Electric energy storage is a technology solution to balancing supply and demand in the grid, across intervals ranging from milliseconds to hours. In the past, pumped hydro storage helped highly-centralized grids move energy from night to day to level the load on the generating stations. Tomorrow’s grids will be more dispersed, with a profusion of smaller, intermittent power sources; the roles of energy storage will be more diverse, and there will be many competing technologies to choose from.
The technology options are complex. Even decades-old technologies such as pumped hydro and lead-acid batteries are seeing further development. Compressed air energy storage, having been demonstrated in the 1980s and 90s, is finally appearing in plans for more widespread deployment, including thermal modifications to increase its ‘round-trip’ storage efficiency. Numerous novel battery chemistries are under development, with electric vehicle demand expected to bring dramatic price reductions for some. Flow battery concepts have allowed a battery’s discharge time to be independent of its power capacity. Flywheels are emerging from small uninterruptible power supply applications and being scaled up for grid ancillary services. Nano-scale techniques are creating capacitors of extraordinary charge density, capable of helping control reactive power and frequency; superconductors are also seeing application in these services.
Because there are numerous applications for storage with diverse requirements, there is no single energy storage technology that can address them all. As seen in the figure, pumped hydro and CAES are typically the most cost-effective option for bulk power management; whereas for transmission and distribution grid support, batteries, flywheels, supercapacitors, and superconducting magnetic storage are generally more suitable.
Positioning of Energy Storage Technologies (Source: EPRI, 2010)
To better understand the potential of electric energy storage in Alberta, the Environment and Carbon Management division at Alberta Innovates - Technology Futures (Tech Futures)has teamed with industry and academic experts to assess the converging needs for infrastructure, market design and emerging technologies. This team has undertaken the following projects:
Energy Storage: Making Intermittent Power Dispatachable
Compressed Air Energy Storage (CAES)
For more information about the Electric Energy Storage group at Tech Futures, please contact:
Andy Reynolds, MSc, PENG, IntPE(UK)
Portfolio Manager - Clean Energy
Tel: 780-450-5531
andy.reynolds [at] albertainnovates.ca