Thanks Zeke, I just saw this and will respond with some ideas. Chris
On 6/26/2026 6:06 PM, Zeke Yewdall via RE-wrenches wrote:
This sounds like the old buy all sell all system with two meters. I
didn't realize any utilities were still doing this. But the way that
we'd do it on a grid-tie system was have one meter
measuring production that then connected into the grid on the utility
side of the meter going to the house. During a sunny day, the energy
used by the house would first be sold to the utility through the
production meter, then bought right back through the normal loads meter.
Doing a battery backup system would, I think, be wired up the same
way. The PV array would have its own grid-direct inverter selling
power to the grid, and then the battery backup system would draw power
from the grid for charging -- it would be set up as a UPS type system,
not knowing that any solar existed at all.
If the grid went down, you would not be able to power the house or
charge the batteries from the solar, as it would be connected on the
dead grid side of any transfer switches from the backup power, and I
think this would meet the utilities intent -- if the grid is down,
they cannot purchase any electricity, so therefore, generating
electricity to recharge your batteries or use would not be allowed.
Frankly, if faced with a tarriff like this, I would seriously look
into what it would take to get rid of the grid connection entirely and
do an actual off-grid system. I figure that most batteries right now
cost about 4 to 5 cents/kWh for energy stored then used. So it would
depend on the load profile and how much was used during the daytime
and how much at night, but if the buy rate is more than 2 or 3 cents
more than the sell rate, I would think it would be cheaper to invest
in batteries and pay 0 markup during the daytime, and 4 or 5 cents
battery cost at nighttime, rather than paying more than 2 or 3 cents
markup all the time.
Usually, even when faced with very unattractive buy/sell rates, I
still recommend that people maintain their grid connection, even if
only to use it in place of a standby generator fill in during winter
weather. Even paying a $50/month standby charge to maintain a grid
connection you almost never use can be cheaper than maintaining an
actual physical generator. But if you aren't allowed to even use your
own solar power on site without incurring their markup, then that
could be a different story.
Zeke
On Fri, Jun 26, 2026 at 10:39?AM Christopher Warfel via RE-wrenches <
[email protected]> wrote:
> > Our local utility has a requirement that ALL generation be sold to
them
> at avoided cost, and that ALL purchases be made at tariff rate. A
couple
> of years ago before installing an EG4 system (which I did my first
one this
> past year), I told the president of the coop that I did not think
that was
> possible with multi mode systems. I've tried a lot of different
settings
> in the EG4 but it seems not to make a big difference.
>
>
> Does anyone have knowledge of how to do this? Signature Solar did not
> have a definitive answer, and what we have tried so far, has not really
> produced the results I was hoping for.
>
>
> Thank you, Chris
>
> >
> --
> Christopher Warfel, PE
> ENTECH Engineering, Inc.
> PO Box 871, Block Island, RI 02807
> (401) 447-5773
On Fri, Jun 26, 2026 at 1:13 PM
<[email protected]> wrote:
Send RE-wrenches mailing list submissions to
[email protected]
To subscribe or unsubscribe via the World Wide Web, visit
http://lists.re-wrenches.org/listinfo.cgi/re-wrenches-re-wrenches.org
or, via email, send a message with subject or body 'help' to
[email protected]
You can reach the person managing the list at
[email protected]
When replying, please edit your Subject line so it is more specific
than "Re: Contents of RE-wrenches digest..."
When responding to posts within the Digest, be sure to restore the
Subject: line to the exact original, and please edit out any
extraneous lines from the quoted message.
Today's Topics:
1. How to sell maximum amount from EG4 (Christopher Warfel)
2. Re: How to sell maximum amount from EG4 (Dave Tedeyan)
----------------------------------------------------------------------
Message: 1
Date: Fri, 26 Jun 2026 10:36:32 -0400
From: Christopher Warfel <[email protected]>
To: [email protected]
Subject: [RE-wrenches] How to sell maximum amount from EG4
Message-ID:
<[email protected]>
Content-Type: text/plain; charset=UTF-8; format=flowed
> Our local utility has a requirement that ALL generation be sold
to them at avoided cost, and that ALL purchases be made at tariff
rate. A couple of years ago before installing an EG4 system
(which I did my first one this past year), I told the president of
the coop that I did not think that was possible with multi mode
systems. I've tried a lot of different settings in the EG4 but it
seems not to make a big difference.
Does anyone have knowledge of how to do this?? Signature Solar did
not
have a definitive answer, and what we have tried so far, has not
really
produced the results I was hoping for.
Thank you, Chris
>
--
Christopher Warfel, PE
ENTECH Engineering, Inc.
PO Box 871, Block Island, RI 02807
(401) 447-5773
------------------------------
Message: 2
Date: Fri, 26 Jun 2026 10:42:53 -0400
From: Dave Tedeyan <[email protected]>
To: [email protected], RE-wrenches
<[email protected]>
Subject: Re: [RE-wrenches] How to sell maximum amount from EG4
Message-ID:
<CAM3Q7f1Qsbhpi=ho6bxe8nkqh-wvlkhrjssm-b_-rk_aw9f...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
You can try contacting EG4 directly. I've had good luck talking to
them as
well when I have had questions. They were good about helping me
derate the
grid sell for a couple inverters to stay below our utilities
residential
limit, and then signing a form for us to give to the utility.
Cheers,
Dave
On Fri, Jun 26, 2026 at 10:39?AM Christopher Warfel via RE-wrenches <
[email protected]> wrote:
> > Our local utility has a requirement that ALL generation be
sold to them
> at avoided cost, and that ALL purchases be made at tariff rate.
A couple
> of years ago before installing an EG4 system (which I did my
first one this
> past year), I told the president of the coop that I did not
think that was
> possible with multi mode systems. I've tried a lot of different
settings
> in the EG4 but it seems not to make a big difference.
>
>
> Does anyone have knowledge of how to do this? Signature Solar
did not
> have a definitive answer, and what we have tried so far, has not
really
> produced the results I was hoping for.
>
>
> Thank you, Chris
>
> >
> --
> Christopher Warfel, PE
> ENTECH Engineering, Inc.
> PO Box 871, Block Island, RI 02807
> (401) 447-5773
>
> _______________________________________________
> List sponsored by Redwood Alliance
>
> Pay optional member dues here: http://re-wrenches.org
>
> List Address: [email protected]
>
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> There are two list archives for searching. When one doesn't
work, try the
> other:
> https://www.mail-archive.com/[email protected]/
> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>
> List rules & etiquette:
> http://www.re-wrenches.org/etiquette.htm
>
> Check out or update participant bios:
> http://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/20260626/74fb284c/attachment-0001.htm>
------------------------------
Subject: Digest Footer
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here: http://re-wrenches.org
List Address: [email protected]
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work,
try the other:
https://www.mail-archive.com/[email protected]/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
------------------------------
End of RE-wrenches Digest, Vol 19, Issue 173
********************************************
--
Zeke Yewdall
PV Engineer
NABCEP #031508-89
[email protected]
303-523-3592
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here:http://re-wrenches.org
List Address:[email protected]
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try the other:
https://www.mail-archive.com/[email protected]/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
--
Christopher Warfel, PE
ENTECH Engineering, Inc.
PO Box 871, Block Island, RI 02807
(401) 447-5773
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here: http://re-wrenches.org
List Address: [email protected]
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try the other:
https://www.mail-archive.com/[email protected]/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
