I’m a legal medical marijuana patient with grow right and I live off grid. I built a little a frame green house last fall and grew pretty well in it. I’m going to upgrade my greenhouse and make it bigger and want to run led grow light off my solar in the greenhouse at night to boost my plants and was wondering what the lowest wattage per plant i can use and what the best led light are or any tips tricks or ideas anyone has to help me get the best for the least
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Solar and night lights = batteries.
200W LED Equivalent should get some bloom.
@Baudelaire may have some thoughts for you.
Well if my math is correct I should be able to pull 500w of 12dc led lights with 300ah worth of batteries for at least 8 hours so with the winters 10+ hours of sun light plus 8 hours of grow lights should put me right where I’d like it. I’m gonna be running autos this winter for more room in my greenhouse and won’t have to worry about the photoperiod getting disrupted
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Love to see pics of your green house
Here is a link to mine.
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That’s beautiful. mine was a throw together with the stuff I had to keep the plants alive last winter I’ll upload some pics when I get home
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Several largish marine type solar panels & voltage regulator/charger, 4 truck batteries, led driver/s and of course the SolStrips cos nothing much else makes sense at that low voltage. Wont be cheap though and it depends on your diy skills 
With a 500w set up any idea how many plants I should grow under it? And if I got the 5w full spec led strips and put like 100 of them spaced out would that help increase my plants?
I’ve been off grid low income for 10+ years so diy is my jam
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You pretty much get back what you put in light wise if everything else is ok so it’s down to plant numbers. Sea of green = fast turn around but high plant count might matter. A few small bushes in pots (my preferred method) and make them take up the space OR you could even do some sort of scrog in a greenhouse with the extra lighting cos leds can be placed close to the plants. It’s your choice to make but don’t make more work for yourself than you need to.
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Pro greenhouses use very low-power lights to preserve the photoperiod, it doesn’t take much. I would rely on the sun in your situation. You could use a few small bulbs to extend the photoperiod and use the sun for everything else.
Wouldn’t it be easier and cheaper to get another crop in by using a tarp over the greenhouse or something? Trying to use artificial lighting powered by solar panels doesn’t sound feasible, seems like it would be really expensive.
I have some of these Philips bulbs that are used to extend photoperiod in ornamental flower greenhouses - they’re only 13 watt bulbs. They use as few as possible to convince the plants the day is longer, they don’t provide much horsepower for actual growing
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I’m just growing for medicinal use for me and my wife we both have our card so we are allowed 24 plants between the 2 of us so I’d just like a steady flow. If I could be harvesting 4+ ounces a week all year around so I don’t have to pay ungodly prices at the dispensaries I’d be loving life
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That really is looking nice in there these days pal I wish i had a garden here but it would just frustrate me like it did at our last place (they don’t grow so well when they think it’s dark all the time) 
I’m gonna be using auto flowering strains this winter so I only need to lengthen the photoperiod to increase yield and potency. 10 hours of light in the winter will still grow my plants but theyre wimpy and imbarrassing. I already have 500w of solar panels plus a 400w wind generator which in our high winds runs 3+ days a week plus a 410ah 12v solar battery.
I get it, so you’re really looking for supplemental lighting, as much as possible. I guess you figure out how many watts you can provide and go from there? does the setup provide A/C current? It sounds cool, having independence from the electrical utility would be awesome.
you probably don’t want a big, flat panel LED fixture because it will block sunlight, a bar-style light would be better. is there a budget number for this?
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Me and my missis both grow for rec and med reasons although it used to be just for rec reasons when we were younger. We still enjoy getting wrecked though I truly wish we could get a permit but in general all we are permitted to do here is exactly what we are told. For anything else you have to break their rules.
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I’m trying to keep it 12vdc I was thinking something like this https://m.ebay.com/itm/Waterproof-Led-Grow-Bar-Rigid-Strip-Light-50cm-Hydroponic-Plant-Growing-Lamp-12V/323105943876?hash=item4b3a9d7144:m:mhgLruZoP804YL3IyVBlTbA
and buy 50 or so I put them all around the places between my glass on the top
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Those strips would need to be only a few inches from the plants and you would risk blocking out the far more powerful sunlight in doing that. A few high powered cobs on individual small heatsinks strung high up would be better but not cheap to do. Especially on battery power alone. If you had a budget of a couple thousand it would be quite easy lol
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I’m still building my bigger greenhouse so any design ideas could help too… I have 4 8ft by 4ft glass panes and was thinking about running them heightwise at a 45 degree angle against the house toward the southeast. Could I run the light strips down between the glass panes or should I flatten out the top and put my lights up top
Ya I have about a $350 dollar light budget or the wife will start getting mad. A 1000+ and I’d have lights but no wife
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What about 12volt florescent lights?