The need for large-scale energy storage has increased in recent years as more variable energy (i.e. solar and wind) has come onto the market. Technology advancements and the creation of new markets are helping to make large-scale energy storage a commercial reality.

While electricity cannot itself be stored on any scale, it can be converted to other forms of energy which can be stored and later reconverted to electricity on demand. This can help smooth out supply from variable renewable energy sources like wind and solar. Electricity storage systems can also provide ancillary services to the transmission system to help maintain system security and reliability.

We are investigating pumped hydro and chemical battery storage solutions to create value for our portfolio and to help facilitate the integration of variable renewable energy into the energy system.

Pumped hydro energy storage

Hydropower and pumped hydro energy storage (PHES) covert the energy of moving water into electricity.

PHES uses water reservoirs as a way of storing energy. Excess energy, either from the grid or a renewable energy source such as a wind or solar farm, can be used during low demand periods to pump water from a lower dam to a higher one, essentially converting the upper reservoir into a giant battery. The stored energy can then be released by returning the water through a hydroelectric turbine into the lower reservoir.

We are currently investigating a range of PHES opportunities throughout Queensland.

Battery (chemical) storage

Batteries are an energy storage technology that use chemicals to absorb and release energy on demand – typically storing energy during times of low demand and releasing energy at times of peak demand. Batteries provide flexibility and can respond quickly (within fractions of a second) to maintain grid stability.

Battery use in the Australian electricity grid is expected to grow in the future due to government policies, technological advances and rapid cost decreases.

We have recently completed a study to understand the opportunities and emerging markets for battery storage, and how it might integrate with our portfolio as it evolves to provide dispatchable and renewable supply.

Opportunities and benefits

Energy storage offers advantages throughout the supply chain including:

  • allowing greater deployment of variable renewable generation;
  • increasing reliability for end users;
  • minimising the fluctuation of electricity prices;
  • improving system reliability; and
  • maximising system flexibility.