1 Introduction

This section provides an overview of the current capabilities of conventional coal and gas fired power plants, without Carbon Capture and Storage (CCS), to operate flexibly. Some of the data included in this section are available in the public domain, others originate from Foster Wheeler’s in-house information.

The main objective of this investigation is to highlight how plants without CO2 capture and storage can operate in the actual electricity market, responding to the normal daily and seasonal variability of the electricity demand. Then, on the basis of the information shown in this section, it will be evaluated how CCS affects the plants operation, in order to understand if and to what extent these plant types can operate in the new flexible electricity market (refer to section D).

Therefore, this section focuses on the main features related to the flexibility of conventional power plants, like: cold and hot start-up and shut-down times, operating load range and the impact of variable and low load operation on plant efficiency, equipment lifetime and operating costs. These considerations are mainly referred to the Combined Cycle, PC and IGCC plants.

It is to be noted that most of the information available in the public domain refer to the combined cycles, especially in relation to the improvements of plant flexibility, due to the latest developments of the technology. Vice versa, much less information is available on the operating flexibility of PC boiler plants, as well as IGCC’s. This is because PC boiler and, moreover, IGCC plants have been designed to operate mainly at base load, due to lower weight of the variable costs (i.e. fuel) on the overall cost of electricity.