Todd,
I agree with using the gvfx inverters assuming he's generating more power then
he is currently using. He said the system was sized for the current load so it
seems like a waste to let such a large battery bank sit at full charge.
Outback does upgrade the boards for free most of the time so that wouldn't be
an issue.
David Lauzon
Northern Arizona Wind and Sun Phone-928-526-8017 / 800-383-0195
Fax-928-527-0729
Website-http://www.solar-electric.com
----- Reply message -----
From: toddc...@finestplanet.com
To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org>
Subject: [RE-wrenches] Off-Grid to Grid-Connected -essential loads
Date: Sat, May 5, 2012 1:28 pm
i am not sure what the advantage is of running in HBX mode? why not simply
grid-tie this where any surplus power (over local use) gets sold to the grid?
also the vfx's can be sent into ob for upgrading to gvfxs. no need to buy new
inverters.
todd
On Saturday, May 5, 2012 12:36pm, "benn kilburn" <b...@daystarsolar.ca> said:
Dan,
I agree, the batteries are a major factor here and as usual much can get lost
in translation when details are left out. My bad, I'll try to bridge the gap a
bit...
What we have here is a complete up and running off-grid system;
-the batteries are Surrette 2YS31P (2V each x 24 = 48V system) ~one year old
-there are two FM80's and a FM60 with a combined 8435 W of PV
-currently there are two VFX3648's (series stack) and there are two GVFX3648's
waiting to be swapped in when the grid connection happens.
-back-up 12kW gen
Welcoming neighbours into the area who are not as open to the limits and
responsibilities of off-grid living, this system owner has agreed to help with
the cost of bringing the grid into the area.
So working with the set-up we have, what i'm thinking (hoping) is that the
system will continue to run off the batteries and the PV will continue to keep
the batteries full and running all the loads and the inverters will be set to
only "buy" from the grid when the PV is not able to maintain a predetermined
battery voltage. Essentially the grid will become the "back-up generator", and
the existing back-up gen will not be seeing any action unless there is no sun
and the grid is down.
It appears that this is programmable via the HBX mode from the Mate. Am i
missing any critical points here?
Currently the main distribution panelboard, which feeds everything (the house
and shop loads) is supplied from the AC-Out bus in the Outback FW-AC, which is
supplied from the VFXs output and when in by-pass mode, from the generator, and
since the (battery) system was originally designed to supply all the loads I
see no reason/purpose to dedicate certain loads to a separate "essential loads"
panelboard, which is what i was getting at with my original post.
Thanks,
benn
DayStar Renewable Energy Inc.
www.daystarsolar.ca
780-906-7807
Certified Construction Electrician Solar Photovoltaic Systems Certified
Certificate # 0007S
HAVE A SUNNY DAY
From: dan@foxfire-energy.comTo: re-wrenc...@lists.re-wrenches.orgDate: Fri, 4
May 2012 18:23:33 -0700Subject: Re: [RE-wrenches] Off-Grid to Grid-Connected
-essential loads
IMHO, the batteries are the real skeleton in the closet here. Sooner or later
they're gonna poop. at 2400 Ah you're likely running a multi string set up, so
it's likely someone's number is already on the board. Even if you set the FX
down to a trickle charge or use some kind of contactor to fake the FX into
thinking the grid is really a gen set, sooner or later the batteries will fail.
Better to design for it now.. Besides, Rather than regulating solar input to
protect batteries, You're better off selling (Storing) power on the grid.
Depending on the age of the batteries or the competence of the operator (Home
Owner), I'd either swap out the FXs for a GVFX (and down size the batteries
when they puke), or loose the current setup all together and go for a
batteryless Grid Tie inverter. (and maybe keep the current setup as a whole
house UPS.. until the batteries poop). Again, depending on the customer, you
might milk these batteries by setting up individual strings on an isolation
switch (like in the marine industry), at least this way you can referee. Good
Luck. db
Dan BrownFoxfire Energy Corp.Renewable Energy
Systems(802)-483-2564www.Foxfire-Energy.comNABCEP #092907-44
-------- Original Message -------- Subject: [RE-wrenches] Off-Grid to
Grid-Connected -essential loads From: benn kilburn <b...@daystarsolar.ca> Date:
Fri, May 04, 2012 5:08 pm To: Wrenches <re-wrenches@lists.re-wrenches.org>
Wrenches,
I have an off-grid client who is going to be connecting to the grid. Since the
system (~9 kW of PV and ~2400 Ah battery) is already well suited for the loads,
I am wondering about the necessity of an essential loads panelboard. I'm not
sure if I see the need since the battery is already sized for all the existing
loads.
The intent is to continue running all the loads from the battery and have the
(Outback) settings so that the grid is only used when the PV isn't able to
maintain a particular battery voltage setting.
Comments, insights into this type of set-up?
Thanks,
benn
DayStar Renewable Energy Inc.
www.daystarsolar.ca
780-906-7807
Certified Construction Electrician Solar Photovoltaic Systems Certified
Certificate # 0007S
HAVE A SUNNY DAY
_______________________________________________ List sponsored by Home Power
magazine List Address: RE-wrenches@lists.re-wrenches.org Options &
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
_______________________________________________ List sponsored by Home Power
magazine List Address: RE-wrenches@lists.re-wrenches.org Options & 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
Sent from Finest Planet WebMail.
_______________________________________________
List sponsored by Home Power magazine
List Address: RE-wrenches@lists.re-wrenches.org
Options & 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
