Session: 08-02. Grid Insights for Electric Power

Submission Number: 178012

Economic Potential of Combined Cycle Flexibility: Bottoming Cycle Hot Standby Mode and Gas Turbine Peak Firing in the European and Us Markets 

In the evolving energy market characterised by increasing renewable penetration and volatile electricity prices, Combined Cycle Gas Turbine (CCGT) plants must enhance both flexibility and profitability while maintaining reliability. Two key drivers to improve short-term dispatch performance are the optimisation of bottoming cycle thermal management with Hot Standby Mode (HSB) during standstill periods and the strategic use of Gas Turbine (GT) Peak Firing (PF) at high market prices. This study examines the techno-economic potential of reducing start-up time and energy in the bottoming cycle and investigates how flexible operation strategies, including increased peak firing, can enhance plant revenue under varying market conditions, thereby ensuring the profitability of reducing start-up stress costs.

The integration of thermal management systems for CCGTs with Warm Keeping (WK) techniques, such as Electric Boiler (EB) and Electrical Tracing (ET), helps reduce start-up (SU) time, maintenance costs, energy consumption, and emissions for the bottoming cycle. Peak Firing (PF) operation enables temporary increases in gas turbine firing, allowing for a boost in Turbine Inlet Temperature (TIT) to enhance power output and capitalise on high electricity prices or meet peak demands. However, this flexibility comes at the cost of accelerated hot-gas-path degradation, which raises maintenance expenses and shortens the plant's lifespan. The study assesses the economic potential of these two techniques, WK and PF, with a detailed market-based dispatch analysis across different electricity pricing scenarios representative of EU and US markets. These scenarios capture the influence of price variability, fuel cost correlation, and carbon pricing policies on the economic outcomes.

A Mixed-Integer Linear Programming (MILP) model has been developed to optimise daily operations scheduling, including technical constraints and economic profit.  The piecewise linearization modelling technique has been deployed to account for all the non-linearities of the off-design performance, and to handle the type of SU. This model is integrated into the Multi-Energy Dispatch Optimiser (MEDO), which was developed to handle the scheduling optimisation process for complex energy systems.

Presenting Author: Andriy Vasylyev University of Genoa

Presenting Author Biography: Andriy Vasylyev is a postdoc researcher at the Thermochemical Power Group (TPG), University of Genoa, where he develops techno-economic models for optimising energy system scheduling. He earned his PhD in Energy System Modelling, focusing on advanced dispatch and optimisation strategies for sustainable energy networks. During his PhD, he collaborated with the International Energy Agency (IEA) on European grid modelling using open-source simulation tools.

Authors:

Andriy Vasylyev University of Genoa
Abhishek Dubey University of Genoa
Alessandro Sorce University of Genoa