Thermal energy is shown in many objects, it is the transfer of heat energy between two object or more. Thermal energy happens when objects touch they share the temperature of which they touch.
A pot on a stove is thermal energy transfer because the heat from the stove is transferring through the pot into the water.
The heat from the fire transfers to the wood and this making the wood catch fire.
This is my solar oven, It has one window and a lid for containing the sun energy and using it to heat food their is also three reflecting flaps to shine the sun straight into the box.