[RE-wrenches] Battery Back-up and Grid Tie

Fri Apr 26 12:30:15 PDT 2013

Batteries actually do better if they are cycled than if they just sit
there.  He may actually extend his battery life.  What kind of batteries is
he using?

*From:* re-wrenches-bounces at lists.re-wrenches.org [mailto:
re-wrenches-bounces at lists.re-wrenches.org] *On Behalf Of *SunHarvest
*Sent:* Friday, April 26, 2013 2:25 PM
*To:* RE-wrenches
*Subject:* Re: [RE-wrenches] Battery Back-up and Grid Tie

I have a crazy...I mean *creative* customer who wants a BB system so that
he can run off-grid during peak and partial-peak rate hours: 1 to 7pm is
peak, 7 to 9pm is partial from PG&E. He got this great idea from a tech at
a reputable power optimizer manufacturer, whom I will not name here, who
said, "you've got the batteries just sitting there; why not put them to
work?"

Initially he wanted his PV to operate while the sun is shining and the grid
is down...and his batteries to supply power when the sun *and* grid is
down. But now he wants his back-up system to do it all. We've touched on
all the obvious points:

- Peak buying is also peak selling

- Physics and efficiency losses determine that the energy he "saves" will
never equal the energy he can put back into his system.

- Decreased battery life due to increased cycling

- Costs for batts and special inverters versus generator

What is the *definitive* argument against BB in general and this "peak
shaving" idea in particular?

Thanks pros.

Eric

SunHarvest

----- Original Message -----

*From:* toddcory at finestplanet.com

*To:* RE-wrenches <re-wrenches at lists.re-wrenches.org>

*Sent:* Friday, April 26, 2013 11:57 AM

*Subject:* Re: [RE-wrenches] Battery Back-up and Grid Tie

our power outages generally come from bad weather too... and of course when
the weather is bad the pv does next to nothing. so for emergency backup, i
recommend a generator.

todd

On Friday, April 26, 2013 10:33am, "Bill Turberville" <billturb at ece-llc.com>
said:

Not very often, and usually for no more than an hour or two, although it
has been down as long as 5 days, either during tornado season, or ice
taking down power lines.  What these people are looking for is Just In Case
a big event happens.  They do not want to have all those panels just
sitting there.

*From:* *re-wrenches-bounces at lists.re-wrenches.org*<re-wrenches-bounces at lists.re-wrenches.org>[mailto:
*re-wrenches-bounces at lists.re-wrenches.org*<re-wrenches-bounces at lists.re-wrenches.org>]
*On Behalf Of *Jay Peltz
*Sent:* Friday, April 26, 2013 12:25 PM
*To:* RE-wrenches
*Subject:* Re: [RE-wrenches] Battery Back-up and Grid Tie

Hi bill

Just how often is your grid down?

Jay

Peltz power

Sent from my iPhone

On Apr 26, 2013, at 10:01 AM, Bill Turberville
<*billturb at ece-llc.com*<billturb at ece-llc.com>>
wrote:

I live in a TVA area where there is a Feed In Tariff.  Everything that is
generated by the PV array feeds into the grid through a Generation Meter
that ties-in ahead of the house meter.  I have started getting calls from
customers who hate having a solar array that does not generate when the
grid is down but the sun is shining, but who also want to get the $.12
premium when the grid is connected.  We have lots of systems with SMA
Sunnyboy inverters, but more with Enphase micro-inverters.  Rather than
trying to reinvent the wheel, what you found to be the best solution for
this type of installation?

W.C. (Bill) Turberville P.E.

President

ECE Solar

Electrical Contracting Enterprises LLC

3080 Stage Post Road Suite 107

Bartlett, TN 38133

901-348-9230 ext 101 phone

901-348-2192 fax

901-289-6346 cell

*billturb at ece-llc.com* <billturb at ece-llc.com>

NABCEP Certified PV Installation Professional 032611-320

_______________________________________________
List sponsored by Home Power magazine

List Address: *RE-wrenches at lists.re-wrenches.org*<RE-wrenches at lists.re-wrenches.org>

Change email address & settings:
*http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org*<http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org>

List-Archive: *
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org*<http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org>

List rules & etiquette:
*www.re-wrenches.org/etiquette.htm*<http://www.re-wrenches.org/etiquette.htm>

Check out participant bios:
*www.members.re-wrenches.org* <http://www.members.re-wrenches.org>

Sent from Finest Planet WebMail.
------------------------------

_______________________________________________
List sponsored by Home Power magazine

List Address: RE-wrenches at lists.re-wrenches.org

Change email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive:
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out participant bios:
www.members.re-wrenches.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20130426/946367c4/attachment-0003.html>