XXI Century Solar Army

Creating an army of forces for a solar future because ‘Water will be the coal of the future’ – Jules Verne, 187


Harry Gray at Emory University, October 12th 2017

Harry B. Gray is a Professor at California Institute of Technology whose research focuses mainly in electron-transfer chemistry. Dr. Gray gave a talk at Emory University on his work regarding solar water splitting systems for the efficient use of solar energy.

The first thing you might be wondering is what was someone like me, a political scientist, doing in a talk like that? In all honesty, I must have understood only half of what Dr. Gray was saying. I was drawn by the basic desire of satisfying my curiosity – now I want to understand more.

Renewable energy production is increasing in the world, but production needs to grow even more and even faster, if we plan to keep global temperatures from increasing. Solar energy, a renewable resource, is a promising option to fossil fuels.

“We will never run out of sunlight” – Dr. Gray .

The prices for solar energy installation have been notoriously decreasing every year: today this energy is cheaper than any other. The main challenge that solar energy faces currently is the storage of the energy produced. Since solar power is an intermittent source of energy [there is no sunlight at night], storage is key for the development of this technology. Nowadays solar energy is either connected to the grid or stored in a battery.

Dr. Gray and his team, CCI Solar, are working on something different: the use of sunlight to split water [H2O] into hydrogen [H2] and oxygen [O2], a process known as water splitting. These gases can easily be stored and used as fuels [oxygen is not a fuel, but makes fuels work better]. Water is abundant on Earth, and sunlight more so – together they seem to be the perfect combination for the generation of electricity.

Nature has been doing this for millions of years; in photosynthesis plants split water to get their food. Some scientists want to replicate this process at a human scale with solar energy, as plants do, and use the gases generated as fuels. Since water splitting takes a long time, a catalyst is required to make it work for humans. A catalyst is a substance that accelerates a chemical reaction (Webster).

The main challenge that water splitting faces is finding a catalyst that is “robust, efficient and scalable”, or in other words: stable, effective and cheap. In order to overcome this challenge Dr. Gray founded the Solar Army, a group of high school students from around the world that tests different elements of the periodic table to analyze their potential to be a good catalyst. After this, CCI Solar tests the elements or combination of elements with the best results.

“The global impact for this research is enormous if we can make it work. I hope we can do it on time.” -Dr. Gray


As Jules Verne said in the Mysterious Island:

“Yes, my friends, I believe that water will one day be employed as fuel, that hydrogen and oxygen which constitute it, used singly or together, will furnish an inexhaustible source of heat and light, of an intensity of which coal is not capable. Some day the coal rooms of steamers and the tenders of locomotives will, instead of coal, be stored with these two condensed gases, which will burn in the furnaces with enormous calorific power. There is, therefore, nothing to fear. As long as the earth is inhabited it will supply the wants of its inhabitants, and there will be no want of either light or heat as long as the productions of the vegetable, mineral or animal kingdoms do not fail us. I believe, then, that when the deposits of coal are exhausted we shall heat and warm ourselves with water. Water will be the coal of the future.” – Jules Verne in the Mysterious Island, 1874.

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