Alternative Energy

Less silicon, more performance

Today, it takes 10 to 12 kilograms of purified silicon to ultimately generate one kilowatt of installed capacity. But rising demand is putting increasing pressure on the cost and availability of silicon. Current, first-generation cells account for almost 95% of the market. Optimizing them, a priority at Photovoltech, calls for a three-pronged attack: thinning down the silicon, reducing material losses and eliminating certain complex steps such as wafer slicing.

Thin films, the second generation

Second-generation (2G) cells usually consist of a glass or ceramic substrate, coated with a just a few microns of amorphous silicon or other semi-conductor materials, such as copper indium gallium diselenide (CIGS).

Granted, 2G sales are still marginal. But producing them uses both less material and less energy.

Wider and more flexible, they are also easier to retrofit and give architects more freedom during the design stage. The hitch is that their low efficiency and production processes make them impractical for use on a large scale for now.

Total has long-standing research partnerships with world-class organizations exploring photovoltaics, including the French Atomic Energy Commission (CEA), the French National Center for Scientific Research (CNRS), Interuniversity MicroElectronics Center (lMEC) in Belgium, the French Institute for Scientific and Technical Information (INIST) and the Interface and Thin Film Physics Laboratory (LPICM) in France. We are working closely with our partners to overcome these obstacles.

Hybrid, quantum, organic and more: toward a third generation of cells

The third generation, still in the laboratory stage, ushers us into another dimension, that of the infinitely small. Several approaches are being tested, including microelectronics, nano-enabled processes and quantum physics. The hybrid cell option — nanocrystalline titanium oxide paired with a conductive polymer — could bring the amount of material needed to deliver one kilowatt of power down to just half a kilogram. Another promising avenue is the use of organic molecules that mimic plant photosynthesis.

At Total, these topics have left the pages of science fiction. In late 2008, we became the strategic core shareholder in Konarka, a U.S. startup that makes organic photovoltaic films out of flexible plastic. Cofounded by Dr. Sukant Tripathy, Howard Berke and Dr. Alan Heeger, a Nobel Laureate in Chemistry, Konarka already offers products suitable for a range of applications. The company has a thick portfolio of patents and licenses and a team of top-notch personnel.

Backed by Total, Konarka will be able to tap the skills and knowledge of several of our subsidiaries, including Atotech, Bostik, Hutchinson, Sartomer and Total Petrochemicals USA Inc., notably in carbon chemistry. By pooling interrelated expertise, Total and Konarka will make faster strides together, both on thin films and the development of future generations of photovoltaics.