Naturgy, Spain: Upgrading gas turbines and using software optimization to reduce fuel consumption by up to 50% 

In the rapidly evolving landscape of renewable energy, Naturgy stands at the forefront of sustainable power generation. With Spain aiming for 160 GW of renewable capacity within a projected 214 GW total by 2030, the company recognizes the critical role of combined cycle plants in supporting this transition. As renewable generation increases, these assets provide the fast response, operational resilience, and efficiency needed to balance intermittent energy sources.

Naturgy operates 11 gas-fired power plants in Spain including the combined-cycle power plants in Sagunto, Palos de la Frontera and Campo. Equipped with Siemens Energy technology, these plants play a vital role in supporting Spain’s power system - continuously adapting its operating profile to meet changing requirements.

As Spain moves towards a greener energy future, Naturgy faces the challenge of integrating a growing share of renewable energy sources into the grid. 

Combined cycle plants are essential for providing stability and mitigating the fluctuations associated with renewable generation. 

However, to effectively support this transition, Naturgy’s gas-fired power plants needed to become more efficient and flexible with a centralized operation of multiple plant units. 

The existing operating profile of their plants required frequent start-ups and shutdowns, leading to increased fuel consumption and operational costs.

To address these challenges, Naturgy partnered with Siemens Energy to upgrade their SGT5-4000F gas turbine fleet installed at the Sagunto, Palos de la Frontera and Campo combined cycle power plants. The primary goals of the upgrade were to enhance the operational flexibility of their fleet and improve fuel efficiency.

Additionally, with a purely software-based optimization, paired with engineering expertise, Naturgy can bring an existing plant back to a competitive level. The implemented solutions include Flex-Power Services™ and Omnivise Performance such as:

• Turn Down: Lowering the minimum load capacity to accommodate varying demand.
• Low Loss Start: Solution based on Nonlinear Model Predictive Control (NMPC) to ensure that each start-up is economically justified and optimized.
• Fast Plant Shut Down: Enabling quicker shutdowns to enhance operational flexibility.

The upgrades helped Naturgy enhance their ability to start and stop the plant operation quickly while reducing the fuel consumption.

• Increased flexibility: The ability to start and stop plants quickly and frequently has enhanced the overall responsiveness of the power generation fleet.
• Reduced fuel consumption: With the implemented upgrades, fuel consumption during the start & stop process has decreased by nearly 50%, leading to lower operational costs and a smaller environmental footprint.
• Enhanced reliability: The improvements ensure a reliable power supply for critical facilities in cities like Valencia, supporting local industries such as refineries and petrochemical plants.
• Well-informed decisions: Before starting the plant, expected revenues and costs are transparently evaluated and compared. The system helps Naturgy decide when and how to start the unit in the most profitable way.
• Flexible & stable operations: The Omnivise T3000 control system supports fast load changes, dynamic operating conditions, and precise coordination of electricity and heat production.

Through close collaboration, Siemens Energy and Naturgy are enhancing the efficiency and flexibility of Naturgy's combined-cycle power plant operations by providing a reliable backbone for an evolving electricity grid. As a leader in the Spanish electricity energy market, Naturgy is playing a key role in accelerating Spain's energy transition into a cleaner future.