Agenda - Planning Commission - 12/02/2010

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iffIllM8iu+,i® ri II ECG a`,d�i'fel/ �II�Un�il _� PAS [,® ? .i.►1 kN,•I�. nk..o. I Ytti1�W9 i:,. �S - IW►.1►WLi�lf.!•d@o�L'tl 1 This large (6no kW) coinmefaatsolarsystem covers almostfiveacrres of rooftop as an accessory useatTh-. , _- . apohs convention Center. stallations that are six feet or less in height may be placed in setbacks. Installations taller than six feet may be allowed within setbacks through a land -use review adjust- ment process. In San Diego safer installa- tions are permitted within rear and side yard setbacks. In Tucson, Arizona, architectural features that are part of a solar energy sys- tem may project up to four feet into required front yard setbacks. Features include over- hangs, moveable insulating walls and roofs, detached solar collectors, reflectors, and piping. Building height limits can also restrict the placement of solar equipment. Photo- voltaic shingles or roof tiles are clearly a part of the roof itself, but photovoltaic or thermal panels will protrude above the roof plane, and potentially above the zoning dis- trict's height limit. A number of cities allow solar equipment to exceed height limits to some degree. In Portland the height of solar panels is not calculated for flush -mounted installations (no more than i8 inches from the roof surface to the top of the panel) on a pitched roof, unless the panels wilt extend above the highest ridge of the roof. In Sacra- mento, California, solar energy systems may exceed building height requirements by up to 20 percent, as well as projecting four feet into yard setbacks. Cities with zoning ordinances that restrict impervious coverage or building coverage on a lot typically do not exempt freestanding solar installations from cover- age limits, although we found a few excep- tions. In San Antonio, Texas, the surface area of ground -mounted collector arrays does not count toward impervious coverage limits, but the mounting poles, footings, and other improvements on the site do. In Santa Rosa, California, pole- and ground -mounted systems are not counted toward impervious coverage. Seattle has one of the more compre- hensive approaches to the placement of solar equipment. Solar collectors are de- fined in the city's code as "any device used QQ Thiszdo kW solar installation is the primary land use on a five -acre parcel of former cropland adjacent to St. Johns College in Minnesota. to collect direct sunlight for use in the heat- ing or cooling of a structure, domestic hot water, or swimming pool, or the generation of electricity." Collectors are permitted by right as accessory uses, and may be placed within side and rear yards with setbacks that vary by district. Solar collectors within yards are not counted toward lot coverage if all setback and height requirements are met. Seattle's code also provides flexible height limits for roof -mounted solar sys- tems. These vary by district; in low -density residential districts solar collectors may exceed the district height limit by four feet, provided that the total height from existing grade to the top of the collector does not exceed the height limit by more than nine feet. In multifamily and nonresidential dis- tricts height allowances are greater; in most nonresidential districts solar collectors may extend up to 15 feet above the maximum height limit, so long as the combined total coverage of the rooftop features do not ex- ceed 25 percent of the roof area when typi- cal features (such as elevator penthouses) are present. Large systems as primary land uses White domestic -scale sotar installations are becoming more widespread, larger utility - scale installations (excluding rooftop instal- lations that are accessory to the primary use) are still rare within the boundaries of most of the Solar Cities. Few cities recognize or distinguish solar power production from any other type of power generation. One can argue that a solar array is a less intensive use than a typical coal- or gas -fired power plant, and could be appropriate in, say, an agricultural district or a business park. How- ever, if large freestanding solar installations are treated only as industrial uses, their placement will largely be limited to indus- trial districts. In most zoning codes, power genera- tion is a use typically allowed only in indus- trial districts. For example, in Salt Lake City, electric generating facilities are permitted within manufacturing districts within 2,64o feet of an existing 138 kV or larger electric power transmission line. Solar farms would similarly be limited to those areas unless defined as a distinct land use from other power production. Such a case recently oc- curred in Tucson, where proposed solar farm installations on closed landfills were denied a zoning permit because the sites were not zoned industrial. ZONINGPRACTICE aa.ao AMERICAN PLANNING ASSOCIATION (pages 71