Solar energy storage using a closed loop thermochemical system based on the reversible dissociation of ammonia, has been investigated at the Australian National University So,over two decades. Theoretical and system studies have indicated that large scale systems offer reasonable thermodynamic and economic performance. Experimental investigation has confirmed the technical viability of the concept. This investigation has looked at the effect of operating parameters on the thermal output achievable from the heat recovery process. Pressure, massflow and inlet gas composition were all found to have significant effects on the output achievable. Maximizing the thermal output via adjustment of reactor wall temperature profiles indicates that the average temperature of the reactor walls is moi-e significant than the shape of the profile. This investigation has indicated the potential and provided the foundations for future exergo-economic optimizations of the system.