<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto">I would tear all the sunny boys and sunny islands out and install two 15 kW Sol-Arks, problem solved. DC coupled. I've done this several times now for existing clients (mostly connected to the grid) but it is so much cleaner and more compact and effective.<br><br><div dir="ltr"><div>Michael D Nelson</div><div>MD Electric & Solar, Inc.</div><div>707-684-0064 mobile</div><div>707-884-1862 office</div><div>www.mdelectricsolar.com</div><div>www.facebook.com/mdelectricandsolar</div><br></div><div dir="ltr"><br><blockquote type="cite">On Oct 24, 2023, at 7:31 AM, William Miller via RE-wrenches <re-wrenches@lists.re-wrenches.org> wrote:<br><br></blockquote></div><blockquote type="cite"><div dir="ltr"><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"><meta name="Generator" content="Microsoft Word 14 (filtered medium)"><style>@font-face { font-family: Calibri; }
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div.WordSection1 { page: WordSection1; }</style><div class="WordSection1"><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Friends:</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">This situation is as yet unresolved. It is complicated enough I created a <a href="https://millersolar.com/MillerSolar/case_studies/36_SIFortress/36_SunnyIslandFortressIntegration.html">web page</a> to describe the scenario so I did not have to explain it over and over. I submitted this to Fortress tech support. They said they had likely not tested the Fortress compatibility with SI in an AC-Coupled system.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">While Fortress technicians and/or engineers ponder the situation I am brainstorming solutions. One idea is to convert to a DC coupled system. DC Charge controllers will have intrinsically better voltage control. The charge controller most likely suitable is the Schneider 600 volt 100 amp unit. I would need two of them. It is compatible with the existing string wiring. In researching it many questions came up about that product’s suitability. There is an integration guide for a Schneider system and Fortress but this would be a mixed system of Schneider and SMA. Would I be able to apply closed loop communication to both systems? Could the charge controllers work in open loop? Has anyone tried anything like this?</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">I will keep you apprised.</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">William Miller</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">Miller Solar</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">17395 Oak Road, Atascadero, CA 93422</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">805-438-5600</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif""><a href="http://www.millersolar.com/">www.millersolar.com</a></span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">CA Lic. 773985</span></p><p class="MsoNormal"> </p><p class="MsoNormal"> </p></div>
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