Coal Units Transition to Two-Shifting in Response to Rooftop Solar Boom in New Energy Normal
The energy landscape in Australia is undergoing a significant transformation. The move from traditional baseload power to more flexible generation methods is a response to increasing rooftop solar energy integration. This evolution marks a new phase in Australia’s energy transition.
Transitioning Coal Units to Two-Shifting
Coal generation companies are adapting to modern energy demands by implementing what’s known as “two-shifting.” This technique allows coal units to flexibly adjust their output, operating at as low as 20% of their capacity or shutting down completely during periods of low demand, particularly in the presence of high solar output.
Key Developments in Two-Shifting
- AGL Energy, operator of Australia’s largest coal fleet, is at the forefront of this transition.
- Notable trials of two-shifting commenced at the Bayswater coal power station in the Hunter Valley.
- The initiative is gaining traction, with coal units frequently adjusting their operations to complement renewable energy sources.
According to Geoff Eldridge from GPE NEMLog, AGL has been effectively utilizing this strategy during low-demand periods. Specific days highlighted for their successful two-shifting operations included March 17, March 22, and April 26.
Operational Insights and Future Implications
In recent weeks, AGL’s Bayswater Unit No. 2 has cycled off in the morning and returned in the afternoon, optimizing operations around peak solar production. This approach of maintaining operational readiness while intermittently shutting down is revolutionary.
Benefits of the two-shifting method include:
- Enhanced flexibility of coal units, allowing them to act more like semi-flexible resources.
- Reduction in daytime oversupply and curtailment issues for the grid.
- Shifting the availability of coal-generated energy to meet evening peak demands.
However, the implementation of two-shifting introduces new challenges. Operators face increased operational stresses and costs associated with cycling coal units on and off. Besides AGL, Energy Australia is exploring a similar approach at the Mt Piper coal generator, considering longer shutdowns to mitigate wear from frequent cycling.
What Lies Ahead for Energy Supply
As the reliability of coal diminishes, alternative energy resources are becoming crucial. The energy landscape is likely to shift toward:
- Peaking gas generators, which offer quick-response capabilities but have limited operational hours.
- Battery storage technologies that are rapidly decreasing in cost and capable of various applications, including energy arbitrage.
- Pumped hydro storage options, despite challenges with current projects like Snowy 2.0.
The evolution of coal units towards two-shifting is a significant indicator of Australia’s commitment to integrating renewable energy and adapting to new energy norms. The shift away from traditional baseload power signifies a broader trend towards more flexible and sustainable energy solutions.
