<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:p="urn:schemas-microsoft-com:office:powerpoint" xmlns:a="urn:schemas-microsoft-com:office:access" xmlns:dt="uuid:C2F41010-65B3-11d1-A29F-00AA00C14882" xmlns:s="uuid:BDC6E3F0-6DA3-11d1-A2A3-00AA00C14882" xmlns:rs="urn:schemas-microsoft-com:rowset" xmlns:z="#RowsetSchema" xmlns:b="urn:schemas-microsoft-com:office:publisher" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns:c="urn:schemas-microsoft-com:office:component:spreadsheet" xmlns:odc="urn:schemas-microsoft-com:office:odc" xmlns:oa="urn:schemas-microsoft-com:office:activation" xmlns:html="http://www.w3.org/TR/REC-html40" xmlns:q="http://schemas.xmlsoap.org/soap/envelope/" xmlns:rtc="http://microsoft.com/officenet/conferencing" xmlns:D="DAV:" xmlns:Repl="http://schemas.microsoft.com/repl/" xmlns:mt="http://schemas.microsoft.com/sharepoint/soap/meetings/" xmlns:x2="http://schemas.microsoft.com/office/excel/2003/xml" xmlns:ppda="http://www.passport.com/NameSpace.xsd" xmlns:ois="http://schemas.microsoft.com/sharepoint/soap/ois/" xmlns:dir="http://schemas.microsoft.com/sharepoint/soap/directory/" xmlns:ds="http://www.w3.org/2000/09/xmldsig#" xmlns:dsp="http://schemas.microsoft.com/sharepoint/dsp" xmlns:udc="http://schemas.microsoft.com/data/udc" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:sub="http://schemas.microsoft.com/sharepoint/soap/2002/1/alerts/" xmlns:ec="http://www.w3.org/2001/04/xmlenc#" xmlns:sp="http://schemas.microsoft.com/sharepoint/" xmlns:sps="http://schemas.microsoft.com/sharepoint/soap/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:udcs="http://schemas.microsoft.com/data/udc/soap" xmlns:udcxf="http://schemas.microsoft.com/data/udc/xmlfile" xmlns:udcp2p="http://schemas.microsoft.com/data/udc/parttopart" xmlns:wf="http://schemas.microsoft.com/sharepoint/soap/workflow/" xmlns:dsss="http://schemas.microsoft.com/office/2006/digsig-setup" xmlns:dssi="http://schemas.microsoft.com/office/2006/digsig" xmlns:mdssi="http://schemas.openxmlformats.org/package/2006/digital-signature" xmlns:mver="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns:mrels="http://schemas.openxmlformats.org/package/2006/relationships" xmlns:spwp="http://microsoft.com/sharepoint/webpartpages" xmlns:ex12t="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:ex12m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:pptsl="http://schemas.microsoft.com/sharepoint/soap/SlideLibrary/" xmlns:spsl="http://microsoft.com/webservices/SharePointPortalServer/PublishedLinksService" xmlns:Z="urn:schemas-microsoft-com:" xmlns:st="" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv=Content-Type content="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 12 (filtered medium)">
<!--[if !mso]>
<style>
v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style>
<![endif]-->
<title>Efficiency Curves of Fronius Inverters?</title>
<style>
<!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
@font-face
{font-family:"Arial Narrow";
panose-1:2 11 6 6 2 2 2 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";
color:windowtext;}
h1
{mso-style-priority:9;
mso-style-link:"Heading 1 Char";
margin-top:12.0pt;
margin-right:0in;
margin-bottom:3.0pt;
margin-left:0in;
text-align:justify;
page-break-after:avoid;
font-size:16.0pt;
font-family:"Arial","sans-serif";
color:navy;
font-weight:bold;}
h3
{mso-style-priority:9;
mso-style-link:"Heading 3 Char";
margin-top:6.0pt;
margin-right:0in;
margin-bottom:0in;
margin-left:0in;
margin-bottom:.0001pt;
page-break-after:avoid;
font-size:12.0pt;
font-family:"Arial","sans-serif";
color:windowtext;
letter-spacing:-.5pt;
font-weight:normal;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p
{mso-style-priority:99;
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:10.0pt;
font-family:"Arial","sans-serif";
color:navy;}
pre
{mso-style-priority:99;
mso-style-link:"HTML Preformatted Char";
margin:0in;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";
color:windowtext;}
span.Heading1Char
{mso-style-name:"Heading 1 Char";
mso-style-priority:9;
mso-style-link:"Heading 1";
font-family:"Cambria","serif";
color:#365F91;
font-weight:bold;}
span.Heading3Char
{mso-style-name:"Heading 3 Char";
mso-style-priority:9;
mso-style-link:"Heading 3";
font-family:"Cambria","serif";
color:#4F81BD;
font-weight:bold;}
span.HTMLPreformattedChar
{mso-style-name:"HTML Preformatted Char";
mso-style-priority:99;
mso-style-link:"HTML Preformatted";
font-family:Consolas;}
p.alist, li.alist, div.alist
{mso-style-name:alist;
margin-top:0in;
margin-right:0in;
margin-bottom:0in;
margin-left:.5in;
margin-bottom:.0001pt;
text-indent:-.15in;
font-size:12.0pt;
font-family:"Times New Roman","serif";
color:windowtext;}
p.ahead3, li.ahead3, div.ahead3
{mso-style-name:ahead3;
margin-top:6.0pt;
margin-right:0in;
margin-bottom:0in;
margin-left:0in;
margin-bottom:.0001pt;
page-break-after:avoid;
font-size:12.0pt;
font-family:"Arial","sans-serif";
color:windowtext;
letter-spacing:-.5pt;}
p.styleaparajustifiedafter0pt, li.styleaparajustifiedafter0pt, div.styleaparajustifiedafter0pt
{mso-style-name:styleaparajustifiedafter0pt;
margin:0in;
margin-bottom:.0001pt;
text-align:justify;
font-size:12.0pt;
font-family:"Arial Narrow","sans-serif";
color:windowtext;}
p.alistnead, li.alistnead, div.alistnead
{mso-style-name:alistnead;
margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Arial","sans-serif";
color:windowtext;}
p.anumlist, li.anumlist, div.anumlist
{mso-style-name:anumlist;
margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";
color:windowtext;}
p.ahead1, li.ahead1, div.ahead1
{mso-style-name:ahead1;
margin-top:0in;
margin-right:0in;
margin-bottom:6.0pt;
margin-left:0in;
text-align:center;
page-break-after:avoid;
font-size:16.0pt;
font-family:"Arial","sans-serif";
color:navy;
font-weight:bold;}
p.styleheading3left0firstline0, li.styleheading3left0firstline0, div.styleheading3left0firstline0
{mso-style-name:styleheading3left0firstline0;
margin-top:6.0pt;
margin-right:0in;
margin-bottom:0in;
margin-left:0in;
margin-bottom:.0001pt;
page-break-after:avoid;
font-size:12.0pt;
font-family:"Arial","sans-serif";
color:windowtext;
letter-spacing:-.5pt;}
p.a-text, li.a-text, div.a-text
{mso-style-name:a-text;
margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";
color:windowtext;}
p.apara, li.apara, div.apara
{mso-style-name:apara;
margin:0in;
margin-bottom:.0001pt;
text-indent:.35in;
font-size:12.0pt;
font-family:"Times New Roman","serif";
color:windowtext;}
p.styleheading1centered, li.styleheading1centered, div.styleheading1centered
{mso-style-name:styleheading1centered;
margin-top:0in;
margin-right:0in;
margin-bottom:6.0pt;
margin-left:.5in;
text-align:center;
page-break-after:avoid;
font-size:16.0pt;
font-family:"Arial","sans-serif";
color:navy;
font-weight:bold;}
p.styleapara1timesnewromanfirstline025, li.styleapara1timesnewromanfirstline025, div.styleapara1timesnewromanfirstline025
{mso-style-name:styleapara1timesnewromanfirstline025;
margin:0in;
margin-bottom:.0001pt;
text-align:justify;
text-indent:.25in;
font-size:12.0pt;
font-family:"Times New Roman","serif";
color:windowtext;
letter-spacing:-.25pt;}
p.ppahead, li.ppahead, div.ppahead
{mso-style-name:ppahead;
margin:0in;
margin-bottom:.0001pt;
font-size:16.0pt;
font-family:"Arial","sans-serif";
color:windowtext;}
p.aparabullet, li.aparabullet, div.aparabullet
{mso-style-name:aparabullet;
margin-top:0in;
margin-right:0in;
margin-bottom:0in;
margin-left:.5in;
margin-bottom:.0001pt;
text-align:justify;
text-indent:-.25in;
font-size:12.0pt;
font-family:"Times New Roman","serif";
color:windowtext;
letter-spacing:-.25pt;}
p.aabulllist1, li.aabulllist1, div.aabulllist1
{mso-style-name:aabulllist1;
margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";
color:windowtext;}
p.aabulllist2, li.aabulllist2, div.aabulllist2
{mso-style-name:aabulllist2;
margin-top:0in;
margin-right:0in;
margin-bottom:0in;
margin-left:1.0in;
margin-bottom:.0001pt;
text-indent:-.25in;
font-size:12.0pt;
font-family:"Times New Roman","serif";
color:windowtext;}
p.equation, li.equation, div.equation
{mso-style-name:equation;
margin-top:0in;
margin-right:0in;
margin-bottom:6.0pt;
margin-left:0in;
text-align:center;
font-size:12.0pt;
font-family:"Times New Roman","serif";
color:windowtext;}
p.wrightpara, li.wrightpara, div.wrightpara
{mso-style-name:wrightpara;
margin-top:0in;
margin-right:0in;
margin-bottom:0in;
margin-left:.25in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";
color:windowtext;}
p.abull, li.abull, div.abull
{mso-style-name:abull;
margin-top:0in;
margin-right:0in;
margin-bottom:0in;
margin-left:.5in;
margin-bottom:.0001pt;
text-indent:-.25in;
font-size:12.0pt;
font-family:"Times New Roman","serif";
color:black;}
span.htmlpreformattedchar0
{mso-style-name:htmlpreformattedchar;
mso-style-priority:99;
font-family:Consolas;}
span.emailstyle37
{mso-style-name:emailstyle37;
font-family:"Calibri","sans-serif";
color:#1F497D;}
span.emailstyle38
{mso-style-name:emailstyle38;
font-family:"Arial","sans-serif";
color:navy;}
span.EmailStyle43
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.Section1
{page:Section1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1027" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=EN-US link=blue vlink=purple>
<div class=Section1>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Peter,<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>All of the events I saw were similar to each other and different
from your experience. What I saw was the inverter operating 40Volts above Max
Power Point (MPP) (it was at 330V when it should have been at 290V). This
caused the inverter to operate at 90% of what a properly operating inverter
would produce. After cycling the inverter off and back on, most went to the
proper MPP, but some went back to the wrong voltage. The consistency is uncanny
and not encouraging. It looks like they have a software problem. It’s
likely other inverter companies have similar problems, but to catch a problem
after so little investigation is depressing.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>We really need a solid MPP tracking test to catch these issues
before they go out broadly into the field. Everybody likes to talk about
inverter efficiency. What is the efficiency of a 95% efficient inverter
producing 90% of available power. Effectively it is 0.95 x 0.90 = 0.855. Nobody
would ever buy an inverter with an 85.5% efficiency, but apparently it happens
regularly.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Bill.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <b>On Behalf Of </b>Peter
Parrish<br>
<b>Sent:</b> Thursday, July 09, 2009 8:19 AM<br>
<b>To:</b> 'RE-wrenches'<br>
<b>Subject:</b> Re: [RE-wrenches] Efficiency Curves of Fronius Inverters?<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'>I have a decidedly skeptical opinion of the Fronius MPP algorithm.
A few years ago, I was one of the first (I believe) to notice a curious
“continuous saw tooth ramping” of the DC current and voltage on a
couple of Fronius IG4000’s. The problem (I was told by Fronius) was
triggered by an increasing Vdc crossing 240 V (the “line voltage”).
The problem was fixed by a SW upgrade. Ignoring the fact that 240 Vac is not a
fixed value, the standard Fronius IG inverter line may have a generic challenge
when Vmp is in the 240 V range. Was this the case?</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'> </span><o:p></o:p></p>
<div>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'>- Peter</span><o:p></o:p></p>
<p> <o:p></o:p></p>
<p class=MsoNormal><!--[if gte vml 1]><v:shapetype id="_x0000_t75" coordsize="21600,21600"
o:spt="75" o:preferrelative="t" path="m@4@5l@4@11@9@11@9@5xe" filled="f"
stroked="f">
<v:stroke joinstyle="miter" />
<v:formulas>
<v:f eqn="if lineDrawn pixelLineWidth 0" />
<v:f eqn="sum @0 1 0" />
<v:f eqn="sum 0 0 @1" />
<v:f eqn="prod @2 1 2" />
<v:f eqn="prod @3 21600 pixelWidth" />
<v:f eqn="prod @3 21600 pixelHeight" />
<v:f eqn="sum @0 0 1" />
<v:f eqn="prod @6 1 2" />
<v:f eqn="prod @7 21600 pixelWidth" />
<v:f eqn="sum @8 21600 0" />
<v:f eqn="prod @7 21600 pixelHeight" />
<v:f eqn="sum @10 21600 0" />
</v:formulas>
<v:path o:extrusionok="f" gradientshapeok="t" o:connecttype="rect" />
<o:lock v:ext="edit" aspectratio="t" />
</v:shapetype><v:shape id="_x0000_s1026" type="#_x0000_t75" alt="" style='position:absolute;
margin-left:0;margin-top:0;width:50.25pt;height:60pt;z-index:251658240;
mso-wrap-distance-left:9pt;mso-wrap-distance-top:0;mso-wrap-distance-right:9pt;
mso-wrap-distance-bottom:0;mso-position-horizontal:left;
mso-position-horizontal-relative:text;mso-position-vertical-relative:line'
o:allowoverlap="f">
<v:imagedata src="cid:image001.gif@01CA00BF.1E9DC4D0" o:title="image003.gif@01CA006D" />
<w:wrap type="square"/>
</v:shape><![endif]--><![if !vml]><img width=67 height=80
src="cid:image001.gif@01CA00BF.1E9DC4D0" align=left hspace=12 v:shapes="_x0000_s1026"><![endif]><span
style='font-size:9.0pt;color:navy'>Peter T. Parrish, Ph.D., President<br>
California Solar Engineering, Inc.<br>
820 Cynthia Ave., Los Angeles, CA 90065<br>
CA Lic. 854779, NABCEP Cert. 031806-26<br>
<a href="mailto:peter.parrish@calsolareng.com">peter.parrish@calsolareng.com</a>
<br>
Ph 323-258-8883, Mobile 323-839-6108, Fax
323-258-8885
</span><o:p></o:p></p>
<p> <o:p></o:p></p>
</div>
<div>
<div class=MsoNormal align=center style='text-align:center'>
<hr size=2 width="100%" align=center>
</div>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <b>On Behalf Of </b>Bill
Brooks<br>
<b>Sent:</b> Wednesday, July 08, 2009 4:20 PM<br>
<b>To:</b> 'RE-wrenches'<br>
<b>Subject:</b> Re: [RE-wrenches] Efficiency Curves of Fronius Inverters?</span><o:p></o:p></p>
</div>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Mark and Jeff,</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>To be clear, manufacturers do not supply the data. It is
required to be tested by a Nationally Recognized Testing Laboratory (NRTL).
Mark’s message could be misconstrued as the data being something Fronius
cooked up.</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>On another note. Anyone notice Fronius inverters having trouble
finding max power? Of the 10 Fronius inverters I have looked at in the past 2 weeks,
4 were operating at a voltage well above max power and losing about 10% of the
available array power.</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Bill.</span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><o:p></o:p></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <b>On Behalf Of </b>Mark
Frye<br>
<b>Sent:</b> Wednesday, July 08, 2009 3:43 PM<br>
<b>To:</b> 'RE-wrenches'<br>
<b>Subject:</b> Re: [RE-wrenches] Efficiency Curves of Fronius Inverters?</span><o:p></o:p></p>
</div>
</div>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Jeff,</span><o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Here is what they submitted to the California Energy Commision:</span><o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><a
href="http://www.gosolarcalifornia.ca.gov/equipment/inverter_tests/summaries/Fronius%20IG%204000.pdf">http://www.gosolarcalifornia.ca.gov/equipment/inverter_tests/summaries/Fronius%20IG%204000.pdf</a><o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Mark
Frye</span> <br>
<span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Berkeley Solar
Electric Systems</span> <br>
<span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>303 Redbud Way</span>
<br>
<span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Nevada
City, CA 95959</span> <br>
<span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>(530) 401-8024</span>
<br>
<a href="http://www.berkeleysolar.com/"><span style='font-size:10.0pt;
font-family:"Arial","sans-serif"'>www.berkeleysolar.com</span></a><span
style='font-size:10.0pt;font-family:"Arial","sans-serif"'> </span> <o:p></o:p></p>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<p class=MsoNormal> <o:p></o:p></p>
<div class=MsoNormal align=center style='text-align:center'>
<hr size=2 width="100%" align=center>
</div>
<p class=MsoNormal style='margin-bottom:12.0pt'><b><span style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'> re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <b>On Behalf Of </b>Jeff
Clearwater, Village Power Design<br>
<b>Sent:</b> Wednesday, July 08, 2009 3:35 PM<br>
<b>To:</b> RE-wrenches<br>
<b>Subject:</b> [RE-wrenches] Efficiency Curves of Fronius Inverters?</span><o:p></o:p></p>
<div>
<p class=MsoNormal>Hey Folks,<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal>Anyone have or know where I can get my hands on the
efficiency vs. wattage curve for the Fronius IG series (the old series - not
the Plus).<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal>I have a 4000 in stock and wondering if I can apply it to a
friend's 2660 watt system without losing much to efficiency at low power
levels.<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal>Best,<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal>Jeff<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'>
<p class=MsoNormal>There are numerous options here: most ground mount
manu's offer ballasted systems, I would look to them 1st. Other systems I've
seen or used - 1) Pour a continuous surface "footer" that is large
enough in size to provide the proper ballast for the uplift in your area, pour
one along the S. edge/legs and another along the back/north legs. 2) Tie all
legs together via a horiz. rail at least 6' wide and embed this in a rock
filled gabion, again of the required weight. 3) Limestone is easy to drill,
useing a hammer drill and extension bit drill 11/16" - 3/4" holes at
least 18" into the stone at an angle, vary all angles as viewed in plan as
they relate to the N/S line of the array (not as they relate to level), to
mitgate pull-out from them all being in a line. i.e. - 1st leg hole is 90
degrees to the N/S line, 2nd leg is 180 from this, 3rd is 45 and so on, in
other words if looking in plan and you could see all holes they would radiate
around the "face of a clock" with each leg hole on a different
"hour". Finally, epoxy in 5/8" all thread, you can pre-bend the
end to come out of the hole verticle or use a swivel connector from Uni-strut,
B-line or equal.<o:p></o:p></p>
</blockquote>
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'>
<p class=MsoNormal>All of these suggestions should be run by a Structural
Engineer before embarking, thus the 1st choice of working with a manu.<o:p></o:p></p>
</blockquote>
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'>
<p class=MsoNormal><br>
<o:p></o:p></p>
</blockquote>
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'>
<p class=MsoNormal>Good luck!<o:p></o:p></p>
</blockquote>
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'>
<p class=MsoNormal>-jeff o<br>
<br>
>From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative
SOLutions<o:p></o:p></p>
</blockquote>
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'>
<p class=MsoNormal><span style='font-size:10.0pt'><br>
<br>
____________________________________________________________<br>
</span><a
href="http://thirdpartyoffers.juno.com/TGL2132/fc/BLSrjnsHGiu92lJJqoMGi0uE8kGS8cyBf0zjvb0ir0FblIZfJXPnNi0BtXC/">Protect
your home before it is too late. Click here for homeowner insurance
information.</a><o:p></o:p></p>
</blockquote>
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'>
<p class=MsoNormal><br>
_______________________________________________<br>
List sponsored by Home Power magazine<br>
<br>
List Address: RE-wrenches@lists.re-wrenches.org<br>
<br>
Options & settings:<br>
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org<br>
<br>
List-Archive:
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org<br>
<br>
List rules & etiquette:<br>
www.re-wrenches.org/etiquette.htm<br>
<br>
Check out participant bios:<br>
www.members.re-wrenches.org<o:p></o:p></p>
</blockquote>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<div>
<p class=MsoNormal> <o:p></o:p></p>
</div>
<pre>-- <o:p></o:p></pre>
<div>
<p class=MsoNormal>~~~~~~~~~~~~~<br>
Jeff Clearwater<br>
Senior Design Engineer<br>
NABCEP (tm) Certified Solar PV Installer<br>
http://www.nabcep.org/<br>
Village Power Design/NorthEast Solar Design<br>
Turnkey Solar Design & Installation for the Commercial Sector<br>
http://www.villagepower.com<br>
gosolar@villagepower.com<br>
<br>
Voice: 413-259-3776<br>
Fax: 413-825-0703<br>
65 Schoolhouse Rd <br>
Amherst, MA 01002<br>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<o:p></o:p></p>
</div>
</div>
</body>
</html>