Feasibility Study of Chemical Energy Storage for an Energy Efficient Commercial Office Space

Abstract: Shifting the load demand of a commercial office space to utilise off peak tariffs would lead to cost savings as power is cheaper at this time. To achieve this shift, chemical energy storage was considered using Lead Acid batteries, Lithium-ion batteries and Advance Lead Acid batteries. The output of these storage types is electricity. Current costs of storage do not support the option of reducing peak demand by adding chemical storage, as electricity from the grid is cheaper over the storage project life. A levelised cost analysis was completed and lithium-ion batteries proved to be the outright best choice for chemical storage in commercial office spaces. Town buildings were analysed and assessed for energy savings in order to reduce overall load demand. Incorporating chemical storage as a viable option was assessed based on cost. Heating, Cooling and lighting proved to be the highest load demands in the buildings. Cost savings in buildings can be better met by increasing the efficiency in buildings, rather than by reducing the cost by shifting the purchase of electricity from peak to off-peak tariffs. More suitable options to chemical energy storage would be to replace standard lights with energy efficient variations, installing an air heat pump to heat the space and ice thermal storage to cool the space. The use of a solar thermosyphon will meet the demand for heated water. Solar energy generation was assessed as an alternative as off-peak electricity stored using chemical storage proved to be too costly. A 50kW system would be suitably sized when peak sun hours were above the local areas average. Net metering could be used to offset costs during the winter months, when the peak sun hours fall below the average.