Solar Panel - What is best One big or two smaller

[Wasnt Me]

It may seem like a daft question?

 

Is a bigger single panel better say 300W or 2 -150W.

 

Obviously this depends on space. But if I can fit a larger single panel it will weigh less that 2 right?

 

Any advice welcome.

 

Thanks

 

 

[spirou]

Weight savings are approximately 6kg (from the first two comparable panels I found) in favor of 300W single panel, plus fewer/shorter wires.

 

What I'd be worried about is proper mounting. It's a large surface to fly off, vibrate etc. Also a possible issue is shading/hotspots. A single panel partially shaded could produce significantly less than two separate where one of them is in the shade. Obviously this largely depends on where you park, possible snow etc. and panel technology (properly functioning bypass diodes).

[mikefitz]

There are some very good deals on large domestic type solar panels, some having advanced technology built in.

Example,

https://www.bimblesolar.com/jinko-305w-smart-panel

 

Provided suitable mountings are used on the rigid roof of a panel van I would think the stress would be compatible to domestic situations. One point to note is that the higher volage of this type of panel requires a MPPT solar controler designed for input panel voltages of around 40 volts.

 

Mike

[Ocsid]

mikefitz - 2019-10-05 6:14 PM

 

There are some very good deals on large domestic type solar panels, some having advanced technology built in.

Example,

https://www.bimblesolar.com/jinko-305w-smart-panel

 

Provided suitable mountings are used on the rigid roof of a panel van I would think the stress would be compatible to domestic situations. One point to note is that the higher volage of this type of panel requires a MPPT solar controler designed for input panel voltages of around 40 volts.

 

Mike

 

This touches on a worthwhile point, the panel's power point voltage to get the potentially higher efficiency MPPT solar controllers can yield.

 

These MPPT optimised panels benefit from a higher voltage to yield more output during the all important low light days. My take being that in good light few of us struggle with yield, it is the poorer light where we need to improve our yield.

Therefore, optimised panels fof MPPT controllers put out higher voltages than the ones we typically use with 12 volt DC PWM controllers [typically these PWM panels work in the 17 to 20 volt range].

 

So back to the original question, what is better a 300 Watt or two 150 Watt panels?

 

If these are not optimised for a MPPT controller and not therefore having say 36 Volts output, then using two 150 Watt panels wired in series so their 17 odd volts becomes 34 volts into a MPPT controller will yield better low light performance.