Should you care about power plant cycling?

Before we say too much on this topic, let us define the term “power plant cycling”. Cycling refers to the operation of electric generating units at varying load levels...

26 December 2012

Before we say too much on this topic, let us define the term "power plant cycling". Cycling refers to the operation of electric generating units at varying load levels (power demand), including on/off and low load variations, in response to changes in system load (demand) requirements. Every time a power plant is turned off and on, the boiler, steam lines, turbine, and auxiliary components go through unavoidably large thermal and pressure stresses, which cause damage.

While this damage may be of interest to metallurgist for reasons such as failure mechanisms, to the managers, this damage directly corresponds to cost. Like all business problems, the decision to manage this damage cost falls in the realm of decision analysis. Should we incur relatively modest maintenance cost and manage our plant operations now – or should we incur huge failure costs. In other words:  Should we care about this cost at all?

Analysts and experts often like to give a system perspective and estimate this power plant cycling cost at 3 – 7 percent of system cost. However, most of the experts ignore the fact that asset managers have to eventually find ways to recover this increased cost. More importantly, by viewing the overall system cost, they discount the fact that there will be individual power plants on a transmission line that has to face increased cycling due to variable renewable generation and (therefore) will have much higher cycling costs in future than in the past.

Googling "power plant cycling" will fetch several hundred articles on the growing interest in this area. More so, with increasing renewables, the perception is that power plant cycling costs will directly impact most fossil generation owner's bottom line.

Do you have a question about power plant cycling or related topics? Please leave your comment below and one of our experts will get back to you.

Today’s expert blogger is Nikhil Kumar, Program Lead - Utility Economics for Intertek. Nikhil is based in Sunnyvale, CA and is leading the Smart - Asset Integrity Management (AIM) services business for the company.