1MAY 10-12, 2011 * Rosemont, Illinois * Donald E. Stephens Convention Center

“Partnered for Success”Major Compressor Cylinder Replacement

Electric Power Conference and Exhibition – May 2011

New Harquahala Generating Company, LLC

2MAY 10-12, 2011 * Rosemont, Illinois * Donald E. Stephens Convention Center

Success

“The secret of achievement is to hold a picture of a successful outcome in the mind.”

- Henry David Thoreau

3MAY 10-12, 2011 * Rosemont, Illinois * Donald E. Stephens Convention Center

Facility Overview

4MAY 10-12, 2011 * Rosemont, Illinois * Donald E. Stephens Convention Center

Partnered for Success

5MAY 10-12, 2011 * Rosemont, Illinois * Donald E. Stephens Convention Center

Unit 2 MCCR Highlights

New Harquahala Generating Company and Siemens partnered in the installation of a newly designed

compressor on Unit 2 in January 2010, the second such modification in the 501G Fleet.

Benefits of the installation

Improved reliability

Reduction in unplanned maintenance intervals for diaphragm hook fit repairs

Predictable planned outage intervals

Long term reduction in maintenance expense

Proven design (V Machine)

6MAY 10-12, 2011 * Rosemont, Illinois * Donald E. Stephens Convention Center

Outage Measurable Statistics

Zero Recordable or Lost Time Accidents

Completed under projected timeline (38 days)

Completed on budget

Conducted in parallel to significant BOP and ST work

Measured Performance

Pre and Post performance data indicated no change in performance

Measured Success

7MAY 10-12, 2011 * Rosemont, Illinois * Donald E. Stephens Convention Center

Metronor Alignment

Support Tooling

MCCR Technology / Customized Tooling

8MAY 10-12, 2011 * Rosemont, Illinois * Donald E. Stephens Convention Center

New Robust Hook Fit Design

Keys to Success

Planning, planning, planning Lessons Learned from Millennium Power

Shared resources Risk Assessment

Begun 120 days before implementation Identified key areas that could have diminished results

TMS Process Communication Proper Documentation

Photographic Written

Quality Assurance Protocol Project Management Tools

Gantt Charts Coast Tracking Technical Engineering Correspondence, PCM’s,

OutFar’s, etc.

9MAY 10-12, 2011 * Rosemont, Illinois * Donald E. Stephens Convention Center

Compared three Units at Harquahala to 501 G Fleet (24 Units)

Note: data sample is for CT only (Econopac)

Three Basic Metrics

Availability Factor, which looks at both Scheduled and Forced Outages

Reliability Factor, focus is on Forced Outages only

Starting Reliability Factor

Period Analyzed

12 Month Rolling Average starting from January 2008 through December 2010;

for example, January 2008 data point represents data from February 2007 to

January 2008

Data Sources: Siemens

Availability & Reliability Trending

10MAY 10-12, 2011 * Rosemont, Illinois * Donald E. Stephens Convention Center

Starting Reliability Factor % 12 Month Rolling Average

11MAY 10-12, 2011 * Rosemont, Illinois * Donald E. Stephens Convention Center

Availability Factor % (CT Only) 12 Month Rolling Average

12MAY 10-12, 2011 * Rosemont, Illinois * Donald E. Stephens Convention Center

Reliability Factor % (CT Only) 12 Month Rolling Average

13MAY 10-12, 2011 * Rosemont, Illinois * Donald E. Stephens Convention Center

Partnership Success!

Thank you!