CCC/189 ISBN 978-92-9029-509-9

October 2011

copyright © IEA Clean Coal Centre

Abstract

Historically, coal-fired power plants have faced competition from other forms of power generation

such as nuclear, natural gas and oil. Like most coal-fired plants, many of these were designed to

operate primarily on base load. However, competition is now increasingly coming from a range of

renewable energy sources that include biomass, geothermal, hydro, solar, and wind. Unlike

conventional power plants, several of these (particularly wind and solar power) are wholly dependent

on prevailing weather patterns and consequently only generate electricity on an intermittent/variable

basis. Changes in operating patterns mean that many existing coal-fired power plants no longer

operate solely on base load, but are now subject to two-shifting or some other irregular form of

operation. Switching a plant originally designed for base load can have implications in a number of

areas that include plant economics, operation and performance. Environmental performance may also

be impaired. This report discusses the growing level of intermittent renewable energy in the global

power sector and examines the potential impact on associated coal-fired plants that have been obliged

to change their mode of operation.