[RE-wrenches] How to sell maximum amount from EG4
Christopher Warfel
cwarfel at entech-engineering.com
Sat Jun 27 05:20:52 PDT 2026
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 <
> re-wrenches at lists.re-wrenches.org> 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
> <re-wrenches-request at lists.re-wrenches.org> wrote:
>
> Send RE-wrenches mailing list submissions to
> re-wrenches at lists.re-wrenches.org
>
> 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
> re-wrenches-request at lists.re-wrenches.org
>
> You can reach the person managing the list at
> re-wrenches-owner at lists.re-wrenches.org
>
> 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 <cwarfel at entech-engineering.com>
> To: re-wrenches at lists.re-wrenches.org
> Subject: [RE-wrenches] How to sell maximum amount from EG4
> Message-ID:
> <adcab7b2-1d88-4896-af75-3bc90406546d at entech-engineering.com>
> 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 <dave at sungineersolar.com>
> To: cwarfel at entech-engineering.com, RE-wrenches
> <re-wrenches at lists.re-wrenches.org>
> Subject: Re: [RE-wrenches] How to sell maximum amount from EG4
> Message-ID:
>
> <CAM3Q7f1Qsbhpi=hO6BXe8nkQH-WvLkHrJSSm-B_-rK_AW9FnVw at 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 <
> re-wrenches at lists.re-wrenches.org> 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: RE-wrenches at lists.re-wrenches.org
> >
> > 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/re-wrenches@lists.re-wrenches.org/
> > 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: RE-wrenches at lists.re-wrenches.org
>
> 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/re-wrenches@lists.re-wrenches.org/
> 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
> zeke at darkforestsolar.com
> 303-523-3592
>
> _______________________________________________
> List sponsored by Redwood Alliance
>
> Pay optional member dues here:http://re-wrenches.org
>
> List Address:RE-wrenches at lists.re-wrenches.org
>
> 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/re-wrenches@lists.re-wrenches.org/
> 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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20260627/bd36ae08/attachment.htm>
More information about the RE-wrenches
mailing list