Thor Forums

[taylorbob1]

Originally Posted by USN Retiree

Excuse my ignorance, what is MPPT controller? How does that differ from a PWM (no idea about that either) that comes stock?

GOOGLE it

PWM Type Solar Controllers vs MPPT Solar Controllers

PROS
– PWM controllers are built on a time tested technology. They have been used for years in Solar systems, and are well established
– These controllers are inexpensive

– PWM controllers are available in sizes up to 60 Amps

– PWM controllers are durable, most with passive heat sink style cooling

– These controllers are available in many sizes for a variety of applications

– MPPT controllers offer a potential increase in charging efficiency up to 30%
– These controllers also offer the potential ability to have an array with higher input voltage than the battery bank

– You can get sizes up to 80 Amps

– MPPT controller warranties are typically longer than PWM units

– MPPT offer great flexibility for system growth

– MPPT is the only way to regulate grid connect modules for battery charging

CONS
– The Solar input nominal voltage must match the battery bank nominal voltage if you’re going to use PWM
– There is no single controller sized over 60 amps DC as of yet

– Many smaller PWM controller units are not UL listed

– Many smaller PWM controller units come without fittings for conduit

– PWM controllers have limited capacity for system growth

– PWM can’t be used on higher voltage grid connect modules

– MPPT controllers are more expensive, sometimes costing twice as much as a PWM controller
– MPPT units are generally larger in physical size

– Sizing an appropriate Solar array can be challenging without MPPT controller manufacturer guides

– Using an MPPT controller forces the Solar array to be comprised of like photovoltaic modules in like strings