There is a large interest in the possibilities in storing produced energy that is not needed at that particular moment or to store energy when the cost for production of electricity is low. For this reason, different types of energy storage systems are used. With a fast development of new technologies and new forms of application for energy storage systems, it is important to also study the existing and potential risks with these types of systems.

This prestudy describes the field, its risks and needs for research. It focuses on risks associated with fire, including explosions and when relevant the production of toxic gases. Although the main focus of the prestudy is different types of energy storage systems, the report contains information also on risks associated with storage of solid biofuels and waste. This means that the report contains information on risks and needs for research for batteries, hydrogen, biogas, liquified gases, biofuels and waste.