DALLAS CENTER, Iowa (AP) — Kent Holst stood in front of the Iowa Stored Energy Park’s municipal utility members and proclaimed, “This time, we have something to show you.”
Holst, the park’s development director, showed the officials a drill rig behind a house on the south side of Iowa Highway 44, two miles west of Dallas Center.
The rig is drilling a 2,800-foot well, which will be used to test the hardness of a sandstone formation. The energy park hopes the formation can hold energy that has been converted into air.
When the municipal utilities that own stored energy need electricity at peak periods, the air will be released to the surface to power turbines in two 134-megawatt generators, making electricity.
The drilling project is the first tangible sign of activity for the long-discussed energy park, though the project is three years away from becoming a part of Iowa’s electricity grid.
The energy park would be one answer to a problem that has long confounded the utility industry: the inability to store electricity.
Holst and other company officials say that Iowa’s bountiful wind energy can be best used if some type of electricity storage is available. For all its popularity and greenness, wind energy can be the least reliable form of electricity generation.
“The wind just doesn’t always blow at the right times when the electricity is needed,” said Thomas Wind of Jefferson, who is a consultant to Iowa Stored Energy Park.
The Iowa Power Fund has put $3.2 million into the project west of Dallas Center in hopes of putting the state ahead of what may be the next big thing in electricity. One other stored energy park, in Alabama, exists nationwide.
Another contribution from the U.S. Department of Energy put the public involvement in the project to about $4.7 million.
“Having storage for energy is one of the critical pieces of Iowa’s energy future,” said Roya Stanley, director of the Iowa Office of Energy Independence who spoke at the annual meeting last week.
About 150 Iowa municipal utilities who are members in the project will provide the rest of the financing, probably through bond sales.
Before that can happen, Iowa Stored Energy Park needs to get geological verification that the sandstone dome in Dallas County can hold air at compressed rates of up to 1,400 pounds per square inch and won’t crack the underground rock formations.
Holst and Iowa Stored Energy Park officials are confident that tests will be favorable, because MidAmerican Energy stores natural gas in similar underground caverns nearby at Redfield.
Iowa Stored Energy Park plans to drill a second test well later this year within about a quarter-mile of the first well site, Holst said.
Eventually, the project will encompass eight to 10 wells and the 260-megawatt generator.
Driller Klint Gingerich of Kalona said the 2,800-foot deep well dug for the company is about 10 times deeper than the average water well in Iowa. Gingerich’s firm drills mostly water and industrial wells in Iowa and neighboring states.
“The deepest well dug in Iowa was a test oil well near Red Oak a few years ago, and that was 3,600 feet deep,” Gingerich said. That well did not produce oil.
As the drill bit goes down, core samples of rock are pulled for analysis. At completion, the well will be encased in concrete.
“The cementing is probably the most nerve-wracking part of the job,” said Gingerich, whose grandfather, Paul, founded the drilling company in 1955. “Otherwise, it’s been a perfect project.”
Iowa Stored Energy Park is pegged as a backup source of electricity for Iowa’s municipal utilities. The big investor-owned utilities, MidAmerican Energy of Des Moines and Alliant Energy, can either generate or buy enough electricity to take care of Iowa customers.
But the surplus of wind energy, expected to amount to up to 15 percent of Iowa’s generating capacity within a half-decade, is a source of spare electricity for municipal utilities.
As for compressed-air storage of the type planned for Dallas County, Gene Berry of Lawrence Livermore Laboratory said in a report last year, “The scale and location-specific nature of energy storage in natural formations is likely to render it of limited benefit” to renewables like wind.