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single Solaron 500 inverter is about 68 dB at 1 meter (= 3.28 feet). Importantly, no noise data <br /> were submitted for the site's step-up transformer(s). <br /> 2. Why the Inverter Noise Data in the Application is Incorrect. <br /> A. In contradiction to the aerial diagram showing nine inverter units scattered broadly across the <br /> site, the Site Plan depicts three 1500 kW triple inverter "stations", each presumably consisting of <br /> three 500 kW inverter units (and, also presumably, at least one step-up transformer). No noise <br /> data were provided by the applicants for this type of triple inverter station configuration, and no <br /> information was provided regarding noise from the step-up transformers that are associated with <br /> them. <br /> In the absence of information from Binks regarding the exact inverter/transformer configuration, <br /> I made the assumption that each station comprises three Solaron 500 inverters (ignoring any <br /> potential contribution of transformer noise) and estimated the combined noise produced by each <br /> inverter station. The triple inverter station noise level can be estimated by summing the noise <br /> from each inverter using the calculation shown in Appendix I. This calculation shows that almost <br /> ten times as much sound pressure and twice as much perceived noise (77.54 dB vs. 68 dB at 1 <br /> meter) will be produced by a triple inverter station compared to a single inverter unit. 77.54 dB <br /> may well be an underestimate of the total noise produced, since the applicants provided no data <br /> on step-up transformer type, location or noise, which should be added to the inverter noise <br /> figure. <br /> B. The distance from the nearest triple inverter station to an adjacent property is much shorter <br /> on the applicant's Site Plan versus what is depicted on their aerial diagram. The triple inverter <br /> station closest to Cascade Drive on the Site Plan is approximately 104 feet from the <br /> Petranka/Gewalt Property (#15 BI A Sec 1 Falls of New Hope Estates). This is in contrast to the <br /> distances shown the aerial diagram, where the shortest distance from a single inverter to the <br /> Cantwell/Wegman Property is ca. 201 feet. Since sound intensity increases exponentially with <br /> decreasing distance to the source, these inaccuracies in distances in the Application are very <br /> important. <br /> 3. What is the Combined Effect of Noisier Inverter Stations Being Sited Closer to <br /> Adjacent Properties than is Depicted in the Binks Application? The closest triple inverter <br /> station shown on the Site Plan is located across from the intersection of Falls Drive and <br /> Cascade Drive. The distance from that inverter station to the closest property line <br /> (Petranka/Gewalt) along Cascade Drive was estimated using the scale on the Site Plan. That <br /> distance is approximately 104 feet. The following Table summarizes the noise levels expected <br /> at the Petranka/Gewalt property line based on the revised noise calculations and triple inverter <br /> distances contained in this document. <br /> Distance (Feet) Distance (meters) Sound Level (dB) <br /> 3.28 1 77.54 <br /> 6.56 2 71.54 <br /> 13.12 4 65.54 <br /> 26.25 8 59.54 <br /> 52.49 16 53.54 <br /> 104.99 32 47.54 <br /> 209.97 64 41.54 <br /> 419.95 128 35.54 <br /> 839.90 256 29.54 <br />