SOLAR INCOME

Even more fascinating than what went into coal, though, is
what has come out of it: enough energy to change the world profoundly.
For billions of years, almost every life form on earth
depended for its existence on energy fresh from the sun, on the
“solar income” arriving daily from outer space or temporarily
stored in living things. Like living solar collectors handily dispersed
all over the planet, plants capture sunshine as it arrives
and convert it into chemical energy that animals can eat. And
plants don’t just convert energy, they store it over time—holding
that energy within their cells until they decay, burn, or get eaten
(or, in rare but important cases, are buried deep within the
planet as a fossil fuel).