The Photo Chemical Cell - Mimicking Nature

Lately there is a lot of talk about the Photo Chemical Solar Cell it seems to have great possibilities because it is cheap and is a product derived from the science that mimics natures own processes. So why bother, we already have panels don't we.

Well yes we do, but our silicon based solar cells do have some downsides. Here is what the full story.

The Difference between Photovoltaic and Photo Chemical Cell's

The workings of the solar panels we are most familiar with depend on the photovoltaic effect. This is the name of the effect which occurs at the junction of two pieces of slightly different silicon.

On purpose on piece of silicon is infected with a tiny amount of an other material. This causes an imbalance of the number of electrons between the layers. When the sunlight reaches the outer silicon layer an electron jumps over the junction between the layers and an electric current is the result. We have a semiconductor that absorbs the sunlight and separates the electrons.
The talk about "a small disturbance" also gives you a clue about the precision necessary on the production. They are build in clean rooms, because one dust particle can be responsible for the malfunctioning of a cell. A solar cell based on the photovoltaic effect has proven to work, is very reliable and has an efficiency of 13-18%. But by nature its produced through an expensive production process.

The Photo chemical Solar Cell on the other hand is a very cheap technology. It depends on a chemical called Titanium Dioxide, which is very cheap and available. And we need only a little of that already cheap material. The development of the Photo Chemical process is in fact the result of studying nature and see how that does the job. The transfer of electrons is a principle where are life depends on.

Cheap Simple Technology

This Titanium Dioxide is great stuff when it comes to absorbing ultra violet light. It is used as a white pigment in paints, toothpaste and sun block. What we do now is make a layer of resistive Titanium Dioxide, as our electron absorber and a conductive layer that allows the electrons to jump over.

Titanium Dioxide now is great as absorber of ultra violet light. The pigment Titanium White is used in paint, toothpaste, sunscreen and the like. We use this material as one electrode, and use something conductive. To allow this process to work we have to add a dye to the Titanium Dioxide to get an arousal effect on the first plate and and electrolyte between the layers. Usually an idodide/triiodide compound.

That's it, cheap, an easy process, and it works. This technology holds great promises. It's cheap so we can incorporate it into building materials.

A Free Ride in you Hydrogen Fuel Cell Car

Your hydrogen car for example can be build with photo chemical solar cell's to generate the electricity needed to get hydrogen from water. At last a car that actually runs on water and get's its energy from the sun.

And why cover roofs with photovoltaic's if we can build photo chemical roofs. And to top it of this type of cell is not necessarily opaque, so it can be used in windows. How about all the South Facing windows of our skyscrapers.

Challenges we need to Overcome

This sounds cool doesn't it and I think it can come to pass. The holdback at the moment is that these cells contain a liquid as the electrolyte between the layers. We need to find ways to prevent this stuff to leak out, dry out or whatever can happen with liquids in a confined space.

A few companies and research institutes, like Gratsel, Hoescht Research, the Max Planck institute and the Institute for Polymer Research are working closely to overcome this challenge. The Photo Chemical Solar Cell has great possibilities, perhaps producing at a lower efficiency rate as Photovoltaic cells but we can use solar energy at a fraction of the cost.