Full Text
Planning Board Meeting Summary Amendments to Title 20, Section 20.45.080 “Wind Energy Conversion Systems” Planning Board Recommendation: On Tuesday, July 20, 2010 with eight members present, the Missoula Consolidated Planning Board voted unanimously to recommend approval of proposed text amendments to the Title 20 Missoula City Zoning Ordinance, Section 20.45.080 “Wind Energy Conversion Systems,” as illustrated to the board in a Planning Board review draft attached to the staff report. Planning Board Discussion: Planning Board reviewed language enabling the installation of wind energy conversion systems (WECS) in April 2009 during the overall Title 20 review. That language was not recommended for inclusion in the final ordinance. Many of the concerns expressed during the April 2009 contemplation of similar WECS regulatory language were again discussed at the July 20, 2010 meeting. Staff’s presentation at the July 20th meeting focused largely upon illustrating the two technologies comprising the WECS market at this time: horizontal axis turbines and vertical axis turbines. Board members responded to the information by considering distinct regulatory pieces for the two turbine types, but later recognized that the review draft included adequate provisions for both horizontally and vertically-oriented units. Significant Board discussion touched on the perceived and actual safety considerations associated with WECS. Specifically, members discussed minimum system height requirements for public safety in the context of allowing maximum flexibility for WECS installations. The Planning Board review draft regulations required all moving parts associated with a WECS to be a minimum of 20 feet above the ground beneath the equipment. This figure, however, precludes the installation of certain vertical axis units able to more effectively utilize turbulent, ground-level winds. These units, unlike typical horizontal axis units, rotate at lower speeds and present less of a safety hazard generally. Board members therefore unanimously voted to revise the regulations to permit vertical axis installations with moving parts no less than 10 feet from the ground, while keeping the 20 foot minimum for horizontal units. Additionally, the Planning Board considered the viability of a provision in the review draft requiring that WECS not generate vibrations perceptible to an individual standing at the edge of a property containing a system. Board members opined that, in the absence a defined numeric maximum, enforcement of this provision would likely be difficult. The board therefore voted unanimously to direct staff to research a revision specifying a measurable, enforceable vibration standard. Alternative Energy Technologies at the University of Montana provided information concerning this directive, and recommended that the provision be removed in light of the characteristics of vibrational energy related to WECS systems. Mr. Brian Kerns of Alternative Energy Technologies noted that any energy capable of causing vibration would dissipate within several feet of the WECS and would not be perceptible at a property line. In response to Planning Board’s directive and Mr. Kerns’s response, the provision was removed in the City ordinance going forward. See pages 21 through 44 of the July 20, 2010 Planning Board Meeting Minutes (included as Attachment for further Planning Board discussion.