Metal hydrides, stationary application

Improvement in metal hydride hydrogen storage has been slow in achieving the targets needed for several applications. But slow, steady progress is foreseen as material processing in the nano-range improves the kinetics, thermodynamics, and capacity of the metal hydride systems so that they become acceptable for some applications perhaps for stationary systems. 

Such hydrides based on intermetallic compounds are not only attractive for stationary hydrogen storage applications, but also for electrochemical hydrogen storage in rechargeable metal hydride electrodes, reaching capacities of up to 400 mAh g. They are produced and sold in more than a billion metal hydride... 

Similar assessments may be made for other applications, notably stationary uses, where the requirements in most cases are less stringent. An alternative tool in evaluation of system performance is a plot of energy density versus power density. Some of the systems under consideration (e.g., many of the metal hydride stores) have filling and dehvery times leading to power densities too low for many applications. 

Other potential apphcations for chemically bound hydrogen storage materials include portable electronics and in-field back-up power where these materials offer potentially far superior gravimetric and volumetric store capacities compared with any of the other technologies. Metal hydrides and complex hydrides are less likely to be favoured for stationary applications if there is no weight or space constraint as these solutions will be more expensive than... 

Hoffman, K.C., et ah. Metal hydride storage for mobile and stationary applications, International Journal of Hydrogen Energy, 1976, 1(2) p. 133-151. 

If we do not wish to store oxygen, the metal-hydride solution is a competitive solution which offers better safety than pressurized storage, particularly in stationary applications where there is no problem of weight. However, this comes at the cost of increased complexity. 

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