<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Allan,<div><br></div><div>As a EV enthusiast, and RE Wrench, I've also thought of, and fielded questions about, direct PV charging an EV. </div><div><br></div><div>- The first issue that usually causes me to not pursue this is getting the most power production from the PV array each day. If the EV is not there, the PV array output is not being used. But it sounds like your customer will have the array grid tied when the EV is not present, so PV output is maximized, and he/she wants to be able to switch to direct EV charging when the EV is present.</div><div><br></div><div>- So the next issue is having an array wired that could both power a grid tie inverter, and charge a 300 vDC EV battery pack. If the grid tie inverter is a 600v string inverter, and the battery pack charge controller is a high voltage string charge controller like the Xantrex 600v PV charge controller, then the array could be wired to satisfy both uses.</div><div><br></div><div>- The next issue is if the Xantrex 600v PV charge controller be set high enough to control charge to a 300v battery pack. Maybe Xantrex could custom make one that could do this, and be adjusted for various battery types.</div><div><br></div><div>- If the charge controller can be found, then a manual transfer switch could be used to shift array output from the grid tie inverter to the car PV charge controller, and back, as desired.</div><div><br></div><div>How's that sound? :)</div><div><br><div>
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: 'Times New Roman'; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Times New Roman" size="3" style="font: normal normal normal 12px/normal 'Times New Roman'; ">Randy Brooks</font></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Times New Roman" size="3" style="font: normal normal normal 12px/normal 'Times New Roman'; ">Brooks Solar, Inc.</font></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Times New Roman" size="3" style="font: normal normal normal 12px/normal 'Times New Roman'; "><b><i>Solar Power for People</i></b></font></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Times New Roman" size="3" style="font: normal normal normal 12px/normal 'Times New Roman'; ">140 Columbia View</font></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Times New Roman" size="3" style="font: normal normal normal 12px/normal 'Times New Roman'; ">Chelan, WA<span class="Apple-converted-space"> <span class="Apple-converted-space"> </span></span>98816</font></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Times New Roman" size="3" style="font: normal normal normal 12px/normal 'Times New Roman'; ">509-682-9646</font></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Times New Roman" size="3" style="font: normal normal normal 12px/normal 'Times New Roman'; "><a href="mailto:Randy@BrooksSolar.com">Randy@BrooksSolar.com</a></font></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Times New Roman" size="3" style="font: normal normal normal 12px/normal 'Times New Roman'; "><a href="http://www.BrooksSolar.com">www.BrooksSolar.com</a></font></p></span>
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<br><div><div>On Aug 23, 2012, at 6:50 AM, Allan Sindelar wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">
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Wrenches,<br>
We have a customer who has built several EVs, and wants to
eventually develop a business around them here. A few years ago we
installed a GT system on his home. He has now moved and wants to
install a system on his new home as well. This time, he'd like to
develop a means by which to charge his EV directly from his array,
avoiding the inefficiencies of inverting to the grid and then
running a grid-based charger. <br>
<br>
I know of no way to do this, but then, I'm a veggiehead (drive an
old Mercedes on waste fryer oil), not an EV aficionado. I suspect
that there are folks out there trying to do this, as it's a logical
objective. Can anyone suggest products, links, or websites for this
customer to explore?<br>
<br>
Here are his notes about this effort:<br>
<blockquote>...this is essentially the idea. to use the EV as
rolling battery backup to dual-purpose the investment in battery.
The second plus is avoiding loss from two inversions dc-ac-dc, the
third being relatively high-amp charge without buying another
charger! and dual purposing the inverter to avoid cost of high-amp
inverter only used for emergencies for a backup.
<br>
<br>
The tech details of EV battery packs that are going to make this a
challenge is the high voltage. The DIY pack running DC are going
to be 120, 144, 156vDC nominal most commonly. Guys running AC
motors and OEMs might run much higher.... closer to 300v.
<br>
<br>
The charge controller or voltage limit switch needs to be user
settable and fairly accurate (+/- 1 volt). The DIY people usually
use a 'finish' voltage of 3.65volts / cell being 'done'. So for a
120v nominal system I would want to set the DC charge to come up
to 139v and either shut down right then, or if it COULD just hold
at 139v until amps drop or a specified time, that would be even
better.
<br>
<br>
I am planning to do a grid-tie system at my new house, and yes,
the intent is to 'stub-in' capability to both quick-charge the
pack direct from the DC side of PV if possible, AND use the car
pack as night-time/emergency backup just to show its possible....
<br>
<br>
My little car has 12kWhr on board, one I'm working on right now
will have 20kWhr onboard.
</blockquote>
Thank you in advance for any assistance.<br>
Allan<br>
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<font face="Times New Roman, Times, serif"><b>Allan Sindelar</b></font><br>
<small><a href="mailto:Allan@positiveenergysolar.com"><font color="#000099" face="Times New Roman, Times, serif"><u>Allan@positiveenergysolar.com</u></font></a></small><font face="Times New Roman, Times, serif"><br>
<span style="font-size: 10pt;">NABCEP Certified Photovoltaic
Installer<br>
NABCEP Certified Technical Sales Professional<br>
New Mexico EE98J Journeyman Electrician<br>
Founder and Chief Technology Officer<br>
<b>Positive Energy, Inc.</b><br>
3209 Richards Lane (note new address)<br>
Santa Fe, New Mexico 87507<br>
<b>505 424-1112</b><br>
<a href="http://www.positiveenergysolar.com/" target="_blank"><u>www.positiveenergysolar.com</u></a><o:p></o:p></span></font><p class="MsoNormal" style="margin-right: 722.25pt;"><span style="font-size: 10pt;"><font face="Times New Roman, Times,
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