'Here comes the sun'

Before university I spent a year working with a chemical engineering company making ink. I was a little disappointed to discover that this did not involve farming squid but instead mixing up various combinations of chemicals. I specialised in conductive inks and by far our the fasting growing demand was for solar cells. This hardly makes me an expert but means I have an interest in the area!

Firstly, some basics. Solar cells (or photovoltaic cells) generate energy by the photovoltaic effect. Light from the sun, made up of photons, hits the semiconductor in the solar cells. This excites electrons in the atoms which make up the semiconductor and releases them from the shell. There is a electrical gradient in the semi conductor which attracts the released electrons which then flow: generating electricity (physics online).

Potential energy - image from Solar Spark

The potential solar energy available is enormous: 120,000 TW per day compared to the global energy use of 15 TW per day (solar spark). However, this is the total sunlight hitting the earth so if we wanted to use it we would have cover the earth in solar cells and have them all work with 100% efficiency. This is not possible but it does demonstrate just how much we could utilise solar energy.

Now back to those squid...