Large or grid-scale energy storage will be a key factor in how quickly we can transition to more renewable energy in our system. The two most common forms of large-scale energy storage are batteries and pumped hydro. We take a look at how large-scale batteries – which are sometimes referred to as grid-scale batteries – will support a transitioning energy system.
What’s in the box?
In simple terms, batteries store electrical energy in chemical form, with lithium-ion being the most common battery chemistry used to store electricity for grid-scale applications. This is the same technology you find in devices such as smartphones and laptops.
Large-scale batteries typically consist of several components – a battery unit or ‘enclosure’ (generally a large fridge-sized box or a shipping container), an inverter to help charge and discharge the battery, and a transformer to step up to high voltage suitable for transmission around the electricity network.
Speed and flexibility
Unlike other forms of energy storage and generation, batteries are particularly valuable because they can respond faster than other energy storage or generation technologies and can help avoid blackouts by turning on and off in fractions of a second. Compared to traditional forms of generation, which can take several hours to reach full output, batteries can respond almost instantly to changes in wind or solar generation and keep supply stable and the lights on.
Batteries are also a great way to supply additional power when demand for energy peaks, such as when people get home from work and start to consume more electricity.
When charged during the day, soaking up excess solar generation that is not used as it is produced, we can “shift” energy from the middle of the day to the afternoon peak period to meet customers’ needs.
While batteries can provide almost instantaneous back-up, the amount of time they can support the system using current technology is relatively short, limited to a few hours at most. This means batteries alone cannot yet be relied upon to support the grid for the longer durations sometimes required, which can be several days in the case of severe outages. Over time, as battery technology improves, it will be able to provide back-up for longer and at lower cost.
Location, location, location!
Large-scale batteries can in theory be placed anywhere along the electricity grid. However, to take advantage of the infrastructure already in place and reduce the cost of the energy produced, Origin is looking at installing large-scale battery technology at many of our existing power stations, including a proposal to develop a 700MW battery project at the Eraring Power station in NSW.
Interestingly, a large-scale battery located next to a power station is not powered by the power station. Large-scale batteries operate independently, are connected to the grid and can continue to operate when the power station is not running or even after it may have retired from service. Origin has committed to exiting coal-fired generation by 2032 and we anticipate that the capacity at Eraring will be replaced by a combination of renewables, battery storage and gas peaking power stations.
Want to learn more?
On episode five of our So Watt? podcast, host Andy Saunders delves into the role batteries will play in the future of the energy network.