Pros and Cons of PWM and MPPT Controllers

PWM Type Solar Controllers	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, usually selling for less than $350 - 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 - 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