| whyreT | SOLAR | BIOMASS | WIND | HYDRO | UNITS |
1 WHY DO WE NEED RENEWABLES ?
1.1 ENERGY TODAY
Most of the energy we use today comes from fossil fuels. Coal, oil,
and natural gas are all fossil fuels created several millions of years
before by the decay of plants and animals. These fuels lie buried
between layers of earth and rock. While fossil fuels are still being created
today by underground heat and pressure, they are being consumed much more
rapidly than they are created. For that reason, fossil fuels are considered
as non-renewable; that is, they are not replaced as soon as we use them.
So, we will run out of them sometime in the future. Moreover burning fossil
fuels leads to pollution and many environmental impacts. Because our world
depends so much on energy, we need to use sources of energy that will last
forever. These sources are called renewable energy. Moreover these renewable
energy sources are much more environmentally friendly than fossil fuels
when they are burned.
Among fossil fuels somehow special character has uranium-nuclear fuel
which can be exhausted in less than 100 years, but in so called breeder
reactors it can multiply and last much more. Nevertheless problems with
radioactive waste, which will present a danger for millions of years and
the the impact of accident in Chernobyl, which showed a risk connected
with nuclear energy, most governments in industrialised world are now abandoning
nuclear power completely. This development continues despite the fact that
nuclear energy, which produce almost zero emissions of greenhouse gases,
can be somehow a solution to global climate change (see bellow). Emissions
of greenhouse gases are now recognised as the most important force behind
the efforts to decrease consumption of fossil power.
WHY DO WE NEED THE CHANGE IN ENERGY USE ?
The main problem isn’t that we use energy, but how we produce and consume
energy resources. As long as we continue to cover our energy needs primarily
by combustion of fossil fuels or nuclear reactions, we are going to have
the problems, the environmental impacts, social and sustainability problems.
What we really need are energy sources that will last forever and can be
used without pollution of the environment.
1.2 ENERGY CONSUMPTION – SUSTAINABILITY PROBLEM
Each year, the equivalent of approx. 10 000 million tons of coal is
consumed on earth as energy. About 40 % from this is based on oil and together
with coal and natural gas more than 90 % of the total energy consumption
result from carbon atoms in these fossil fuels. The consequence will be
a global warming (greenhouse effect) and the lack of resources in the future.
1.2.1 History of energy consumption
Ancient discovery of fire and the possibility of burning wood made
available, for the first time, fairly large amount of energy for mankind.
Later (4000 and 3500 years B.C.) after the first sailing ships and windmills
were developed and the use of hydropower began via water mills or irrigation
systems, cultural development began to accelerate. For several thousands
years human energy demands were covered only by renewable energy sources
– sun, biomass, hydro and wind power. It was only until the start of industrial
revolution and the ability to transform heat into motion, when energy consumption
and industrial development accelerated rapidly. The industrial revolution
was a revolution of energy technology based on fossil fuels. This occurred
in stages, from the exploitation of coal deposits to oil and natural gas
fields on a global scale. It has been only half a century since nuclear
power began being used as an energy source. After this fossil-based era
world nears the beginning of another major transition, away from fossil
fuels and towards renewable energy sources once again.
Fundamental shift in the energy picture can be found in the enormous
increase of energy demand since the middle of the last century. That increase
is the result not only of industrial development but also of population
growth. World population grew 3.2 times between 1850 and 1970, per-capita
use of industrial energy increased about 20-fold, and total world use of
industrial and traditional energy forms combined increased more than 12-fold.
1.2.2 HOW MUCH DO WE USE
Today fossil fuels such as coal, oil and natural gas account for 90%
of total primary energy supply. Estimated total world consumption of primary
energy, in all forms (including non-commercial fuels like biomass), is
approximately 400 EJ per year, equivalent of some 9500 million tonnes of
oil (mtoe) per year.
Annual world primary energy consumption,1992 by source.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
1.2.3 FUTURE TRENDS
The magnitude of energy problem that may face future generations can
be illustrated by the simple calculation. The population of the world in
1990 was approximately 5 billion people. The UN estimates of population
trends show it continuing to increase to around 8 billion by 2025, but
stabilising towards the end of the next century at somewhere between 10
and 12 billion people. Most of that increase will be in the less developed
countries. According to the US DOE (Department of energy) outlook for energy
use throughout the world continues to show strong prospects for rising
levels of consumption over the next two decades, led by growing demand
for end-use energy in Asia. World energy demand in 2015 is projected to
reach nearly 562 quadrillion British thermal units (Btu). The expected
increment in total energy demand between 1995 and 2015 - almost 200 quadrillion
Btu - would match the total world energy consumption recorded in 1970,
just before the energy crisis of 1973.
Two-thirds of all energy growth will occur in developing economies
and economies in transition, with much of that growth concentrated in Asia.
Energy growth in the developing countries of Asia is projected to average
4.2 percent per year, compared with 1.3 percent for industrialized economies.
The U.S. growth rate is expected to average only about 1 percent per year.
As recently as 1990, U.S. energy consumption exceeded total consumption
in the nations of developing Asia by 33 quadrillion Btu. By 2015, energy
use in developing Asia is expected to exceed U.S. consumption by 48 quadrillion
Btu.
According to the report of US DOE by 2015, oil use is expected to exceed 100 million barrels per day, a consumption rate 50 per cent greater than in 1995. Oil trading patterns are expected to shift markedly as oil consumption in Asia Pacific areas far outpaces domestic production gains, leading to a large increase in imports from Middle East suppliers. World-wide, coal use is projected to exceed 7.3 billion tons by 2015, compared with 5.1 billion tons in 1995. Growth in coal use will be regionally concentrated, occurring for the most part in India and China.
Natural gas is expected to have the highest growth rate among fossil
fuels, at 3.1 percent a year, gaining share relative to oil and coal. By
2015 natural gas consumption on a Btu basis will exceed the total oil consumption
recorded for 1995, at a level equivalent to two-thirds of the oil consumption
projected for 2015. Natural gas consumption in 1995 was only about 55 percent
of oil consumption.
According to US DOE prediction only about 8 percent of projected growth
in energy demand over the next two decades will be served by non-fossil
fuel sources. In fact, the non-fossil (commercial) fuel share of world
energy consumption declines from 15 percent to 12 percent over the projection
period. Thus, world carbon emissions are likely to increase by 3.7 billion
metric tons, or 61 percent, over the 1990 level by 2015. The Climate Change
Convention of 1992 commits all signatories to search for and develop policies
to moderate or stabilize carbon emissions. However, even if all the developed
countries were able to achieve stabilization of their emissions relative
to 1990 levels, overall world carbon emissions would still rise by 2.5
billion metric tons over the next two decades.
Per capita energy use in the world’s industrialized economies, which
far exceeds the levels in newly emerging economies, is expected to change
only moderately in the next two decades. In some emerging economies (for
example, India and China), per capita energy use may double. Even with
such growth, however, average per capita energy use in the developing countries
will still be less than one-fifth the average for the industrialized countries
in 2015.
In the longer term, consumption of oil as the principal source of commercial
energy today, will start to decline after the transition phase (between
2020 and 2060). It is expected that natural gas will continue to be used
as long as price and availability are satisfactory but as reserves reduce
or prices rise coal (which is usually less expensive than natural gas and
its international prices are unlikely to rise) will command a greater proportion
of the market. To maintain energy levels and because of world-wide environmental
concerns some experts predict that coal will have to be utilized cleanly,
where gasification process will be the most environmentally friendly way
of its future utilization.
The transition to a sustainable energy system requires that share of
renewable energy sources will continually grow. Renewables combined with
a system of new technologies, can contribute to a considerable extent to
energy requirements in the time horizon beyond 2020. Report for the UN
Solar Energy Group for Environment and Development suggests that using
technology already on the market or at the advanced engineering testing
stage, by the middle of the next century renewable energy sources could
account for 60 percent of the world’s electricity market and 40 percent
of the market for fuels used directly.
1.2.4 RESERVES OF FOSSIL FUELS
Fossil fuels are valuable natural energy sources which required several
millions of years for their creation but are now rapidly being depleted.
The prominent worry that fossil fuels will run out was reported almost
30 years ago by the influential book Limits to Growth. This book reported
a series of computer simulations of future resource use in which world
fuel consumption continued to rise exponentially. The predicted result
was an ultimate collapse in fuel supplies, regardless of the amount of
fuel assumed to be available. These fears came into sharp focus in the
1973 fuel crisis, when the member nations OPEC were able for the first
time to co-ordinate their policies and raised the price of oil dramatically.
One of the factors which gave the OPEC states the power to exert their
influence so strongly was that the USA, formerly a major exporter of oil
, had become an importer. United States had used up most of the easily
obtainable oil from the Texas oil fields.
The shortage expected in the dramatic concerns of those days do not
seem imminent at present. The general principle that the amount of fossil
fuels remaining is ultimately limited and cannot last for ever is obviously
true, but estimating how long they will last is not a simple process. In
any year, newly reported figures for „proven reserves“ of oil, gas and
coal are available. Proven reserves are generally taken to be those quantities
which geological and engineering information indicate with reasonable certainty
can be recovered in the future from known deposits under existing economic
and operating conditions. A useful figure of the merit for fuel reserves
is the reserve/production ratio. If the proven reserves remaining
at the end of any year are divided by the production (consumption) in that
year, the result is the time that those remaining reserves would last if
production were to continue at the then-current level.
According to the British Petroleum statistics the reserves/production
(R/P) ratio of the world’s fossil resources is estimated as:
FUEL R/P RATIO
Oil
40 years
Natural gas 62 years
Coal
224 years
Like the fossil fuels, uranium is also one of the depletable natural
resources. If uranium is only used in a once-through cycle where it is
burned in a reactor only once and disposed as a waste thereafter, confirmed
reserves are destined to be depleted in the next 60 years.
The reserves/production ratio for any region also gives an indication
of the dependence of that area on more favoured regions. For example, for
oil, the reserve/production ratio was less than 10 years for Western
Europe and for North America it was about 25 years. Obviously, both regions
would be in dire straits if they could not import oil from Middle East,
where the ratio is nearly 100 years. The Middle East has some 60 % of the
world’s reserves of oil, and Saudi Arabia alone contains about 25 %.
For gas the situation is somewhat different, because of the massive
reserves in the former Soviet Union. This region holds some 40 % of the
worlds reserves of gas, and another 40% of gas is in the OPEC region. The
world as a whole is greatly dependent upon a limited number of regions
which have most of the reserves. The reserve/production ratio for coal
are much larger and much more evenly distributed. Unfortunately, coal has
disadvantages compared to oil and gas. Coal burning creates more CO2 per
unit of energy released than is the case with gas and oil, and more sulphur
dioxide and nitrogen oxides.
OIL
At some moment during the next five years, we will have consumed more
than one half of the total usable fossil oil on Earth. To date, we have
extracted 807 billion barrels of crude oil. Only an estimated 995 billion
barrels remain that can be extracted at current production costs. If the
world-wide rate of oil consumption remained a constant 24 billion barrels
of oil per year, we would run out of oil in 2040. But consumption is not
static-it is increasing by about 2 percent per year. It seems clear that
demand for oil will overshoot supply well before 2040. At some point between
2010 and 2025, all fuel from fossil oil will be too expensive for the average
consumer to afford. Exactly when that point comes will depend largely on
the actions of Middle Eastern countries.
Exploration for oil, the most important fossil fuel today, is a very
expensive business. The amount of exploration is dependent upon economic
conditions, particularly the price of oil, and upon political conditions.
The world’s proven reserves of oil have increased from some 540 billion
barrels in 1969 to just over 1000 billion barrels in 1992, but this does
not mean that potential reserves are unlimited. The earth has been surveyed
in great detail by the oil companies, and the easiest, cheapest and most
promising reservoirs have all been found. Except for the huge pool of oil
in the Middle East, the world’s most readily exploitable sources of oil
and gas have been used up. It is only because of this that such difficult
sources of oil as the North Sea and Alaska have become economically viable
- that is, the price of oil has risen enough to make them worth exploiting.
In physical terms, the more difficult reserves require deeper holes or
extraction in more difficult environments, and the use of more materials
and effort to supply the same result.
NATURAL GAS
In 1970, world-wide annual consumption of natural gas was 850 billion
cubic meters. Today, annual consumption is over 2000 billion cubic meters
and is increasing at 3.5 percent per year. A 3.5 percent annual increase
in consumption will deplete natural gas reserves by 2050. However, the
increase in consumption of natural gas is accelerating at an astonishing
rate. Cheap supplies of natural gas will be depleted by 2040. This fact
is recently completely neglected by power companies which are building
new natural gas power stations to give customers in their area cheaper
and cleaner electricity. Experts believe that by 2010, the supply of electricity
from new natural gas power facilities will jump to 100,000 megawatts in
USA alone. Natural gas power plants are attractive to investors. They have
relative short pay back time (an average six year in the USA) and can produce
electricity for a cheap rate of two to three US cents per kilowatt-hour.
It seems clear that the demand for natural gas fuel will increase in the
near future but will slow down in the second half of the next century.
1.3 ENVIRONMENTAL EFFECTS OF ENERGY USE
Most important environmental impacts caused by energy sources are global
climate change and acid rain – both of which have the origin in the combustion
of fossil fuels and lead to global or transboundary effects.
1.3.1 CLIMATE CHANGE
During the last few decades, concern has been growing internationally
that increasing concentrations of greenhouse gases in the atmosphere will
change our climate in ways detrimental to our social and economic well-being.
Climate change or global warming means a gradual increase in the global
average air temperature at the earth’s surface. Abundant data demonstrate
that global climate has warmed during the past 150 years. The majority
of scientists now believe that global warming is taking place, at a rate
of around 0,3 ?C per decade, and that it is caused by increases in the
concentration of so-called “greenhouse gases” in the atmosphere. The most
important single component of these greenhouse gas emissions is carbon
dioxide (CO2). The major source of emissions of CO2 are power plants, automobiles,
and industry. Combustion of fossil fuels contributes around 80 percent
to total world-wide anthropogenic CO2 emissions.
Another source is global deforestation. Trees remove carbon dioxide
from the air as they grow. When they are cut and burned that CO2 is released
back into the atmosphere. Massive deforestation around the globe is
releasing large amounts of CO2 and decreasing the forests’ ability to take
CO2 from the atmosphere.
The second major greenhouse gas is methane (CH4). It is a minor by-product
of burning coal, and also comes from venting of natural gas (which is nearly
pure methane). Different fossil fuels produce different amounts of CO2
per unit of energy released. Coal is largely carbon, and so most of its
combustion products are CO2. Natural gas, which is methane, produces water
as well as CO2 when it is burned, and so emits less CO2 per unit of energy
than coal. Oil falls somewhere between gas and coal in terms of CO2 emissions,
as it is made up of a mixture of hydrocarbons. The amount of CO2 produced
per unit of energy from coal, oil and gas is in the approximate proportion
of 2 to 1,5 to 1. This is one of the reasons why there is a move towards
greater use of natural gas instead of coal or oil in power stations, despite
the much greater abundance of coal.
1.3.1.1 HOW GLOBAL WARMING WORKS
The earth’s atmosphere is made up of several gases, which act as a
“greenhouse”, trapping the sun’s rays as they are reflected from the earth’s
surface. Without this mechanism, the earth would be too cold to sustain
life as we know it. Since the industrial revolution, humans have been adding
huge quantities of greenhouse gases, especially carbon dioxide (CO2) to
the atmosphere. More greenhouse gases means that more heat is trapped,
which causes global warming. By burning coal, oil and natural gas increases
atmospheric concentrations of these gases. Over the past century, increases
in industry, transportation, and electricity production have increased
gas concentrations in the atmosphere faster than natural processes can
remove them leading to human-caused warming of the globe.
1.3.1.2 THE EVIDENCE
Recently, alarming events that are consistent with scientific predictions
about the effects of climate change have become more and more commonplace.
The global average temperature has increased by about 0.5° C and sea
level has risen by about 30 centimetres in the past century. 1998 was the
hottest year since accurate records began in the 1840s, and ten of the
hottest years have occurred during the last 15 years.
Official confirmation of global climate change came in 1995, when the
UN Intergovernmental Panel on Climate Change (IPCC), an officially appointed
international panel of over 2,500 of the world’s leading scientific experts,
found that “… the balance of the evidence suggests a human influence on
the global climate.” It has been concluded that the temperature on this
planet during this century has steadily risen with the higher concentration
of carbon dioxide, at a rate in accordance with theoretical prediction
and that this is an effect which would continue to raise the temperature
for another 75 years even if carbon dioxide emission was stopped today.
The following are events which consistent with scientists predictions
of the effects of global warming. The past two decades have witnessed a
stream of new heat and precipitation records. Glaciers are melting around
the world. There has been a 50 percent reduction in glacier ice in the
European Alps since 1900. Alaska’s Columbia Glacier has retreated more
than 12 kilometres in the last 16 years while temperatures there have increased.
A huge section of an Antarctic ice shelf broke off. Some scientists think
this may be the beginning of the end for the Larsen B ice shelf, which
is about the size of Connecticut. Severe floods like the devastating Midwestern
floods of 1993 and 1997 are becoming more common. Infectious diseases are
moving into new areas. Corresponding with global warming, sea levels have
risen, and climatic zones are shifting. All these changes exemplify the
environmental impact of global climate change. Global warming and climate
change pose a serious threat to the survival of many species and to the
well-being of people around the world.
1.3.1.3 FUTURE IMPACTS OF CLIMATE CHANGE
The IPCC estimates that air temperatures will increase by another 1-3.5°C,
and sea levels may rise by up to 1 meter over the next 100 years. Changes
of this magnitude will affect many aspects of our lives. Here are some
of them :
More people will die from heat stress. Severe heat waves like the one
that killed hundreds of people in Chicago in 1995 will become more frequent.
Children and the elderly are most vulnerable to heat stress.
Tropical diseases will spread. Infectious diseases such as Malaria,
Dengue fever, encephalitis, and cholera that are spread by mosquitoes and
other disease-carrying organisms which thrive in warmer climates will be
able to advance into new areas. This will lead to more incidents like malaria
outbreaks in New Jersey and Dengue fever in Texas.
Seas level will rise. Rising sea level will erode beaches and coastal
wetlands destroying essential habitat and leaving coastal areas more
prone to flooding. Just a 50 centimetres sea level rise would double the
global population at risk from storm surges.
The water cycle will be disrupted. As the water cycle intensifies,
some areas will experience more severe droughts, while others will have
increased flooding. This variability will stress areas that are already
prone to water quality and quantity problems.
Food crop yields will be affected. A warmer climate will increase irrigation
demands and the range of certain pests, but it will also extend the growing
season for some areas. While some countries will find their food production
increases with a warmer climate, the poorest countries that are already
subject to hunger are likely to suffer significant decreases in food production.
Endangered species will suffer. Some of the most vulnerable plants,
animals, and ecosystems will suffer major changes. Ten species at high
risk from global warming are: Giant Panda, Polar Bear, Indian Tiger, Reindeer,
Beluga Whale, Rockhopper Penguin, Snow Finch, Harlequin Frog, Monarch Butterfly,
and Grizzly Bear.
Coral reefs will be harmed. Overheating of ocean waters, as a result
of global warming, can lead to coral bleaching, which is a breakdown of
the complex biological systems that corals have evolved in order to survive.
1.3.2 ACID RAIN
Another side effect of fossil fuels combustion and resulting emissions
of pollutants is acid rain (or acid deposition). In the process of burning
fossil fuels some of gases, in particular sulphur dioxide (SO2) and nitrogen
oxides (NOx) are created. Although natural sources of sulphur oxides and
nitrogen oxides do exist, more than 90% of the sulphur and 95% of the nitrogen
emissions occurring in North America and Europe are of human origin. Once
released into the atmosphere, they can be converted chemically into such
secondary pollutants as nitric acid and sulphuric acid, both of which dissolve
easily in water. The result is that any rain which follows is slightly
acidic. The acidic water droplets can be carried long distances by prevailing
winds, returning to Earth as acid rain, snow, or fog.
Natural factors such as volcanoes, swamps and decaying plant life all
produce sulphur dioxide, one of the contributing gases to acid rain. These
natural occurrences form some kind of acid rain. There are also some cases
where acid rain may be produced naturally, which is also bad for the environment
but occurs in much lower amounts and quantities than that of those found
in urban areas. Between the 1950’s and the 1970’s the rain over Europe
increased in acidity by approximately ten times. In the 1980’s however,
acidity levels decreased, but although many countries have started to do
something about pollution that causes acid rain, the problem is not going
away.
Acid rain is often phrased as “acid precipitation”. On the pH scale,
rain usually measures 5.6. Anything below this measurement is said to be
acidified rainfall. The chemical equation for acid rain is as follows:
SO2 (Sulphur dioxide) + NO (Nitrogen Oxide) + H2O (Water) = Acid rain
Water solutions vary in their degree of acidity. If pure water is defined
as neutral, baking soda solutions are basic (alkaline) and household ammonia
is very basic (very alkaline). On the other side of this scale there are
ascending degrees of acidity; milk is slightly acidic, tomato juice is
slightly more acidic, vinegar, lemon juice is still more acidic, and battery
acid is extremely acidic. If there were no pollution at all, normal rainwater
would fall on the acid side of this scale, not the alkaline side. Normal
rainwater is less acidic than tomato juice, but more acidic than milk.
What pollution does is cause the acidity of rain to increase. In some areas
of the world, rain can be as acidic as vinegar or lemon juice.
This acid rain can cause damage to plant life, in some cases seriously
affecting the growth of forests, and can erode buildings and corrode metal
objects. The primary component involved in corrosion is acid rain. It is
estimated that the damage to metal buildings alone amounts to about 2 billion
dollars yearly. The highest emissions of sulphur come from those sectors,
which use the most energy and the highest sulphur-content fuels, that is
solid fuels and high sulphur heavy fuel oil. Solid fuels are the most polluting
fossil fuels locally and globally. These fuels range from hard coals to
soft brown coals and lignites, which have high proportion of combustion
waste and pollutants such as sulphur, heavy metals, moisture and ash content.
One of the major problems with acid rain is that it gets carried from
a mass acid rain producing area to areas that are usually not as badly
affected. Tall chimneys that are built to ensure that the pollution that
is produced by factories is taken away from nearby cities, puts the pollution
into the atmosphere. When these particles get picked up by the moisture
in the air, they form acids. As a result they become a part of the clouds.
Then these clouds get carried off by wind, which means that when the rain
falls it may be a long distance away from where the acidic particles were
picked up from. An example of this would be Central and Eastern Europe
and Scandinavia. Sweden suffer from acid rain because of huge sulphur emissions
from Eastern European power plants with low emission standards and because
of wind blowing the particles over to their country.
DAMAGE TO TREES AND SOIL
When acid rain falls, it can effect forests as well as lakes and rivers.
In many countries around the world, trees are suffering greatly because
of the results of acid rain. A lot of trees are losing their leaves and
thinning at the top. Some trees are affected so severely that they are
dying. To grow, trees need healthy soil to develop in. Acid rain is absorbed
into the soil making it virtually impossible for these trees to survive.
As a result of this, trees are more susceptible to viruses, fungi and insect
pests and they are not able to fight them and they then die.
DESTRUCTION OF BUILDINGS
Acid rain can have a severe effect on buildings. Materials such as
stone, stained glass, paintings and other objects can be damaged or even
destroyed. It slowly, but gradually, eats away at the material until there
is virtually nothing left. Building materials crumble away, metals are
corroded, the colour in paint is spoiled, leather is weakened and crusts
form on the surface of glass. In certain parts of the world many famous
and ancient buildings are been damaged by acid rain. St. Paul’s’ Cathedral
in London is having it’s stone work eaten away by acid rain. In Rome the
Michelangelo statue of “Marcus Aurelius” has been removed to protect it
from air pollution.
ACID RAIN AND LAKES
Acid rain damages soil when it falls onto the ground. It also has a
noticeable effect when it falls directly into or is washed into lakes.
Most of the animal and plant life in clean lakes and rivers are unable
to tolerate acid rain. They can be poisoned by substances that the acid
washes out from the surrounding soil into the water. All over the world
there are examples of plant life and animal life suffering a lot or even
not surviving the effects of acid rain. For example, thousands of lakes
in Scandinavia are without any kind of life, whether it be animal or plant.
Over the past years they have received a lot of acid rain as a result of
the wind blowing the particles into their country form places such as England,
Scotland and Eastern Europe. Since the 1930’s and 40’s some Swedish lakes
have increased acidic levels in their rain water by up to 1,000 times.
The interactions between living organisms and the chemistry of their
aquatic habitats are extremely complex. If the number of one species or
group of species changes in response to acidification, then the ecosystem
of the entire water body is likely to be affected through the predator-prey
relationships of the food web. At first, the effects of acid deposition
may be almost imperceptible, but as acidity increases, more and more species
of plants and animals decline or disappear. As the water pH approaches
6.0, crustaceans, insects, and some plankton species begin to
disappear. As pH approaches 5.0, major changes in the makeup of the
plankton community occur, less desirable species of mosses and plankton
may begin to invade, and the progressive loss of some fish populations
is likely, with the more highly valued species being generally the least
tolerant of acidity. Below pH of 5.0, the water is largely devoid of fish,
the bottom is covered with undecayed material, and the near shore areas
may be dominated by mosses. Terrestrial animals dependent on aquatic ecosystems
are also affected. Waterfowl, for example, depend on aquatic organisms
for nourishment and nutrients. As these food sources are reduced or eliminated,
the quality of habitat declines and the reproductive success of the birds
is affected. Both natural vegetation and crops can be affected.
HUMAN HEALTH
We eat food, drink water, and breathe air that has come in contact
with acid deposition. Canadian and U.S. studies indicate that there is
a link between this pollution and respirator problems in sensitive populations
such as children and asthmatics. Acid rain also makes some toxic elements,
such as aluminium, copper, and mercury more soluble. Acid deposition can
increase the levels of these toxic metals in untreated drinking water supplies.
High aluminium concentrations in soil can also prevent the uptake and use
of nutrients by plants.
1.3.3 BAD AIR QUALITY
Beside greenhouse gases, SO2 and NOx emissions that cause acid rain,
emissions of particulate matter contribute to bad air quality. Fuel combustion
is the most important source of anthropogenic nitrogen oxides, while fuel
combustion and evaporative emissions from motor vehicles are the main sources
of anthropogenic volatile organic compounds (VOCs). Motor vehicles account
for a considerable fraction of the total emissions of nitrogen oxides and
VOCs in Europe and North America. NOx emissions also contribute to the
formation of tropospheric photochemical oxidants. Photochemical oxidants,
especially ozone (O3), are among the most important trace gases in the
atmosphere. Their distributions show signs of change due to increasing
emissions of ozone precursors (nitrogen oxides, or VOCs, methane and carbon
monoxide). According to World Health Organisation air quality guidelines
for ozone limit values are frequently exceeded in most parts of developed
countries. In the lower troposphere, close to the ground, ozone is a strong
oxidant that at elevated concentrations is harmful to human health, materials
and plants. In the upper troposphere, ozone is an important greenhouse
gas and contributes greatly to the oxidation efficiency of the atmosphere.
There are reported several ozone and other photochemical oxidants effects
on human health, materials, and crops. Increased ozone level can cause
premature ageing of lungs and other respiratory tract effects like impaired
lung function and increased bronchial reactivity. Increased incidence of
asthmatic attacks, and respiratory symptoms, have been observed. Ozone
contributes to damage to materials such as paint, textile, rubber and plastics.
In the case of crops and some sensitive natural types of vegetation or
plant species, exposure to ozone will lead leaf to damage and loss of production.
Other photochemical oxidants cause a range of acute effects including eye,
nose and throat irritation, chest discomfort, cough and headache. As a
second consequence of increases in global trace gas emissions, a further
decrease is expected to occur of the self-cleansing capacity of the troposphere.
This would result in longer atmospheric residence times of trace gases
and, consequently, an enhanced greenhouse effect and an increased influx
of ozone-depleting trace gases into the stratosphere.
Heavy metals like arsenic (As), cadmium (Cd), mercury (Hg), lead (Pb)
and zinc (Zn) are also released during fuel combustion. Lead pollution
as the result of road traffic emissions have decreased markedly since early
80s due to increased consumption of unleaded gasoline and use of catalysts
in cars. Nevertheless this sector remains the main source of lead in atmosphere.
Beside emissions of pollutants there are also some other impacts of
fossil fuel combustion on local environment. Here microclimatic impacts
like origination of fogs, less sunshine etc. are the results of large amounts
of water vapour effluents from cooling towers of power plants.
1.3.4 SEA POLLUTION
Damage caused by the transport of oil is related to the pollution of
the seas. Here as the scale of oil production has increased during the
twentieth century, the quantity of oil transported around the world, most
of it by the sea, has also increased. To cope with this increase, in a
highly competitive market, the size of oil tankers has increased to the
point where they are by far the largest commercial ships. Even in routine
operation, this results in large quantities of oil being released into
the seas. The tankers fill up with water as ballast for return journeys.
When this is emptied, significant quantities of oil are released as well.
Despite the fact that the transport of oil is generally a safe industry,
the scale of it, and the size of tankers, means that when accidents do
occur they have a large effect. Although the number of accidents is small
in proportion to the number of tanker journeys, thousands of minor incidents
involving oil spills from tankers, and oil storage facilities occur annually.
Between 1970 and 1985 there were 186 major oil spills each involving more
than 1300 tonnes of oil. In 1989, the tanker Exxon Valdez ran aground off
Alaska, releasing 39.000 tonnes of oil to form a slick covering 3.000 square
kilometres and causing widespread environmental damage. People usually
tend to think of the seas as a vast reservoir which can soak up limitless
quantities of whatever we put into it. In fact, the scale of pollution
from oil is such that clumps of floating oil are now common almost anywhere
in the world’s oceans.
1.4 SOCIAL PROBLEMS RELATED TO ENERGY USE
Beside environmental problems associated with large-scale use of fossil
and nuclear fuels and the problems with sustainability there are also social
problems arising from present trends of energy utilization.
1.4.1 Political and economic problems
In the earlier stages of the industrial revolution, fuel sources were
local and widely distributed. Industrial activity tended to grow in areas
where local sources of coal were available. As the transport associated
with industrialisation spread and developed, fuels began to be transported
from more and more distant places. Now, with the most accessible sources
of oil and gas depleted, fuels are transported around the world from small
number of major producing areas. The result is that the major industrial
nations have become dependent upon supplies from those producing nations,
in particular oil from the Middle East, and are highly vulnerable to disruption
of these supplies. This vulnerability and dependence has been a major factor
shaping world politics. A series of major economic and political crises
has resulted from Sues crisis in 1956 to the 1970s, oil crisis to the Gulf
war in early 1990s. Since the producing nations are generally weak militarily
and the consuming nations are generally stronger, latter are under pressure
to dominate the former economically, politically and if necessary, militarily
to maintain access to oil (most important fuel today).
1.4.2 VULNERABILITY DUE TO CENTRALISATION
A related aspect of vulnerability in the present form of industrialisation
is the centralized nature of fuel production and distribution. Electricity
is generated in relatively few, very large power stations, and distributed
through the country. Oil is imported in giant tankers, and converted to
fuel in large refineries for further distribution. Concerns have been expressed
that these large, vital installations offer potential target for terrorists
or military opponents. As has been seen in recent years in the Middle East
(Gulf War), the result can be massive ecological damage as well as economic
devastation. The normal response to such vulnerability is to put greater
resources into security and to increased level of protection. High level
of centralisation leads also to problems with employment. Decentralized
energy production and utilization which is the case of renewable energy
sources can create much more new jobs than centralized fossil fuel installations.
1.4.3 MILITARY DANGERS FROM NUCLEAR PROLIFERATION
Nuclear weapon proliferation is one of the biggest threat to the world
peace today with several countries already in or trying to be a member
of “nuclear club”. In developed countries nuclear electricity industries
grew out of nuclear weapons development. The earliest nuclear reactors
were built to produce material for nuclear bombs. There has always been
a close connection between the two terms of the technology used, so that
military spending on research and development for nuclear weapons technology
has in effect been a major subsidy for civilian nuclear electricity industries.
Nuclear fuel is not directly useful for nuclear weapons. Much further processing
is needed. However, for a country wishing to develop nuclear weapons without
publicly revealing the fact, an obvious approach would seem to be combine
weapons development with a nuclear electricity generation industry.
1.5 RENEWABLE ENERGY SOURCES
Fortunately, solutions exist to cut greenhouse gas emissions, reduce
acid deposition, improve air quality and to solve social problems related
to recent energy use. Shifting investment from fossil fuels like coal and
oil to renewable energy and energy efficiency would allow cleaner, more
sustainable sources of energy to take their rightful place as market leaders.
Renewable energy systems use resources that are constantly replaced
and are usually less polluting. All renewable energy sources – solar energy,
hydro power, biomass and wind energy have their origin in activity of the
Sun. Geothermal energy which, because of its inexhaustible potential, is
sometimes considered as renewable source is getting energy from the heat
of the earth.
Renewable energy is a domestic resource which has the potential to
contribute to or provide complete security of energy supply. Countries
that depend on imports of fossil fuel resources are in danger due to the
risk of sharp rise of the cost of imported energy (mainly oil). This is
particularly so for developing countries, where the oil import bill adds
every year to the problem of financing an already large external deficit.
Renewables are virtually uninterruptible and is of infinite availability
because of its wide spread of complementary technologies - thus fitting
well into a policy of diversification of energy supplies. Renewable resources
are well-recognized as a good way to protect the economy against price
fluctuations and against future environmental costs. Technologies based
on renewables are largely pollution-free and make zero or little contribution
to the greenhouse effect with its predicted drastic climatic changes. In
addition, they produce no nuclear waste and are thus consistent with environmental
protection policies, building towards a better environment and sustainable
development.
1.5.1 FUTURE OF RENEWABLES
The shape of our future will be largely determined by how we generate
and apply technological innovation the most powerful force for progress
in the modern world. The renewable energy sources are able to have a strong
transformative effect on the whole of society in the coming decades. By
virtually all accounts, renewable energy resources will be an increasingly
important part of the power generation mix over the next several decades.
Not only do these technologies help reduce global carbon emissions, but
they also add some much-needed flexibility to the energy resource mix by
decreasing our dependence on limited reserves of fossil fuels. Experts
agree that hydropower and biomass will continue to dominate the renewables
arena for some time.
However, the rising stars of the renewables world - wind power and
photovoltaics - are on track to become strong players in the energy market
of the next century. Wind power is the fastest-growing electricity technology
currently available. Wind-generated electricity is already competitive
with fossil-fuel based electricity in some locations, and installed wind
power capacity now exceeds 10,000 MW world-wide. Meanwhile, PV electricity
- although currently three to four times the cost of conventional, delivered
electricity - is seeing impressive growth world-wide. PV is particularly
attractive for applications not served by the power grid. Advanced thin-film
technology (a much less expensive option than crystalline silicon technology)
is rapidly entering commercial-scale production. Perhaps even more promising
than the technical developments in renewables are the resounding endorsements
from major energy companies like Enron, Shell, and British Petroleum, which
have invested heavily in PV and wind in recent years and are planning significant
increases in these and other renewables efforts.
The energy-starved developing world, which accounts for a large portion
of the projected new electricity demand over the next 20 years, is considered
one of the biggest markets for renewables. Many of these countries are
attracted to the modular nature of renewable energy technologies,
which can be located close to the users. The renewable technologies are
far cheaper and quicker to install than central-station power plants and
their extensive lengths of transmission line.
Renewables are also gaining favour in industrialized countries. In
the USA, national surveys show that well over half of consumers are willing
to pay more for green power, and a number of power companies are now offering
this option. In Europe, strong public support for clean energy is causing
the renewables market to expand rapidly. In 1997, the European Commission
released a white paper on renewable sources of energy, in which it noted
that renewables are unevenly and insufficiently exploited in the European
Union. Contributing less than 6% to the EU’s energy consumption,
it called for a joint effort to increase this level for export potential
and to address climate change. More than half of Europe’s energy
is imported, and will rise to 70% by 2020 without action. Different scenarios
show the contribution of renewables by 2010 to range from 9.9% to 12.5%,
but a goal of 12% renewables share (“an ambitious but realistic objective”)
was set, to be achieved through the installation of one million PV roofs,
15,000 MW of wind and 1,000 MW of biomass energy. The current 6% share
includes large-scale hydro, which will not expand for environmental reasons.
Growth is expected from biomass, followed by 40 GW of wind and 100 million
square metres of solar thermal collectors. Photovoltaics will grow
up 3 GWp, geothermal by 1 GWe and heat pumps by 2.5 GWth. Total capital
investment to achieve the 12% target will be 165 billion ECU (1997-2010),
but it would create up to 900,000 new jobs and drop CO2 emissions by 402
million tonnes/a.
The European Wind Energy Association estimates up to 320,000 jobs would
be created if 40 GW of wind power is installed, the PV Industry Association
says it would create 100,000 jobs if 3 GWp is met, the Solar Industry Federation
estimates 250,000 jobs under its market objective, and another 350,000
jobs could be created to meet the export market. The white paper proposes
a number of tax incentives and other fiscal measures to encourage investments
in renewable energies, and measures to encourage passive solar. “The
overall objective of doubling the current share of renewables to 12% by
2010 can be realistically achieved,” it concludes, and the contribution
of renewables to electricity generation could grow from 14% to more than
23% by 2010 if appropriate measures are instituted.
Job creation is one of the most important features related to the development
of renewable energy sources. The employment potential of renewables can
be estimated according to the following data:
1.5.2 HIDDEN COST OF FOSSIL FUELS UTILISATION
It is important to note that when energy experts are comparing different
energy sources the question of their price is the crucial one and renewables
are mostly considered as more expensive than fossil fuels. What is not
known is the fact that such a comparison is usually based of wrong estimation
of costs. When we pay the electric bill to the power company or fill up
our car’s tank, we usually pay a specific price for the energy which does
not express the full cost related to energy consumption. What we do not
pay are many hidden costs associated with our energy usage. And there are
several of them. Hidden social and environmental costs and risks associated
with fossil-fuel use are principal barriers to the commercialization of
renewable technologies. It is a well recognised fact that current markets
mostly ignore these costs. In effect, relatively harmful sources, e.g.,
high sulphur coal and oil, are given an unfair market advantage over benign
renewable sources. Since competing conventional technologies are able to
pass on to society a substantial part of their costs (such as environmental
degradation and health-care expenditures) renewable sources, which produce
very few or no external and may even cause positive external effects such
as job creation, rural regeneration and foreign-exchange earnings, are
systematically put at a disadvantage. Internalising all these costs therefore
must become a priority if a “level playing field” is to be created.
While it is extremely difficult to quantify the external costs of such
pollution, and some simply cannot be quantified, several studies show them
to be substantial. For example, a German study concluded that the external
costs (excluding global warming) of electricity generated from fossil-fuel
plants are in the range of 2.4-5.5 US c/kWh, while those from nuclear power
plants are 6.1-3.1 c/kWh.
According to the another study sulphur dioxide from US coal burning
plants is costing U.S. citizens USD 82 billion per year in additional health
costs. Reduced crop yields caused by air pollution is costing US farmers
USD 7.5 billion per year. What is important on these US figures is the
fact that US citizens are actually paying between 109 billion and 260 billion
dollars yearly in hidden energy costs. In other countries similar patterns
can also be found.
Had external economic effects been included in the market allocation
process, renewable technologies would be in a far better position to compete
with fossil fuels, and there might already have been a substantial shift
to the penetration of renewable in the market.
ENERGY SUBSIDIES
Many governments are heavily subsidising the energy industries. It
is interesting to note that the energy technologies with the worst health
and environmental impacts usually receive the most government money. The
worst polluters, nuclear and combustion technologies, in the U.S. alone
receive 90% of the government money. The renewable energy technologies,
which offer little or no side effects, receive the least government support.
Solar technologies (both PV and thermal together) receive in the USA only
3% of the government money. At the bottom of the list is conservation with
2% of the subsidy dollars. And there is not much difference in other countries
of the world. This is amazing since renewables and energy savings offer
relief from our energy problems and has no environmental side effects.
Something is really wrong here.
MILITARY
World’s dependence on imported oil requires that military will keep
the international supply lines open. The U.S. military is spending between
14.6 and 54 billion dollars yearly just defending the oil supplies coming
from the Persian Gulf. On the low side, the National Defence Council places
the Persian Gulf military cost at 14.6 billion. On the high side, the estimate
of 54 billion is made by the Rocky Mountain Institute. There are also other
hidden national security costs. One of these is military aid to oil producing
nations. Another is diplomatic and foreign policy decisions made on the
basis of imported oil.
RADIOACTIVE WASTE
The major problem associated with nuclear power is, “What do we do
with the radioactive waste?” To date, no one has a viable disposal solution
for the thousands of tonnes of high level radioactive waste nuclear power
plants generate. This problem is made more severe because it is a long
term problem. For example, plutonium (Pu239) has a radioactive half-life
of 24,400 years and is environmentally dangerous for over several hundred
thousands years. We are making nuclear decisions now that will affect our
planet, and all life forms on it, for millennia in the future. The World
Watch Institute estimates the disposal costs of nuclear waste at between
1.44 and 8.61 billion dollars per year. Radioactive waste disposal is not
actually disposal, but containment. We will have to deal with high level
waste for thousands of years. We now have no method of actually disposing
of high level waste. We simply store it and hope our children can figure
out a safe way to deal with it. This estimate doesn’t include the cost
of nuclear accidents. What does a “Chernobyl or Three Mile Island” cost
to clean up?
1.6 LITERATURE
Energy World, James and James Sci. Publ. January 1999
EPRI Journal, July/August 1985
TOP