Trying to get a greenhouse off a generator

[707grower]

Hey everyone. I am new and extremely novice to how solar works and what I need. I thought I would jusy=t buy some cheap panels a few batteries one of these all in one systems and I could power the planet or some thing .

So first what I am trying to do. I have a greenhouse that's very off grid, we usually use a diesel generator to power, that's 30'x100' where I grow... will say...tomatoes . anyways we have about 28 wall mounted 16" oscillating fans that pull about 50 Watts ea. it will have to run about 15 hours a day with 12 hours being during the day with sun(except on cloudy days I guess).

so from watching the YouTube channel and asking around it seems like ill need 1400 watts of solar panels and about 21 kWh of battery storage? which seems like over kill to me. do I need that much storage if most the time its running during the day or worse case cloudy/rainy day?

Thanks for any advice.
Kevin

 

[OzSolar]

so from watching the YouTube channel and asking around it seems like ill need 1400 watts of solar panels and about 21 kWh of battery storage? which seems like over kill to me. do I need that much storage if most the time its running during the day or worse case cloudy/rainy day?

Welcome.

I used to like to share a tomato now and then with some friends on the river but they just make me sleepy now. However the body does have some aches that it didn't 20 years ago so maybe I should try them again?

So no lights? No water pumping?

Quick math:

1st you have to figure out you kWH then you can figure out the rest.

28 x 50w x 15hrs = 21 kWh/day

Generally speaking lets assume you'll have less than ~6 hrs in the summer and maybe ~3 hrs in the winter to make those 21 KWH. (others might chime in and point out that in California you will have different hrs so you can fine tune the numbers better for your location)

21kWh/6hrs = 3.5 kW array (not sure how you got 1.4 kW)
21kWH/3hrs = 7 KW array is probably the minimum size you should go with.

You inverter won't be 100% efficient plus lots of other details that aren't critical to painting the big picture result that 21kWh of battery will get you around 3/4 of a day of back up or less and that's assuming you're using LiFEPO4 with 90% DOD.

 

[707grower]

Welcome.

I used like a tomato now and then but they just make me sleepy now. But the body does a have some aches that it didn't 20 years ago so maybe I should try them again?

So no lights? No water pumping?

Quick math:

1st you have to figure out you kWH then you can figure out the rest.

28 x 50w x 15hrs = 21 kWh/day

Generally speaking lets assume you'll have less than ~6 hrs in the summer and maybe ~3 hrs in the winter to make those 21 KWH. (others might chime in and point out that in California you will have different hrs so you can fine tune the numbers better for your location)

21kWh/6hrs = 3.5 kW array (not sure how you got 1.4 kW)
21kWH/3hrs = 7 KW array is probably the minimum size you should go with.

You inverter won't be 100% efficient plus lots of other details that aren't critical to painting the big picture result that 21kWh of battery will get you around 3/4 of a day of back up or less and that's assuming you're using LiFEPO4 with 90% DOD.

thanks for the info, seems like I was right about how much battery storage I need, might have to reconfigure the fan situation.

As far as using "tomatoes" to ease your pain defiantly use CBD all the healing stuff with out the downside effects.

Thanks

 

[OzSolar]

thanks for the info, seems like I was right about how much battery storage I need, might have to reconfigure the fan situation.

As far as using "tomatoes" to ease your pain defiantly use CBD all the healing stuff with out the downside effects.

Thanks

You're welcome.

Yes, It's almost always best to spend some extra time and money on reducing the loads than it is to make the system larger.