Three reasons why flexible engine power plants are a crucial technology for Australia’s energy transition

Australia's energy future will be under constant discussion as we get closer to 2030 and we approach key milestones associated with hitting the nation's emissions reduction targets. 

One thing is certain, additional capacity will be required to meet demand as Australia looks to retire its coal power stations. While more renewables are coming online, something else is also needed to support the transition – flexibility and balancing capabilities. We need to look no further than South Australia for a successful transition blueprint. In fact, the state has become a global exemplar for renewable energy adoption.  

A key part of South Australia's success is flexible engine power plants, alongside renewables and battery energy storage. Currently, the flexible engine power plants run on gas, and help balance the power system during renewable droughts and peak demand periods.  

Ultimately, there are three important reasons why flexible engine power plants are the ideal power generation technology to support Australia's transition to renewables: 

Providing fast and flexible power support for renewables to facilitate the retirement of coal power stations 

Retiring coal power stations is a significant and vital milestone for Australia's 2030 emissions targets and the transition to net zero. As more and more renewables come online, there needs to be sufficient generation capacity in the power system to cover renewable energy droughts, which may last days or weeks. Gas engine-based power plants are perfect for this duty. 

Flexible engine power plants provide a reliable and scalable support for balancing renewables – while consuming 20-30% less fuel than traditional gas power stations. The flexible characteristics of these engines, such as the short start-up time, fast ramp-up rate, and shut-down capabilities makes engine-based power plants the best generation technology to follow and support unpredictable and intermittent renewable generation. They are ideal for both minute-level balancing and longer-term balancing by substituting renewable generation during non-renewable periods. Flexible engine power plants can effectively replace renewable generation partially or totally during longer renewable drought periods, providing the confidence and capacity to retire Australia's fleet of coal power station. 

The speed and responsiveness of flexible engine power plants also helps to reduce renewable curtailments when there is too much renewable energy. Flexible engines can quickly reduce and adjust their output to match the power demand and variability of renewable sources. This means that engines can ensure that all renewable energy is utilized effectively while still enhancing the grid stability and allowing higher integration of renewables into the system. 

Facilitating the lowest cost energy system for businesses and consumers 

Achieving the lowest cost energy system for consumers requires the overall power system to have the optimal mix of energy sources. This needs to take into account the different costs and utilisation rates, and constraints of each energy source or technology across the entire power system. A suboptimal mix of energy will result in more curtailment and a more expensive way to meet energy needs during scarcity periods, which raise costs to end-users. 

Flexible engines are a proven technology that support balancing renewables. As they are complementary to renewables, they run only when needed - usually during critical balancing periods, such as high demand or renewable droughts. Having engines as part of the system, alongside renewables and energy storage provides the lowest cost energy system for businesses and consumers.  

Creating a pathway to zero emissions with future-ready design 

Engine power plants are future-proof, because they are essentially fuel agnostic.  At the moment, natural gas is the most common fuel in thermal balancing applications, but in the future, it is expected that new renewable, carbon-free fuels will become available for power generation. Recently in AEMO's integrated system modelling plans, natural gas has been highlighted as an integral part of the cost-optimal solution for Australia's energy mix. 

However, once the time is right, the flexible engine power plants can transition to sustainable fuels, such as hydrogen, ammonia, ethanol and methanol to help reach the final milestone of a net zero power system. The longevity of the technology and new fuel possibilities are attractive to investors as they will not be stuck with a stranded asset as Australia transitions to a net zero system.  

Final thoughts 

As 2030 approaches it's important to remember that Australia has a proven blueprint for significant emissions reduction from its energy system. In the state of South Australia, the (not so) secret to its success is renewables, energy storage and flexible engine power plants operating on gas, playing a vital role balancing capacity during times of droughts and peak demand.