When it comes to big-dig construction projects, public attention over the last few years has focused on the publicly subsidized Vikings football stadium that will cost $975 million.

Meanwhile, a bigger, more critical, but less publicly electrifying project will complete about $1 billion worth of work this year alone. It's the $2.2 billion overhaul of the state's electrical transmission system and replacement of 1970s-vintage technology that dates to before the Metrodome was built.

Electrical transmission gets little respect.

"Rodney Dangerfield is the patron saint of transmission systems," quipped Will Kaul, vice president of transmission at Great River Energy and chairman of the CapX2020 group of 11 Minnesota utilities involved in the 800-mile project.

The nine-year process has been marked by landowner disputes and several lawsuits. Regardless, the huge upgrade, to be completed by 2015, will mean a more reliable, efficient, cleaner way to power Minnesota.

Moreover, it will widen the electric highway to finally accommodate all the wind energy that has come on line in recent years and the ability to dispatch power as needed within the 11-state Midwest Independent Transmission System Operator (MISO). This network functions as a wholesale market for buyers and sellers of excess generation in the Midwest.

"There area a number of wind farms waiting for transmission lines in southwestern Minnesota and surrounding states," said Beth Soholt, executive director of Wind on the Wires Minnesota, an industry trade group. "Transmission facilitates keeping the lights on … and cost-effective energy because it allows energy to flow back and forth in a more robust wholesale market. It creates more energy choices and lets Minnesota and the other states meet their multiyear renewable energy standards."

In short, Minnesota, North Dakota and Iowa — among the biggest national wind generators — have been unable to sell all the wind power they generate because there is inadequate transmission capacity to wind fields such as those along the Buffalo Ridge in southwestern Minnesota.

"When this is done, you'll have a lot more wind-generated transmission from South Dakota and North Dakota all the way to La Crosse, Wisconsin," said Mike Gregerson, a veteran engineer who is a consultant to CapX2020. "No more notifications from MISO that the grid is too full and they can't use your energy.''

Gregerson said the project should lower the average cost of energy because MISO will be able to move around the cheapest energy better. "And in most cases, that's wind because there's no fuel costs," he said.

Wind constitutes about 12 percent of the 100,000 megawatts of power typically generated in the 11-state MISO territory, including Manitoba, said John Lawhorn, a MISO official. Minnesota produces about 15 percent of its energy from wind. In fact, one day last November, MISO reported that wind generated a record 25 percent of output in its territory.

Minnesota, Iowa, Illinois and Ohio have legislative mandates to generate 25 percent of their juice from alternative energy, including wind, dams, garbage burners and solar, by 2025. And adjacent states generally are shooting for up to 15 percent.

Including the Minnesota overhaul, MISO predicts that its member utilities will spend more than $5.5 billion upgrading transmission infrastructure by 2015.

The final leg of the Minnesota projects — a 345-kilovolt, high-voltage power line through southeastern Minnesota, which starts just inside the eastern South Dakota border, was approved last spring by the Minnesota Public Utilities Commission. The five-segment project includes a span that is partly completed between St. Cloud and Fargo, N.D.

A 2010 University of Minnesota Duluth economic impact study projected up to 8,000 construction jobs annually and that each dollar spent on CapX2020 would stimulate another $1.93 of spending.

"Last year, we supplied 8,700 tons of rebar and CapX2020 was worth about $8 million to Ambassador Steel, and it goes for another couple years," said Kent Swanson, a salesman with Ambassador Steel of Minneapolis, which makes rebar for pole foundations from recycled scrap. "We have about 40 people on the project at various times during the year."

Mark Jenkins, a geotechnical engineer and project manager for Braun Intertec of Bloomington, called CapX2020 the single-largest infrastructure project in Minnesota. Braun, which does soil-test borings and tests construction materials such as concrete and steel for structural engineers, will employ an average of 30 people on the project through 2013.