20-50 w solar panels

gambit83

guys, just wondering if anyone would know where to buy solar panels between 20-50w? thanks

rolion

gambit83 wrote: »

guys, just wondering if anyone would know where to buy solar panels between 20-50w? thanks

Looks small...in size and power !
Any reason?

gambit83

rolion wrote: »

Looks small...in size and power !
Any reason?

just to power a small unit

rolion

Hi,

I've looked everywhere...cant find more cost effective than here ...

Enjoy it.

freddyuk

Here's some
http://www.adverts.ie/parts-accessories/solar-panel-50-watt/5685263

gambit83

thanks for the links, just noticed that some panels are polycrystalline and others are monocrystalline, after doing some searching online it looks like the mono are slightly more efficient but also more expensive although the articles I read weren't based on Irish conditions, I would which would be better for a Irish climate? It's basically a small motor that I want to run off them.

freddyuk

At this level I would not concern yourself with how efficient a module might be as the differences will be tiny if any. More important is the efficiency of the overall design of the set up.

20-50W is too small, it's into silly territory, price per watt soars the smaller you go.

A 250W 24V module would be less than double he price of a 50W.

gambit83

Sir Liamalot wrote: »

20-50W is too small, it's into silly territory, price per watt soars the smaller you go.

A 250W 24V module would be less than double he price of a 50W.

ah ok......i appreciate your input but while is it silly territory??

from my calculation a 30w solar panel should be more than enough to power the unit even in winter. why would i go to the extra expense of buying a solar panel if i don't need it, and then i'm pushing up the selling price of the product i'm making onto the the good consumer unnecessarily, which would be a significant increase and be a stumbling block to selling it!? also the fact that a 250w panel would look ridiculously over-sized on the unit

gambit83

gambit83 wrote: »

but while is it silly territory??

Because the price per watt is double or triple that of a larger module. Modules that small are usually marketed as portable phone chargers where a larger battery would be a better investment.
Car battery trickle chargers where the module can't compensate for the parasitic drain most days.
Solar floodlights where the LVD is too low and the discharge is often higher than the charge capabilities.

I get about 4Wh a day some days in Winter from a 150W module.

If it's all you need then don't let me stop you.

freddyuk

Lots of cheap car battery chargers sold on auction sites using just a 10w module and crocodile clips. Won't keep the car clock and alarm going! Be afraid.....
For constant tiny load I would go +50wp but for intermittent controlled loads you can use 30wp depending on the DESIGN.
Batteries need a full charge regularly or they will fail. Solar will struggle to do this in winter.

Ni-Cd cells are complete discharge tolerant.
As are nickel-iron...pity they're not much good at anything else. I like Ni-Cd for motor loads.

Mono panels are my first choice for Irish weather but I'll hang poly if the price is right.