Sustainability analysis of energy storage systems for the energy system transformation
Battery storage systems represent an essential flexibilization option for the success of the German energy system transformation. These technologies must meet a wide variety of requirements, such as high technological performance, low costs and environmental impacts. Scientists at the Karlsruhe Institute of Technology (KIT) have analyzed the sustainability of various batteries for stationary applications, taking into account stakeholder interests. In line of this, a publication on the CO2 footprint and life cycle costs of different batteries was published. The article was voted one of the best articles of 2017 by the journal "Energy Technology."
The German government has set itself the ambitious targets in frame of the energy turnover of increasing the share of renewable energies to 80 percent by 2050. This goes hand in hand with an increased need for flexibility in the electricity grid, which will increasingly be characterized by fluctuating generation behavior from solar and wind energy. In this context, energy storage systems represent an important flexibility option for the success of the energy turnaround. One challenge is to take a broader perspective on the sustainability of these technologies. For this challenge, a combination of life cycle assessment, uncertainty simulation and battery size optimization is used.
In contrast to earlier work, dynamic load profiles are used to optimize the size and lifetime of batteries. Additionally, potential impacts of future technology developments such as decreasing battery prices or longer battery life times are considered. Lithium-ion batteries are among the most promising battery technologies for many applications due to their high performance and comparatively long service life. Classical lead-acid batteries may seem cheap to purchase at first glance, but are less recommendable for stationary applications due to their short service life and efficiency.
In September 2018, the journal "Energy Technology" selected the published results as one of the best articles of 2017. The authors of the article – Manuel Baumann, Jens Peters, Marcel Weil, and Armin Grunwald – are members of a joint research group of KIT-ITAS and the Helmholtz Institute Ulm (HIU). They deal with sustainability assessments of existing and new energy storage technologies, i.e., their impact on the environment, economic and social impacts, resource requirements and potential roles in a future closed-loop economy based on renewable energies.
Successful doctorate by Manuel Baumann
Manuel Baumann, who wrote his doctoral thesis on the subject at KIT and the Universidade Nova de Lisboa and was supervised by Marcel Weil, took a holistic perspective on the subject. The tailor-made approach of constructive technology assessment in combination with systems analysis makes it possible to investigate the visions and expectations of the actors regarding battery storage and its sustainability and to use this information for the future use of these technologies.
The research results combine the perspectives of technology-related and non-technology-related actors using multi-criteria decision making methods to identify more sustainable technologies. Problems related to the use of battery storage are the lack of business models, regulations and doubts about their technical and economic viability. As a highlight can be considered the proof, that the expectations of sustainability criteria are strongly dependent on the different perspectives taken by the involved stakeholder groups. Technology-related players such as technology developers and system integrators concentrate on economic and technological criteria which reflects the concentric orientation of this group. In contrast, more technologically distant players such as representatives of municipal utilities, NGO´s and politicians perceive environmental impacts and social criteria as more important. However, there is little consensus among the actors on the significance of the criteria, which suggests that there is a need for further research.
As part of the joint Helmholtz Initiative Energy System 2050 and research topic 4, ITAS is developing a concordant sustainability assessment concept together with colleagues from Forschungszentrum Jülich (FZJ) and Deutsche Luft- und Raumfahrt (DLR). The aim is to provide a methodology as well as assumptions to enable a common life cycle-based sustainability assessment of different energy technologies (biogenic energy sources, energy storage, and hydrogen) for the energy system transformation.