Expert: Tom Whiting - 6/29/2009

Question
The Sun produces a tremendous amount of energy and will for the next 5 billion years, should we concentrate on capturing this energy by solar cells and wind turbines, rather than depend on oil which will run out shortly or nuclear power of which we cannot control the waste products?

Answer
Hi Marlene,
(Pretty name, I always liked that name for a girl).  
I take it this is more an opinion question rather than a factual
astronomy question, because it's more physics (energy) related.

Well, except for government-sponsored and company sponsored experimental prototypes of both solar and wind energy, it's all going to depend on the cost. Money rules, and the cost to collect
all that "free" sunlight and heat coming toward the Earth from the
sun, that you suggest in your initial statement, is expensive.

Once the cost of stuff like fuel oil (diesel fuel) and gasoline
reach the point, as oil supplies dwindle, where the average cost
analysis is cheaper to go solar and wind (and even nuclear), then we will.
But as long as a litre of gasoline remains below, say one US dollar,
then the other sources can't compete with their higher costs.
But once a litre of gasoline reaches 2 US dollars, then it will be
profitable for companies to mass produce the alternate forms of
energy.  So it's all cost related, on the massive scale.
And we can assume with continuous inflation (goods always become
more and more expensive over time, except in a world wide depression-gasoline was only 0.25 US cents per gallon when I was a teenager!)...and with the expected eventual real shortage of oil
and natural gas, the break even point is not too far away, perhaps in another 10-20 years or so.

And I wouldn't discount nuclear power either...soon spacecraft
will be less expensive to operate, and perhaps soon, say another
50 years, we could rocket-ship (unmanned of course) all that nuclear waste harmlessly right into the sun, which of course wouldn't hurt anything.
(The sun already contains 99.86% of the mass of the Solar System
already; you can fit 1.3 million Earth's inside the sun.)
OR, even store it on the far (back side) side of the moon, which
probably wouldn't hurt anything there either. (All future lunar
bases will be either at the poles of the moon, or the front facing
side...for radio contact with the Earth.)

On a longer range, perhaps 100 years, humans probably will develop
fusion power, fusing hydrogen nuclei to form helium nuclei, duplicating what goes on inside the core of the sun.  And very very long range, the very best source of energy would be matter anti-matter reactions, (like what powers the Starship Enterprise in science fiction TV shows)..but that's probably 4 or 5 centuries from now.
So it's good we're starting the space program now (actually it started with the Russian Sputnik satellite launch on Oct. 4, 1957) because there is a lot of work to do, and more spinoffs to be reaped, from a continuing space program....new forms of energy production is just one of those spinoffs.
It's almost a shame to burn oil now, because other industries are
so dependent on it too...plastics, lubrication, etc.  But right now,
as long as fossil fuel remains cost effective, the world will stick with fossil fuels (oil, natural gas, coal) as long as they can...but you're right...time is running out, and that's why just recently we ARE seeing a fast increased research in use of solar and wind power.  But that won't really take off on a massive scale until the price of fossil fuel...skyrockets.  And it's just a matter of time when it will.
Just my opinion...which is what you asked for,
Clear Skies,
Tom Whiting
Erie, PA USA