CASPER - A budding wind energy industry in Wyoming added approximately 289 turbines and more than 465 megawatts of electrical generation capacity in the state during the past year.

Another 162 turbines are under construction, and wind developers have ambitions for adding at least another 3,000 turbines over the next 10 years, according to an informal survey by the Casper Star-Tribune.

Although wind developers expect turbines and mechanical upgrades to easily exceed 20-year contractual warranties and power purchase agreements, there's no set standard for setting aside funds to decommission wind turbines and related facilities.

"That's probably one of the largest areas of concern I hear as a policymaker," said Sen. Jim Anderson, R-Glenrock.

Anderson made the comment at a community meeting with Duke Energy officials Tuesday evening, where several members of the public shared his concern.

Anderson lives near Glenrock, where Duke Energy is constructing the 66-turbine Campbell Hill wind farm and proposes to build another wind farm. The Top of The World wind farm would be the fifth in Converse County.

Anderson also serves on a legislative task force that will research and make recommendations on several unresolved issues regarding wind energy, including decommissioning.

When regulated utilities such as Tri-State and Rocky Mountain Power Cooperative build wind facilities, they are required to include the cost of decommissioning in their rates. But there's no set standard that applies to nonregulated merchant wind developers such as Duke Energy as it applies to private, state and federal lands.

Converse County Commissioner Ed Werner is among several county officials who will share information with the legislative wind task force. Werner said the current strategy for ensuring that facilities built by merchant wind developers are decommissioned is to write a provision in individual contracts with the landowner.

While legally binding, a contractual provision just doesn't provide the same assurance as a posted bond or cleanup fund, Werner said. He said one idea is to require that a minimum bond requirement be met 15 years after the in-service date.

Werner said that merchant wind developers have big upfront costs but very little overhead to continue operations.

A 15-year deadline to meet a bonding requirement should give developers plenty of time to meet their upfront costs and plan for the bonding amount, Werner said. And because wind developers are typically obligated to meet a 20-year power supply agreement, they have an incentive to keep wind facilities operating smoothly for at least 20 years.

In fact, a Duke Energy official said during Tuesday's public meeting that the company expects its wind turbines and ongoing technical upgrades should ensure production well beyond an initial contract of 20 years.