Battery storage system with five megawatts of capacity
Researchers at RWTH Aachen seek credible answers on the costs and savings potential of battery storage power plants together with industry partners. A modular battery storage power plant, unique worldwide, with five megawatts of capacity is currently being developed for this purpose.
|Project status||Test phase|
|Typical plant size (energy)||Approx. 4 MWh|
|Typical plant size (output)||5 MW|
|Storage loss||Approx. 0.1%/day|
|Service life of the plant||Up to 20 years, depending on technology|
|Response time on supplying energy||Approx. 100 ms|
|Efficiency (AC/AC)||Subject to application and battery type approx. 90%|
|Cycle durability||Subject to application and battery type up to 10,000|
|Typical discharge time||45 to 60 minutes|
|Typical period between storage and withdrawal||Heavily application-dependent – from seconds to several hours|
|Application examples||Integration of renewable energy, balancing power, power trading|
|Project duration||July 2013 until June 2017|
The special feature of the M5BAT is the modular structure of the medium-voltage storage system, which interconnects different battery technologies. M5BAT stands for “modular multi-megawatt multi-technology medium-voltage battery storage system“. Lithium-ion batteries are used as short-term power storage units, energy is supplied by high-temperature batteries over several hours and lead acid batteries are used for short and medium discharge times.
Technical and economic optimisation potential is identified by the researchers during construction and operation of the plant. Target cost estimates for storage system applications, such as primary and secondary control, are furthermore produced by the researchers. This allows for conclusive information on the revenue thresholds from which battery storage power plants can be economically operated, in due consideration of economies of scale, particularly with respect to battery cells, or on regulatory incentives that need to be created. The results are subsequently summarised in a manual for battery storage power plants, which is intended to be used for cost planning and for operating battery storage power plants.
Further optimisation of battery power plant during operation
Construction and operation of the plant is intended to produce conclusive data on service life, costs and savings potential. This, above all, also includes peripheries for installation of the battery plant in addition to the actual costs for the battery cell. In addition to the housing, these also include battery management and battery diagnostics systems, the central plant controller and thermal management. The researchers test and optimise the interaction of the different battery types for various application profiles. The researchers furthermore hope to develop an energy management system for the plant encompassing the batteries, inverters and control system.
Battery storage systems enjoy universal application
Electrochemical storage devices enjoy trade appeal due to their independence of geographic constraints, as common with compressed air storage units and pumped storage power plants, and because relatively short planning terms are typically associated with their installation. It is therefore necessary to build expertise in the development of low-cost designs, in optimising operation and in conducting comparative technological analyses and to test the performance capability of various technologies under realistic operational conditions, unbiased as to the result.