advice please 500watt max usage, 1400ish watt system

ROTTEN · January 2014

Hello friends.

I have been reading on solar energy for a while now, for a few years now I have read
a little here and there and finally this past week I have started pricing out my greenhouse
that I want to be solar powered.

I'll have a rather small load but the thing is the load is during the day time when the sun
is hot and I need my exhaust fans to be running.

Here are what ill need to run
2x 110watt exhaust fans for roughly 10 hours a day, pretty much from 10am to 8pm(or from when it rises to 70'F in greenhouse)
1x 150watt water pump for a fish tank that will be within the green house.

Now I have done some intense reading this past weekend and really dived straight into the solar power OFF GRID with batteries.

The main question and wonder that I have is this...

Im planning on having roughly 750watts of solar panels(3x 260watters) so id imagine that on a cloudy day
the panels will be making maybe 200watts, which is PLENTY for the greenhouse since if its cloudy its not super hot inside it
and the fans dont need to be on but the fish tank water pump needs to be on ALL the time.
I dont need any lights in there, maybe a tiny LED lamp or even a 12watt CFL.

what I want to happen is this.
During a clear sky or even during any day time hour, id like the panels to be where the power is being pulled from
so this can leave the batteries available with full charge throughout the night 12-14 hours running a 150watt pump.

Here are the components that I have come up with to build this solar setup.
I do plan on expanding a bit, so I know/think i over sized things well enough.

I just need some expert advisement and a little critiquing to help me along this journey.
I have read a lot in teh past few days. lol head is spinning almost.

Panels
Hyundai HiS-260MG 260w Mono
Mono-crystalline Type
Nominal output (Pmpp) : 260
Voltage at Pmax (Vmpp) : 31.0
Current at Pmax (Impp) : 8.4
Open circuit voltage (Voc) : 37.5
Short circuit current (Isc) : 8.9
Output tolerance : +3/-0
http://www.affordable-solar.com/store/solar-panels/Hyundai-HiS-260MG-260w-Mono-Black-Frame

Charge Controller
Morningstar Tri-Star TS-MPPT-45
http://www.wholesalesolar.com/products.folder/controller-folder/MorningstarMPPT%20TS%2045.html

Battery
Concorde AGM PVX-1290T Sealed Deep Cycle Battery, 129 Amp Hour 12 Volt
http://www.solar-electric.com/concorde-sunxtender-pvx-1290t.html

Inverter
Samlex 1,000 Watt Sine Wave Inverter, 120 volts AC Output, 12 Volts DC Input
http://www.solar-electric.com/samlex-pure-sine-wave-inverter-pst-1000-12.html

what i really need to know is if im on the right path with this and any other literature anyone has
for me to read ill read it. Im right now going over this forum and reading any of the basic beginning stuff
i can find.

From what I read, the components I got there seem like that should be plenty for what I want to do.
I just wanna make sure.

if anyoen can break anything down for me in terms of what all these components will output on an average
sunny/partially sunny day that would be great too.

I figure that I should be able to pull 1k watts from that inverter from the batteries without an issue.
I just wanna know those other details.

Like will I have to ALWAYS pull from teh batteries then rely on the panels to keep them charged, WHILE im using them?
can that happen?

BB. · January 2014

Re: advice please 500watt max usage, 1400ish watt system

Welcome to the forum Rotten,

First questions revolve around the loads--In general, things that run for many hours per day--Tend to add up quickly--Which drives up battery and solar array sizing...

Looking at your power needs:

ROTTEN wrote: »

Here are what ill need to run
2x 110watt exhaust fans for roughly 10 hours a day, pretty much from 10am to 8pm(or from when it rises to 70'F in greenhouse)
1x 150watt water pump for a fish tank that will be within the green house.

2x 110 Watts * 10 hours per day = 2,200 Watt*Hours per day (fans)
1x 150 Watts * 24 hours per day = 3,600 Watt*Hours per day (water pump)
==================================================
5,800 WH per day = 5.8 kWH per day

That is not a small system... I am going to make some first pass simplifications--It may over size the system by 20% or so--But it does not matter for the moment.

A typical system would have 2 days of storage and 50% maximum discharge on the battery bank. Of course, during bad weather, you may not need to run the fans--But just for simplicity assume loads are used every day (sunny or not):

5,800 WH * 1/0.85 AC inverter eff * 2 days of storage * 1/0.50 max discharge * 1/48 volt battery bank = 569 AH @ 48 volt battery bank

Or, very roughly, 16+ times your one AGM battery you looked at.

Then there is sizing the solar array--First based on the size of the battery bank... Nominally, ~5% to 13% rate of charge:

569 AH * 58 volts charging * 1/0.77 panel+controller deratings * 0.05 rate of charge = 2,143 Watt array minimum
569 AH * 58 volts charging * 1/0.77 panel+controller deratings * 0.10 rate of charge = 4,286 Watt array nominal
569 AH * 58 volts charging * 1/0.77 panel+controller deratings * 0.13 rate of charge = 5,572 Watt array "cost effective maximum"

And sizing the array based on the amount of power you use per day--Guessing an average of 4 hours of sun for 9+ months of the year:

5,800 WH * 1/0.52 end to end system eff * 1/4 hours of noon time equivalent sun per day = 2,788 Watt Array minimum (based on loads+sun)

All of this is "worst case" analysis (charge during the day, run all loads at night, minimum of 4 hours of sun per day, etc.)...

Even if my assumptions are way out of wack, and you can reduce the above by 1/3rd to 1/2 (run fans only during sunny weather) and you use AGM batteries (more expensive but more efficient)--Does the above system (or 1/3 to 1/2 smaller of the above system) make economic sense to you?

"Typical" Batteries will last ~5-7 years (if taken care of). New electronics (inverter, charge controller) every ~10+ years.

If so, we can go further into the details.

If not, then start looking at your needs--Can you do natural venting with the green house? Can you run the water pump 30 minutes out of every hour? Can you use more efficient pump+PM type motor? Can you reduce back pressure on pump (lower pressure, lower flow rates, less energy used)?

The details analysis is a bit more "ugly" and work--But it only makes sense once we know more about the details for the power usage (12 months a year, 9 months a year, utility power available, roughly where is the green house)?

Are you going off grid solar to save money or because there is now utility power nearby?

Sorry for all of the questions and sizing such a large system... Off Grid solar power is not cheap (if done right, and needs to be reliable).

But done for the right reasons can be a whole lot nicer that running a genset 24x7.

-Bill

ROTTEN · January 2014

Re: advice please 500watt max usage, 1400ish watt system

BB. wrote: »

2x 110 Watts * 10 hours per day = 2,200 Watt*Hours per day (fans)
1x 150 Watts * 24 hours per day = 3,600 Watt*Hours per day (water pump)
==================================================
5,800 WH per day = 5.8 kWH per day

That is not a small system... I am going to make some first pass simplifications--It may over size the system by 20% or so--But it does not matter for the moment.

Even if my assumptions are way out of wack, and you can reduce the above by 1/3rd to 1/2 (run fans only during sunny weather) and you use AGM batteries (more expensive but more efficient)--Does the above system (or 1/3 to 1/2 smaller of the above system) make economic sense to you?
Ya, the cost isnt really an issue because the greenhouse has to be off grid, the run to the Utility
power IS WAY TO LONG and would be worth just putting in a solar system. For the gauge cable id need the cost of that
run of cable along will be hefty enough to look into solar power

"Typical" Batteries will last ~5-7 years (if taken care of). New electronics (inverter, charge controller) every ~10+ years.

If so, we can go further into the details.

If not, then start looking at your needs--Can you do natural venting with the green house? Can you run the water pump 30 minutes out of every hour? Can you use more efficient pump+PM type motor? Can you reduce back pressure on pump (lower pressure, lower flow rates, less energy used)?
I actually already incorporated natural ventilation into the greenhouse, the FANS are to be used
for kind of "last resort" purposes of forcing out hot air... IF IT NEEDS IT(but i over designed EVERYTHIGN so i shouldnt even need
to use the fans that often AT ALL, talking maybe 3-4 hours a day and thats only 1 fan so thats only roughly 500watts(i always round up)

The details analysis is a bit more "ugly" and work--But it only makes sense once we know more about the details for the power usage (12 months a year, 9 months a year, utility power available, roughly where is the green house)?
Location of greenhouse is to far for grid-tie plus I dont want that ill pay for off-grid.

Are you going off grid solar to save money or because there is now utility power nearby?
Im going off-grid and expense is no issue but would like to keep it around 2 grand but if i haev to spend
a little more grab an extra battery or panels then thats fine, the purpose of this is so I dont have the greenhouse has
NO BILLS attached to it, it will be free standing and self sufficient.

The Solar system will be located WITHIN the greenhouse, and the panels will be only... 30-50ft away from the charge controller
so we have VERY short runs.

Sorry for all of the questions and sizing such a large system... Off Grid solar power is not cheap (if done right, and needs to be reliable).
No worries at all brother man, ask more questions this is exactly what I wanted someone to do,
ask me questions and work with what I know (very little) in relation to what I want to accomplish

But done for the right reasons can be a whole lot nicer that running a genset 24x7.

-Bill

Lastly, you answered all my questions besides one.

This is what im confused about when it comes to this solar jive.
Can I have the setup be smart enough(ill buy whatever equipment that will make it happen)
that when its DAY TIME and ANY POWER is being created from the panels, is it possible to have
the system regulate and distribute the power directly from the panels to my fans?

like, If i have to get just 1x 260watt panel with expectations that its performance will only be about
50% on days to just run the single fan "during the day time hours" these fans dont need to run at night time,
so a full massive battery bank will kind of be a waste of money for the most part because in reality
what I'll actually require from the batteries would be what is utilized during the NO SUN LIGHT hours, aka Fish Pump
(I can also use a smaller air pump to utilize an AIR LIFT effect in the fish tank, that will work and cut my wattage
by half with the fish tank pump)

this is what I want to happen, if this is possible let me know if there is a better way to do this id appreciate the secret

Id like to have 2-3 panels that power the fans through the DAY HOURS
then id have 1-2 EXTRA panels that will be used to recharge the batteries, IF those first 2-3 panels are
being used to their full capacity and have no more left over power to charge the batteries.

I might be looking at this wrong or making it complicated... But i wont lie... the standard design
of a solar system off-grid is designed for HOMES and HUMAN LIVING, not PLANT LIVING or GREENHOUSES
which they require most of their power DURING the day where as Humans use most their power at night time.

I have the opposite situation compared to a HOME installation...

you kinda get what im saying? lol

sry if im wordy lol

I really appreciate the quick reply.
Im planning on starting the greenhouse build in March-April, so the solar wont
be ORDERED until construction STARTS since I wont need those components until the
greenhouse is finished.

Ill be sure to post pictures and updates for you all here when i start building this baby,
i think it will be a nice useful thread with great info. At least for a GREENHOUSE
application rather then a HOME application.

also, im most likely going to get OVER KILL on the amount of panels to run that small 200 watt load
throughout the day just in case its cloudy, with a larger panel array i should still be able to generate something
from the cloudiness in order to satisfy that 200 watt load.

here is the fan ill be using if that will help at all.

http://www.littlegreenhouse.com/accessory/vent-info2.shtml

the 16"

Thanks so much

looking forward to learning more

jcheil · January 2014

Re: advice please 500watt max usage, 1400ish watt system

Why not just use direct-powered solar fans?
Then they would only operate in the daytime. Similar to the ones you can put on your roof for attic cooling?
I have one, I think it was around $220 at Home Depot. Has its own small solar panel and thermostat and obviously only runs in the daytime when the sun is out.

BB. · January 2014

Re: advice please 500watt max usage, 1400ish watt system

If you need fans only when the sun is up, then going direct drive (solar panels => Linear Current Booster => DC Fans) can be a much better idea. Just adding batteries and an AC inverter makes the system about 4x more expensive and you have the nightmare of battery maintenance/replacement/charge management/etc.).

Something like this:

http://www.greenwired.net/dc-ventilation/

Note--You want brushless motors (like computer fans with electronic commutation). Brushed motors have a limited life (a few months between brush changes for 24 hour per day operation). Notice the above fans only have ~5,000 hour life... If you need 10 hours per day, that is 500 days... If you only need 50x per year, that is still a 10 year life. You will have to search around for good quality DC powered fans.

Note that DC powered fans have lots of words saying how great they are--And you will see that they are usually like a 1/10 HP or less... Compared to a 1/3 to 1/2 HP--They simply do not move near as much air. So, get "real CFM" numbers (against your expected back pressure) so you don't get an over priced "dinky fan" that really does not move much air when compared to a typical AC fan.

The Linear Current Booster (LCB) better matches the output of a solar panel (higher voltage/lower current, especially at sun rise/sun set) to that of a motor (low voltage/high starting/running current). LCB's are not cheap, but will crease low light performance from your solar array.

Then we are back to the rest of your loads (the fish tank pump(s) and some lighting to get around after sunset). A bit more information (hours of operation, seasonal needs, backup genset options, etc.) would be helpful.

There are Solar Charge Controllers with programmable output that can turn on "optional loads" when the batteries are fully charged. The Midnite Classic family is one with lots of options to do this ("Waste Not" Function).

But until we know more about your pumping requirements and (roughly) where the installation will be (nearest major city to figure out your seasonal sun) so we can size the rest of the system.

-Bill

ROTTEN · January 2014

Re: advice please 500watt max usage, 1400ish watt system

jcheil wrote: »

Why not just use direct-powered solar fans?
Then they would only operate in the daytime. Similar to the ones you can put on your roof for attic cooling?
I have one, I think it was around $220 at Home Depot. Has its own small solar panel and thermostat and obviously only runs in the daytime when the sun is out.

hum..... that might be what im going to have to do....
Maybe setup a little micro solar system. with the fan and maybe fans on the SAME panel setup.

that makes sense now that i think about it.
It would enable me to do what i want to do.

BUT i just wanna know that if what I stated before is possible id rather do that.
If there is a piece of equipment that I dont know about that will intuitively select power source
depending on POWER CREATED.

like if its super cloudy... and the panels are only making 100 watt...then some piece of equipement
id like to then switch over the batteries... then say when the sun comes back out and more intense
the panels start pushing maybe 180watt... which will then be plenty to run the fan.

just so many questions and things i wanna know, but can only do so much at once lol

ROTTEN · January 2014

Re: advice please 500watt max usage, 1400ish watt system

BB. wrote: »

If you need fans only when the sun is up, then going direct drive (solar panels => Linear Current Booster => DC Fans) can be a much better idea. Just adding batteries and an AC inverter makes the system about 4x more expensive and you have the nightmare of battery maintenance/replacement/charge management/etc.).

Something like this:

http://www.greenwired.net/dc-ventilation/

Note--You want brushless motors (like computer fans with electronic commutation). Brushed motors have a limited life (a few months between brush changes for 24 hour per day operation). Notice the above fans only have ~5,000 hour life... If you need 10 hours per day, that is 500 days... If you only need 50x per year, that is still a 10 year life. You will have to search around for good quality DC powered fans.

Note that DC powered fans have lots of words saying how great they are--And you will see that they are usually like a 1/10 HP or less... Compared to a 1/3 to 1/2 HP--They simply do not move near as much air. So, get "real CFM" numbers (against your expected back pressure) so you don't get an over priced "dinky fan" that really does not move much air when compared to a typical AC fan.

The Linear Current Booster (LCB) better matches the output of a solar panel (higher voltage/lower current, especially at sun rise/sun set) to that of a motor (low voltage/high starting/running current). LCB's are not cheap, but will crease low light performance from your solar array.

Then we are back to the rest of your loads (the fish tank pump(s) and some lighting to get around after sunset). A bit more information (hours of operation, seasonal needs, backup genset options, etc.) would be helpful.

There are Solar Charge Controllers with programmable output that can turn on "optional loads" when the batteries are fully charged. The Midnite Classic family is one with lots of options to do this ("Waste Not" Function).

But until we know more about your pumping requirements and (roughly) where the installation will be (nearest major city to figure out your seasonal sun) so we can size the rest of the system.

-Bill

Oh sry lol

Im in Cleveland, Ohio

Ok the 500gph water pump is 45 watt... but lets over estimate here and just call it 100watts...
(now you get an idea of how much I over estimate, very conservative, if anything i should always have
extra power in order to run... what 10watts of lights for only maybe an hour..)

Dont worry about lighting, that isnt a concern, i have a flash light and plus i dont garden at night time.... lol

The only power now will be the 100watt water pump that will be running 24/7
I COULD cut that into 12/7 having it run 30mins every hour rather then the full hour.
But with that being said Ill most likely swap this out and add a air lift setup that will
then only require a 20-34watt air pump... so ya i jsut want some wiggle room
for that random item i might want to plug in.

Thats the ONLY power usage.
Super simple super small...

but gives me ability to upgrade and add a 2nd water/air pump if need be.

I know this stuff isnt that complicated its just nowhere on the net is it really realyl broken down.
There are teh basics everywhere but im beyond that now, i want specific things to happen, if they are possible.

Ill look into those DC fans now.
I only need around true 500cfm
I have near zero back pressure, lots of windows that open automatically via Thermal expansion of an oil.

zoneblue · January 2014

Re: advice please 500watt max usage, 1400ish watt system

ROTTEN wrote: »

Ok the 500gph water pump is 45 watt... but lets over estimate here and just call it 100watts...
(now you get an idea of how much I over estimate, very conservative,

No in this business talking a wild guess is just a recipe for throwing money at the problem.
Get a meter and measure its draw. Then find out if there aother brands that draw less. Then you know you load, and can go ahead with your design, confident that it will work.

BB. · January 2014

Re: advice please 500watt max usage, 1400ish watt system

ROTTEN wrote: »

Oh sry lol

Im in Cleveland, Ohio

PV Watts. Fixed array, tilted to Latitude (~41 degrees from horizontal):

Month    Solar Radiation (kWh/m 2/day)
1      2.49     
2      3.34     
3      4.09     
4      4.94     
5      5.48     
6      5.56     
7      5.55     
8      5.47     
9      4.90     
10      3.91     
11      2.18     
12      1.68     
Year      4.14

You have some pretty "dark" winters there... What is your growing season and what is your estimated power usage (by season, if it matters).

My father-in-law has a koi pond, and that 1/3rd HP pump running 24x7 is probably 1/2 his electric bill (if not more).

Ok the 500gph water pump is 45 watt... but lets over estimate here and just call it 100watts...
(now you get an idea of how much I over estimate, very conservative, if anything i should always have
extra power in order to run... what 10watts of lights for only maybe an hour..)

Like Zoneblue says--you cannot guess. It will be next to useless (almost as bad as having me guess).

A Kill-a-Watt meter for AC loads, a Doc Watson or similar for smaller DC loads.

The only power now will be the 100watt water pump that will be running 24/7
I COULD cut that into 12/7 having it run 30mins every hour rather then the full hour.
But with that being said Ill most likely swap this out and add a air lift setup that will
then only require a 20-34watt air pump... so ya i just want some wiggle room
for that random item i might want to plug in.

Air lift may use more power for less flow--But there are other advantages (airation, etc.). Watch to not put the pump below water level--You can siphon out all your water if you have failed line or check valve in the pump.

Thats the ONLY power usage.
Super simple super small...

but gives me ability to upgrade and add a 2nd water/air pump if need be.

Just 2x more--That is all. :roll:

Give me Watt*Hour usage per day, by season, and what seasons (if it matters).

I know this stuff isnt that complicated its just nowhere on the net is it really really broken down.
There are the basics everywhere but im beyond that now, i want specific things to happen, if they are possible.

Like most things in life, good planning makes the rest of it look much easier. Once we have the "numbers", it is pretty much "cook book" to come up with the basic design.

-Bill

ROTTEN · January 2014

Re: advice please 500watt max usage, 1400ish watt system

Hey guys,

OK i been busy lately and have not had much time to jump back on this research.

BUT i did find this fan on ebay for decent price.

Claims a lot, but id like more info.
I messaged the guy to see if he can give me any kind of motor information, make model ect...

http://www.ebay.com/itm/NO-RESERVE-Exhaust-Fan-12V-Volt-DC-Solar-powered-attic-roof-vent-greenhouse-hood-/121255131904

while I wait for a reply or spend time searching, what you guys think from first glance?

Just found this video also.

Fast forward to 5:30minutes
.....

tell me that video is fake please??? lol
http://www.youtube.com/watch?v=TN1gTSw5Udc

http://scorigin.com/

HAHAHA then i just see this video..

EPIC

http://www.youtube.com/watch?v=O7Mf0ehaq1I

computer fans lol

advice please 500watt max usage, 1400ish watt system

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