When fast reactions mean money in the bank20 October 1999
Reducing the reaction times of gas turbines can enable operators to cash in on the premium prices paid for frequency control and peak power in the deregulated market.
Frequency stabilization and peak load power generation are two modes of operation that can be very attractive to grid operators, particularly in the smaller electricity networks, as exemplified by Ireland and Israel for instance. These modes can command top prices and the ability to offer them can be very profitable for power plant operators, who are facing increasing competitive pressures. The key to exploiting this market potential is being able to react very fast to changing grid conditions.
Recognizing the premiums that can be earned by being quick off the mark, Siemens sees big potential for a technology it calls FAST IGV – an upgrade package for gas turbine compressor inlet guide vanes which makes them fast-acting.
FAST IGV "can reduce the reaction time of your V94.2 turbine from roughly 50 seconds to just 3 seconds – and change output by roughly 30 per cent in these 3 seconds," says Siemens.
The modification, involving the Stage 1 compressor stationary blades, is estimated to have a payback time of less than four years, depending on grid code regulations. It can be done, says Siemens, during scheduled maintenance with no additional downtime. The upgrade essentially consists of two parts:
Experience in the field
There are currently eight V94.2 gas turbines operating with FAST IGV – two at Poolbeg, Ireland, four at Gezer, Israel, and another two at Yang Pu, China. Feedback to date has been positive, with FAST IGV becoming increasingly recognised as a powerful, some would say essential, technology for achieving grid stabilization.
A particularly dramatic demonstration of the merits of the modification happened at Gezer. Following installation of the FAST IGV there, a test run was performed with a simulated drop in grid frequency. Shortly after the test just such a drop happened for real. However, the FAST IGV reacted as intended and has operated effectively ever since, reports the Gezer station operations manager, Shlomo Shmuely, who estimates the amortization period as less than three years.