Re: [Emc-users] OT note to Erik C - Solar batteries
On 13.02.19 12:04, Chris Albertson wrote: > On Tue, Feb 12, 2019 at 5:07 PM Greg Bentzinger via Emc-users < > emc-users@lists.sourceforge.net> wrote: > > > > > The shop will always have to be on the grid, the big CNC's have 26Kw or > > higher startup loads. If the house is off grid then my electric bill will > > be a 100% business expense. > > (/Greg) > > Have you looked at battery specs? A Tesla Model 3 battery can supply 211 > Kw. That is many times your 26 Kw requirement. I think even a used > battery that was recoved from a crashed car should be abe to supply way > more than 26 Kw.The weak link is going to be the inverter. A number of inverter brands can be parallelled, sometimes using a separate network connection to aid synchronisation or load sharing. Three 5 kW or two 8 kW inverters would provide that short term output well within their ratings, I think. Erik ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT note to Erik C - Solar batteries
On Tue, Feb 12, 2019 at 5:07 PM Greg Bentzinger via Emc-users < emc-users@lists.sourceforge.net> wrote: > > The shop will always have to be on the grid, the big CNC's have 26Kw or > higher startup loads. If the house is off grid then my electric bill will > be a 100% business expense. > (/Greg) > Have you looked at battery specs? A Tesla Model 3 battery can supply 211 Kw. That is many times your 26 Kw requirement. I think even a used battery that was recoved from a crashed car should be abe to supply way more than 26 Kw.The weak link is going to be the inverter. -- Chris Albertson Redondo Beach, California ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT note to Erik C - Solar batteries
Here's a fellow in AU with a test of cheap vs expensive solar panels. Turns out the $90 panel puts out significantly more amps than the $300 panel he bought.https://www.youtube.com/watch?v=3-sc4rlV93g Some commenters note the cheap panel is using the newest thing in PV cells. No contact wires across the front to block some light and the face is matt finish instead of gloss so that likely helps absorb more light. But wow, $90 for a 100 watt rated panel. Even if it falls apart after 10 years it's still pretty cheap, especially in a place with high cost per KWH. Tesla doesn't use lithium polymer, they use lithium ion. In the Model S the pack is chock full of 18650 cells, just like in most laptops that aren't super thin. The Model 3 and Model X are doing things differently. The relatively easy to remove Model S battery is a legacy of when Tesla had plans to build fast battery swap stations, but only built one that was never used. Look up Rich Rebuilds on YouTube. He rebuilt a Model S that spent a week half submerged, used pretty much everything but the body shell from another one that had been rolled. He's rebuilt a second Model S, bought a used Model X (which took Tesla several months to deliver) and while waiting for that one he bought a Model X that was in a flood and is taking it all apart to rebuild. In the middle of all that has been his not so secret "secret" project of transplanting a Model S drivetrain into the back of a Porsche 911. He's not gone ALL electric, he has a Z06 Corvette. Never has said what his regular job is but it has to be pretty good to drop all that coin on Teslas. On Tuesday, February 12, 2019, 9:48:34 PM MST, Erik Christiansen wrote: On 13.02.19 01:05, Greg Bentzinger via Emc-users wrote: > A trend I have been noticing in the DIY solar crowd is to salvage the > batteries from wrecked Tesla or Mercedes Hybrids. The Batteries are > series wired for output in the 400VDC range but can be rewired in > parallel for a 50-60VDC output. Just need to be sure the charge > controller has a custom or Li-po setting. I'm not sure there are any wrecked Tesla or Mercedes Hybrids in Australia yet. I could lose a hand in the scrum for the battery or motor. What also scares me about Li-po is what happened to early Dreamliners, smartphones, and a few other gadgets which went up in smoke. ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT note to Erik C - Solar batteries
On 13.02.19 01:05, Greg Bentzinger via Emc-users wrote: > A trend I have been noticing in the DIY solar crowd is to salvage the > batteries from wrecked Tesla or Mercedes Hybrids. The Batteries are > series wired for output in the 400VDC range but can be rewired in > parallel for a 50-60VDC output. Just need to be sure the charge > controller has a custom or Li-po setting. I'm not sure there are any wrecked Tesla or Mercedes Hybrids in Australia yet. I could lose a hand in the scrum for the battery or motor. What also scares me about Li-po is what happened to early Dreamliners, smartphones, and a few other gadgets which went up in smoke. LiFePO4 batteries aren't cheap, but they don't appear to catch fire, and are said to be more robust than Li-po. The redflow ZnBr flow battery is a techno-nerd's dream, but it's too expensive for me. NiFe batteries are said to be robust and long lasting, but fussy to care for. > I hope to rig up a 6Kw bank here at the ranch so it can handle the > Inrush starting demands of my deep well pump. Yup, even the latest hybrid inverter will output around 60% more taking power from the PV array than it will from the batteries. (Saves melting 'em, I'll admit.) Here the standard offering for domestic use is a 10 kWh bank, with double that advised for off-grid. (Two 10 kWh banks would be good for 6 kW drain, but it'd take an above-average inverter to do it.) > If I can off load the spare refrigerator, freezer chest and well pump > that will be about half my domestic electric cost. With luck I can > eventually get the whole house on solar + wind power. There's an article out in webland on converting a freezer to a fridge, to take advantage of the better insulation and that the cold air doesn't all tumble out when the door opens. We've been off-grid for 53 years, first candles and kero lamps, finally a generator, but still a gas fridge. That's not much chop on a 45°C day. I'm putting in 24v LED lighting, and a little 24v fridge/freezer for its much lower power consumption - important after the sun goes down. I was going to put a heat pump (for hot water) in the roofspace to cool that instead of installing aircon, but a belated calculation shows I'd need to blow through 800 m³/h of air for 4.3 hours to raise 50 litres of water by 20°C if the air is cooled by 20°C. That'd do me for summer, else the water heating is by in-flue heat exchanger on the wood heater. What I'd _really_ like to do now is find a smallish water-source heatpump (they all seem to be very big units for slab heating from a lake or groundwater). A modest unit could slowly cool a one or two tonne indoor insulated water tank while heating water in the HWS. Storing tens of kWh of "cool" in this cheap way would be great for cooling after the sun goes down. (Might have to import one, if I can find it. Hmmm, I have a fat 230:110v transformer in the garage, just in case.) > The shop will always have to be on the grid, the big CNC's have 26Kw > or higher startup loads. If the house is off grid then my electric > bill will be a 100% business expense. (/Greg) That's serious power. My machines are only 1.5 kW each, and the battery would only be needed for a cloud coming over, during the day. There are a _lot_ of 100% clear days 8 or 9 months of the year out there. One thing I've cottoned onto just in time is the fallacy of "Point your array toward the equator for maximum output." That'll drop your off-grid aircon out (or flog the battery) in the late afternoon when it's still hot, but the sun's both dipped and swung a surprising amount away from the equator as it's going down. I'll now be splitting my array - half facing due north (southern hemisphere), and half west-facing to keep an aircon plugging away on a 45°C afternoon. The hybrid inverter serves as both PV inverter and battery inverter/charger, previously separate in AC-coupled systems, saving quite a bit of cost. I like that a lot, and will be watching the new offerings until I have to screw one to the wall. We're limited in the array oversizing allowed if we're on-grid, but off-grid it's a case of anything the inverter is rated for. As a 6 kW array will only deliver 3 kW on a good winter's day, according to the boffins, I figure on passing a few extra panels up to the installers. In summer the excess will at least shade the roof. (And pay dividends on an overcast day.) Hope there's enough useful stuff there to make the OT worth it. Erik ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT note to Erik C - Solar batteries
A friend of mine recently replaced his aging lead acid battery bank with a wrecked Tesla battery. He documented the project on YouTube. Good stuff with lots of great DIY info. It's very interesting if you're a geek, even if you aren't planning on hacking a battery for your solar powered house. Here's the first in the video series. https://www.youtube.com/watch?v=qpPYkqpe-Ms On 2/12/19 8:05 PM, Greg Bentzinger via Emc-users wrote: (Greg) Erik, A trend I have been noticing in the DIY solar crowd is to salvage the batteries from wrecked Tesla or Mercedes Hybrids. The Batteries are series wired for output in the 400VDC range but can be rewired in parallel for a 50-60VDC output. Just need to be sure the charge controller has a custom or Li-po setting. I hope to rig up a 6Kw bank here at the ranch so it can handle the Inrush starting demands of my deep well pump. If I can off load the spare refrigerator, freezer chest and well pump that will be about half my domestic electric cost. With luck I can eventually get the whole house on solar + wind power. The shop will always have to be on the grid, the big CNC's have 26Kw or higher startup loads. If the house is off grid then my electric bill will be a 100% business expense. (/Greg) ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] OT note to Erik C - Solar batteries
(Greg) Erik, A trend I have been noticing in the DIY solar crowd is to salvage the batteries from wrecked Tesla or Mercedes Hybrids. The Batteries are series wired for output in the 400VDC range but can be rewired in parallel for a 50-60VDC output. Just need to be sure the charge controller has a custom or Li-po setting. I hope to rig up a 6Kw bank here at the ranch so it can handle the Inrush starting demands of my deep well pump. If I can off load the spare refrigerator, freezer chest and well pump that will be about half my domestic electric cost. With luck I can eventually get the whole house on solar + wind power. The shop will always have to be on the grid, the big CNC's have 26Kw or higher startup loads. If the house is off grid then my electric bill will be a 100% business expense. (/Greg) ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
