EmeraldØsiris
Well-Known Member
Yeah... you could be right. I read many places that a 5kw system produces about 20kwh per day. 12 x 650w lights would need 94kw per day. You'd need 40 x 670w panels to produce this in a day.
LED vs Solar Power (Offgrid)
- Thread starter EmeraldØsiris
- Start date
bk78
Well-Known Member
You realize the year is 2022 and not 2000 right?That's the average price per lbs in the US. Where I am at I'd get $3000 per
wag040
Well-Known Member
You would need 18 hour run time for vegging right? So your 7. 8kw load over 18 hours is 140.4 kwh. Where I am at, we would get about 4.5 hours of sun on average over the year so that would mean you need roughly a 31.2 kw solar array to generate that amount of kwh per day. However if you are running this year-round, consider designing for worse case sun. For me it would be 2-2.5 hours so that now means you need even more solar, more like 56kw. The solar panels don't run your loads, the batteries do. The solar charges the batteries through a charge controller which is separate or integrated into the inverter. To carry your load just off batteries, assuming a 48V battery bank, you would need 2,925 amp hours. That is just for 1 day. If this is all mission critical, a generator would be a must IMO. Having one will also allow you to reduce your solar array and battery sizes.
Check out Sol Ark inverters. They are compatible with many battery options and are solid inverters.
Check out Sol Ark inverters. They are compatible with many battery options and are solid inverters.
EmeraldØsiris
Well-Known Member
no, I'm still stuck in 2020.... I don't even live in the states, so not my turf anyways... In other words, I don't care what the price is. What I care about is the actual cost of running 12 lights with solar... Some hostile tokers here for sure.
EmeraldØsiris
Well-Known Member
nah. Flowering room only. Lights only. 93.6kw per day.
Best answer yet. Do you know if there are any benefits of DC-DC over a DC-AC other than led drivers and inverter costs?
I see that a 1000ah battery bank at 48V holds 50kwh of power.
The relationship between panels and batteries? Can a battery completely drain? BMS?
Ideally what I'm tryna figure out is how to design a flowering room with different diodes to get a 1000ppfd even coverage in a 4x4 on 650w/h lights x 12.
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bk78
Well-Known Member
Hostile, I haven’t seen any hostility in this thread?
EmeraldØsiris
Well-Known Member
Hey thanks man, with electricity prices getting up there it sure makes sense to begin thinking differently, especially long term. I would probably grow rows of 3 in each 4x8, so a total of 12 in each. Total plant count would be 72... So I'd use a 100x cloner and veg them pretty tight, probably on grid (no smell) and transport them to site. Either that or just put up more panels and setup a mother and veg room.
I looked at a battery pack today that was 600kg. It held 50kwh of power! It was also 8000dollars. I think I'd rather go with individual car battery style bank with a BMS to cut costs. I'd even look into a diesel generator as backup or to charge batteries if needed... trying to avoid that though.
Yeah there will be a lot of other odds and ends to deal with too such as dehumidification, airconditioning, inline fans etc. Everything would be on IOT and I'd probably invest in automatic irrigation and fertigation. Should be as easy as just using an app... really. I don't sing to my plants, i feed them.
Ways to save would be to have sunrise and sunset programmed to the LED's... also reduce PPFD towards the end of the grow. Just that would probably cut the kwh's significantly! Perhaps also using more diodes spread on the area would also increase efficiency.
Cost wise it seems daunting... and it probably is... that's why I'd like to try to get a better understanding of the actual numbers and how to tweak them.
wag040
Well-Known Member
Depending on where you are, it can be challenging getting DC rated equipment which is why most go with AC. Other than some DC-AC conversion efficiency losses, both setups can work well.
Battery chemistry will determine your depth of discharge. If you go lead acid or sealed (golf cart) style batteries, then ideally you only want to drain them by 50%. The newer lithium and similar types can be drained almost 100%.
Rurumo
Well-Known Member
It isn't financially feasible to do this and someone is going to wonder why you have a big field of solar panels. Better to look into using a closed/heated greenhouse with sun as your primary light source, then use LED as a supplemental source as needed when the sun drops. Or better yet, just grow an outdoor crop every year.
CochiseChronic
Active Member
I grow with LED off-grid on solar. I can run 2 SF-4000 + ac with power too spare. I have 3kw system 12 panels + 12 batteries 3/48volt bundles. Right around 3k$. U can find good used panels and great used batteries if u look
EmeraldØsiris
Well-Known Member
Nice. Do you run AC current? I'm trying to figure out what the lumen difference is between the loss of inverting from DC to AC on both panels and led drivers.
This guy runs a pretty comprehensive test on the sf-4000's:
Lots of bang for buck there. Have a look at these: https://www.arrow.com/en/products/si-b8v521b20ww/samsung-electronics?region=nac
You can pick up 100 of these for under $700. They are rated at 51.5 watts per 2 foot strip, so that is 5150watts of light at 167lumen per watt. 12 of these in a 4x4 space would give even spacing, but roghly 1400ppfd+ per 4x4 area at 600w.
EmeraldØsiris
Well-Known Member
Did a lil research and found that that a 50khh system makes about 6000kwh per month.
12 lights at 96.3kw per day would would consume 2808kw per month. Therefore the right system for this setup would be a 25kwh system. The best price/quality I can find on a system like this is from a Chinese company called Yangtze Solar.
They are 700w panels. My calculations were not that far off.
Total cost for this system would be $32000 before say 30% tax credit.
The cheapest Tesla is 47,000 to put that into perspective. I'd say a solar system would be a better investment for a grower running 12 lights. Average US yearly cost on-grid for this setup would be $5593. You'd pay off the system for that in 5.7 years. I don't even want to do the math on the bud produced in that time, but with a gram per watt we're talking outrageous numbers.
I'm thinking more along the lines of a 50kwh system for a purpose-built underground grow room built with precast concrete. Then I'm going to build a house on top of that.
12 lights at 96.3kw per day would would consume 2808kw per month. Therefore the right system for this setup would be a 25kwh system. The best price/quality I can find on a system like this is from a Chinese company called Yangtze Solar.
They are 700w panels. My calculations were not that far off.
Total cost for this system would be $32000 before say 30% tax credit.
The cheapest Tesla is 47,000 to put that into perspective. I'd say a solar system would be a better investment for a grower running 12 lights. Average US yearly cost on-grid for this setup would be $5593. You'd pay off the system for that in 5.7 years. I don't even want to do the math on the bud produced in that time, but with a gram per watt we're talking outrageous numbers.
I'm thinking more along the lines of a 50kwh system for a purpose-built underground grow room built with precast concrete. Then I'm going to build a house on top of that.
EmeraldØsiris
Well-Known Member
Edit on that. The total system cost for 50kwh system would be $16,000 shipped as I've opted for a on-grid tied system without mounting brackets.
Electricity prices here for 100kwh x 12hours a day x 365 days a year is $13,000 per year just to run the 12 lights. That is not taking into account vegging. Then you have A/C and dehumidifyer which will add up also. With a system like this I would be able to run the entire household along with growing high quality indoor bud year around. Will also be able to power some greenhouses.
All in all... I think it is completely feasible. Excess produced would also give credit on a grid tied system.
Electricity prices here for 100kwh x 12hours a day x 365 days a year is $13,000 per year just to run the 12 lights. That is not taking into account vegging. Then you have A/C and dehumidifyer which will add up also. With a system like this I would be able to run the entire household along with growing high quality indoor bud year around. Will also be able to power some greenhouses.
All in all... I think it is completely feasible. Excess produced would also give credit on a grid tied system.
bk78
Well-Known Member
You ordering this from alibaba with these prices?
Oldguyrealy
Well-Known Member
Generators don't hold up. Solar should work fine if you have the panels to charge your Batteries.
If you can I would run DC LED will run just fine.
If you can I would run DC LED will run just fine.
EmeraldØsiris
Well-Known Member
Yes, that's the plan - Yangtze Solar, made by Trina solar https://www.alibaba.com/product-detail/Panel-Solar-700w-Free-Shipping-Yangtze_1600266640352.html?spm=a2700.galleryofferlist.normal_offer.d_title.342d6c4cZWk272&s=p
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