That was just [Light Emitting Diodes]

Context: The meme is a play on the version where patchy the pirate complains about steam power just being boiling water, which is itself a play on Patchy being disappointed at the SpongeBob lost episode just being 'cheap walk cycles'

Solar panels work through reversing the process in which LEDs produce light, quite literally being made from special LED designed to work in reverse. All diodes can do this to an extent, but solar panel LEDs are especially good at it.