Research update: New way to store sun’s heat

Modified carbon nanotubes can store solar energy indefinitely, then be recharged by exposure to the sun. CAMBRIDGE, Mass. A novel application of carbon nanotubes, developed by MIT researchers, shows promise as an innovative approach to storing solar energy for use whenever it's needed. Storing the sun's heat in chemical form ' rather than converting it to electricity or storing the heat itself in a heavily insulated container ' has significant advantages, since in principle the chemical material can be stored for long periods of time without losing any of its stored energy. The problem with that approach has been that until now the chemicals needed to perform this conversion and storage either degraded within a few cycles, or included the element ruthenium, which is rare and expensive. Last year, MIT associate professor Jeffrey Grossman and four co-authors figured out exactly how fulvalene diruthenium ' known to scientists as the best chemical for reversibly storing solar energy, since it did not degrade ' was able to accomplish this feat. Grossman said at the time that better understanding this process could make it easier to search for other compounds, made of abundant and inexpensive materials, which could be used in the same way.