oak eroei
marketing types and scientists tout their solar cells as being 17% efficient. that means they convert 17% of the sunlight energy incident upon them into electrical energy. plants are only 5% efficient. science wins! right? wrong. the important number is the amount of energy output divided by the amount of energy input. for solar cells that's between 1 and 5. an oak tree requires the investment of a single acorn. yet over its lifetime it will produce millions of acorns. nature wins. we're not even in the right game.