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There are some decent quality linear fluorescents with 12 vdc ballasts on the market, too. I would consider a combined system: one fluorescent for overall room lighting, and some LEDs for task lighting around the perimeter. I don't like the LEDs alone, but mixed they can be very effective. One advantage of Travis's suggestion, is that the inverter will act as Low voltage disconnect on the higher wattage fluorescent, but you could still have the LEDs on DC. Thus the main light goes out, and tells everyone to go home, but the LEDS let them know where the door is, and avoids total chaos.<div><br><div> <span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div>R. Walters</div><div>Solarray.com<span class="Apple-tab-span" style="white-space:pre"></span></div><div>NABCEP # 04170442<span class="Apple-tab-span" style="white-space:pre"><span class="Apple-style-span" style="white-space: pre; "> </span></span></div><div><br class="khtml-block-placeholder"></div><br class="Apple-interchange-newline"></span> </div><br><div><div>On Aug 18, 2009, at 5:58 AM, Travis Creswell wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><o:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region"> <o:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PostalCode"> <o:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="State"> <o:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City"> <o:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"> <o:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="Street"> <o:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="address"> <o:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PersonName"> <!--[if !mso]> <style> st1\:*{behavior:url(#default#ieooui) } </style> <![endif]--> <style> <!--a:link {mso-style-priority:99;} span.MSOHYPERLINK {mso-style-priority:99;} a:visited {mso-style-priority:99;} span.MSOHYPERLINKFOLLOWED {mso-style-priority:99;} /* Font Definitions */ @font-face {font-family:"MS Mincho"; panose-1:2 2 6 9 4 2 5 8 3 4;} @font-face {font-family:Tahoma; panose-1:2 11 6 4 3 5 4 4 2 4;} @font-face {font-family:"\@MS Mincho"; panose-1:2 2 6 9 4 2 5 8 3 4;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 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";} a:link, span.MsoHyperlink {color:blue; text-decoration:underline;} a:visited, span.MsoHyperlinkFollowed {color:purple; text-decoration:underline;} span.EmailStyle17 {mso-style-type:personal; font-family:Calibri; color:#1F497D;} span.EmailStyle18 {mso-style-type:personal-reply; font-family:Arial; color:navy;} @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="1026" /> </xml><![endif]--><!--[if gte mso 9]><xml> <o:shapelayout v:ext="edit"> <o:idmap v:ext="edit" data="1" /> </o:shapelayout></xml><![endif]--> <div class="Section1"><p class="MsoNormal"><font size="2" color="navy" face="Arial"><span style="font-size: 10.0pt;font-family:Arial;color:navy">I don’t have time to do the exact math but think a small inverter and linear fluorescent is a clear winner of your trying to adequately light the bulk of the class room.<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="navy" face="Arial"><span style="font-size: 10.0pt;font-family:Arial;color:navy"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="navy" face="Arial"><span style="font-size: 10.0pt;font-family:Arial;color:navy">Linear fluorescent has lumens per watt in the upper 80’s. CFL (DC or AC) is upper 40’s and LED is the same as CFL and maybe a little worse depending on whose products you are comparing. You’ll also note that it’s next to impossible to get Lumens per Watt specs from LED suppliers. It’s like the new car company refusing to publish a MPG spec but readily waves a made up spec that alludes to MPG but isn’t really. I’ve been asking the numerous LED manufactures that call on me for samples so I can do side by side testing with CF and LF and NONE of them call back a 2<sup>nd</sup> time so I’m really still quite nervous about LED for “real” applications. Ok sorry about that LED rant….LED’s are cool they are not the panacea they are being made out to be,<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="navy" face="Arial"><span style="font-size: 10.0pt;font-family:Arial;color:navy"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="navy" face="Arial"><span style="font-size: 10.0pt;font-family:Arial;color:navy">Two evenly spaced fixtures that use a single 4’ tube will almost adequately light the entire room of that size and use about 60 watts total. Total Lumens would be ~5400. Assuming the tare and efficiency losses put the Morningstar 300 at net efficiency of approx 85% that take our lumens per watt to something in the mid 70’s which is still much better then DC LED and DC CFL.<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="navy" face="Arial"><span style="font-size: 10.0pt;font-family:Arial;color:navy"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="navy" face="Arial"><span style="font-size: 10.0pt;font-family:Arial;color:navy">Best, Travis Creswell<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="navy" face="Arial"><span style="font-size: 10.0pt;font-family:Arial;color:navy">Ozark Energy Services<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="navy" face="Arial"><span style="font-size: 10.0pt;font-family:Arial;color:navy"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="navy" face="Arial"><span style="font-size: 10.0pt;font-family:Arial;color:navy"><o:p> </o:p></span></font></p> <div> <div class="MsoNormal" align="center" style="text-align:center"><font size="3" face="Times New Roman"><span style="font-size:12.0pt"> <hr size="2" width="100%" align="center" tabindex="-1"> </span></font></div><p class="MsoNormal"><b><font size="2" face="Tahoma"><span style="font-size:10.0pt; font-family:Tahoma;font-weight:bold">From:</span></font></b><font size="2" face="Tahoma"><span style="font-size:10.0pt;font-family:Tahoma"> <a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a> [<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">mailto:re-wrenches-bounces@lists.re-wrenches.org</a>] <b><span style="font-weight: bold">On Behalf Of </span></b>Walt Ratterman<br> <b><span style="font-weight:bold">Sent:</span></b> Monday, August 17, 2009 5:34 PM<br> <b><span style="font-weight:bold">To:</span></b> '<st1:personname w:st="on">RE-wrenches</st1:personname>'<br> <b><span style="font-weight:bold">Subject:</span></b> Re: [<st1:personname w:st="on">RE-wrenches</st1:personname>] Solar 12 volt DC lighting for school in <st1:country-region w:st="on"><st1:place w:st="on">Haiti</st1:place></st1:country-region></span></font><o:p></o:p></p> </div><p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size: 12.0pt"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D">Hello Lee,<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D">Walt here.<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D">I will be leaving for <st1:country-region w:st="on"><st1:place w:st="on">Haiti</st1:place></st1:country-region> in about a week, and be there for three….<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D">We have done lots of schools. If you are strictly 12V, your choices primarily are 12V CF and LED lights. There are lots of pros and cons to both.<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D">The real question is what you intend to use the lights for.<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D">If you go to our photo gallery (link from home page: <a href="http://www.sunepi.org">www.sunepi.org</a> ), and check out the Sierra Leone gallery, you will see some clamp-on LED Lights that are 12V and are used for night time studying. They are pretty much task lights and are low level. If you are trying to keep the system really small in terms of watts of solar panels, (and cost) these can be great, but again – the primary question is what will the light be used for.<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D">A step up from that would be the 12V CFL’s. Might be tough to get in <st1:country-region w:st="on"><st1:place w:st="on">Haiti</st1:place></st1:country-region> (for replacements). I can check next week and let you know.<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D">If you have any kind of distances involved, you will probably want to consider an inverter (Morningstar SS-300 is great) to avoid the losses associated with 12V dc wiring.<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D">Feel free to contact me off line if you want to go over this some more….<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D">Thanks,<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D">Walt<o:p></o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="2" color="#1f497d" face="Calibri"><span style="font-size:11.0pt;font-family:Calibri;color:#1F497D"><o:p> </o:p></span></font></p> <div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in"><p class="MsoNormal"><b><font size="2" face="Tahoma"><span style="font-size:10.0pt; font-family:Tahoma;font-weight:bold">From:</span></font></b><font size="2" face="Tahoma"><span style="font-size:10.0pt;font-family:Tahoma"> <a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a> [<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">mailto:re-wrenches-bounces@lists.re-wrenches.org</a>] <b><span style="font-weight: bold">On Behalf Of </span></b>Lee Bristol<br> <b><span style="font-weight:bold">Sent:</span></b> Monday, August 17, 2009 2:53 PM<br> <b><span style="font-weight:bold">To:</span></b> <st1:personname w:st="on">RE-wrenches</st1:personname>@lists.re-wrenches.org<br> <b><span style="font-weight:bold">Subject:</span></b> [<st1:personname w:st="on">RE-wrenches</st1:personname>] Solar 12 volt DC lighting for school in <st1:country-region w:st="on"><st1:place w:st="on">Haiti</st1:place></st1:country-region><o:p></o:p></span></font></p> </div><p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size: 12.0pt"><o:p> </o:p></span></font></p><p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size: 12.0pt">Can anyone recommend lights for a school in <st1:country-region w:st="on"><st1:place w:st="on">Haiti</st1:place></st1:country-region>. I am going there in a couple of months to install a 12 volt solar PV system and need to illuminate seven 16 x 20 foot school rooms. I am so confused by all of the light bulb options, base options, CFL vs LED, what wattage is required, etc. I would expect that two fixtures with bulbs would suffice for a room. Any ideas?<o:p></o:p></span></font></p><p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size: 12.0pt">There is no grid power available…this is really out in the boondocks.<o:p></o:p></span></font></p><p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size: 12.0pt"> <o:p></o:p></span></font></p><p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size: 12.0pt">Thanks<o:p></o:p></span></font></p><p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size: 12.0pt">Lee<o:p></o:p></span></font></p><p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size: 12.0pt">-- <br> Lee Bristol<br> NABCEP Certified Solar Designer/Installer<br> <br> Chief Technology Officer<br> Standard Solar, Inc.<br> <st1:street w:st="on"><st1:address w:st="on">202 Perry Parkway, #7</st1:address></st1:street><br> <st1:place w:st="on"><st1:city w:st="on">Gaithersburg</st1:city>, <st1:state w:st="on">MD</st1:state> <st1:postalcode w:st="on">20877</st1:postalcode></st1:place><br> (301) 944-5105<br> (240) 479-1510 (c)<br> <a href="http://www.standardsolar.com">www.standardsolar.com</a><o:p></o:p></span></font></p> </div> </o:smarttagtype></o:smarttagtype></o:smarttagtype></o:smarttagtype></o:smarttagtype></o:smarttagtype></o:smarttagtype></o:smarttagtype><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">_______________________________________________</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">List sponsored by Home Power magazine</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Options & settings:</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">List-Archive: <a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">List rules & etiquette:</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">www.re-wrenches.org/etiquette.htm</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Check out participant bios:</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">www.members.re-wrenches.org</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div> </blockquote></div><br></div></body></html>