Ameren Transmission Co. will begin work on expansion plans to invest an estimated $1.3 billion over 10 years. The Midwest Independent Transmission System Operator announced yesterday that its Board had approved its Transmission Expansion Plan 2011 (MTEP11), which includes the ATX projects.

According to MISO, the total investment for all of the MTEP11 projects is expected to be $6.5 billion over 10 years, including $5.1 billion with respect to 16 multi-value projects (MVPs). Three of those approved MVPs are the ATX projects.

The ATX projects approved by MISO's board are a part of the Grand Rivers projects, consisting of the Illinois Rivers and Spoon River transmission line projects in Illinois and Mark Twain transmission line project in Missouri. These projects address regional transmission needs as well as public policy goals. These projects also increase stakeholder value across the MISO footprint. A robust, regional transmission system enhances competition in power markets and increases consumer access to least-cost generation, regardless of fuel type.

The ATX projects approved today by the MISO board consist of:

• The Illinois Rivers project, preliminarily estimated to cost $860 million, will span 331 miles with a new 345-kilovolt transmission line, crossing the Mississippi River near Quincy, Ill., continuing east across Illinois to the Indiana border. Key benefits include improved power transfer capability in the region and delivery and integration of renewable generation.
• The Spoon River project in Illinois, preliminarily estimated to cost $180 million, will span 70 miles of new 345-kilovolt transmission line from Oak Grove to Galesburg, Ill., continuing near Peoria, Ill. Key benefits include improved reliability in the northwestern Illinois area and integration of renewable generation.
• The Mark Twain project in Missouri, preliminarily estimated to cost $230 million, will span 89 miles in Missouri of new 345-kilovolt transmission line from the Iowa border to Adair, Mo., on to Palmyra, Mo. Key benefits include enhanced ability to import power from the upper Midwest and delivery and integration of renewable generation.