Mono Solar Panel gives output in low light or Cloudy climate whereas Poly Solar Panel generates power only in sunlight.
If you created a new account after or while ordering you can edit both addresses (for billing and shipping) in your customer account.
PWM is old technology which charges battery when Solar Panel gives current output whereas MPPT is latest technology & it converts Solar Panel Voltage into current & charges battery with its current as well as current converted from Panel Voltage.
MPPT Solar Inverters are not costly in fact they are cheaper because you can connect less number of cheaper 24V solar panel & save on solar structure / wires. Also MPPT solar Inverters generates more energy.
Square wave Inverter are old technology inverters are slightly cheaper than latest Sine wave technology inverters. Our household electrical appliances like fan, Fridge, TV & other are made for Sine wave output which is supplied through electricity meters. If you use square wave inverters than fan gives humming sound & electrical appliances require frequent repairs because of mismatch. You should always buy Sine wave Inverter for trouble free usage of electrical appliances & save on repairs of appliances.