Solar Cells & Plant Cells: Converting Solar Energy

Although both solar cells and plant cells harvest energy from the sun, the main difference is that plant cells convert solar energy into chemical energy, whereas man-made solar cells convert solar energy into electrical energy.

 

Before we get into the differences, let’s talk about their similarities.

Both solar and plant cells absorb photons, or particles of light and energy. These photons then transfer their energy to electrons within each cell. Any given electron can only absorb energy from a specific range of colors within the light spectrum, meaning the right photon must connect with the right electron to be able to transfer its energy. Luckily, the sun emits virtually an infinite amount of photons. Once the electron absorbs the photon’s energy, it is now considered an excited electron. For a more detailed look into the similarities, check out this educative article by Richard Gaughan.

 

Now, this is when things begin to differ. Here’s a simple breakdown of some of the key differences:

 

Plant Cells	Solar (Photovoltaic) Cells
External requirements are sunlight, water, carbon dioxide, and minerals	External requirement is sunlight
Produces carbohydrates, oxygen, and protons by moving excited electrons from one molecule to another until it settles	Produces electricity through the release of excited electrons immediately into a circuit
Too much sunlight can damage or kill	Can never have too much sunlight, does not damage
Naturally less efficient photon absorption	Artificially maximizes efficiency of photon absorption
Energy can be stored and used as needed	Electrical current can disappear if not used right away or stored in a battery