Solar pioneer Michael Grätzel wins Millennium prize

Often known as Grätzel cells, these low-cost photovoltaics are being developed for use in Africa and India by Welsh company G24 Innovations.

The Millennium Prize, awarded every other year by the Technology Academy Finland, recognises ‘innovations that promote well-being and sustainable development.’ Grätzel’s first prize, worth €800,000 (£660,000) will fund further research at the Ecole Polytechnique Fédérale de Lausanne, where he is the director of the laboratory of photonics and interfaces.

The two other shortlisted nominees, plastic-electronics pioneer Prof Sir Richard Friend of Cambridge University and Prof Stephen Furber of Manchester University, developer of the Reduced Instruction Set Computing compact microprocessor, won €150,000 (£124,000) each.

Grätzel first developed his cells at Lausanne in 1988, while looking for ways to mimic the way that plants convert sunlight into the energy that powers their metabolisms.

They use an organic dye to absorb solar energy, releasing an electron into nanoscale crystals of titanium dioxide, which is conducted to the cells’ electrodes by an iodide-containing electrolyte. The components are cheap and non-toxic, and the cells can be made using a roll-to-roll printing process.