SLAYTON — Invenergy Solar Farm’s Project Development Senior Manager Dan Litchfield,Thermal Development Manager Robert Howard and Westwood’s Environmental Services Director Eric Hansen, presented a proposal to develop an energy storage in Murray County to the county board Tuesday.

Using a PowerPoint presentation, Litchfield explained the concept of storing the electrical energy at the Big Lake Wilson solar farm site. It may also include the smaller site, he said.

Showing a slide with a bell curve, Litchfield described the choppy service that solar energy could produce if not modified with stored electricity. A cloudy day could make reception of electricity static-y, just like some satellite television service, but with stored energy, it is much smoother.

The operation of a storage unit will improve economics of a solar provider.

“It potentially defers some of the distribution or transmission,” he said. “It’s a good investment over the long run.

“Storage is becoming mainstream,” he said, “and about to become a much bigger deal. Batteries respond in milliseconds, not minutes like generators.”

Litchfield said that there should be an improvement in economics if a solar project in the community as it increases investment in the community and provides jobs and improves some grid distribution.

“Solar farms with rows running north and south can either be on a fixed tilt system or a flexible tilting one.

“These have a single axis tracker,” he said. “In the morning, they will tilt east, at noon they will tilt flat and in the evening, they will tilt west.”

A couple of factors may determine their full use of that feature would include large buried rocks, excessive mowing and such. However, the commissioners were assured that the cover selected for the site would not only reduce excessive mowing, but establish a native prairie that will be maintenance-free and provide a habitat of pollinating plants.

Commissioners wanted to know more about the project, so they asked some questions.

“Will there be a glare safety factor?” Commissioner Gerald Magnus asked.

“No,” Litchfield said.

“Will Invenergy pay for any tiling the stakes poke through?” Commissioner Glenn Kluis asked.

“We have to figure that out, yet,” Litchfield said. “What we’ve committed to do is to build uphill so drainage occurs naturally, avoid tile if possible and replace any that get punctured.”

“What’s the life expectancy?” Commissioner Lori Gunnink asked.

Litchfield said that the life expectancy was up to 50 years.

“Will there have to be an upgrade five to 10 years down the road?” Commissioner Dave Thiner asked.

Litchfield said that there may be a small percentage of loss in the panels, but they’ll still be fully functional 25 years down the road.

What about upkeep, Gunnink wanted to know.

Litchfield responded that it would take 18 months of construction in which some local workers would be involved, like graders, post insertion, things that were simple and repetitive.

However, there were not many jobs on the maintenance end of it.

“There’s a 15-foot deep standard depth for the posts,” Hansen said. “If you hit a boulder, you need to look to a different anchoring system or excavate the rock. You can’t move the field, so you have to find a solution that doesn’t disturb the soil foundation much.”

Permitting would start in 2018, and construction in mid-2019, Litchfield said.