Q's: How big of a solar panel would I need to power 2 120 mm fans and where to purchase such a panel?

[Zim Hosein]

So, as the thread title states, I would like to know how big of a solar panel I would need to power 2 120 mm fans and where would I purchase one? Thanks in advance! :beer:

 

[Rubycon]

What are the fan specs? Typically amperes @12V. A half amp at 12V needs 6W of power to run so two would mean you need 12W. A 15W battery charger type panel would work fine. It will be more expensive if you need it permanently mounted outdoors as it has to be protected against the elements, etc.

 

[Zim Hosein]

Originally posted by: Rubycon
What are the fan specs? Typically amperes @12V. A half amp at 12V needs 6W of power to run so two would mean you need 12W. A 15W battery charger type panel would work fine. It will be more expensive if you need it permanently mounted outdoors as it has to be protected against the elements, etc.

Figures I'd be unprepared for your questions Rubycon!

Basically I want to use 2 Antec computer case fans powered via a solar panel for indoor use only. Make any sense?

 

[Rubycon]

I would presume you either have a skylight or want the panels on your roof. Lighting indoors is not going to make any solar panel put out sufficient power to turn a fan. (unless you have some powerful plant growing bulbs for "high times".) And that's about all I have to say about that! :laugh:

A 10-15W battery charger type panel should suffice for < $100.00. If the fans need to run 24/7 you will need a larger panel to cover the draw plus battery charge rate and sufficient capacity to run the fans at night and on cloudy days where output is less than nominal.

You know it wasn't going to be that easy, eh?

 

[91TTZ]

Correct answer: spend the money on a hooker

 

[Tiamat]

Not going to be easy. There are many things that alter the efficiency of solar cells. Concentrators, quantum dots, thin-film laminates, etc. How big depends on how much money you have and if there is a manufacturer/supplier.

For indoors use, you probably won't find any solutions for your needs.

A good estimate is the solar panel that is going on the new Toyota prius (in terms of what you can buy immediately today).

I could be wrong, but I think it outputs 50 Watts total. 2x 120mm fans are probably 5 Watts.

 

[JasonCoder]

Originally posted by: 91TTZ
Correct answer: spend the money on a hooker

Yeah but the ho is a one shot (so to speak) deal, whereas this setup keeps on giving, and the no disease thing is nice too...

 

[Zim Hosein]

Originally posted by: Rubycon
I would presume you either have a skylight or want the panels on your roof. Lighting indoors is not going to make any solar panel put out sufficient power to turn a fan. (unless you have some powerful plant growing bulbs for "high times".) And that's about all I have to say about that! :laugh:

A 10-15W battery charger type panel should suffice for < $100.00. If the fans need to run 24/7 you will need a larger panel to cover the draw plus battery charge rate and sufficient capacity to run the fans at night and on cloudy days where output is less than nominal.

You know it wasn't going to be that easy, eh?

1. I was hoping that the indoor lighting would be enough!
2. Figures Rubycon!

Feel free to lock this thread up since my idea won't work!

 

[Tiamat]

Originally posted by: Zim Hosein

Originally posted by: Rubycon
I would presume you either have a skylight or want the panels on your roof. Lighting indoors is not going to make any solar panel put out sufficient power to turn a fan. (unless you have some powerful plant growing bulbs for "high times".) And that's about all I have to say about that! :laugh:

A 10-15W battery charger type panel should suffice for < $100.00. If the fans need to run 24/7 you will need a larger panel to cover the draw plus battery charge rate and sufficient capacity to run the fans at night and on cloudy days where output is less than nominal.

You know it wasn't going to be that easy, eh?

1. I was hoping that the indoor lighting would be enough!
2. Figures Rubycon!

Feel free to lock this thread up since my idea won't work!

Yeah, unfortunately, solar cells (commercially available ones) do not absorb really well for indoor lighting. Also, when you have an array of them, blocking even a small fraction of the array will cut the power output dramatically.

 

[SunSamurai]

Originally posted by: Zim Hosein

Originally posted by: Rubycon
I would presume you either have a skylight or want the panels on your roof. Lighting indoors is not going to make any solar panel put out sufficient power to turn a fan. (unless you have some powerful plant growing bulbs for "high times".) And that's about all I have to say about that! :laugh:

A 10-15W battery charger type panel should suffice for < $100.00. If the fans need to run 24/7 you will need a larger panel to cover the draw plus battery charge rate and sufficient capacity to run the fans at night and on cloudy days where output is less than nominal.

You know it wasn't going to be that easy, eh?

1. I was hoping that the indoor lighting would be enough!
2. Figures Rubycon!

Feel free to lock this thread up since my idea won't work!

HA.

Or you could just turn the light off for 5x the power savings.

 

[arcenite]

Originally posted by: Zim Hosein

Originally posted by: Rubycon
I would presume you either have a skylight or want the panels on your roof. Lighting indoors is not going to make any solar panel put out sufficient power to turn a fan. (unless you have some powerful plant growing bulbs for "high times".) And that's about all I have to say about that! :laugh:

A 10-15W battery charger type panel should suffice for < $100.00. If the fans need to run 24/7 you will need a larger panel to cover the draw plus battery charge rate and sufficient capacity to run the fans at night and on cloudy days where output is less than nominal.

You know it wasn't going to be that easy, eh?

1. I was hoping that the indoor lighting would be enough!
2. Figures Rubycon!

Feel free to lock this thread up since my idea won't work!

 

[iGas]

Depends on the fan motor, bearing designs, and CFM out put.

A 12V 120mm fan total load drawn can be less than 1W to several Watts. Then calculate the quality/efficiency of the solar panel * the Watts input that you requires. And, make sure to check the solar panel energy rating for full/direct sun to over cast.

 

[iGas]

That said, one of this, or this one should do just fine pending weather condition.

[add]
Oops, almost forgot about Fresnel. Add a big ass Fresnel lens in front of the solar panel ++ mirrors and that should increase the out put of the solar panels.

 

[Rubycon]

Originally posted by: iGas
That said, one of this, or this one should do just fine pending weather condition.

[add]
Oops, almost forgot about Fresnel. Add a big ass Fresnel lens in front of the solar panel ++ mirrors and that should increase the out put of the solar panels.

Second one is ideal.

RE: Fresnels...

Yes it's true that you can increase the insolation over a given surface area which will increase the output of the cells however they will heat up...way up! It's easy to crack the cell or protective glass. A fresnel from a projection TV set can destroy a panel instantly if placed too close to the waist. Additionally if you don't have a tracking mount and the beam shifts to your roof it could cause a fire! :Q

 

[ElFenix]

Originally posted by: Zim Hosein
Feel free to lock this thread up since my idea won't work!

Zim Hosein
Elite Member
Off Topic Moderator

:boggle;

 

[Red Squirrel]

Originally posted by: ElFenix

Originally posted by: Zim Hosein
Feel free to lock this thread up since my idea won't work!

Zim Hosein
Elite Member
Off Topic Moderator

:boggle;

I found that odd too. Or is it that mods can't lock their own threads? lol.

For the panels suppose if you put them in a window that gets sun, that might work?

I would love to go solar and have some on my roof. Just don't know what kind of effect the weight of snow would have on them, and I'd need a mechanism to clear the snow or they'd be useless.

 

[Rubycon]

Originally posted by: RedSquirrel

Originally posted by: ElFenix

Originally posted by: Zim Hosein
Feel free to lock this thread up since my idea won't work!

Zim Hosein
Elite Member
Off Topic Moderator

:boggle;

I found that odd too. Or is it that mods can't lock their own threads? lol.

He dropped his bottle of locktite in his beer. :laugh:

 

[BoomerD]

It'd be too easy to buy a wall-wart type of power supply to run the fans? (quite a bit cheaper in initial purchase price for sure)

 

[HappyPuppy]

Zim, I thought you were a college boy. You should know better.

 

[Zim Hosein]

Originally posted by: Rubycon

Originally posted by: RedSquirrel

Originally posted by: ElFenix

Originally posted by: Zim Hosein
Feel free to lock this thread up since my idea won't work!

Zim Hosein
Elite Member
Off Topic Moderator

:boggle;

I found that odd too. Or is it that mods can't lock their own threads? lol.

He dropped his bottle of locktite in his beer. :laugh:

:laugh:

Seriously though, I don't lock threads that I created on principle.

 

[randay]

it would be more efficient to turn off the lights and use a regular power supply.

 

[Suspicious-Teach8788]

what kind of efficiency do you expect?

what kind of solar panel?

- Triple junction GaAs?
- Monocrystalline Si?
- Poly Si?
- Amorphous Si?
- CIGS?
- CdTe?

I'd say you can expect 10% and above for most solutions.

So if each 120mm fan uses about... 12v x 0.5A = 6W of power. 12W total. Assuming 10% cell efficiency and 1000 W/m^2 solar irradiance, you need 0.12 m^2 of a solar panel. This is like BARE minimum though. You're assuming MAX solar irradiance which means direct sunlight with no clouds at all.. I'd go with double the size at least.

 

[Baked]

Get a cat wheel, it generates more power than a hamster wheel.

 

[Sea Moose]

It can be done



This is a basic block diagram of how you would have to wire it up

Solar panel ---> Solar panel regulator ---> Battery ---> Fan




You mount the solar panel and run it into the regulator which feeds the battery. you wire the fan off the battery. The regulator basicly makes sure the batt is never overcharged and helps extend battery life.

If you have a 6watt fan get a 15watt panel.

always make sure you panel is larger than the load.