[RE-wrenches] AC V DC RE: electrolysis
To answer the original question, AC will not cause electrolysis. The electrons must be pushed consistently in one direction for that. That’s why people use battery chargers to power electrolysis systems for de-rusting old iron artifacts. In fact, pipeline operators will run a low amp DC current in the “wrong” direction to prevent corrosion. You could just put a standard furnace control 24v transformer on the output of the generator and it would activate the relay. Hilton Dier III Renewable Energy Design Missisquoi River Hydro LLC ___ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@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
[RE-wrenches] Intermittent
Hello Wrenches Here’s a classic problem for you. I installed an array of 11 Trina 380s on a ground mount, commissioned January 6 of this year. It worked fine for a while, but in the last week it has had an intermittent power problem. For example, this morning it was putting out zero watts at the inverter. I measured voltage at the disconnect at the array and got zero volts. I checked all the connections and wires and it all seemed solid. I had to leave so I couldn’t start isolating modules. I came back this afternoon and it was producing an appropriate amount of power for the light conditions. What’s the most obvious thing that could be going on? Some kind of micro crack and thermal expansion? Thanks, Hilton Dier III Renewable Energy Design Missisquoi River Hydro LLC ___ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@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
[RE-wrenches] gravity storage of excess PV generation
A one metric ton weight on a 30 meter tall tower has a potential energy of 81 watt hours. I’d stick with batteries. The only places gravity storage works are where you have “free” height and huge amounts of free weight. That is, an existing lake at a good elevation for pumped storage. But on that note, it’s cheaper to buy and opportunistically fill a 1,000 gallon plastic storage tank than to buy the batteries needed to fill that storage tank on demand. Store the final product if you can. Hilton Dier III Renewable Energy Design Missisquoi River Hydro LLC ___ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@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
[RE-wrenches] LG Chem RESU warranty
Just as a bit of context, LG is in the middle of a gigantic warranty recall and replacement of every 2019-2022 Chevy Bolt battery pack. As far as I can tell the recall is overly cautious, but it’s good that they are stepping up. It’s not an excuse for bad service, but an explanation for why there might be a shortage of both batteries and attention. Hilton Dier III Renewable Energy Design Missisquoi River Hydro LLC ___ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@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
[RE-wrenches] Onboard PV Charging Kit for Electric Vehicle
My first question is the voltage of the truck’s battery pack. If it’s below the 118V of the array you should charge the pack directly with just a charge controller to minimize losses. There is absolutely no reason to add another battery pack separate from the drive pack. The drive pack is undoubtedly heavy enough without a second pack that doesn’t contribute to propulsion. The inefficiency of solar>controller>battery>inverter>charger>battery would be a significant loss. If the propulsion pack is higher than 118 volts you have a problem. You’ll need a 1kW DC to DC converter that will boost the voltage to some value well above the pack voltage. I’m imagining that this would be difficult to find. Then you would need a charge controller that would tolerate the output of the DC-DC converter. Maybe just a voltage tripped relay and a DC contractor. It’s a slick looking rig. Good luck. Hilton Dier III Renewable Energy Design Missisquoi River Hydro LLC ___ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@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
[RE-wrenches] SMA alternative?
Esteemed Wrenches, I am a long time fan and installer of SMA string inverters. I have a project right now which is a ground mounted array of 12 Trina 380s, so just over 4.5 kW. SMA inverters seem to be unavailable for the foreseeable future. What would be your recommendations for an alternative? I know it’s unfashionable, but I’m not a fan of micro inverters. Thanks, Hilton Dier III Renewable Energy Design Missisquoi River Hydro LLC ___ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@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
[RE-wrenches] Today’s mindbender
I just had an off grid client have his cousin install an electric water heater and wonder why his system went down overnight on low battery. But that was just typical newbie off grid mission creep. You have a full on disaster there, right from the get go. A client with unrealistic expectations that require extraordinary departures from normal practice. I mean, driveway melt, hot tub, AC, multiple refrigerators, zero planning; it sounds like an elaborate joke. I have learned and relearned the great truth that the most important client is the one you turn away. That demanding, picky, unrealistic, clueless, careless deadbeat that will eat your time, money, and emotional energy. This is one where you walk away. If you somehow manage to install 14 kW and surmount the amperage/ service entrance problem (Mo’ amps, mo’ problems) I will bet the rent that this client will be perpetually dissatisfied. He will crash his battery bank in the first outage. Call the client. Say “I’m sorry, but I can’t figure out a way to make this work that satisfies my standards. I don’t think I can make you a satisfied client.” Move on, happy in the knowledge that you dodged a tactical nuclear weapon. Best of luck, H Hilton Dier III Renewable Energy Design Missisquoi River Hydro LLC ___ List sponsored by Redwood Alliance Pay optional member dues here: http://re-wrenches.org List Address: RE-wrenches@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
