|
For decades, there have been delirious proclamations that
the world would soon run on solar energy. Those statements always have
sounded too good to be true -- and, sure enough, they always have been
false. In the famous "Peanuts" comic strip, each year Lucy promised to
hold a football so Charlie Brown could do a placekick. Each year as Charlie
Brown charged the ball, Lucy pulled it away at the last moment, and Charlie
Brown landed on his back. Likewise, each year solar promoters with no
serious scientific credentials tell us solar energy is the answer to our
problems.
Solar's failed promises
Hope springs eternal, however, so the news media continue to publish
glowing stories of solar homes despite years of failed predictions.
Coincidentally or not, most high-profile solar enthusiasts tend also to be
anticapitalist collectivists who wish every family unit operated off its own
individual windmill or photovoltaic cell instead of the 1,911 U.S. power
stations containing 9,493 power-generating turbines driven by steam provided
from water heated by coal, natural gas, nuclear energy or liquid petroleum.
The usual socialist suspects have been
Pollyannaishly predicting the success of the futile wind-solar venture for
more than 40 years. Examples abound.
- In 1977 Dennis Hayes, founder of Earth Day, predicted that by the year
2000, 40 percent of global energy would be from renewable sources.
- In 1978 Ralph Nader said all power would be solar in 30 years. In 1997
he repeated that claim.
- In 1996 Sen. Ted Kennedy, D-Mass., predicted solar energy would be the
primary source of energy in the 21st century.
Beneficiaries of tax breaks
Experience tells us the wind in most places does not blow steadily enough
and predictably enough to be an economical power source. Moreover, the sun's
energy is too widely dispersed and the land area required to collect it too
vast for solar to become a large-scale power source. At best, a pleasant
niche exists in the remotest of places and for the most affluent enviro-zealots.
In reality, solar and wind power remain on today's radar screen only as a
result of wasteful tax breaks to appease the green community.
But don't take my word for any of this. Read the second edition of "The
Solar Fraud" by the Mr. Wizard of academic physics, Howard C. Hayden,
professor emeritus of the University of Connecticut.
Fun to read
Hayden's book is a fun read that can bring you to tears of laughter and
embarrass you with the simple things you never thought of when many of us
naively believed the world could run on solar energy. Additionally, all the
complex physics and supporting math is there for those who choose to read
it.
After a warm introduction to the subject, where we get to know Hayden,
Chapter 2 tells the history of U.S. energy supplies. Hayden defeats the
solar zealots on their own premises throughout Chapter 3. Then in Chapter 4
he poses all the questions you would like answered but never thought to ask.
Hayden writes: "Many people evidently see solar energy only as a
political or economical question. Some imagine, perhaps, that we simply lack
the political will to make solar energy happen. Some others think that if we
would just throw money at the problem, we'd become a solar nation. There is
an oft-repeated adage that if we would give Exxon a solar depletion
allowance, we'd be using solar energy tomorrow."
However, solar energy is first and foremost a topic of science and
engineering. It is worth exploring how solar energy actually works in all
its various manifestations. The subsequent chapters deal with those
questions. Chapter 5 discusses the light that arrives at the Earth from the
sun. We have only one sun, and all of the solar energy manifestations
ultimately depend upon that light. It is worthwhile to understand sunlight
itself.
Natural energy collection inefficiencies
Chapter 6 deals with conservation and efficiency. These topics are
related to solar energy only in that they can improve the use of solar
energy. The oldest use is the burning of firewood, which is responsible for
about 3 percent of U.S. energy. Chapter 7 discusses the production of
biomass from sunlight and the production of ethanol from corn. Hydropower is
the subject of Chapter 8, and wind power is covered in Chapter 9.
When we put up a dam to produce hydropower, the water that generates our
power has been evaporated from all over the Earth and has fallen as
precipitation somewhere in the collection area upstream from the dam.
Similarly, the wind that drives our wind turbines picked up its energy from
remote places. However, when we use solar energy directly for heat or for
production of electricity (Chapters 10 and 11), we must collect it ourselves
with devices we manufacture for that purpose. Our collection area is only as
large as our collector devices.
In Chapter 12, Hayden discusses other ways of harvesting solar radiation,
including ocean waves, tides and geothermal energy, all of which have proven
almost totally inefficient.
Heating degree-days
Do you really understand what a heating-degree day is? Have you been
embarrassed to ask? Among the many lessons you will learn in this book is
this simple concept:
"One measure of the heating requirements of a given geographical area is
the number of degree-days. When the average temperature for a day is below
65 degrees F, it will be necessary to provide some heat for the home. (If
the average temperature is above 65 degrees F, the heat from the human
inhabitants, the lights and the appliances is adequate to keep the house
warm)."
If the average temperature for a day is 40 degrees F, then 25 degree-days
(the difference between 65 and 40 times one day) are recorded. By the end of
the heating season, there may be 1,000 degree-days in one location and 8,000
degree-days in another. A similar total is kept for cooling degree-days, a
sum that determines how much air conditioning a house will need.
[to top of second column in
this article] |
Energy efficiency
The United States today consumes 100 quadrillion BTU or "quads"
of thermal energy each year. In 1950 the figure was 35 quads; in
1910 about 7 quads, not counting horses and other agricultural
sources of energy.
Hayden quotes Peter Huber, author of "The Efficiency Paradox"
(Forbes, Aug. 20, 2001): "The efficiency of energy-consuming devices
always rises, with or without new laws from Congress. Total
consumption of primary fuels arises alongside. The historical facts
are beyond dispute. When jet engines, steam power plants and car
engines were much less efficient than they are today, they consumed
much less total energy too."
But the efficiency paradox is nothing new. In the 19th century,
the efficiency of steam engines was steadily improving as a result
of James Watt's steam engine. For a while, the consumption of coal
decreased by as much as one-third, but in the subsequent 33-year
period, Hayden tells us, the consumption increased 10-fold.
English economist Stanley Jevons commented on the paradox in
1865: "It is wholly a confusion of ideas to suppose that the
economical use of fuel is equivalent to diminished consumption. The
very contrary is the truth. It is the economy of its use which leads
to extensive consumption. It has been so in the past and it will be
so in the future."
Wind power no answer
Because air must leave a wind turbine with some velocity and
hence some energy, only some of the kinetic energy of the wind is
taken by the turbine. It turns out that only 59 percent of the
energy carried by the wind could be extracted by a perfect wind
turbine; the very best real wind turbines peak at about 50 percent
efficiency, and then only under ideal conditions.
With the elegance of Einstein's equation of relativity and the
delight of a Mr. Wizard, Hayden explains the physics and complexity
of turning the wind's kinetic energy into electricity.
Wind farms, he writes, can generate electrical power at the rate
of 1.2 watts per square meter for most sites and up to about 4 watts
per square meter in the rare sites where the wind always comes from
one direction -- though Hayden has been unable to find any.
Now suppose the goal is to provide enough energy to average 1
billion watts of energy around the clock, the power output of one
typical traditional power plant. At 1.2 watts per square meter, the
land area requirement is about 833 square kilometers.
Imposing inefficiencies
Hayden puts that land area into perspective: He writes, "Imagine
a 1-mile-wide swath of wind turbines extending from San Francisco to
Los Angeles. That land area is what would be required to produce as
much power around the clock as one large coal, natural gas or
nuclear power station that normally occupies about 1 square
kilometer."
Hayden makes it clear that if wind were a viable power source,
utilities would be champing at the bit to use it. Utilities use
every technology available to cut their fuel costs; they would
gladly use photovoltaic and wind turbines if they were economical.
Solar cells unworkable
There are not many people left who believe acres and acres of
mirrors following the sun will ever answer any of our energy needs.
Some of us still cling to the idea that we can efficiently heat a
swimming pool or hot water for the home with direct sunlight, though
the numbers of such solar-collecting devices are declining.
However, because few of us understand the magic of the
photovoltaic cell that runs our pocket calculators, many still hold
out hope for them.
A short description of the solar problem is that no matter how
you design the system, it will always be inefficient and capture
only a small, uneconomical amount of solar energy. The best solar
cells available on a large scale have an efficiency of about 10
percent; they can capture only about 10 percent of the solar energy
that strikes the cells.
There is a seductive fallacy about solar cells: that more exotic
materials and increasingly clever computer-type designs will cause
the price of the cell to drop dramatically. However -- unless you
are still dazzled by the old alchemists' idea of turning lead to
gold -- Hayden will easily convince you this just is not so.
Hydrogen not the answer
The last tidbit of this book I want to share with you regards
hydrogen as a form of energy. By now, most of our readers know
hydrogen is not a new form of energy but only a conveyer of energy,
and not a very efficient one at that.
With current technology, the process of removing hydrogen from
water or methane and then burning the hydrogen as fuel results in a
net energy loss of 38 percent. Similarly, fuel cells typically are
60 percent efficient, meaning only 60 percent of the 140 megajoules
of energy within each kilogram of hydrogen can be usefully squeezed
out.
Hydrogen, in short, shows no promise of being a near-term power
source.
Finally, it is worth noting that the wonderful energy conversion
table that can be found in Appendix A is by itself worth the cost of
this book.
[Jay Lehr, science
director for The Heartland
Institute]
"The Solar Fraud: Why Solar Energy Won't Run the World," second
edition, Howard C. Hayden, Vales Lake Publishing LLC, January 2005,
281 pages; $20.36 paper, ISBN 0971484546
|
