Agenda - 05-27-2014 - C1 - Laserfiche WebLink

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24 Ambient Temperature ( "Heat Island ") Question -Does the presence of ground- mounted solar PV arrays cause higher ambient temperatures in the surrounding neighborhood (i e , the "heat island" effect)? Bottom Line All available evidence indicates that there is no solar "heat island" effect caused by the functioning of solar arrays. Cutting shade trees for solar PV might increase the need for cooling if those trees were shading buildings This is primarily a concern in town centers and residential areas (locations where large ground- mounted PV is not encouraged) and is a potential impact of any development activity that requires tree - cutting More Information- All available evidence indicates that there is no solar "heat island" effect caused by the functioning of solar arrays. Solar panels absorb photons from direct sunlight and convert it to electricity This minimizes the likelihood of substantially changing temperatures at the site or the surrounding neighborhood For an area with no PV system, solar energy impacting the ground is either reflected or absorbed. There is no research to support heat production from the solar panels themselves Sunpower, a private solar manufacturer, conducted a study on the impact of solar PV on the local temperature and concluded that a solar PV array can absorb a higher percentage of ambient heat than could a forested parcel of land without an array. The study points out that while solar PV modules can reach operating temperatures up to 120 degrees Fahrenheit, they are thin and lightweight and therefore do not store a large amount of heat. Because of this, and the fact that panels are also shown to cool to ambient air temperature shortly after the sun sets, the Sunpower study concludes that the area surrounding a large -scale solar array is unlikely to experience a net heating change from the panels If trees are removed that were previously shading a building, that building could get warmer in full sunshine than when the trees were shading it The June 1, 2011 tornado that ripped through Western Massachusetts created an opportunity to empirically measure the affects of the loss of neighborhood trees on temperatures and air humidity in the streets A report by the U S Department of Agriculture Forest Service concluded that in the tornado - impacted neighborhood in Springfield, Massachusetts, daily mean morning and afternoon temperatures were typically greater than in the unaffected neighborhood and forest sites, but were similar at night Residents noted increased use of air - conditioning units and an overall increase in energy costs in July and August of 2011. Resources• SUNPOWER, Impact of PV Systems on Local Temperature, July 2010 USDA Forest Services report- http://www.regreenspringfield.com/wp- content /uploads/ 2011 /11 /tornado %20climate %20report %203 pdf