Certainly. Some actual experience in the field may be helpful as well as far as an actual install goes, too. But really, for a setup like mine, it is a matter of properly sizing components and wiring and installing everything to code. There isn't a whole lot of craziness going on aside from just have a LOT of equipment that needs to be tied in appropriately.
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Plan: Off grid solar with a Model S battery pack at the heart
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Certainly. Some actual experience in the field may be helpful as well as far as an actual install goes, too. But really, for a setup like mine, it is a matter of properly sizing components and wiring and installing everything to code. There isn't a whole lot of craziness going on aside from just have a LOT of equipment that needs to be tied in appropriately.
View attachment 73209
Six more modules.
For about 15 minutes I had a P85D with 117kWh of battery power on board.
Who is selling individual modules and how does the price compare with a full pack? i just need to buy a few.
An individual module tear down and some single cell testing would be interesting if you are going to keep the damaged pack and make it a sacrificial one for... SCIENCE!
Questions:
- No intumescent goo as the pictures seem to suggest despite the Tesla patents?
- Actual Ah capacity of a cell via testing
- Current capacity of the fused links
- Any interesting BMS goodies
I quite possibly will tear down the damaged module. It isn't physically damaged, however some coolant seemed to have leaked into the plastic tray on the bottom of the module, a bunch of cells were corroded and a few cell level fuses had popped by the time it reached me. Coolant probably was leftover in the loop and leaked during shipment.
I don't have the rest of the damaged pack, just the 6 intact modules. I'll likely have a spare, and probably tear apart the damaged one.
I did notice that the BMS was trying to balance the cells on 2 out of 6 of the modules. When I tested the individual cell sets on those two modules there were out of balance by up to 80mV. Odd to see them doing anything without the main BMS hooked up. However they weren't making any progress better balancing after ~24 hours it seemed, so I disconnected the boards.
(The temperature difference of the modules themselves is just reflected IR since I removed the plastic cover on those two)
> the idea of being off grid and developing a completely enclosed annual energy system is fascinating to me [adiggs]
The PLAN here was off-grid but apparently things went horribly wrong, and the grid-tied siren song held sway. Such is the power of the grid.
> When you look at off-grid applications, you need to understand where power production "goes" when there's no demand for it (unlike a grid-tie, where you simply feed other demand in the grid). [FlasherZ]
Solar Panels can operate open circuit, so lacking any demand from the fully charged battery bank you can just open the switch. Which is probably what the controllers do.
Wind turbine alternators likewise do not require any load, so an easy task for the controllers to handle. WT alternators (Bergey's anyway) produce 3 phase power at up to 600vdc. If one had a Euro ModelS with 3 phase chargers (or a 3 phase Chademo adapter) one would be sorely tempted.
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The PLAN here was off-grid but apparently things went horribly wrong, and the grid-tied siren song held sway. Such is the power of the grid.
> When you look at off-grid applications, you need to understand where power production "goes" when there's no demand for it (unlike a grid-tie, where you simply feed other demand in the grid). [FlasherZ]
Solar Panels can operate open circuit, so lacking any demand from the fully charged battery bank you can just open the switch. Which is probably what the controllers do.
Wind turbine alternators likewise do not require any load, so an easy task for the controllers to handle. WT alternators (Bergey's anyway) produce 3 phase power at up to 600vdc. If one had a Euro ModelS with 3 phase chargers (or a 3 phase Chademo adapter) one would be sorely tempted.
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Not referring to my setup, since I'm still setting up for off-grid use. Grid is my backup generator. As of right now I have no intention of feeding power back into the grid at all. That may change if I have a substantial overproduction in the summer months. However, as of right now I see no reason to do so, nor do I see any reason to pull power from the grid on a regular basis.
Tedkidd
Member
I won't cancel my grid service, but my usage will be 0 kWh. I'll keep the grid as a backup via my manual transfer switch. Since the grid connection fee with zero usage is somewhere around $10/mo, I figure it can't hurt to keep it even though I should never really need it.
Fares Almazrooei
Desert T
As far as I can tell all the products on that page are single phase, not split phase 120V/240V typical in USA. I will limit my comments as to suitability to just that one point.
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Not that I've ever found Alibaba graphics to be completely reliable, but the unit shown does have L1/L2/N output terminals - again, not speaking for suitability for any other purpose. I can't tell from the description there whether the L1/L2 terminals are at 240V or 0V from each other, though - so it's definitely not confirmed.
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InTheShadows
Active Member
It won't pass code in the USA. It's not UL rated (UL Pending means nothing) and it doesn't comply with 1741. 1741 isn't technically needed for off grid, UL is required though.
The way it is configured currently it doesn't shut down fast enough for 1741 and the ac voltage tolerance is too high to meet the requirements. There is a phase tolerance for 1741 as well and the specs don't define it.
Also most newer inverters have built in DC arc fault. It's required in 2014 NEC (it might be required in 2011 NEC as well but I'm not positive since 2011 was never adopted in my trade area) , this inverter doesn't have that either.
Tedkidd
Member
If your utility allowed you to sell back at a high rate during peak (and buy cheap at night during bad weather), how complicated would that be to facilitate?
nwdiver
Well-Known Member
Super easy with the Outback Radian. For every watt that goes into the battery you get <90% back so you'd need to make sure the math works.
Interconnecting any distributed generation requires approval. Grid connected ESS is a special case and Solar City has had problems with California utilities approving these interconnections. If I were to do it, I would arrange the system so that the battery backed inverter was not grid connected.
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Could depend on who defines 'interconnecting'. With the new NEC code requirements (yet to be mastered) and other political push-backs underway, who knows how local inspectors are going to view your nice big 'either-or' switches or the little slider-plate logic switches (that do the same thing)? They may view these as being 'too close for comfort' and demand full grid tied protection be installed. If they *can* be easily tampered with, then sooner or later they probably will be, thus causing danger to power line workers.
Having a separate EVSE located out back connected to the renewable energy plant is one thing, but feeding a water heater in the house from both sources is yet another. Better to install a 2nd water heater separately connected for RE only!! But how about your 1kw refrigerator? Looks like that big boy will have to stay permanently on the Grid. :crying:
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TheTalkingMule
Distributed Energy Enthusiast
Germany pays the same rate regardless of hour, but gives preference to the primarily residential solar load feeding into the grid at midday. This has essentially bankrupted every large German utility firm, so you can imagine the impact to debt-laden US utility companies if you started selling high all day and buying low all night.
That's where we're headed, but I would expect to receive a tiny bit of existential push-back from the legacy utility providers in the short term.
Tedkidd
Member
If I recall correctly, people in CA with batteries and solar were catching grief about their net metering and tou. Utilities wanted to credit avoided cost.
These utility shenanigans are seppuku, the final straw for consumer goodwill.
Hopefully things will be different in NY. Deregulation didn't bring Enron here, and now with the public service commission REV they are trying to consider how to insure all interests are fairly recognized for the value they bring. Batteries and demand management offer huge potential.
We have a growing CCA (Community Choice Aggregation) movement in California which offers me some hooe.
