solar powered UPS

hi guys
m studing electronics at graduation level.i want to make a solar powered uninterepted power supply. but i nevr found any useful info on internet.if any one hve idea about this project kindly contact me

How much power do you need?

What do you want the mains to back up the power if the battery runs flat?

Is very simple.

Connect the solar panels to a charge controller and a set of lead acid batteries connected to an inverter.

The inverter should have a low voltage disconnect which will turn it off when the battery voltage runs too low.

Use a DPDT relay to switch to mains power when the inverter stops working.