The higher penetration of distributed renewable energy within Australia is occurring by virtue of the lower capital costs associated with Wind and Solar in comparison to traditional large scale centralised fossil fuel generation.
Since the black outs in South Australia in late 2016 and the retirement of base load power stations, firming up renewables by way of dispatchability has become the order of the day. This is because the higher % penetration of renewables has resulted in a less stable environment. However large scale high energy storage still only results in relatively short time duration support to the grid in terms of total demand. A solution is the deployment of High Power lithium batteries in conjunction with new and existing relatively low capital cost gas fired generation enabling the batteries to be the source of synthetic inertia spinning reserve, also providing on line frequency and voltage support, with a minimum of turbines on line. When there are peaks in demand the batteries can rapidly respond and meet the demand whilst other generation sources come on line. This type of application and also the increasing demand for high power UPS for data centres has resulted in the development and evolution of new lithium battery chemistries. For example, Kokam have recently released a battery capable of a power to energy ratio of 10 therefore a 10 MWh battery can deliver 100MW discharging in 6 minutes. It should be noted that a battery energy storage system is more sensitive to the total energy capacity installed than the power capacity. Also, the footprint is small enabling deployment within existing infrastructure. Hence this approach is cost effective.
This evolution enables the firming up of renewables with distributed gas generation more efficiently filling the gap. The small scale batteries support a reduced number gas turbines needing to be on line at any time and a significantly higher proportion of renewables in the overall generation portfolio.
3 key takeaways from this presentation:
1.New lithium battery technology is enabling very rapid discharge capability with a small footprint
2.This has application as a very effective source of synthetic spinning reserve and instant source of energy for ancillary grid support services
3.Deployment of such batteries, with rapid response generation sources, such as gas turbines enables a higher proportion of renewables to be reliably deployed in the generation mix.