Grid-Tie Inverters with Batteries [RE-wrenches]

Joel Davidson joeldavidson at earthlink.net
Tue Sep 7 18:31:47 PDT 2004


 

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Save up to 67% on Omaha Steaks + Get 6 FREE Burgers and a 
FREE Cutlery Set + Cutting Board!
http://click.topica.com/caacBBEbz8Qcsbz9JC9a/OmahaSteaks
-------------------------------------------------------------------

Hello Robert,

Solar Integrated Technologies (SIT) has its computers' server on an SW4048
inverter PV UPS. There was a power outage and the computer server worked
fine. However, the phone system was not on the PV UPS and had to be
re-booted. Now the phone system is on the PV UPS too.

The Davis, California Food Co-op put a SIT 30 kW batteryless solar roof on
their building. The existing 5 kW rack-mounted array powering the SW4048 PV
UPS is still in place.

Battery versus batteryless is not an either/or proposition. A lot of
businesses are going solar with batteryless PV systems. It makes sense to
have a PV UPS too.

Do any other PV businesses have both battery and batteryless PV for
operations in addition to show-and-tell?

Best regards,
Joel Davidson
----- Original Message ----- 
From: "lizardlists at houston.rr.com" <rollerton at houston.rr.com>
To: <joeldavidson at earthlink.net>
Sent: Tuesday, September 07, 2004 3:51 PM
Subject: Re: Grid-Tie Inverters with Batteries [RE-wrenches]


> I was at my Vets office this weekend with the new cat...
>
> They just recently had Dell PCs installed in all their examining rooms,
you
> could see they had an electrician run conduit to each room, with a 110v
> duplex outlet about 12" down from the celing.  The first thing I noticed
was
> that the size of the "power" parts was as big as the whole pc system.
>
> The next thing I noticed was that they had tie wrapped a UPS to the wall
of
> each room.  There are now about 20 individual UPS boxes, powered by a
newly
> installed seperate circuit.   So right there you have to wonder if:
>     one bigger UPS (or Grid-tie with batteries) would have been less
> expensive (probably),
>     less space (yes), and less maintenance (consumer UPS batteries are
> usually good for 1 to 3 years),
>     and reliable (wait until year 2 and see how many of the UPS can keep
it
> up past 15 seconds)
>
> Insult to injury, plugged into that UPS was the power converter (AC to DC)
> for the system, and for the flat screen monitor;  so you could wonder
about
> the efficiencies here.
>
> I doubt if using a larger UPS every crossed the mind of the guy selling
the
> system to the Vet's office. He probably probably insisted on the $120
units
> in an effort to reduce the support calls he expects to receive every time
> there is a power glitch.
>
> I wonder what efficiencies there would be with a more centralised DC power
> system for office computing, there seems to be a lot of advantage in the
> telco world with -48vdc.
>
>
>
>
>
> My metro houston house,
>
> 2o years old.  I haved two 1500W ups hard wired to outlets in my office.
My
> TVs have 1000W UPS on each one.  I count 6 seperate UPS units.
>
> I have two hardwired, battery powered, emergency lights.
>
> Power goes off about once a month for more than 30 seconds.  I would say
> there is a spike every two weeks long enough to crash a PC.
> You can count on at least one outage a year of more than 2 hours.
>
> If I was going to be here for life, I would rewire the 110V circuits to a
> central UPS.  I am in a residential area, in heavy woods so solar in not a
> viable option
>
>
>
> Rural Arizona
>
> Power interruptions at least once a week, long enough to reset all the
> electrics.
> Figure one outage a week in the summer monsoon season, of 1 to 2 hours or
> more.
> figure two outages a year of longer than 4 hours.
>
> All buildings have hardwired emergency lighting,
> TV on 1000W UPS.  PCs on 1500W UPS.  Servers on 2500W UPS.  I count 5
> seperate UPS units.
>
> Grid-tie no batteries.
>
> House re-wired for Grid-tie with batteries on the 110V circuits.  Plan to
> implement that in about a year and retire the UPSs

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Amazing Diet Patch
The fastest - Easiest way to lose weight! Try it now FREE!
http://click.topica.com/caacBBBbz8Qcsbz9JC9f/MyDietPatches
-------------------------------------------------------------------

- - - -
To send a message: RE-wrenches at topica.com

Archive of previous messages: http://lists.topica.com/lists/RE-wrenches/read

List rules & etiquette: www.mrsharkey.com/wrenches/etiquete.htm

Check out participant bios: www.mrsharkey.com/wrenches/

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com
--^----------------------------------------------------------------
This email was sent to: michael.welch at homepower.com

EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9.bWljaGFl
Or send an email to: RE-wrenches-unsubscribe at topica.com

For Topica's complete suite of email marketing solutions visit:
http://www.topica.com/?p=TEXFOOTER
--^----------------------------------------------------------------






More information about the RE-wrenches mailing list