Here is a simulation showing how a buck-boost will work.
It illustrates how you can deliver a charge a 12V battery from a PV panel putting out just 11V at 130 mA.
By putting a choke on the supply feed, and an input smoothing capacitor, you can draw continuous current from the PV panel.
Most of the resistors are 'invisible', inserted to portray some amount of resistance in components.
A 220 uH coil can be operated at a frequency of tens of kHz. If you wish to convey 7.5 A from your PV panel, then your coil must be able to carry more than that amount of current.
An output capacitor is not needed when you are charging a battery.
A switched-coil converter should not be operated without a load. You may get high voltage spikes if you do. Furthermore an output capacitor will charge to an unpredictably high voltage.