Solar Power

More info please:

What is the capacity of the panel and what is the output in volts? What are you doing further? Is there a battery involved? What is the issue? These questions can contribute to an answer that makes sense.

sir, it is a 15watt solar panel giving 12v output. I am powering a 40watt bulb using this. this DC voltage is stored in a battery and then converted to AC using an inverter. Will LTC3780 buck boost act as a MPPT controller?

It is a far better solution than using a series regulator for charging a battery, the first one not being able to even charge the battery when the output voltage is too low. Check if your panel is putting out really 12 volts in the sun. It should be more normally. (say between 17 and 20 volts as example) The Chip will make your charging system perform well. So like Joshi said with one word: YES. Good luck.

If you use a 12Volt dc Compact flourescent lamp you wont need an inverter because it is in the lamp. For charging the battery you only need to limit the voltage when it is charged. 15 Watts barely produces enough current to trickle charge a car battery but I guess it works.

A 23 watt full spectrum CFL produces the same light as a 100 Watt incandescent lamp but twice as long.