Solar Panel : How Does It Work

However, the first real use of the photo electric effect to generate power happened over 100 years later at Bell laboratories in 1954. By 1958, solar power was being used to produce power on U.S. spacecraft. Since that time, the methods have stayed the same, but the components of today’s solar cells are so much more efficient that they have become a major source of alternative energy around the globe. But how do solar panels work?

Solar Panel Basics

The basic mechanism behind a solar panel is something you learned about in high school science, electron shells and valence bonding. Bet you never thought you’d need to know about that in your everyday life. Here is a quick refresher.

• Molecules seek to attain a balance between the number of protons and electrons in each of their atoms.
• When they are in balance, the molecule is stable.
• When the molecule is not in balance, from either gaining or losing an electron, it seeks to remedy this by returning to balance.

When sunlight hits a solar panel, photons from the light dislodge electrons from the molecules in the upper layer of the solar panel. These electrons are the source of the electricity that is generated by the panel.

Composition of the Solar Cell

The smallest unit of a solar panel is an individual solar cell. Several cells are wired together to create a module. Each module is placed within a panel and is designed to supply electricity at a particular voltage, most commonly 12 volts.

Every solar cell consists of several major components sandwiched together in a thin wafer. They can be assembled as follows:

In a traditional solar cell

• Glass panel
• N-Silicon layer
• P-Silicon layer
• Glass panel

In an organic solar cell

• Thin film plastic or acrylic layer
• Carbon nanotube layer
• Organic electrolyte layer
• Thin film plastic or acrylic layer

Titanium dioxide dye panel

• Upper shell
• Electrical conductor
• Electrolyte layer
• Catalyst layer
• Lower shell

Traditional Solar Panels

In traditional solar panels, the shell layers were, up until quite recently, made primarily of silicon. Silicon is not a very efficient natural conductor, so it must be prepared in a process known as “doping.” The two shell layers are combined with different compounds to make them more efficient. One layer is doped with phosphorous for the positively charged (N-Silicon) panel, and the other is doped with boron for the negatively charged (P-Silicon) side.

New Organic Panels

Understanding how solar panels work in the traditional sense will help you understand why the new organic solar panels are getting such a buzz. Traditional solar panels are very rigid and costly to produce. New organic panels have the potential to eliminate both of these issues.

The Chemistry of Titanium Dioxide Solar Cells

In one new type of cell, a small amount of sunlight is absorbed into a hardened acrylic top layer. Just beneath this layer is a dye sensitized layer of titanium dioxide. This is the molecule that the electrons are knocked off from by absorbed photons. These electrons are routed out of the cell via electrical conductive wires attached directly to the titanium dioxide layer of the cell. The electrons travel through this wire creating a direct current – this is the electricity. The electric current can be routed to a converter to power alternating current tools or to a battery bank for later use.

Which Type Will Win Out?

As solar technology continues to improve, we will see the death of the traditional silicon based solar panel. Whether activated die or organic solar panels become the industry standard will likely be determined by how efficient the organic offerings can become. They have the advantage of being thin enough to be flexible and adaptable enough to be placed on several different types of material. Only time will tell, but either way it goes, solar power is going to be a huge part of future power generation. One day, the power of the sun might be directly powering your espresso machine.