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Plan: Off grid solar with a Model S battery pack at the heart
- Thread starter wk057
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- Energy Environment Policy
Yeah, kinda like that. Vague info thats probably intentionally misleading. I was trying to figure out how it works. Does it more or less re-use the inverter as a grid tie, which presumably means it stops back feeding when the unit kicks on, or does it require additional hardware and have absolutely nothing to do with it? I suppose the thing could run off the DC even while the unit is running, but this all sounds very questionable, presumably it would want a good 200-400VDC, and I noticed one install had 2 panels.
That is a damn nice unit, however. I'd like to buy one, but I had a hard time trying to get just the condenser shipped to my door. I guess Lennox is protective of its equipment and I couldn't find anyone to sell it to me, it has to be 'installed'.
Has your pool ever frozen before? Do you have to heat your pool to keep it from freezing?
Let's say you put a really big blanket over the pool, added no heat, and in the course of the entire winter the coldest it would get is 50℉. So you have 18° till freezing. One btu lowers 1lb of water 1℉ in 1hr.
Let's assume you have a 20k gal pool. That's 166k lbs. Almost 3million btus to lower your pool those 18°. Let's say your running a heat exchanger off of your 5 ton unit that's 60k btu/hr. Thus it would take about 50hrs to freeze your pool.
Note: This is just a hypothetical case.
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This is a really cool way to approach heat though. Use the heat by product from cooling to heat water(or other liquids), and vice versa in the winter. The epitomy of an energy efficient home would have your fridge, freezer, pool, chilled water, hot water, etc. all done with heat exchange. In the winter all the excess cold could be used to make ice...
Let's say you put a really big blanket over the pool, added no heat, and in the course of the entire winter the coldest it would get is 50℉. So you have 18° till freezing. One btu lowers 1lb of water 1℉ in 1hr.
Let's assume you have a 20k gal pool. That's 166k lbs. Almost 3million btus to lower your pool those 18°. Let's say your running a heat exchanger off of your 5 ton unit that's 60k btu/hr. Thus it would take about 50hrs to freeze your pool.
Note: This is just a hypothetical case.
- - - Updated - - -
This is a really cool way to approach heat though. Use the heat by product from cooling to heat water(or other liquids), and vice versa in the winter. The epitomy of an energy efficient home would have your fridge, freezer, pool, chilled water, hot water, etc. all done with heat exchange. In the winter all the excess cold could be used to make ice...
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schueppert
Member
That Lennox unit is really nice, but the bundling with solar is mostly smoke and mirrors. It's an AC unit (as in alternating current, not air conditioning) that they are putting together with an Enphase-based solar solution.
This is going to be dependent on how much hot water you use, how you use it, and the house layout, but drain water energy recovery is generally easy to pop in.
http://www.renewability.com/uploads/documents/en/gen_res_bro.pdf
My unit saves a peak of ~27%, but it takes a few minutes for maximum effect. With PVC drains it should work better. Probably not terribly economical with a heat pump water heater, however it does save some energy.
http://www.renewability.com/uploads/documents/en/gen_res_bro.pdf
My unit saves a peak of ~27%, but it takes a few minutes for maximum effect. With PVC drains it should work better. Probably not terribly economical with a heat pump water heater, however it does save some energy.
As you may remember, you have a unified system that is slightly larger than mine in some respects; massively larger in others. One of the kludgier aspects I have to deal with is in that my PV arrays are of two different vintages & different specs, I also then need have two separate charge controllers (for the interest of The Shadows: one is a FlexMax80 and the other a MidNite Classic).
At any rate, I emboldened that snippet of yours as above because I ran into quite a situation this winter/spring - I found out the hard way that the charge controllers themselves take a very, very dim view of a low voltage reading on their downstream side. More specifically: regardless of how much solar insolation the panels, and thus the charge controllers, may be seeing, they will not operate if the battery bank is at too low a voltage. Now, I did not determine what that point is, but in order to kickstart the system I did have to bypass the controllers with generator-derived electricity into the batteries in order to satisfy the ccontrollers that all was, indeed, all right in the system. And once again, thanked my lucky stars for those overly bulky, older technology, but hugely robust Pb-Ca AGM batteries I have: no harm done. In brief, then: you may wish to confirm that 36V is not lower than the cutoff point for your MidNites to be happy.
I hope this helps -
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cashie
Member
Been busy for the past few weeks. Will have an update soon.
I'm having withdrawals... :wink:
Almost a month in...
So! Thank you all for waiting patiently.
A lot has happened over the past few weeks... not really related to this project. Long story short: got married, went to Hawaii. :biggrin:
Left NC for NJ (where our wedding was and a lot of our family lives) on 5/26 in the morning, got married on 5/30, back to NC on 6/1 in the morning, arrived home late 6/1, packed and such on 6/2, left for the airport at 5AM on 6/3, flew to Atlanta, then from Atlanta to Honolulu. On 6/8 flew from Honolulu to Hilo on the Big Island, spent the day there, then flew back to Honolulu that evening. On 6/11 did the reverse and ended up back home this morning on 6/12. Phew. Lots of moving around.
Anyway. I left my system off-grid while I was away, figuring even with just the roof setup there was no way I'd run out of power with the HVAC set to "away" and only a few things running, like the pool pump. Was averaging only ~35 kWh/day while away. Seems like a lot, but it's not too bad all things considered. Batteries were staying pretty close to my full set point during the day. Wasted quite a few kWh by not having loads available. Occasionally I would see them full with full sun and crank the A/C for a few hours to burn off some juice.
On Saturday, 6/6 at ~11PM my home network went down. Nothing was reachable. I figured my cable provider was having problems and decided to leave it be until morning. In the morning, still not reachable and no indication that my router machine had tried to re-establish contact with any of the my remote servers since 11PM the night before. Odd.
I had a relative crashing at my place at night while I was away, and he called me soon after this and told me the power was out. Weird. I woke up my wife's P85, on the charger in the garage, and it said "Charge Port Open, Connect Charge Cable" or something along those lines. Power was off! My TED system's display for my grid panels was functioning (locally, no remote access with no power to my network equipment).
Inverter monitor was blinking with a red light indicating an "Event." Calling up that menu on the device my relative read, "Loose DC Neg Terminal GS-1." Weird, not really possible. No breakers tripped or anything, but no power from the inverters. My relative wasn't comfortable tinkering with anything, so I called a friend and he headed over to check it out.
He removed the dead front to that inverter's load center. Connections were all fine. No fuses or breakers popped, etc. Weird!
Decided a full shutdown and reset was in order. Then decided to just partially bring the system online. No need for 8 inverters running/waiting while no one was really there using power. Decided to power on just the first four to easily cover HVAC loads.
Closed all of the DC breakers, no problems. No events. Good so far. Closed the AC output breakers. No problems. AC input breakers. No problems.
However, even though the controller showed the inverters were on, no power was being output to loads (at this point the only AC breaker closed was for the lighting in the area). Weird.
I told him to turn the inverters off on the controller, and back on. He did this and I heard a *POP* accompanied by a scream from my friend. "WHOA!!!"
"What happened?!", I said.
"This one inverter just lit up like a Christmas tree and sounded like it exploded," he replied.
"Wonderful."
Turns out the 175A DC breaker for one module on the master inverter (far right) had tripped.
Well, no sense playing games while I'm 5000 miles away. Decided to just shut everything down. Inverters, charge controllers, solar combiners, everything.... and flip the transfer switches back to the grid until I got back.
House was back online. My network came back up, checked logs and such. Turns out I don't have the ethernet switch that connects the inverters and charge controllers to my home network on a UPS. So, when the power went out my home network was online for ~45 minutes or so on UPS's, except the equipment couldn't send any notifications since that switch wasn't powered. *facepalm* I blame the designer of this system..... oh wait......
So, got home this morning and got on the phone with Outback Power tech support. (I had emailed them the details earlier in the week.) With them on the line we went to diagnose the issue. I removed the covers and dead fronts from the first two inverters before calling.
Found out pretty quickly. As soon as I closed the DC breakers for the far right inverter. It appeared to catch fire inside and released quite a bit of magic smoke. The DC breaker tripped within a few seconds while I was turning around to grab my fire extinguisher. Was ready, aiming, and about to fire the extinguisher when it died out on it's own. (All inside the aluminum housing of the 4kW inverter sub-module.) I was giving the tech on the phone a blow by blow as these things took place. We both agreed that the problem part had been found.
Not sure why the module failed in this manner, but they're overnighting a replacement module and control board for that inverter, which I should be able to install next week.
I then went through and retested each other inverter individually. All were fine. I then reconfigured them with the second inverter as the new master inverter (required moving some low-voltage comm wires to different ports and changing settings on each unit). Back up in running using 7 out of 8 of the inverters.
Battery bank is full, so, running basically directly off of the sun for the moment and wasting some percentage of power. Should be fine tomorrow, though. Overnight I'll use the pack a bit and in the morning it'll be recovering at full power.
Overall though, not too bad. Faulty module. 1 out of 16. Protective devices worked as they should. Pretty good stuff.
I was asked elsewhere when talking about all of this: "Is that a significant hazard when nobody's home, or does it automatically cut power and have sufficient fire suppression?" to which my response was: "The breaker tripped when it happened both times (when my friend was here and this morning). I also have automatic fire suppression (few small halon tanks connected to sprinklers) along with a central station monitored fire and burgler alarm system. If a smoke detector goes off the fire department is on their way." It's also worth noting that all of the equipment is inside aluminum enclosures which are mounted to a concrete wall block wall. Pretty contained, IMO.
That's my update. The ground mounted array's layout is being finalized. Will likely get permits and material ordered for their racking within the next couple of weeks.
So! Thank you all for waiting patiently.
A lot has happened over the past few weeks... not really related to this project. Long story short: got married, went to Hawaii. :biggrin:
Left NC for NJ (where our wedding was and a lot of our family lives) on 5/26 in the morning, got married on 5/30, back to NC on 6/1 in the morning, arrived home late 6/1, packed and such on 6/2, left for the airport at 5AM on 6/3, flew to Atlanta, then from Atlanta to Honolulu. On 6/8 flew from Honolulu to Hilo on the Big Island, spent the day there, then flew back to Honolulu that evening. On 6/11 did the reverse and ended up back home this morning on 6/12. Phew. Lots of moving around.
Anyway. I left my system off-grid while I was away, figuring even with just the roof setup there was no way I'd run out of power with the HVAC set to "away" and only a few things running, like the pool pump. Was averaging only ~35 kWh/day while away. Seems like a lot, but it's not too bad all things considered. Batteries were staying pretty close to my full set point during the day. Wasted quite a few kWh by not having loads available. Occasionally I would see them full with full sun and crank the A/C for a few hours to burn off some juice.
On Saturday, 6/6 at ~11PM my home network went down. Nothing was reachable. I figured my cable provider was having problems and decided to leave it be until morning. In the morning, still not reachable and no indication that my router machine had tried to re-establish contact with any of the my remote servers since 11PM the night before. Odd.
I had a relative crashing at my place at night while I was away, and he called me soon after this and told me the power was out. Weird. I woke up my wife's P85, on the charger in the garage, and it said "Charge Port Open, Connect Charge Cable" or something along those lines. Power was off! My TED system's display for my grid panels was functioning (locally, no remote access with no power to my network equipment).
Inverter monitor was blinking with a red light indicating an "Event." Calling up that menu on the device my relative read, "Loose DC Neg Terminal GS-1." Weird, not really possible. No breakers tripped or anything, but no power from the inverters. My relative wasn't comfortable tinkering with anything, so I called a friend and he headed over to check it out.
He removed the dead front to that inverter's load center. Connections were all fine. No fuses or breakers popped, etc. Weird!
Decided a full shutdown and reset was in order. Then decided to just partially bring the system online. No need for 8 inverters running/waiting while no one was really there using power. Decided to power on just the first four to easily cover HVAC loads.
Closed all of the DC breakers, no problems. No events. Good so far. Closed the AC output breakers. No problems. AC input breakers. No problems.
However, even though the controller showed the inverters were on, no power was being output to loads (at this point the only AC breaker closed was for the lighting in the area). Weird.
I told him to turn the inverters off on the controller, and back on. He did this and I heard a *POP* accompanied by a scream from my friend. "WHOA!!!"
"What happened?!", I said.
"This one inverter just lit up like a Christmas tree and sounded like it exploded," he replied.
"Wonderful."
Turns out the 175A DC breaker for one module on the master inverter (far right) had tripped.
Well, no sense playing games while I'm 5000 miles away. Decided to just shut everything down. Inverters, charge controllers, solar combiners, everything.... and flip the transfer switches back to the grid until I got back.
House was back online. My network came back up, checked logs and such. Turns out I don't have the ethernet switch that connects the inverters and charge controllers to my home network on a UPS. So, when the power went out my home network was online for ~45 minutes or so on UPS's, except the equipment couldn't send any notifications since that switch wasn't powered. *facepalm* I blame the designer of this system..... oh wait......
So, got home this morning and got on the phone with Outback Power tech support. (I had emailed them the details earlier in the week.) With them on the line we went to diagnose the issue. I removed the covers and dead fronts from the first two inverters before calling.
Found out pretty quickly. As soon as I closed the DC breakers for the far right inverter. It appeared to catch fire inside and released quite a bit of magic smoke. The DC breaker tripped within a few seconds while I was turning around to grab my fire extinguisher. Was ready, aiming, and about to fire the extinguisher when it died out on it's own. (All inside the aluminum housing of the 4kW inverter sub-module.) I was giving the tech on the phone a blow by blow as these things took place. We both agreed that the problem part had been found.
Not sure why the module failed in this manner, but they're overnighting a replacement module and control board for that inverter, which I should be able to install next week.
I then went through and retested each other inverter individually. All were fine. I then reconfigured them with the second inverter as the new master inverter (required moving some low-voltage comm wires to different ports and changing settings on each unit). Back up in running using 7 out of 8 of the inverters.
Battery bank is full, so, running basically directly off of the sun for the moment and wasting some percentage of power. Should be fine tomorrow, though. Overnight I'll use the pack a bit and in the morning it'll be recovering at full power.
Overall though, not too bad. Faulty module. 1 out of 16. Protective devices worked as they should. Pretty good stuff.
I was asked elsewhere when talking about all of this: "Is that a significant hazard when nobody's home, or does it automatically cut power and have sufficient fire suppression?" to which my response was: "The breaker tripped when it happened both times (when my friend was here and this morning). I also have automatic fire suppression (few small halon tanks connected to sprinklers) along with a central station monitored fire and burgler alarm system. If a smoke detector goes off the fire department is on their way." It's also worth noting that all of the equipment is inside aluminum enclosures which are mounted to a concrete wall block wall. Pretty contained, IMO.
That's my update. The ground mounted array's layout is being finalized. Will likely get permits and material ordered for their racking within the next couple of weeks.
Bangor Bob
Member
Likely a case of electronic infant mortality, but yeah, it could have picked a better time...
