Very Very New check my work please

[carolinaken]

Putting together my first solar off grid system. Im 59 years young and this is my first attempt. . So far I have been using the Renogy brand. I wanted to give it a try, so putting together a 300W system together for my green house.. My desire to run fans, grow lights. I would like to run a a heater in winter months but from what I have read I have my doubts I can do that with what I have . So far I have placed a 40amp mppt charge controller with remote trace meter, 2000w inverter. On the way are 3- 100w monocrystaline panels and 2- AMG 12v 100ah deep cycle acid batteries. . I HOPE this is a good setup. I would like some info on where to place fuses and what size. I know one should be between controller and batteries, and one between batteries and converter. ANY and all help of information would be greatly appreciated. Thank you / Ken

[SunEagle]

Well the good news is that with 300 w of panels, a 12v 200Ah battery and an MPPT CC you have a nicely balanced system

The bad news is that battery system is rated 2400 watt hours (12v x 200Ah = 2400) and you could probably get about 600 wh or 25% DOD each day. I don't know what you need to run your fans lights, etc but 600 wh is not much.

[J.P.M.]

Putting together my first solar off grid system. Im 59 years young and this is my first attempt. . So far I have been using the Renogy brand. I wanted to give it a try, so putting together a 300W system together for my green house.. My desire to run fans, grow lights. I would like to run a a heater in winter months but from what I have read I have my doubts I can do that with what I have . So far I have placed a 40amp mppt charge controller with remote trace meter, 2000w inverter. On the way are 3- 100w monocrystaline panels and 2- AMG 12v 100ah deep cycle acid batteries. . I HOPE this is a good setup. I would like some info on where to place fuses and what size. I know one should be between controller and batteries, and one between batteries and converter. ANY and all help of information would be greatly appreciated. Thank you / Ken

Most folks start by learning about the solar resource and something about energy use and loads and then starting with a plan before they buy anything. Good news is you started small. Bad news is you don't know what your doing (yet) and that PV systems are not usually easy to scale up.

I'd suggest learning and studying more before you proceed further.

[carolinaken]

Have a watt meter.. The fan ( if I recall correctly ) .45 watts. It only runs when greenhouse gets over 100 degrees. so time it runs is limited to heat of the day. The grow lights are led and I have not tested them with a meter yet, Also limited about of time 2 - 3 hours in winter months. Any advice on fuses ? What upgrades might I need to grow later on ? 3rd battery ?

[carolinaken]

Also should a trickle charge the batteries until full before using them? I have head reg car battery chargers are too aggressive of a charge ??

[Mike90250]

I use an old fashioned kerosene railroad lamp for keeping the greenhouse above freezing in the winter.

[MichaelK!]

Also should a trickle charge the batteries until full before using them? I have head reg car battery chargers are too aggressive of a charge ??

No, that is NOT correct. If your battery bank is 200AH, then a good charging rate is 20A. Few automotive chargers go that high. If it does, set it to the closest setting to 20 and use that.
You are correct though that full batteries are happy batteries. Periodicly monitor their state of charge, and get them fully charged any way you can byweekly or so.

Did you mean your fan uses 45watts? I seriously doubt the .45watt value. Two amps at 12V would produce the needed power, and 10 hours of the fan running would consume ~1/10 of your total capacity.

[Sunking]

Stop what you are doing. It is not going to work because everything is grossly undersized.

[carolinaken]

Sunking and Suneagle can discuss... -- Suneagle --Well the good news is that with 300 w of panels, a 12v 200Ah battery and an MPPT CC you have a nicely balanced system. I think Im fine just to run a fan and a few led light at random if not.. Solar is over rated

[J.P.M.]

Solar is over rated

Or you are misapplying PV. Solar thermal is usually better suited for keeping things in a greenhouse warm.

[Mike90250]

...... Solar is over rated

No, solar is over hyped. Applying solid engineering principals, and it's just fine.

Oh wait, my new expensive Porsche is junk, I can only fit 1 car-seat and 1 bag of groceries in it. Porsche is so overated....

[SunEagle]

Sunking and Suneagle can discuss... -- Suneagle --Well the good news is that with 300 w of panels, a 12v 200Ah battery and an MPPT CC you have a nicely balanced system. I think Im fine just to run a fan and a few led light at random if not.. Solar is over rated

What I am saying is that your system design is ok but small and if you didn't design it for the correct daily watt hour usage it will fail. Sunking is trying to save you money up front be trying to tell you that small solar / battery systems can be a waste of money so maybe you should not purchase anything.

Depending on what that fan and led light actually consumes will determine if that system will work or not. Remember it may only provide about 600 watt hours each day which is easy to use up depending on how you really run your loads.

By the way I build a small solar / battery system for about $2500 and it barely provides me 700 watt hours a day.

[Sunking]

I think Im fine just to run a fan and a few led light at random if not.. Solar is over rated

Maybe, maybe not. Solar is hyped on the unknowing public who knows nothing about energy and led to believe it is cheap and endless. Nothing could be further from the truth.

A 300 watt panel with a 12 volt 200 AH battery will provide you roughly 500 to 700 watt hours of electricity per day in summer and far less in winter. That is less than 10-cents of electricity per day.

First issue you have is your inverter is grossly over sized for your panel and batteries. Your batteries can only handle a 500 watt inverter. Next issue is you have no clue of how much power you need in a day. 500 to 700 watt hours might work, or might not. No one knows because you have not told us. Lets do some simple math.

Watt Hours = Watts x Hours. simple 5th grade math.

So if you have say a 50 watt fan and run it for 10 hours = 50 watts x 10 hours = 500 watt hours.

So now your job is to figure out how much power you will use in a day worse case. You have to determine how much power in watts all the motors and light use, and how many hours per they wil be used. Example if they add up to say 300 watts, and you want to run them 10 hours per day you are SOL because 300 watts x 10 hours = 3000 watt hours or 6 times more than your system can deliver. With a 300 watt load only gives you 1.5 to 2 hours run time.

Forget the heat idea, it is not going to happen.

[carolinaken]

SunKing / Thanks for the info == Knew the heat was not going to happen as why I have ac in the green house . I run an oil filled heater presently. Checked the watts on the fan today 97 watts on high setting. It ran 4 times today for no longer then 5 minutes. in 8 hours. It was not a very hot day. Not sure im getting what I should from my panels as Im not sure what numbers I should have ,, On control panel below panel icon / 20.9v - 2.4 amp.. battery icon 13.8v 3.0 a. I do have and old 350watt inverter I can switch to.

[carolinaken]

What i hoped to get with this system .. first of all.-- just to try solar and get my feet wet.. goals are,, run fan in summer and lights / maybe / in winter..the greenhouse is a new build and Im not sure what my exact times will be for fan or lighting . I have to see how things go with the green house and the solar combined.. both are new .