Conserve electricity and use energy-efficient appliances, but also support efforts to retire aging coal plants and rethink the national energy grid.

Wind farms won't be much use if they can't connect to our coal-friendly grid.

RODALE NEWS, MADISON, WI—It's ironic that, at a time when two-year-old cellphones are considered old technology, we're still charging those phones with an energy system that was developed 100 years ago. Our national energy grid is so old that some areas are using transmission lines that go back 50 years. And the consequences affect our environment as well as our utility bills. The generation of electricity accounts for 40 percent of our nation's greenhouse-gas emissions, according to the Department of Energy, compared with 20 percent from transportation, and coal-fired power plants are one of the nation's largest emitters of mercury, which has made much of the freshwater fish in this country unsafe to eat.

THE DETAILS: Despite the fact that 30 states have set goals for getting renewable energy sources like solar and wind online, generating the power isn't the biggest challenge. The real barrier will be getting those renewables hooked up to our disproportionately coal-friendly national energy grid. "As long as coal plants keep running, there are structural things about the way the electricity system works that prevent wind power from being used," said Katie Nekola, energy program director at Clean Wisconsin, an environmental advocacy group, at last weekend's Society of Environmental Journalists conference. Each region's electricity is controlled by a regional system operator, which, Nekola said, "is basically a guy sitting in a control room with a bunch of levers and switches that decide which electric power plants are going to run at any given time." The power can come from anything from wind to coal to natural gas, and the plants are turned off and on based on demand and on how much energy they're generating.

But coal plants can't be easily turned off and on, and operators need to keep coal plants running at a certain minimum load, Nekola explained. So they tend to stay connected. And as long as a coal plant is hooked up to the grid, it takes the place of a cleaner energy source. Also, we don't always need all the power that could be generated at any given time. "In periods of low demand, which are more and more frequent now because of the recession, there's too much power on the system," Nekola explains. "So something has to get knocked off, and it's typically wind," she said.