GE Tops 50% Engine Efficiency as Gas Engine Market Heats Up

GE Power & Water announced Mar. 5 that it had achieved 50.1% gas-fired J920 FleXtra reciprocating engine during a test run at the Jenbacher facility in Austria. This is the first time a reciprocating engine has reached 50% efficiency.

The 9.5-MW J920 FleXtra, introduced for 50-Hz applications in 2013 and 60-Hz in 2014, is the largest engine in GE’s line-up, which it has been developing since acquiring the Jenbacher product line in 2003. In combined heat and power applications, the J920 genset can achieve efficiencies up to 90%.

GE is investing $1.4 billion in distributed power technology and has been expanding its reciprocating engine offerings aimed at the distributed power market. GE introduced its new 616 diesel engine in 2014 and added two-stage turbocharging to its J624 line last year.

Once relegated mainly to on-site and back-up power and small grids (such as islands), reciprocating engines are rapidly becoming an option for utility-scale applications as gas prices remain low and their efficiency advantages in rapid-cycling applications become clear.

Wärtsilä announced in early March that it had received an order for a 56-MW engine-based power plant in Coffeyville, Kan. The plant, to be owned by Coffeyville Municipal Light and Power (CMLP), is intended to leverage the fast-ramping capabilities of Wärtsilä’s 50SG gas engines to generate revenue from the Southwest Power Pool’s (SPP’s) new spot market. Wärtsilä reported that its existing engine plants in the SPP region have seen a 10-fold increase in runtime since the spot market opened.

The CMLP plant will also back up the substantial wind generation, an application for which engine-based plants have become very popular because of their efficiencies in fast-changing environments. Portland General Electric (PGE) reached commercial operation at its 220-MW Port Westward Unit 2 plant near Clatskanie, Ore., in December. That plant, also supplied by Wärtsilä and comprising 12 50SG engines, is designed to balance wind and solar generation, as well as provide load-following and peaking services. PGE has been challenged by the increasing renewable generation in the Pacific Northwest, and has been rapidly adding fast-ramping gas plants over the past few years.

Wärtsilä is also adding a 112-MW engine plant to Basin Electric Power Cooperative’s Pioneer Station plant in Williston, N.D., in addition to expansions at several other existing plants in the Midwest.

—Thomas W. Overton, JD is a POWER associate editor (@thomas_overton, @POWERmagazine).