Light induced water splitting using multijunction thin film silicon solar cells

It has been widely recognised that fossil fuel reserves are not sucient to cover the energy demand of our societies in the future, even if the energy utilisation would stagnate on today's level. The extent of the problem is also associated with the emission of the greenhouse gas CO2 upon combustion of fossil fuels that can lead to unpredictable climate changes on earth. Nature's own processes of fuel generation based on biomass utilisation are considered to be not ecient enough to replenish the used resources on a short time scale. To relieve this predicament, a transition from fossil fuels to renewable energy sources is therefore imperative and unavoidable. Renewable and carbon-free energy from wind and solar radiation are the only means which can fully replace fossil fuels and are able to cover an increasing energy demand in the future. But up to now, these uctuating energy resources lack an appropriate and effcient storage technology.