Minnesota Metro Emissions Reduction Project (MERP)
Xcel Energy’s $1 billion voluntary Minnesota Metro Emissions Reduction Project (MERP) initiative involved a package of projects to significantly reduce air emissions from three Twin Cities-area power plants while increasing electricity output by around 300 megawatts. MERP reflects our commitment to provide reliable energy to customers while reducing the environmental impact of generating that power.
MERP legislation
MERP stems from an emissions reduction bill passed during the 2001 legislative session as a result of work by legislative leaders, state agencies, the Izaak Walton League, Xcel Energy and others. The legislation encourages utilities to make voluntary emissions reductions and provides a mechanism for utilities to recover the costs for qualifying voluntary emissions reduction projects through an increase on customer bills.
Our energy experts thoroughly evaluated emissions reduction alternatives at our Twin Cities plants to identify projects that provide significant environmental benefits at a reasonable cost to our customers. Our MERP proposal was authorized in 2002 by the Minnesota Public Utilities Commission. The average cost to a typical residential customer is about $3.50 a month.
Environmental benefits
Our MERP projects were completed over three years, from 2007 to 2009, and reduced air emissions by the following amounts.
Emissions Results
| S02Sulfur Dioxide |
39,000 tons/yr |
93 percent reduction |
| N0xNitrogen Oxide |
34,000 tons/yr |
91 percent reduction |
| Mercury |
34,000 tons/yr |
91 percent reduction |
| Particulates |
730 tons/yr |
55 percent reduction |
| C02Carbon Dioxide |
1.8 million tons/yr |
21 percent reduction |
High Bridge Plant |
Riverside Plant |
Below is a summary of improvements made at each of the three affected generating plants:
Allen S. King Plant Rehabilitation Project (Oak Park Heights, Minn.)
Project involved rehabilitating the existing coal-powered unit with a new turbine, upgraded steam generator and state-of-the art emissions control equipment.
Completed: July 2007
Upgraded capacity: 500-550 megawatts
High Bridge Plant Combined Cycle Project (St. Paul, Minn.)
Project involved replacing existing coal operations with a new natural gas combined-cycle facility that includes two combustion turbines, corresponding heat-recovery steam generators and a new steam turbine.
Completed: May 2008
Upgraded capacity: 575 megawatts
Riverside Plant Re-powering Project (Minneapolis, Minn.)
Project involved replacing two existing coal-powered units with a natural gas combined cycle arrangement, including two combustion turbines and corresponding heat-recovery steam generators used to drive an existing steam turbine.
Completed: May 2009
Upgraded capacity: 460 megawatts