Somebody coined the term "breaker masking" for this issue. https://floridasolardesigngroup.com/is-plug-in-solar-safe-the-wiring-danger-that-marketing-will-not-tell-you-about
Jason Szumlanski Principal Solar Designer | Florida Solar Design Group NABCEP Certified Solar Professional (PVIP) Florida State Certified Solar Contractor CVC56956 Florida Certified Electrical Contractor EC13013208 On Thu, May 28, 2026 at 3:55 PM Zeke Yewdall via RE-wrenches < [email protected]> wrote: > Yes... if the PV is not on the last outlet in the string, there is the > potential for overloading a portion of the string if someone plugged in > more than 16A of heavy loads farther out on the string -- the wire portion > between the PV backfeed and the next outlet could have more amperage on > it. Same issue as when your backfed breaker isn't on on the opposite end > of the busbar from the grid feed. > > I remember the OK4U inverter from Trace. Back when mechanical meters just > spun backwards. It was discontinued before I ever lived somewhere with > grid power, so never got to use one. > > Then they started putting electronic readers on the mechanical meters, and > they only counted how many times the black line went by, not which > direction, so were effectively ratcheted, and I believe all of the standard > electronic ones now are ratcheted in the software. Or, they're smartmeters > that immediately report back if you sell a few watts ever. I've seen > people run into that numerous times when self consumption systems blipped > below 0 watts during load changes, when the inverter wasn't programmed for > enough baseload draw from the grid. > > On Thu, May 28, 2026 at 12:27 PM Bryan Norkunas <[email protected]> > wrote: > >> Was this considered balcony solar back in 1998? >> >> Bryan Norkunas >> PV-Cables, Inc. >> 989 Milton Ave Ste 1-D >> Ferndale, CA 95536 >> 707-923-3000 office >> >> ------------------------------ >> *From:* RE-wrenches <[email protected]> on >> behalf of Jay via RE-wrenches <[email protected]> >> *Sent:* Thursday, May 28, 2026 12:10:27 PM >> *To:* RE-wrenches <[email protected]> >> *Cc:* Jay <[email protected]>; Zeke Yewdall <[email protected]>; >> RE-wrenches <[email protected]> >> *Subject:* Re: [RE-wrenches] Balcony Solar >> >> Hi Zeke >> >> I see a few issues. >> >> If there is a circuit with A as the first outlet then B,C,d. If the 16A >> is put into B then C and D now have the potential for 36 amps. Bit high for >> 12 ga wire. >> >> As to the meters as far as I know most all meters unless configured for >> bidirectional use either are mechanical ratcheting so they cant count >> backwards. Or are electronic and I’m unclear as to what happens. I e heard >> they count up either direction so if your selling power the meter adds or >> it might just lock like the ratcheting. I guess depending on the meter. >> >> Finally I live in an all electric house and for most of the year, 8+ >> months when I’m not using heat, my daytime base loads are like 200 watts. >> Of course if someone is home then could be laundry etc. >> >> A small system say 400 watts or less is going to be mostly used for some >> daytime self consumption. But 2000 watts is way overkill and for most it >> seems it will be wasted for the consumer. And as you say it’ll make people >> mad about how little it’s doing. >> >> Finally as to dates. I had a OK4U made by NKF back in 2000 grid tie micro >> inverter for a single 100 watt panel plugged into an outlet on my deck. I >> keep reading it’s a new idea, nope. >> >> Big push lots of hype. >> >> >> >> On May 28, 2026, at 9:40 AM, Zeke Yewdall via RE-wrenches < >> [email protected]> wrote: >> >> >> Trying to wrap my brain around exactly what this entails. Specifically >> in Colorado, as that's where I still do most of my design work, but also in >> other places if it's different/better/worse/etc.... >> >> This is the actual text of the Colorado bill >> https://leg.colorado.gov/bill_files/116074/download >> >> From reading it... it appears that it's limited to 1920 watts AC output, >> and limited to one system per address. Systems under 391 watts AC output >> are exempt from a number of other requirements (which seem to pertain >> mostly to NABCEP certified supervisors and licensed electricians), but >> still have to be UL listed. Does that imply that licensed electricians or >> NABCEP certified installers must install ones between 391 watts and 1920 >> watts? >> >> It appears that utilities cannot require approval, a fee, or any >> modifications to the house electrical system (4a) but can require being >> notified of the installation and size (4b) >> >> I am wondering how this works with ratcheted meters, which is the norm >> nowadays in Colorado. I have asked Xcel for their guidance on this. >> >> In general... the idea of balcony solar seems very problematic. While >> I'm totally in support of more solar on the grid, and making smaller >> systems more doable, I have lots of questions on how this will work in >> reality. >> >> 1) Structural issues: Most homeowners do not know how to properly mount >> solar panels against the winds that we have in Colorado. It's normal for >> cars and neighbors to be assulted by wandering trash cans during every >> windstorm... adding errant solar modules to this doesn't seem like a good >> idea. Most temporary solar racking I've seen from manfucturers (from RV >> solar sellers mostly) is completely inadequate to withstand 100+mph winds >> as well. How will proper securing of the solar modules be enforced? >> >> 2) Electrical integration: 1920 watts is a fully loaded 20A 120 volt >> output (16A continuous). If it is a new, high quality outlet, it should be >> good for that, but what if it is a old outlet on the deck that's gotten all >> loose from 30 years of power tools and christmas lights being plugged and >> unplugged? What if it's the $1.99 consumer version of the outlet, not the >> $8.99 commercial version? I've seen the cheaper ones, and many old loose >> ones, burn up when used with electric space heaters, which is a similar >> amperage and time span load to a full size balcony solar system. >> >> 3) Metering: Since most all utilities in Colorado now use ratcheted >> meters, it will be a problem if the system exports without somehow getting >> a bidirectional meter. If it is a lightly loaded apartment, where a 1920 >> watt system would really make a different in energy use, then it's likely >> the baseload will be below 1920 watts midday, and it needs to export. If >> it's a larger house where the baseload midday is over 1920 watts, then >> export isn't the issue, but the problem is that people will install a 1920 >> watt system when they really need a 5 or 8 or 12kW system to affect their >> bill much -- and then they'll just decide that "solar doesn't work" and it >> will give solar a bad name for more people. Given that most people don't >> understand kWh and energy use, and marketing always seems to overpromise >> what equipment can do, I don't expect that a majority of consumers will >> understand that a 1920 watt system is not sufficient to make a significant >> impact for a majority of houses out there. I've even had customers install >> 10kW systems, and not understand that by adding a hot tub and electric >> water heater and heat pump and electric range at the same time, they >> overwhelmed the production of the system, and that's why their bill >> actually went up. >> >> 4) Licensure and permits: This could solve some of the issues above... >> but Colorado allows homeowners to pull permits so licensure and training of >> the installer is still no guaranteed. And most building departments have a >> permitting process that's aimed at larger systems... a large system >> requiring 10 pages of documentation and an engineers stamp and a $500 >> permit fee is not unreasonable. But for a $2000 balcony kit... how can >> permitting enforce some basic standards, without becoming a insurmountable >> hurdle. Also, as a professional installer, I found that fixed costs were >> a large portion of the cost of installing a system. My cost to do >> drawings, get a PE stamp for the roof/racking, file for a permit, file for >> interconnection agreement, and roll a truck were pretty much the same for a >> 3kW system or a 10kW system. There was more onsite labor for the 10kW >> system doing racking and modules, but even electrical wiring was about the >> same onsite labor for both sizes. Onsite labor should be much less for a >> balcony solar system, especially if plugging into a deck outlet (replacing >> it with a brand new commercial quality 20A outlet maybe). But costs for >> drawings, permitting, interconnection won't be different unless a different >> system is made. Materials are obviously more for the larger systems, but >> labor made the overall total cost quite a bit higher per watt for the >> smaller systems, and going to a one or two panel system could be even more >> share for the off-site labor portion of the total cost. If building >> departments and utilities put the balcony solar systems through the same >> paperwork as larger systems, I can easily see that costing more than the >> materials or onsite labor. >> >> >> >> -- >> 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 >> >> > > -- > 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. 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