These conversion processes can, broadly, be divided into two classes: in the first class, an unsuitable carrier of energy is converted into a more suitable one. Here, the crux is to destroy as little useful energy as possible, transferring all the energy to the new carrier. Hydrogen, for instance, is an excellent energy source but a lousy carrier, and this triggers the search for materials that can store and release hydrogen and the search for materials that can facilitate such conversions. The actual harvesting of the energy occurs in the second class of conversions, where the energy is released into a form that the user needs (electrical, mechanical, propulsion, etc). Here, we need to capture harmful waste materials of the exhausted carrier, for instance CO2.
There is wonderful potential for nanoscience in these conversions. The possibilities are not limited to only the use of nanostructured materials as the energy carriers themselves – such materials are generally too expensive and complicated for such a role. Rather, materials with controlled features at the nanometre scale can facilitate many of these conversions of energy-carrying molecules, and controlling their architecture with nanoscience promises much more precision and much better yields. Increased precision will translate into less waste of energy, extended use of carrier molecules, and reduced emissions of unwanted products such as CO2.
Back to theme 2: Energy