Comparing energy storage options for renewable energy integration

Increasing penetrations of fluctuating energy sources for electricity generation, heating, cooling and transportation increase the need for flexibility of the energy system to accommodate the fluctuations of these energy sources. Controlling production, controlling demand and utilizing storage options are the three general categories of measures that may be applied for ensuring balance between production and demand, however with fluctuating energy sources, options are limited, and flexible demand has also demonstrated limited perspective. This paper takes its point of departure in an all-inclusive 100% renewable energy scenario developed for the Danish city Aalborg based on wind power, bio-resources and low-temperature geothermal heat. The paper investigates the system impact of different types of energy storage systems including district heating storage, biogas storage and electricity storage. The system is modelled in the hourly energy systems analyses model energyPRO with a view to investigating how the different storages marginally affect the amount of wind power that may be integration applying the different storage options. Results show the largest potential but also most costly potential for actual electricity storages.