There are many different materials and methodologies to constructing solar cells. Today, we are taking a look at the current market leader – silicon solar cells.
Silicon is used everywhere in our world. Applications include steel refining, chemical industries, and semiconductor electronics such as computers and cell phones. It is also used to make solar cells.
Why is silicon the material of choice for making solar cells today? Here are a few reasons:
- Silicon has a band gap of 1.1 eV, which is not far off of the optimal value of 1.34 eV for generating power from sunlight.
- There has already been so much research and manufacturing techniques developed for silicon that it may be the best understood material in the world.
- Silicon is the second most abundant element in the earth’s crust.
Here is what a typical silicon solar cell looks like.
When silicon solar cells are installed in the field, they are installed as part of a module – each module contains a large number of solar cells that are connected with each other.
Some reasons we use solar cell modules instead of making a single giant solar cell are:
- It is easier and more cost effective to make small cells.
- It’s better to have a high voltage and low current since you will have less series resistance loss. The voltage of each cell in the module adds up to produce a final voltage.
The National Renewable Energy Laboratory is pushing to have 5 cents per kWh residential solar PV by 2030, and silicon solar cells will play a large part in making that dream a reality.