Here is the real technical version. In a crystal, like the bonds [between silicon atoms] are made of electrons that are shared between all of the atoms of the crystal. The light gets absorbed, and one of the electrons that's in one of the bonds gets excited up to a higher energy level and can move around more freely than when it was bound. That electron can then move around the crystal freely, and we can get a current.



Step 1: Light is absorbed by the solar cell and excites the electrons

First, light strikes a photovoltaic cell and is absorbed by the semiconducting material it is made from (usually silicon). This incoming light energy causes electrons in the silicon to be knocked loose, which will eventually become the solar electricity you can use in your home.



Step 2: Electrons begin to flow, creating an electrical current

There are two layers of silicon used in photovoltaic cells, and each one is specially treated, or “doped”, to create an electric field, meaning one side has a net positive charge and one has a net negative charge. The electric field causes loose electrons to flow in one direction through the photovoltaic cell, generating an electrical current.



Step 3: The electrical current is captured and combined with other solar cells

Once an electrical current is generated by loose electrons, metal plates on the sides of each solar cell collect those electrons and transfer them to wires. At this point, electrons can flow as electricity through the wiring to a solar inverter and then throughout your home.



Many photovoltaic cells together produce electricity for your home

A photovoltaic cell on its own cannot produce enough usable electricity for more than a small electronic gadget. In order to produce the amount of energy, a home might need, solar cells are wired together to create solar panels, which are installed in groups to form a solar energy system. A typical residential solar panel with 60 photovoltaic cells combined might produce anywhere from 220 to more than 400 watts of power.

Depending on factors like temperature, hours of sunlight, and electricity use, property owners will need varying amounts of solar panels to produce enough energy. Regardless, installing a solar panel system will likely include several hundred solar photovoltaic cells working together to generate an electrical current.



Why Solar panels keep costs down

It is pretty simple why solar panel technology keeps dropping in price. There is a law called Swanson’s Law and it describes the observation that the price of solar photovoltaic modules tends to drop 20 percent for every doubling of cumulative shipped volume. As the volume of panels doubles, the price goes down 20 percent. So far, this means that panels have cut their price in half every 10 years.

The nature of silicon already naturally turns light into electricity. There are no moving parts on the panels. Therefore they are able to work tirelessly for years naturally. Then as the technology grows more popular, the costs go down. As the technology becomes universal, solar panel cost and innovation will continue to improve.

When a new technological breakthrough happens in the solar industry, the cost is initially expensive, but they drop rapidly because again this is a natural form of matter that we don’t have to mess with too much. There is no engine, there are no turbines to create the power, just the solar cells doing what they do naturally.

To learn more about how you can join the solar revolution, please visit HahaSmart and try out our Price Checker Tool yourself. You can not only see how much a solar panel system would cost in your area, but you can see how much you would save in the next 20 years in electricity costs.

For information relating to going solar don’t forget to visit our solar blog section for more handy guides and articles.