wow lots of locations, this looks like the final clearing out?
Background: https://www.sacbee.com/news/business/article239721438.html
Background: https://www.sacbee.com/news/business/article239721438.html
Last edited:
100+ MOBILE SOLAR GENERATORS AUCTION
- Thread starter Ralo
- Start date
I doubt it. There have been a number of multiple location auctions and I think they have a ton of inventory to move. Trying to maximize their liquidation dollars.
It’s amazing to see what these go for at auction and then see them pop up on Craigslist at quadruple or more what folks paid for them intact or parted out.
And they are back again, multiple cities and dates:
bidindustrial.com
National Auctions Specializing In Heavy Industrial Machinery & Equipment
BidIndustrial.com provides online auctions at a local & national reach for industrial machinery, heavy equipment & commercial real estate.
bidindustrial.com
People are asking triple or quadruple the auction prices:
Solar trailer with batteries, generator and LED light towers. -...
Selling a mobile solar generator trailer. It is coming with bateries, generator and Led light towers. It is in very good working condition. Trailer specs: MFG Date: 08/2015 Make: Carson trailer...
phoenix.craigslist.org
Consumerbot3418
Fitting square pegs into round holes... for fun?
Just bought one of these from the Atlanta auction, about to head on a road trip to go pick it up!
I got the model with the diesel generator, and I'm hoping to find a way to integrate the components into a grid-tied system (net metering is available) with battery/diesel backup. It looks like that may be more complicated than I'd hoped, or perhaps even impossible? Kinda hoping @Hedges will weigh in with some information or advice. If I've understood correctly, these SI units are capable of passing the diesel gen's power through, as well as using it to recharge the batteries. I'm wondering if I could switch the generator's input over to grid power, and then use AC coupling to supplement the limited PV on this unit, and feed the grid as long as it's up? Then, if the grid goes down, run off batteries, and manually switch over to the diesel gen in case of extended outage. I guess there are hybrid inverters that are better integrated for this scenario (like Outback units), but the DC Solar trailers seemed like too good of a deal to pass up, and I've always liked SMA equipment!
I got the model with the diesel generator, and I'm hoping to find a way to integrate the components into a grid-tied system (net metering is available) with battery/diesel backup. It looks like that may be more complicated than I'd hoped, or perhaps even impossible? Kinda hoping @Hedges will weigh in with some information or advice. If I've understood correctly, these SI units are capable of passing the diesel gen's power through, as well as using it to recharge the batteries. I'm wondering if I could switch the generator's input over to grid power, and then use AC coupling to supplement the limited PV on this unit, and feed the grid as long as it's up? Then, if the grid goes down, run off batteries, and manually switch over to the diesel gen in case of extended outage. I guess there are hybrid inverters that are better integrated for this scenario (like Outback units), but the DC Solar trailers seemed like too good of a deal to pass up, and I've always liked SMA equipment!
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 20,600
All of that should work well.
You just have to figure out how your main breaker panel allows this.
Easiest would be if you had a main breaker at the meter, and separate breaker panel. Then SI could wire in between. But 1s2p SI can only pass through 56A 120/240V. If your loads could draw more current, better to have a separate important loads panel. You can used manual interlocked breakers to backfeed main breaker panel if desired. (I bought four SI and wired 2s2p for 112A pass through.)
I'm not clear yet whether the trailers use a shunt to inform SI what current comes from Midnight, or if it has a data cable and interface instead.
I is possible to have DC coupled PV get backfed into the grid for net metering, but that requires the Midnight SCC to be set to a higher voltage than SI wants; SI bleeds that off backfeeding the grid.
For Grid + generator, you could add a transfer switch, and wire a signaling contact to an SI digital input to let it know when generator is being used. Or manual interlocked breakers. Or a power cord, plugged into grid or generator. Just come up with a way to let SI know so it prevents backfeed of generator.
AC coupling (Sunny Boy with "Grid Backup" or "Rule 21") would be a good way to add PV. SI can be programmed to charge battery bank at whatever current is optimum for it (hope you got good batteries.) With AC coupling it can hold charge current steady at that rate.
The DC coupled PV would recharge battery even if discharged below SI disconnect (80% DoD), but I suggest getting a relay for "load shed". Tie AC coupled PV to output of SI, and use load shed relay to connect your house. That way, at 70% DoD the house gets disconnected but AC coupled PV remains connected to recharge faster. The shed loads are reconnected at 50% DoD.
Consider improving ventilation. DC Solar ignored the 12" space all sides instructions, crammed SI into a small box with a small exhaust fan. Otherwise it might cause derating in the event of high power coming from battery. When most power comes from Sunny Boy however, less power in Sunny Island.
You just have to figure out how your main breaker panel allows this.
Easiest would be if you had a main breaker at the meter, and separate breaker panel. Then SI could wire in between. But 1s2p SI can only pass through 56A 120/240V. If your loads could draw more current, better to have a separate important loads panel. You can used manual interlocked breakers to backfeed main breaker panel if desired. (I bought four SI and wired 2s2p for 112A pass through.)
I'm not clear yet whether the trailers use a shunt to inform SI what current comes from Midnight, or if it has a data cable and interface instead.
I is possible to have DC coupled PV get backfed into the grid for net metering, but that requires the Midnight SCC to be set to a higher voltage than SI wants; SI bleeds that off backfeeding the grid.
For Grid + generator, you could add a transfer switch, and wire a signaling contact to an SI digital input to let it know when generator is being used. Or manual interlocked breakers. Or a power cord, plugged into grid or generator. Just come up with a way to let SI know so it prevents backfeed of generator.
AC coupling (Sunny Boy with "Grid Backup" or "Rule 21") would be a good way to add PV. SI can be programmed to charge battery bank at whatever current is optimum for it (hope you got good batteries.) With AC coupling it can hold charge current steady at that rate.
The DC coupled PV would recharge battery even if discharged below SI disconnect (80% DoD), but I suggest getting a relay for "load shed". Tie AC coupled PV to output of SI, and use load shed relay to connect your house. That way, at 70% DoD the house gets disconnected but AC coupled PV remains connected to recharge faster. The shed loads are reconnected at 50% DoD.
Consider improving ventilation. DC Solar ignored the 12" space all sides instructions, crammed SI into a small box with a small exhaust fan. Otherwise it might cause derating in the event of high power coming from battery. When most power comes from Sunny Boy however, less power in Sunny Island.
@Consumerbot3418 yup just unplug at the gennie input on the rear of the white box with the SMA's in it.
Good video overview here...
Good video overview here...
If you got one with the light towers on it I may be interested in the towers if you don’t need them.
Consumerbot3418
Fitting square pegs into round holes... for fun?
Sorry for the delayed response--life is quite busy now, as we're renovating and moving into a home! After an uneventful pick up, I got home to find that everything seems to work rather well--the batteries are supposedly at 100% SoC, but I intend to water/equalize before measuring their actual capacity.
@Hedges, thank you so very much for the helpful, detailed reply. The house in question actually has the main service in the garage (which used to be the main house), and is wired in as a subpanel, so it's already as you described. With no central HVAC, and gas appliances, it's hard to imagine ever pulling over 50 amps, although the 2s2p config would give some comfort/breathing room, for sure. I'll have to chew on your ideas/suggestions for a while. Considering discarding the notion of backfeeding grid-tie out of the SI units. For the 2kw of PV, just not sure it's worth the effort. I guess AC coupled units can backfeed the grid if it's up, and assist SI during an outage... I might ping you in the future to offer feedback on whatever design I end up coming up with, if you don't mind?
@Picasso, thanks for the video link. Nice overview, learned a few things despite already having a good sense of how everything works.
@JoeHam, actually did get one with light towers that I don't really need. Seems like they'd interfere with the PV harvest... My kid just got his ham radio license, though, so we may end up using one of them as an antenna mast. Safe to assume that's what you had in mind? Let me know if you're interested in one of them!
@Hedges, thank you so very much for the helpful, detailed reply. The house in question actually has the main service in the garage (which used to be the main house), and is wired in as a subpanel, so it's already as you described. With no central HVAC, and gas appliances, it's hard to imagine ever pulling over 50 amps, although the 2s2p config would give some comfort/breathing room, for sure. I'll have to chew on your ideas/suggestions for a while. Considering discarding the notion of backfeeding grid-tie out of the SI units. For the 2kw of PV, just not sure it's worth the effort. I guess AC coupled units can backfeed the grid if it's up, and assist SI during an outage... I might ping you in the future to offer feedback on whatever design I end up coming up with, if you don't mind?
@Picasso, thanks for the video link. Nice overview, learned a few things despite already having a good sense of how everything works.
@JoeHam, actually did get one with light towers that I don't really need. Seems like they'd interfere with the PV harvest... My kid just got his ham radio license, though, so we may end up using one of them as an antenna mast. Safe to assume that's what you had in mind? Let me know if you're interested in one of them!
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 20,600
Sure, no problem.
The 2kW DC coupled can take care of recharging batteries if Sunny Island ever shuts down for low SoC, but I would still suggest a load-shed relay (and shedding any heating loads like a dryer at a different SoC.)
Just a pair, 2s1p should be good. Up to 12.7 kW of Sunny Boy can backfeed through them to the grid.
The 2kW DC coupled can take care of recharging batteries if Sunny Island ever shuts down for low SoC, but I would still suggest a load-shed relay (and shedding any heating loads like a dryer at a different SoC.)
Just a pair, 2s1p should be good. Up to 12.7 kW of Sunny Boy can backfeed through them to the grid.
Congratulations to your kid, I got my license when I was 13 and still at it almost 5 decades later.
I will send you a PM to see where you are located and what you want for it. I’ve always wanted a mobile antenna tower trailer and that tower would be a good starting point.
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 20,600
Well, it was a good idea. Balanced load so little strength required (until snow shifted all to one side.)
I'd repair that to be a transport restraint, and add struts to support 2.5' from the hinge rather than 2.5" for use deployed.
Consumerbot3418
Fitting square pegs into round holes... for fun?
A quick follow-up on my trailer, and a question at the end for anyone else trying to use the trailer during outages. We had some nice weather recently, so I took the opportunity to check out the batteries. All were a bit low, but even, with the top of the plate showing. 10 gallons of distilled water later, they're all topped off. Every single cell was between 2.05-2.08V, vast majority at 2.6 or 2.7V--quite happy! After a 3 hour equalization run, I pulled about 16kWh out, and the SoC landed at 60%, so it looks like most of the capacity is there. Lucky me!
Without doing enough research, I purchased an entire DIY solar kit (8.76kW system with 7.7 Sunny Boy), and then I came across @Hedges post describing the poor interaction between his Sunny Island and Sunny Boy, with relays banging on and off, unless the Sunny Boy was placed in "off-grid" mode.
Now it looks like I've dug a hole for myself. It looks like I have the following two options, neither of which is attractive:
I'm now seriously considering a different inverter that will more smoothly handle supporting the Sunny Island in an outage... perhaps one that doesn't require a GridGuard code to switch between on/off grid? Since I haven't even taken delivery of the system yet, or applied for interconnection with the utility, I still have some time to weigh options. I'm curious to know if anybody else has already implemented an AC-coupled system to support the Sunny Islands when the trailer is being used as an emergency generator?
Without doing enough research, I purchased an entire DIY solar kit (8.76kW system with 7.7 Sunny Boy), and then I came across @Hedges post describing the poor interaction between his Sunny Island and Sunny Boy, with relays banging on and off, unless the Sunny Boy was placed in "off-grid" mode.
Now it looks like I've dug a hole for myself. It looks like I have the following two options, neither of which is attractive:
- Run the Sunny Boy in Grid-Tie mode. In an outage scenario, it will support the Sunny Island, which will charge the battery, then kick Sunny Boy offline completely when the battery is topped off, without smoothly dialing back the power output
- Install the Sunny Boy in Off-Grid mode, at the cost of being held hostage to being dependent on Sunny Island to handle any backfeed into the grid for net metering. I'd like to be able to keep the trailer intact, and be able to move it, so I really don't want to do this.
I'm now seriously considering a different inverter that will more smoothly handle supporting the Sunny Island in an outage... perhaps one that doesn't require a GridGuard code to switch between on/off grid? Since I haven't even taken delivery of the system yet, or applied for interconnection with the utility, I still have some time to weigh options. I'm curious to know if anybody else has already implemented an AC-coupled system to support the Sunny Islands when the trailer is being used as an emergency generator?
Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 20,600
My problem was primarily with 10000TLUS, which was documented to support grid-backup but didn't. SMA gave me a workaround (offgrid) and has now changed their compatibility list.
You should be good now with "Rule 21" "frequency-watts". Not sure if you need a software update to support it. That should run smoothly, adjusting output to match load + charging.
You probably have to request grid-guard code to change the setting.
Consumerbot3418
Fitting square pegs into round holes... for fun?
I sort of killed two birds with one stone, by choosing "start" from the generator menu on the Sunny Island. The equalization was overdue from the timing setup in the menu, so I guess the Sunny Island was just waiting for available power to run the equalization, because once the generator started, the SI started dumping power into the batteries. I set generator back to "auto", and it shut the generator down once the equalization completed, without my intervention.
I just charged our plug-in hybrid vehicle two times. It takes almost exactly 8kWh to charge it from flat to full. Could also have connected a 1200 watt space heater for 13 hours and 20 minutes, but hate to be wasteful!
Consumerbot3418
Fitting square pegs into round holes... for fun?
Right, taking away a feature that was supposed to have been supported at the time of purchase. I remember now.
This makes me feel a lot better! I suppose some of my anxiety stems from the fact that I'll only have 10 hours before I'm locked out of making any changes to the grid parameters, along with the difficulty I've had finding information about the configuration options. For all I know, there may not even be an "offgrid" setting on the -41 models... Hopefully, my utility will be okay with the CA Rule 21 setting being enabled!
Oh, and that link is exactly what I had been looking for, thank you! (I had found a similar link on SMA's blog to Off-Grid Tech Info, but that link was dead)
Similar threads
