Originally Posted by RoccoFreya
Here's the thing, mono-crystalline panels seem to be slightly more expensive compared to their poly-crystalline comparative; but are they worth the price considering their better efficiency? If that's the case, perhaps home depot still has the best deal.
190watts for 315$, but does this mean that a MPPT
controller is necessary for the around 36v's max its putting out?
ALSO - why is the amperage about the same for a 100watt and 190watt? - (5.4amps) Doesn't amps directly relate to amount of power being expressed? OR is it that you only need a larger watt panel if your trying to run higher voltage? - which in our case, is not necessarily.
Greatly appreciate all the input
Product Comparison Page
Solar panel effeciency is just related to size of the panel for the amount of watts.
So a more efficient 100w panel won't put out more power than less efficient 100w panel it will just be physically smaller.
There is considerable overlap in efficiency of mono and poly panels, so you have to sums to see how efficient the panels are. The 100w panel in the link is 0.64 sq meters which is reasonably good.
Yes an MPPT regulator is necessary with the larger panel because of the higher voltage of the panel. If a MPPT regulator is used with the 190w panel it will convert the extra voltage for current
and the 190w panel will put more power into the batteries than the 100w panel.(roughly 1.9x as you would expect)
Another way of understanding it looks like both the 100w and the 190w panels use the same cells in their construction, but the 190w panel has more of these cells.
Each cell adds about 0.6v @ 5.4A as the cells are in series the voltage goes up, but the current
stays the same. To feed the battery with more current we need to trade
the volts or amps which needs a MPPT regulator.