1
INTRODUCTION
WE ARE ALL CITIZENS OF EARTH
The blue and white planet, with South American and Antarctic visible.
Photo JPL, NASA.
CHAPTER ONE SAMPLE FROM "SOLAR ENERGY" 2005
1
INTRODUCTION
WE ARE ALL CITIZENS OF EARTH
The blue and white planet, with South American and Antarctic visible.
Photo JPL, NASA.
1.1
COMMENTS ON ENERGY AND SOCIETY
Industrialized societies run on
energy, a tautological statement or an oxymoron in the sense that it is
obvious. Population, gross domestic product (GDP), consumption and
production of energy, and production of pollution for the world and the
United States will be considered. The United States has less than 5% of
the world population, however it generates around 24% of the gross
production and 25% of the carbon dioxide emissions (Fig. 1.1). Because
population has increased and the amount of energy per person has also
increased in the developed countries, the developed countries consume
the most energy and produce the most pollution. On a per person basis,
the U.S. is the worst (most energy use and most pollution generated).
Figure 1.1. Regional comparison for world population, gross domestic production and carbon dioxide emissions. Other developed countries includes Australia, New Zealand, and Japan. Source of data, United Nations.
The energy consumption in the United States increased from 32.0 Quads to 98.5 Quads from 1949 to 2000 (Fig. 1.2). 1 Quad = 1015 British Thermal Units (discussed in Ch. 2) There is an increase in efficiency in the industrial sector, primarily due to the shock of the oil crisis of 1973.
Figure 1.2. United States consumption of energy by sector for year 1949 and 2000. See table below for size of Quad. Source of data, Energy Information Agency.
However
you must remember that correlation between gross domestic production
(GDP) and energy consumption does not mean cause and effect. The oil
crisis of 1973 showed that efficiency is a major component in gross
national product and the use of energy.
It is enlightening to consider how the United States has changed in terms of energy since WWII. Ask you parents or even your grandparents about their lives in the year 1950 and then compare with your family today. One dilemma in the developing world is that a large number of villages and others in rural areas do not have electricity.
Residential: Space heating and cooling, lights, amount of space per person
Transportation: Number of vehicles in the family
Commercial: Space heating and cooling for buildings, lights
Industrial: ?
A
thought: A solar clothes drying (a clothes line) does not add to the
GNP, but every electric and gas dryer does. They both do the same
function. We may need to think in terms of results and efficiency ways
to accomplish that function or process.
1.2
TYPES OF ENERGY
There are many different types of energy. Kinetic energy is energy
available in the motion of particles, for example wind. Potential
energy is the energy available because of the position between
particles, for example water stored in a dam, the energy in a coiled
spring, and energy stored in molecules (gasoline). There are many
examples of energ; mechanical, electrical, thermal (heat), chemical,
magnetic, nuclear, biological, tidal, geothermal, psychic, and so on.
In reality there are only four interactions (forces between
particles) in the universe; nuclear, electromagnetic, weak, and
gravitational. In other words all the different types of energy in the
universe can be traced back to one of these four interactions. This
interaction or force is transmitted by an exchange particle. The
exchange particles for electromagnetic and gravitational interactions
have zero rest mass and with this comes the speed limit of light, 3 * 108
m/s or 186,000 miles/hr for transfer of energy and information. Even
though gravitational interaction is very very very weak, it is
noticeable when there are large masses. The four interactions are a
great example of the how a scientific principle covers a immense amount
of phenomena.
| Interaction | Particle | Strength | Range, m | Exchange Particle |
| Nuclear (strong) | quarks | 101 = 10 | 10-15 | gluons |
| electromagnetic | charge | 100 = 1 | infinite | photon |
| weak | leptons | 10-15 | 10-18 | weakons* |
| gravitational | mass | 10-39 | infinite | graviton |
The source of solar energy is the nuclear interactions at the core of the sun, where the energy comes from the conversion of hydrogen into helium. This energy is primarily transmitted to the earth by the electromagnetic waves which can also be represented by particles (photons). In this course we will be dealing primarily with the electromagnetic interaction, although hydro and tides are energy due to the gravitational interaction.
We will use exponents to indicate large and small
numbers. The exponent indicates how many times the number is
multiplied by itself, or how many places the decimal point needs to be
moved. Powers of ten will be very useful in order of magnitude
problems, which are rough estimates.
103 = 10*10*10 =
1000
10-3 = 1/103
= 0.001
We will also use meter, kilogram, seconds for units with English units
in ( ) to give you a feel for value.
Note there is a discrepancy between the use of billions in the US (109)
and England (1012). If there is a doubt, we will
use exponents or the following notation for prefixes.
|
Small |
Large |
||
| nano | 10-9 | kilo | 103 |
| micro | 10-6 | mega | 106 |
| milli | 10-3 | giga | 109 |
| tera | 1012 | ||
| Quad (quadrillion BTU) | 1015 |
British Thermal Unit (BTU)
1.3
RENEWABLE ENERGY
Solar energy is referred to as renewable and/or sustainable energy
because it will be available as long as the sun continues to shine.
Estimates for the life of the main stage of the sun are another 4 to 5
billion years. The energy from the sunshine, electromagnetic radiation,
is referred to as insolation. The other main renewable energies are
wind, biomass, tides, waves, and geothermal. Wind energy is derived
from the uneven heating of the earth's surface due to more heat input
at the equator with the accompanying transfer of water by evaporation
and rain. In this sense, rivers and dams for hydro energy are stored
solar energy. The third major aspect of solar energy is the conversion
of solar energy into biomass by photosynthesis. Animal products such as
whale oil and biogas from manure are derived from solar energy. Tidal
energy is primarily due to the gravitational interaction of the earth
and the moon. Another renewable energy is geothermal, due to heat from
the earth from decay of radioactive particles. Volcanos are fiery
examples of geothermal energy reaching the surface from the interior
which is hotter than the surface.
Overall 14% of the world's energy comes from biomass, primarily wood and charcoal, but also crop residue and even animal dung for cooking and some heating. This contributes to deforestation and the loss of topsoil in developing countries.
In contrast, fossil fuels are stored solar energy from past geological ages. Even though the quantities of oil, natural gas, and coal are large, they are finite and for the long term of 100s of years they are not sustainable.
1.4
ADVANTAGES/DISADVANTAGES
The advantages of renewable energy are: sustainable (non depletable),
ubiquitous (found everywhere across the world in contrast to fossil
fuels and minerals), and essentially non-polluting.
The disadvantages of renewable energy are: variability, low density, and generally higher initial cost. For different forms of renewable energy, other disadvantages or perceived problems are visual pollution, odor from biomass, avian with wind plants, and brine from geothermal. I am sure that where ever a large renewable facility is to be located there will be perceived and real problems to the local people. For conventional power plants using fossil fuels, for nuclear energy, and even for renewable energy there is the problem of not in my backyard.
1.5
ECONOMICS
Business entities always couch their concerns in terms of economics. We
can not have a clean environment because it is uneconomical. Renewable
energy is not economical. We must be allowed to continue our operations
as in the past, because if we have to install new equipment, we can not
compete with other energy sources. We will have to reduce employment,
jobs will go overseas, etc.
The different types of economics to consider are pecuniary, social, and physical.
Pecuniary is what everybody thinks of as economics, DOLLARS.
Social economics are those borne by everybody and many businesses want the general public to pay for their environmental costs. A good example is the use of coal in China. They have laws (social) for clean air, but they are not enforced. The cost will be paid in the future in terms of health problems, especially for the children today. If environmental problem(s) affect(s) someone else today or in the future, who pays? The estimates of the pollution costs for generation of electricity by coal range from $0.005 to 0.10/kWh.
Physical economics is the energy cost and the efficiency of
the process. There are fundamental limitations in nature due to
physical laws. In the end
Mother Nature always wins
or the corollary, pay now or probably pay more in the future.
On that note, we should be looking at life cycle costs, rather than our
ordinary way of doing business, low initial costs. Life cycle
costs refers to all costs over the lifetime of the system.
Finally, we should look at incentives and penalties for the
energy entities. What each entity wants is subsidies for themselves and
penalties for their competitors. Penalties come in the form of taxes,
environmental and other regulations, while incentives come in the forms
of break on taxes, do not have to pay social costs on their product,
and the government pays for research and development. How much should
we subsidize businesses for exporting overseas? It is estimated that we
use energy sources in direct proportion to the incentives that source
has received in the past. There are many examples of the above.
1.6
ORDER OF MAGNITUDE ESTIMATES
In terms of energy consumption, production, supply and demand and
design for heating and cooling, estimates are needed and an order of
magnitude estimate will suffice. By order of magnitude, we mean an
answer to within a power of ten.
Example: How many seconds in a year. With a calculator it is
easy
365 days * 24 hr/day * 60 min/hr * 60 sec/hr = 31,536,000
When you round to one significant digit, this becomes 3 * 107
seconds.
Order of magnitude estimate. For the above
multiplication round each number with a power of ten, then multiply and
add the powers of ten
4 *102 * 2 *101
* 6 *101
* 6 * 101 =
4 * 2 * 6 * 6 *105 = 288 * 105
= 3 * 102 * 105
= 3 * 107
1.7
GROWTH (EXPONENTIAL)
Our energy dilemma can be analyzed in terms of fundamental principles.
It is a physical impossibility to have exponential growth of any
product or exponential consumption of any resource in a finite system.
| The present rate of consumption and the size of the
system give a tendency for people to perceive the resource as either
infinite or finite. The total energy output of the sun and the amount
of mass in the solar system appear to be an infinite source at the
present rates of use, even though the solar system is finite. The
energy dilemma is defined within the context of the system and our
present energy dilemma is due to the finite amount of fossil fuels on
the earth.
The easy way to understand exponential growth (Fig. 1.3) is to use the example of money. Suppose Sheri receives a beginning salary of $1/year with the stipulation that the salary is doubled every year, a 100% growth rate. It is easy to calculate the salary by year (Table 1.1). After 30 years, her salary is one billion dollars per year. |
Figure 1.3. Exponential growth curve |
Table 1.1. Salary
by year with a growth rate of 100%, doubling time of one year.
|
Year |
Salary, $ |
Amount = 2t |
Cumulative $ |
|
0 |
1 |
20 |
1 |
|
1 |
2 |
21 |
3 |
|
2 |
4 |
22 |
7 |
|
3 |
8 |
23 |
15 |
|
4 |
16 |
24 |
31 |
|
5 |
32 |
25 |
63 |
|
t |
2t |
2t+1 - 1 |
|
|
30 |
1 * 109 |
231 - 1 |
Notice that for any year, the amount needed for the next period is equal to the total sum for all the previous periods plus one.
There are numerous historical examples of growth; population, 2-3%/yr; gasoline consumption, 3%/yr; world production of oil, 5-7%/yr; electrical consumption, 7%/yr. Notice that if we plotted the value per year for smaller rates of growth (Fig. 1.4), the curve would be the same as Figure 1.3, only the time scale along the bottom would be different. Notice that for population growth, the projection for the future assumes that the growth rate will decrease from 1.35% today to 0.5% in 2050. The United Nations projects a leveling off at 11 billion people by 2200. HOWEVER EVEN WITH DIFFERENT RATES, THE FINAL RESULT IS STILL THE SAME. WHEN CONSUMPTION GROWS EXPONENTIALLY, ENORMOUS RESOURCES DO NOT LAST VERY LONG.
This is the fundamental flaw in term of ordinary economics ($) and announcing growth in terms of percentages. How long do they want those percentages to increase? Nobody wants to discuss how much is enough. The theme since President Reagan is that all we need is economic development and the world's problems will be solved.
Figure 1.4a Growth of
human population (millions) since the year 1000 A.D.
Figure 1.4b Human
population (millions) since the year 1900. Squares are
predicted values by UNDP.
| T2 = 69/R -- where R is the % growth per unit time | 1.1 |
Doubling times for some different
yearly rates are given in Table 1.2.
Table 1.2.
Doubling times for different rates of growth.
| Growth %/year |
Doubling Time years |
| 1 |
69 |
| 2 |
35 |
| 3 |
23 |
| 4 |
18 |
| 5 |
14 |
| 6 |
12 |
| 7 |
10 |
| 8 |
8 |
| 9 |
8 |
| 10 |
7 |
| 15 |
5 |
1.8
SOLUTIONS
We do not have an energy crisis, since you will learn energy can not be
created or destroyed. We have an energy dilemma because of the finite
amount of readily available fossil fuels. Fossil fuels are our main
energy source today. The problem is twofold: population is 6.3 * 109
and growing toward 11 * 109 and developing
countries want the same standard of living as developed countries. The
world population is so large that we are doing an uncontrolled
experiment on the earth's environment. However the developed countries
are the major contributors to this uncontrolled experiment.
The solution depends on local, national, and world policies. What do you do as an individual, and what policies do we implement as a society at the state and national level? I have mine, what are yours?
REFERENCES
Links
Energy Information Administration,
US Dept. of
Energy
www.eia.doe.gov
This
site contains a lot of information on US and international energy
resources and production.
International energy outlook
http://www.eia.doe.gov/iea/
Data
files can be downloaded, PDF and spreadsheets.
Oil and gas production in
Texas is regulated by the Texas Railroad Commission.
http://www.rrc.state.tx.us/divisions/og/og.html
United Nations: Information on population and
projections on population
http://www.un.org/esa/population/unpop.htm
US Census has information
on world population
http://www.census.gov
Scientific American can be
searched for articles since 1993, however you will have to pay for each
article you download.
http://www.sciam.com
National Geographic
Magazine has a section on Earth Pulse. See March 2001 for comments on
global energy consumption.
http://www.nationalgeographic.com
Books and articles are
included for general information.
John Gever, Robert Kaufmann, David
Skole, Charles Vorosmarty, Beyond Oil, The Threat to Food and
Fuel in the Coming Decades, Ballanger Publishing, 1987.
Thomas Lee, Ben Ball, Richard
Tabors, Energy Aftermath, Harvard Business School
Press, 1990.
Walter Youngquist, GeoDestinies, The Inevitable
control of Earth Resources over Nations and Individuals,
National Book Co, 1997.
Michael T. Klare, Resource Wars, The New Landscape of Global
Conflict, Metropolitan Books, 2001.
Kenneth S. Deffeyes, Hubbert's
Peak, The Impending World Oil Shortage, Princeton
University Press, 2001.
Kenneth Leeb and Donna Leeb, The
Oil Factor, Warner Business Books, 2004.
W. Wayt Gibbs, The Artic
Oil & Wildlife Refuge, Sci Am, V 284, No 5, May 2001, p 62.
Articles from Scientific American,
March 1998.
Colin
J. Campbell and Jean H. Laherrere, The End of Cheap Oil
Richard L. George, Mining for Oil
Roger
N. Anderson, Oil Production in the 21st Century
Safaa
A. Fouda, Liquid Fuels from Natural Gas
Articles from Scientific American,
Energy and Environment, September 1995.
William Hoagland, Solar Energy
Harold P. Furth, Fusion
Robert A. Frosch, The Industrial Ecology of the 21st Century
Donald L Plucknett and Donald L. Winkelmann, Technology for Sustainable
Agriculture
Outline for an Ecological Economy
PROBLEMS