[RE-wrenches] DC, or not DC, Dat is Da question (Two Load Questions)

[Brian Mehalic]

I for one like a DC light in my inverter room.  Just sayin'...

Brian Mehalic
NABCEP Certified Solar PV Installer™ R031508-59
IREC ISPQ Certified Affiliated Instructor/PV US-0132

PV Curriculum Developer and Instructor
Solar Energy International
http://www.solarenergy.org



On Tue, Dec 11, 2012 at 2:05 PM, Chris Daum <chris at oasismontana.com> wrote:

> **
> The Sundanzers can be converted for AC use at the factory for a nominal
> cost, and they claim it affects efficiency very little.
>
> Chris Daum
> Oasis Montana Inc.
> 406-777-4309
> 406-777-0830 fax
> www.oasismontana.com
>
>
>  ------------------------------
> *From:* re-wrenches-bounces at lists.re-wrenches.org [mailto:
> re-wrenches-bounces at lists.re-wrenches.org] *On Behalf Of *Larry
> Crutcher,Starlight Solar Power Systems
> *Sent:* Tuesday, December 11, 2012 11:56 AM
> *To:* RE-wrenches
> *Subject:* [RE-wrenches] DC, or not DC, Dat is Da question (Two Load
> Questions)
>
> Why would one specify DC voltage appliances or lighting for off grid
> systems today when we have sub-buck-a-Watt PV solar power?  If you have
> space, you can make the added power that conventional AC appliances draw
> for very low cost. It could even be argued that the cost for DC items,
> wiring, distribution gear and labor will cost much more than simply adding
> more PV solar and staying all AC.
>
> I don't like wasting resources and I understand old school thinking when
> PV modules were very expensive, but with high efficiency AC appliances and
> low cost inverters and PV modules, does it still make any sense? Shine some
> light on my thinking.
>
> Larry Crutcher
> Starlight Solar Power Systems
>
>
>
>
>
>  On Dec 10, 2012, at 9:12 PM, Allan Sindelar wrote:
>
> Wrenches,
> We still try to encourage prospective off grid customers to do a full load
> analysis as an initial step in the system design process. To the point:
>
> 1) What is a good watt-hours/day figure to use for a typical, modern, new,
> carefully chosen, fairly large conventional AC chest freezer, if kept in a
> heated indoor location? Assume 65 degrees and seldom opened.
>
> I will encourage that the freezer be located in a shaded, protected
> outdoor location, in order to greatly reduce winter energy consumption, but
> I need a good base figure to work with.
>
> The proposed system will most likely be 48Vnom, so a Sundanzer or similar
> DC freezer is out.
>
> 2) Same question for a ceiling fan, for general slow circulation of winter
> heat. The energystar.gov list gives relative cfm efficiency but not
> wattages. Is 55W still a good figure to use as a default?
>
>
> I have attached a condensed energystar.gov list for the freezers, but
> wonder what other off grid Wrenches typically use. Also, I'm not sure that
> Wrenches posts allow attachments, so this may not appear with my message.
>
> Thank you,
> Allan
> --
> *Allan Sindelar*
> *Allan at positiveenergysolar.com* <Allan at positiveenergysolar.com>
> NABCEP Certified Photovoltaic Installer
> NABCEP Certified Technical Sales Professional
> New Mexico EE98J Journeyman Electrician
> Founder and Chief Technology Officer
> *Positive Energy, Inc.*
> 3209 Richards Lane (note new address)
> Santa Fe, New Mexico 87507
> *505 424-1112*
> *www.positiveenergysolar.com* <http://www.positiveenergysolar.com/>****
>
> *****************
> *
>
> <Freezers Product List.xlsx>
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