I'll amplify on what Doug said. It is helpful to use the terms
"energy" and "fuel," and to distinguish between them. The two
terms refer to very different problems, but it's easy to confuse
them if you've never studied this. If you already know this stuff,
skip the rest of this email message.
"Energy" usually refers to "energy source" -- i.e., from where do
you get the energy. You might get it from special kinds of
materials -- coal, petroleum, uranium, etc. -- that you dig up
from under the ground (not renewable). Or you might get it from
wind or solar or oxen (renewable).
"Fuel," or "energy storage," refers to energy that you store for a
while, to use later. Examples are gasoline, batteries, compressed
air, hydrogen. (Hydrogen is created from water by electrolysis, a
process which uses energy; then later hydrogen is burned, a
process which releases energy.)
Every use of energy requires a source; most uses of energy require
storage. Most transportation requires some energy storage. A car
equipped with solar panels and no storage would work fine on a
sunny day, but would come to a halt at night or when the sun went
behind a cloud.
Gasoline is a confusing case, because the storage medium
(gasoline) is so closely related to the source (petroleum).
The "energy crisis" is really four different crises:
(a) Our society's chief sources of energy have been nonrenewables
(such as petroleum and coal), and we're running out of them. We
need to convert to renewable energy sources.
(b) Our chief forms of fuel (i.e., storage) have been based on
nonrenewables -- e.g., gasoline based on petroleum. Actually,
gasoline could become a renewable: scientists have recently
figured out ways to synthesize gasoline from the CO2 in the air or
in seawater. The synthesis process requires energy, but you could
get that from solar power. However, achieving this on a practical
scale may still be years away. (Using such a fuel would then be
(c) Most of our sources and uses of energy have had all sorts of
toxic wastes as byproducts -- in particular, nuclear wastes and
greenhouse gases. We need to convert to clean energy.
Actually, there's a big overlap between these different crises,
because it turns out that there's a lot of correlation between
clean and renewable.
On 6/7/14, 6:02 AM, Doug Kalmer wrote: