Final answer:
The convection cells that facilitate plate tectonics are powered by the energy from the Earth's core, with heat being a key driver of mantle convection, which in turn moves the tectonic plates.
Step-by-step explanation:
The convection cells in the asthenosphere that are responsible for plate tectonic movement are powered by the heat from the Earth's core. This heat drives the process of mantle convection, by which the interior heat of the Earth is transported to cooler regions of the upper mantle. As heat escapes from the Earth's interior, it causes warmer material to rise and cooler material to sink, creating the convective flow that moves the tectonic plates.
Another example of convection is found in the Sun, where energy transport occurs through radiation, conduction, and convection, the latter being significant in the outer layers of the Sun. The Earth's interior is kept molten partly due to nuclear decay, which releases energy that slows down the cooling process, further sustaining the convection in the mantle.