Where to buy panels very less price

If this business is very good for future generation and present generation if we set up a business for solar panels nowadays two types of solar panels day and night. For the day 1 everyone knows about the panel but nowadays we are hearing about night solar panels.
so what to buy solar panel in very less price to get good benefits and provide customers in a very low rate to develop our nation energy requirement in here government sectors can’t help us to setup this types of needs for a small business setup sellers