Alliant Energy spokesman Justin Foss says his company expects a 40 percent operating capacity for the turbines they install. “New designs, new technology and better understanding of how they operate is allowing us to generate energy from them more often,” Foss says.
He says the turbines can stop iF there is not enough wind, and also have to be shut down if the wind is too strong. “It needs a wind speed of between seven and 45 miles-an-hour to operate. Our new turbines are going to go from between just below seven all the way up into 60 mile-an-hour winds to be able to generate that energy,”Foss says, “that’s just improved design and technology that allows them to capture more of that wind and turn it into energy.”
The turbines are also shut down for maintenance. “They do go through routine maintenance at least twice a year — so each turbine gets serviced at least twice a year — so they will shut that down while it’s being serviced,” Foss explains.
The capacity of the power grid is another factor that might lead to turbines being shut down. “Sometimes we just get too much wind on the grid. And it’s not because we’ve got too much wind here, but maybe there is just not enough demand on that day,” Foss says. “We see that Saturdays, Sundays and Mondays we have the lowest demand on the power grid. And if you’ve got too much energy going onto the grid that will cause problems and you have to shut some stuff off to match the demand with how much is being generated.”
He says all the changes have allowed them to increase the turbine use to 40 percent. “If you look back just a few years ago — even a decade ago — it was in the 20’s and 30’s,” Foss says.
Information from the American Wind Energy Association says Iowa generates nearly 37 percent of is electricity from wind.