Aurora stoplight turbines fall short of expectations in energy production 

Typically, complaints about wind turbines revolve around their appearance, a perceived threat to birds and noise.

Not so much for two city-operated turbines erected on Aurora’s far East Side.

According to city engineers, for several months after the two 38-foot turbines were installed at McCoy Drive and Frontenac Street and at Fifth Avenue and Waterford Drive, the main complaint they heard from residents was that the turbines were not spinning often enough.

The city of Aurora installed the turbines in February 2011 to power light signals at the two intersections. But two years later, the project has fallen somewhat short of expectations.

The turbine project cost $117,400, paid for using funds from a U.S. Energy Efficiency and Conservation Block Grant, a Federal Recovery Act program.

At the time of their installation, city traffic engineers estimated the turbines would not only power the traffic signals but also generate excess energy – 10 to 20 times what the traffic signals would use – that could be added back into the grid through an agreement with ComEd.

“The turbines have not experienced the output we had hoped for,” said Aurora spokesman Dan Ferrelli. “While they are generating enough energy in general to power the traffic signal, we are not seeing a consistent excess of electricity generation.”

On average, according to city engineers, the turbines have an energy output of about 15 kWh per week. That is roughly enough energy to run a home desktop computer and monitor eight hours a day, seven days per week.

City engineers estimate the savings, including the electricity generation itself plus saved distribution costs, to be approximately $50 a month.

Initial setbacks

A couple factors have contributed to the low returns, engineers said. For one, the turbine at Fifth and Waterford has experienced regular technical issues since it was installed, but for the past six months, the turbine has been up and running smoothly, and has not required any maintenance.

The turbine at Frontenac and McCoy has been operational only about 75 to 80 percent of the time, according to engineers. Heavy winds, more than 30 mph, can put the turbine out of service, and engineers must manually reset it.

The turbines have been, in short, a learning experience.

“We learned that turbines will be accepted in neighborhood areas when they are strategically placed … and also learned some steps we could take to make them more efficient,” Ferrelli said.

In fact, at both turbines, electricity output has been steadily increasing: in late February, the turbine at McCoy and Frontenac averaged 20 kWh a week, and at Fifth and Waterford, engineers measured 30 kWh a week output.

Better, but not enough to justify a turbine on every corner, at least for a while.

When the stoplight turbines were first installed, city officials had hoped to expand their investment in wind energy by installing several more turbines at Aurora’s police station. That idea was nixed by the Aurora City Council after a cost-benefit analysis of the plan showed that it would take several years for the city to see a return on the investment.

“That does not mean there will never be turbines at the police department or other city facilities, it just means that we will keep an eye on how this technology evolves,” Ferrelli said.