According to LOAD WHAT IS THE PROCEDURE OF SELECTING SOLAR PANEL SIZE AND BATTERY SIZE (IF MY LOAD IS 2KW,12V?

Whats the best and cheapest process to store...
Answers:    A bunch of things to consider.

How many kilowatt hours per day do you intend to use?

What is the insolation number for your nouns?

The number of kWh times the insolation number gives you a rough idea of the size of the solar array.

If the nouns is to be continuous, the batteries will have to transport the load when the sun is not shining. If you must have power during long period of stormy weather, the battery might have to be huge.

If the nouns is AC, you will need an inverter.This info will just achieve you started.