Storing compressed air to replace lead batteries according to the BE of Adit
One of the main difficulties encountered by solar and wind energy is the problem of storage of surplus electricity. Indeed, energy production is rarely a perfect fit with the need (too much or too little wind, no sun at night ...) and therefore it is necessary to store the excess electricity produced. Usually used lead batteries to perform this task.
A young business Lausanne, Enairys, is betting another system: storing compressed air. Environmentally friendly (no heavy metals) and economic (longer life), the method is not new but has remained to date unexploited because its yield is low. Indeed, the compression of the air causes its heating and therefore thermal losses, resulting in a yield of about 25% only. (Econologie.com Note: it is only the compression performance and not the overall performance of this storage)!
With the assistance of the Industrial Electronics Laboratory and the Industrial Energy Systems Laboratory at EPFL implanted, Enayris offers to either mechanical piston base but liquid piston system. The water used can regulate the heat flow and significantly improves the efficiency of batteries now achieve 60-65% (or almost the performance of a lead battery, which is 70%).
The air is compressed by means of an electric motor coupled to a hydro-pneumatic compressor and stored in cylinders connected to each other. When electricity is a need, the air is extracted to power the same machine that runs this time as alternator.
The patents were filed by EPFL and Enairys has an exclusive license. To date, it has completed the creation of the prototype demonstration and intended for now such facilities in remote areas or in emergency power supplies for sensitive systems subject to unstable power grids.
Source: « Le stockage d’énergie par air comprimé prêt à remplacer les batteries au plomb » – Le Temps – 24/06/08