Updated

The city of Des Moines, Iowa has only seen a $13 return on its investment so far after spending $16,000 last year on three electric car charging stations.

The ChargePoint units, installed in front of the Franklin Avenue Public Library and funded by a mix of city, state and library money, have been used just 13 times since last spring, the Des Moines Register reports. Each use generates one dollar of revenue.

Des Moines Public Library Director Greg Heid believes the low return isn’t an issue yet.

“I think this will be taking off as electric cars catch on and as people see this as an alternative,” he told the newspaper.

Iowa has 40 electric vehicle charging sites state-wide, and there are 6,416 across the U.S., the Department of Energy says.

Click for more from the Des Moines Register.