In the first instance it is important to distinguish between two different ways to employ solar energy for households. Both approaches imply installation of flat deep-blue rectangular panels on a house roof (alternatively on a wall or on the ground), which makes them look alike. However, the operating principle and capabilities of PV panels and thermal collectors are different. PV (photovoltaic panels) generate electricity. The direct current is converted to alternating current by inverter at the correct voltage. This solar power can be stored in high-performance batteries, fed into the public power grid or instantly used at your home. In turn, solar thermal collectors absorb solar warmth and transfer in to use for heating or hot water supply.
PV (photovoltaic panel): solar light excites electrons in the semiconductor material of the PV panel, and an electric current is generated.
Solar collector: selective coating of a panel absorbs solar heat and transfers it to a heat transfer agent, which does the heating work.