IEA designed and built an 11.4 MW diesel fired standby power generating plant for a large industrial customer in central Iowa. The system was built in three phases over a 10-year period in order to keep pace with customer load growth.

It was originally designed to include three 1.6 MW diesel generators, a single utility feed, and two customer load ties. Several years later, an additional two 1.6 MW engines, a second utility connection and two additional load ties were added. Lastly, a 1.6 MW engine, a 1.8 MW engine, an additional utility feed and two more customer load ties were added. 

In 2019 the utility supplier relocated the substation feeding the facility.  This eliminated all 3 utility feeders and the six customer load ties.  The new system consists of a single utility feeder and generator tie.

The completed system consists of:

• Seven walk-around enclosure diesel generators, 11.4 MW total generating capacity

• A single 12,000 gallon above ground storage tank with 100-gallon day tanks in each enclosure.

• Seven 4.16 kV switchgear sections, each with a generator circuit breaker and Woodward EasYgen generator controls.

• A single utility feed.

• A Tie circuit breaker connecting the generator bus to the utility

• A Master PLC cabinet for system control.

• Rockwell Software RSView SE Human Machine Interface (HMI) software for remote monitoring and control.

• A 15” Allen Bradley Panelview color touchscreen operator interface.

The system generates power at 4,160 Volts.  The seven generators are connected to a common generator emergency buss and then to a tie circuit breaker.  The tie circuit breaker is connected to an IEA owned 12/16/20 MVA transformer that steps voltage up from 4.16 KV to 24.9 KV.

The transformer is connected to S&C Vista distribution switchgear which connects to the incoming utility via an automatic recloser.

Modes of Operation:

• Standby mode (power outage)

• Import mode (maintain a set KW import level while in parallel with the utility)

• Base Load mode (generators produce a fixed output while in parallel with the utility).

In addition, each engine can be manually loaded while in import or base load mode. It features Load Sense/Load Demand capability; the system will automatically start or stop engines as required by actual plant loads.

The system can be controlled locally or remotely, via IEA’s state of the art Supervisory Control and Data Acquisition (SCADA) system.