The use of protein crystallography led in 1995 to Richard Cogdell's (botany) and Neil Isaacs's (chemistry) research groups determining the three dimensional structure of a light-harvesting complex (LH2) from the purple bacterium Rhodopseudomonas acidophila.

Richard Codgell, 2009

"There is a process on Earth that already uses solar power to make fuels. This process is photosynthesis. Indeed all our current fossil fuels represent photosynthesis that took place millions of years ago."

The LH2 complex is a major component of the photosynthetic apparatus of those species of bacteria that use light as a source of energy. In these bacteria, bacteriochlorophyll pigments in the light-harvesting complexes absorb light. This energy is then funnelled to another large protein-pigment complex, called the reaction centre, where it is converted into a chemically useable form. This capture and transfer process operates with nearly 100% efficiency.

The structure of the light-harvesting complex revealed how the energy is captured and then transmitted on to a reaction centre. It showed how the protein scaffold holds the pigments in precise orientations that maximise the efficiency of energy transfer; how the assembly protects itself against damage by species of reactive oxygen formed by the incident light; and how some bacteria have adapted to grow under low-light conditions by mutating specific amino acids in the proteins.

This study has led to research into ways of using solar energy to produce fuels.