My tomatoes are solar powered;-)
Solar Panels can help out when SHTF assuming one can stay put.
My potato clock worked pretty well in 4th grade.
Right now my tomatoes are 1000 watt UltraSun Metal Halide Powered via good ol electricy powered by mostly oil and some nuclear. soon to switch over to high Pressure sodium.
My fruit trees are solar powered. I am a reality based greenie. Most greenies are city dwellers with unrealistic ideas how the natural world functions. They see stuff on TV or take a hike in the woods once a year. Many liberal greenies live in the suburbs and still learn nothing from the simple lawn that grows outside their door