Power Generation

• 1,000 Megawatts (MW) of power generation capacity.
• Plants located in Colorado, Nevada, Wyoming and California.
• Nearly all our capacity is under long-term tolling contracts with load-serving electric utilities.
• We serve growth markets in the West by providing coal-fired base-load power and natural gas-fired peaking power capacity.
• Las Vegas power plants encountered operational issues in 2005 requiring extended maintenance periods. Excluding these two plants, our generation fleet's availability exceeded industry norms; our gas-fired plants had 99% availability and our coal-fired plant's availability exceeded 95%.

Generation Project In Progress - Wygen II

• Wygen II, a 90 megawatt, base-load, coal-fired generation facility at our Wyodak energy complex near Gillette, Wyoming, is currently under construction. We expect it to be completed in early 2008.
• Wygen II utilizes water-saving, air-cooled condensing technology pioneered by our Company in North American back in the 1960s.
• Wygen II will feature the latest available emissions control technology, including mercury reduction, which once again puts our Company at the leading edge of responsible environmental protection.