The sun doesn’t shine at night and the wind doesn’t always blow at times of peak demand. Given these well-understood limitations, renewables have traditionally been seen as unlikely to compete with gas and nuclear for base-load generation of electricity.
But storing energy at grid-scale using batteries has started to become a realistic option, allowing the network to rely on a greater amount of renewably generated power.
Benefits beyond storage
Until now, batteries have often been dismissed as too expensive and too short-lived for grid-scale storage. Today, thanks in part to the consumer-led expansion in affordable lithium-ion battery production, utility-scale batteries are becoming a reality. This became clear in 2017 when Elon Musk’s Tesla took just 100 days to get the Hornsdale wind farm’s lithium-ion battery storage centre online, bringing dependable renewable energy to 70,000 homes in an area of South Australia previously suffering black outs. Crucially, the centre started to earn back the investment almost immediately.
Batteries can also help with other technical issues such as grid stability, reactive power compensation, voltage control and frequency control, which are all required for the smooth running of the grid. Lithium ion isn’t necessarily the very best battery technology for grid support – proposed liquid metal batteries could offer longer lifespans and different grid support services. In San Diego, California battery storage has already been recognised as a viable way for the state to meet its ambitious carbon emission reduction targets.
Why utilities should invest
With the right batteries available, what the sector needs now are the right mix of additional incentives for developers to incorporate battery storage into their renewable energy projects. For example, with batteries installed, utilities could implement measures such as time-of-generation tariffs. These would pay more for energy supplied in peak periods and would help to make the storage sums add up.
Batteries and the self-aware grid
Adoption of battery storage is being bolstered by the introduction of digital technology that allows the grid to learn about customer use and behaviour, enabling trends to be spotted and pre-empted. Smart thermostats and smart meters, which learn and predict customers’ energy use, are providing information that helps balance load and generation. This new level of understanding and insight can then help developers to decide on the precise mix of renewable generation and storage, to gain the best return on their investment.
For utility companies, these benefits are best realised by working with a partner that understands the grid at every stage, from power generation and storage to distribution and consumer behaviour. The technology now exists to run these vastly smarter grids, but the implementation requires a combination of new thinking, a digital strategy and a commitment to flexibility.
It is an exciting time to work in utility-scale battery storage. With the increasing dangers of climate change making daily headlines, it’s critical that the world’s electricity grids fully embrace renewable energy and batteries are ready to play their part.