It's been about a month since we learned the proposed Big Stone II power plant won't be built, and it's not clear what's going to replace the electricity it was supposed to generate.
In short, the options don't look good -- at least not for traditional power plants-- for some of the same reasons that killed Big Stone II: high construction costs, uncertainty about demand and federal greenhouse gas regulations.
In 2007, Minnesota imposed a ban on new coal-fired power plants. They emit huge amounts of carbon dioxide, which scientists say contributes to global warming. The Big Stone II plant was grandfathered in, but now it won't be built.
Minnesota also prohibits new nuclear plants.
State officials say they expect Minnesota will need 4,000 megawatts of new power by 2025. That's about as much as the state's three biggest power plants combined, and officials are scratching their heads to see where that could come from.
"It's an open question," said Bill Glahn, who directs the state's Office of Energy Security. He said the best option might be a technology called combined-cycle natural gas, which can be really expensive.
"We might have to struggle along with a solution that's not going to minimize cost, and might raise some concerns about how reliable our system is going into the future," he said.
But utilities are working hard to reduce the need for new power plants. They're experimenting with technologies to store wind and solar power, to make those sources more reliable, and they're learning how to make electricity anywhere.
At the corner of Snelling and University in St. Paul, there's a big building that's not only green on the outside, but getting greener all the time on the inside. Assistant building manager Jason Sklar has figured out something he calls coasting.
"The building is warmed up in the afternoon, and that occupancy goes down at 4:00 p.m.," Sklar said. "So we shut down and bring it into night mode a little bit sooner than 5:00 p.m. when most people punch out."
Reducing the heat an hour before people leave saves both energy and money.
Up on the roof, four rows of solar panels produce electricity when the sun shines and manager Mike Koch said that's when they need it the most, especially in the summer.
"As you might imagine, on those really hot July days when our air conditioning is going full-bore, and we have all of our computers on, and the sun's beating down, that is when having our solar panels doing their job to the max," Koch said. "[It] makes them really worth their while."
That's because they bring down the building's peak electricity use, and that brings down the electric bill. For Xcel Energy, bringing down peak usage helps reduce the need for new power plants.
Xcel is paying for two-thirds of the cost of the panels because the building is in what they're calling an "energy innovation corridor." As the light rail line is built along University Avenue, Xcel is rolling out a lot of energy-saving and energy-producing projects.
Greg Palmer, Xcel's director of account management, said the company's goal for the corridor is to save enough electricity to power about 7,000 homes, and to increase that by another 7,000 every year.
"Here we're doing a very concentrated marketing effort to try and get the template, for how we can do it statewide, up and running," Palmer said.
Most of the utilities involved in the Big Stone project are also looking at alternatives.
One of them, Great River Energy, is looking at logging or farm waste to power small electric generators that can heat buildings at the same time.
Bob Ambrose is director of governmental affairs at Great River Energy. He said the silver lining in the recession is it's giving utilities some breathing room before they're forced to build new plants.
"We may need additional renewable resources, and we may make purchases from the grid, but we really aren't anticipating additional baseload facilities for a number of years," Ambrose said.
In those years, researchers will be working to squeeze all the energy they can from existing technologies, and trying to develop new ones.