Energy Storage (Reviews and Prospects of ICEF 2017 Concurrent Sessions)
Energy storage is a key technology for decarbonization and supporting the smart society. Therefore, it is an imperative topic for ICEF. The session room was occupied fully because it attracted a high level of interest. Globally installed non-pumped hydro electricity storage has grown rapidly, over 50% per year and reached 3.5 GW in 2016. However, storage needs will remain largely answered by existing and/or planned pumped hydro, over 200 GW in 2025. Various storage technologies such as battery, flywheel, supercapacitors, CAES, hydrogen can provide a range of services including voltage regulation, frequency regulation and even seasonal storage. Deployment of energy storage and electric vehicles looks progressing on track to satisfy two degree scenario owing to recent battery technology improvements and cost reductions.
We identified pros and cons of various storage technologies and further needful innovation. The electric bus depot operator can offer different services such as voltage control for local distribution system operator, balancing services for aggregators, and smoothing services for producers of intermittent renewable energy. Solar heating systems with smart solar heat stores with heat pump can help integrating wind power in the energy system and contribute to an increased penetration of renewable energy in both form of power and heat.
Energy storage technology can enhance energy system flexibility and integrate high share variable renewable resources. Stationary energy storage for power system, mobility energy storage for transportation, and stationary thermal storage system are particularly focused this year and their technology roadmaps and each topics in each technological area were presented and discussed.
In the panel discussion, importance of not only battery technology but also other storage technologies development and further utilization of electric vehicles for grid stability was emphasized. Dr. Kari Maki, VTT Technical Research Center of Finland, proposes demand response is the perfect way of smart electric vehicle charging, and integration of smart charging and the local PV generation may minimize the power exchange with the grid. Social innovation such as new electricity market design is required. In addition, examples of solar heat storage technology were presented and importance of thermal energy storage, especially for cold climate regions is pointed out.
One of the future topics at ICEF includes vehicle to grid (V2G) integration and virtual power plant (resource aggregation). Vehicle–grid integration can facilitate supply-demand balancing of power systems with high penetration of solar PV and wind power with lower electricity costs and emissions reduction.