In 2005, Siemens announced the development of the world's largest, most powerful gas turbine. Two-years later, on schedule, the prototype of the SGT5-8000H was installed at the Irsching 4 gas turbine power plant.

High operational flexibility – the ability of a power plant for fast start-up and to adjust load output fast and predictable to changing market requirements – is an essential prerequisite to ensure economic success in a liberalized market. The paper describes upgrade opportunities for combined cycle power plants, which were originally built as base load plants and are now – due to changing market conditions and fuel prices – forced to operate as peak load plants or as cycling plants with daily start-up.

The US electric power industry has changed dramatically since the downturn of the gas-turbine-based market in the early 2000's. In the years prior to this, nearly all combined-cycle plants were planned, permitted and built with the expectation to be operated predominatly in base load.  With the addition of excess generating capacity in the industry coupled with rising natural gas prices, many of the new plants had to address a new set of challenges posted by nightly and weekend shutdowns and subsequent fast start-up requirements to remain economically viable.

This paper challenges the conventional method of fuel-based bottoming cycle power augmentation in a combined cycle plant, in which a fuel source is combusted in the hot flue gas stream internal to a combined cycle HRSG - also known as supplementary firing or duct firing. Although duct firing is an effective means of increasing plant capacity, it significantly reduces the plant efficiency. Additionally, as the world fuel markets continue to incur a substantial increase in demand, power plant owners and operators are more actively seeking plant solutions that provide better performance flexibility. Retrofitting applications are also explored. Ancillary advantages of the CFCC plant are enumerated, along with economic comparisons of plant Life Cycle Costs.

The changed market conditions have an influence on the operating profile of every power plant in order to be dispatched. Combined cycle power plants often do not strictly operate in a base loadlike regime running 8000 hours per year. Many units are operating in a daily start-stop regime with units starting up to two times a day. In this market environment, an economic model that incorporates only a certain amount of base load hours with fix power revenues will not describe the full picture, additional earnings from the above mentioned market opportunities would not be considered. To be more accurate, an extended approach for evaluating a cycling plant with high flexibility is necessary. Key parameters for operational flexibility are for example start-up time, standby operation and shut-down time. This paper describes an approach for evaluating flexibility for combined cycle cycling power plants.

This paper discusses a new power plant concept by means of case studies for the main CHP applications. The CHP plant concept for 5-13 MW gas turbines reflects the requirements of this market segment. The first stage the development is based on the Siemens’ SGT-300 industrial gas turbine which is designed for highly efficient combined heat and power generation. The power plant systems are packaged into modular unit, which are pre-engineered and packaged into containers and interconnected on the construction site. The paper investigates improvements in economic value for the end user of such a plant, considering aspects such as construction and erection time, lifecycle cost and operational flexibility.

By introducing new technologies to the established SGT-300, introduced in 1990 as the Tempest, Siemens have delivered a product which meets both today’s legislative requirements associated with emissions and the key business needs of reliability and high plant thermal efficiency. This paper explains the impact of newly developed technology in improving market fit in terms of emission control, reliability and overall plant efficiency and demonstrates the impact of these three critical advances in technology on European cogeneration applications.

A fast start-up plant gives plant owner business opportunities like utilizing hourly and seasonal market arbitrage, participation in ancillary energy markets or peak shaving. These factors can be implemented in an economic evaluation model and improve the economic benefit of a project.
This paper gives an overview about recent improvements with respect to operational flexibility, the technical features of a cycling plant and it shows an approach for economic evaluation of flexibility.

Reducing water consumption and avoiding effluents is a general goal nowadays. On one hand the water consumption affects the project profitability due to additional initial and life cycle costs like expenses for the demineralised water supply and for waste water disposal.
On the other hand avoiding high water consumption and avoiding waste water disposal is an important contribution to environmental protection and finally can help to ease the permitting phase of a project.
This paper presents an example how Siemens Reference Power Plants are designed to achieve the target of low water consumption and low waste water disposal.

In the 400 MW class, Siemens provides two 50 Hz single shaft Reference Power Plants called SCC5-4000F Single Shaft. Both are based on the SGT5-4000F gas turbine, the SGen5-2000H hydrogen cooled generator and a steam turbine coupled through a self shifting and synchronizing (SSS) clutch to the generator.
The paper addresses the Reference Power Plant development process, the single shaft design referring to a SCC5-4000F Single Shaft (SST5-5000) and features for high operating flexibility.

Avoiding emissions is a general goal nowadays. On one hand producing emissions affects the project profitability due to additional initial and life cycle costs like expenses for waste water disposals and the subsequent supply of demineralised water.
On the other hand avoiding emissions is an important contribution to environmental protection and finally can help to ease the permitting phase of a project.This paper presents two examples how Siemens Reference Power Plants are designed to achieve the target of low emissions.

The demand for highly-efficient combined cycle power generation using natural gas has not changed which allows to use well-proven concepts like the Siemens Single-Shaft combined cycle concept.

The continental European power system is the result of synchronous interconnection of the electricity networks of the separate transmission system operators (TSOs) involved. To ensure smooth operation of the system and to enable grid disturbances to be controlled, a number of technical rules and recommendations need to be followed in operation of this system. The rules and recommendations of the “Union for the Coordination of Transmission of Electricity (UCTE)” form a common basis for this, providing minimum requirements to be met for grid operation on this system, which is operated in overall synchronism. These rules and recommendations leverage the exchange of electric power beyond the boundaries of the separate countries that form this synchronously interconnected system, and also promote nondiscriminatory.