composed by
Dr. M A Islam
EEE, IIUC
In the last 100 years, the Earth
warmed up by ~1° C
100 years is nothing by geological time scales!
M A Islam, EEE, IIUC
Can we predict the past?
Climate change due
to natural causes
(solar variations,
volcanoes, etc.)
Climate change due
to natural causes
and human
generated
greenhouse gases
M A Islam, EEE, IIUC
CO2 Concentration, Temperature, and Sea Level
Continue to Rise Long after Emissions are Reduced
Sea-level rise due to ice
melting: several millennia
Sea-level rise due to
thermal expansion:
centuries to millennia
CO2 emissions peak
0 to 100 years
Temperature stabilization:
a few centuries
CO2 stabilization:
100 to 300 years
CO2 emissions
Today
1,000 years
100 years
M A Islam, EEE, IIUC
Chu
… but there may be a bigger problem!
M A Islam, EEE, IIUC
Consumption of Energy Increased by 85%
Between 1970 and 1999
By 2020, Consumption will Triple
Quadrillion Btu
700
Projections
History
600
500
400
300
200
100
0
1970 1975 1980 1985 1990 1995 1999 2005 2010 2015 2020
M A Islam, EEE, IIUC
2010
M A Islam, EEE, IIUC
Energy conservation and
efficiency can buy time
(a factor of ~2)
but the fundamental problem remains
M A Islam, EEE, IIUC
M A Islam, EEE, IIUC
Electrical generation
Switch from petroleum to coal
and natural gas
Why has hydroelectric
declined?
When did nuclear go up?
M A Islam, EEE, IIUC
Estimates of depletable energy resources in the U.S.
Numbers = how long it would last if all energy came from one source
Resource
recoverable
recoverable and hoped for
Coal
125
1300
Petroleum
5
50?
Natural gas
5
50?
Oil shale
0
2500
Conventional reactors
3
15
Breeder reactors
115
750
106 to 109
Fusion
Geothermal surface
deep rock
0.2
60
0
600
M A Islam, EEE, IIUC
Estimates of renewable energy
Numbers = proportion of current U.S. energy needs that could be supplied for
an indefinite period.
Tidal energy
0.1
Organic Waste
0.1
Photosynthesis
0.23
Hydropower
0.14
Wind Power
5
Solar radiation
740
M A Islam, EEE, IIUC
(in the U.S. in 2002)
25-50 ¢
25
20
15
Cost
10
1-4 ¢ 2.3-5.0 ¢
6-8 ¢
5-7 ¢
6-7 ¢
5
0
Coal
Gas
Oil
Wind
Nuclear
Courtesy
Nate
Lewis
M A Islam,
EEE, IIUC
Solar
$0.05/kW-hr
14
12
8
Brazil
$/GJ
Europe
10
6
4
2
0
Coal
Oil
Biomass
Elect
www.undp.org/seed/eap/activities/wea
M A Islam,
EEE, Lewis
IIUC
Courtesy
Nate
Potential Sources of Energy when
Fossil Fuels Run Out
Magnetic Plasma
Confinement,
Inertial Fusion
Nuclear
Fusion
Waste &
Nuclear Proliferation
Nuclear
Fission
10 TW = 10,000 new 1 GW
reactors: i.e., a new
reactor every other day for
the next 50 years
M A Islam, EEE, IIUC
Solar, Wind and Water
We do not know how to store electrical
energy on a massive scale
M A Islam, EEE, IIUC
Geothermal
Heat near surface of
the earth = geysers,
volcanoes, hot
springs
M A Islam, EEE, IIUC
Solar to Chemical Energy
CO
2
H2
O2
e
e
Sugar
sc
H2 O
M
sc
M
H2O
O2
Photosynthesis
Semiconductor/
liquid junctions
M A Islam, EEE, IIUC
Photovoltaic and
electricity to
chemical
M A Islam, EEE, IIUC
M A Islam, EEE, IIUC
“Unlike corn ethanol, cellulosic ethanol has
potential to achieve near-zero net carbon
emissions.
Cultivation of cellulosic feedstocks requires
very low energy inputs and, if sustainably
managed, the carbon released during fuel
combustion is reabsorbed by the growth of
new feedstocks.”
M A Islam, EEE, IIUC
Geothermal Energy in More Details
Use heat to make steam to turn
turbine for electrical generation
Note: deep hot waters are
corrosive to best to inject clean
water in a closed system and bring
it back to the surface as steam.
M A Islam, EEE, IIUC
In U.S., much done on
public land = cheap
Very little potential in east
and mid west
M A Islam, EEE, IIUC
World wide distribution of
volcanos, hot springs, etc.
Japan, Iceland,New Zealand
big users of geothermal.
M A Islam, EEE, IIUC
M A Islam, EEE, IIUC
Although hot areas near surface are limited, the earth is hot
everywhere if you go down far enough.
M A Islam, EEE, IIUC
Bright idea!? – drill deep enough to find heat. Since rock is a poor conductor of
heat, set off a big bomb to crack the rock and allow heat to move – then pump
down water to make steam.
M A Islam, EEE, IIUC
Hydropower in More Details
M A Islam, EEE, IIUC
Hydropower = dams
Not much used in world,
why??
M A Islam, EEE, IIUC
Norway,
Zambia,
Ghana big
users
M A Islam, EEE, IIUC
M A Islam, EEE, IIUC
Most unused hydropower in U.S. = Alaska,
In World = Canada, Russia
M A Islam, EEE, IIUC
o It is also another absolutely clean source of energy.
o Hydroelectricity does not "use" water, all of the water is
returned to its source of origin.
o Hydroelectric power can be created 24/7 indefinitely assuming
that the body of water it is utilizing never runs dry.
o The power plants, once in place, do not create any waste
byproducts in their conversion.
o Dams constructed can also shut their gates and conserve the
water for use when power is in higher demand.
o Location = unused rivers are in extreme north or low population
areas
o Competition with recreational uses and environmental concerns
o Hard to build dams in populated river valleys
o Siltation of dams – limited life.
M A Islam, EEE, IIUC
Tidal Power
1. In areas of large tides
2. Anywhere – build
offshore dam
M A Islam, EEE, IIUC
Tidal power anywhere
Highest tides in the
world = Bay of Fundy
16 meters = 48+ feet!
1. No dam – but a turbine.
M A Islam, EEE, IIUC
Advantages of Tidal Energy
1) It is an inexhaustible source of energy.
2) Tidal energy is environment friendly energy and doesn't produce greenhouse
gases.
3) As 71% of Earth’s surface is covered by water, there is scope to generate
this energy on large scale.
4) We can predict the rise and fall of tides as they follow cyclic fashion.
5) Efficiency of tidal power is far greater as compared to coal, solar or wind
energy. Its efficiency is around 80%.
6) Although cost of construction of tidal power is high but maintenance costs
are relatively low.
7) Tidal Energy doesn’t require any kind of fuel to run.
8) The life of tidal energy power plant is very long.
9) The energy density of tidal energy is relatively higher than other renewable
energy sources.
M A Islam, EEE, IIUC
Disadvantages of Tidal Energy
1) Cost of construction of tidal power plant is high.
2) There are very few ideal locations for construction of plant and they too are
localized to coastal regions only.
3) Intensity of sea waves is unpredictable and there can be damage to power
generation units.
4) Influences aquatic life adversely and can disrupt migration of fish.
5) The actual generation is for a short period of time. The tides only happen twice
a day so electricity can be produced only for that time.
6) Frozen sea, low or weak tides, straight shorelines, low tidal rise or fall are some
of the obstructions.
7) This technology is still not cost effective and more technological advancements
are required to make it commercially viable.
8) Usually the places where tidal energy is produced are far away from the places
where it is consumed. This transmission is expensive and difficult.
M A Islam, EEE, IIUC
Wind Power in More Details
Banning Pass
M A Islam, EEE, IIUC
M A Islam, EEE, IIUC
Best wind location = Aleutian Islands,
why no wind development there?
M A Islam, EEE, IIUC
Best U.S. localities
Midwest, mountains
And coastal areas.
M A Islam, EEE, IIUC
Netherlands =
coastal
development
M A Islam, EEE, IIUC
England = off shore
M A Islam, EEE, IIUC
ADVANTAGES OF WIND POWER:
1. The wind is free and with modern technology it can be captured
efficiently.
2. Once the wind turbine is built the energy it produces does not cause green
house gases or other pollutants.
3. Although wind turbines can be very tall each takes up only a small plot of
land. This means that the land below can still be used. This is especially the
case in agricultural areas as farming can still continue.
4. Many people find wind farms an interesting feature of the landscape.
5. Remote areas that are not connected to the electricity power grid can use
wind turbines to produce their own supply.
6. Wind turbines have a role to play in both the developed and third world.
7. Wind turbines are available in a range of sizes which means a vast range
of people and businesses can use them. Single households to small towns
and villages can make good use of range of wind turbines available today.
M A Islam, EEE, IIUC
DISADVANTAGES OF WIND POWER:
1. The strength of the wind is not constant and it varies from zero to storm force.
This means that wind turbines do not produce the same amount of electricity all the
time. There will be times when they produce no electricity at all.
2. Many people feel that the countryside should be left untouched, without these
large structures being built. The landscape should left in its natural form for
everyone to enjoy.
3. Wind turbines are noisy. Each one can generate the same level of noise as a family
car travelling at 70 mph.
4. Many people see large wind turbines as unsightly structures and not pleasant or
interesting to look at. They disfigure the countryside and are generally ugly.
5. When wind turbines are being manufactured some pollution is produced.
Therefore wind power does produce some pollution.
6. Large wind farms are needed to provide entire communities with enough
electricity. For example, the largest single turbine available today can only provide
enough electricity for 475 homes, when running at full capacity. How many would
be needed for a town of 100 000 people?
M A Islam, EEE, IIUC
Solar Energy in More Details
1. Solar Thermal
M A Islam, EEE, IIUC
At focal point = heat liquid – steam
to turn turbine
M A Islam, EEE, IIUC
M A Islam, EEE, IIUC
M A Islam, EEE, IIUC
M A Islam, EEE, IIUC
M A Islam, EEE, IIUC
Hard =
Soft =
1. Big plants
1. Decentralized
2. Centralized production
2. units per household
M A Islam, EEE, IIUC
M A Islam, EEE, IIUC
Energy efficient house; wind
power on roof. Solar panels
for heat and electricity.
M A Islam, EEE, IIUC
Solar electricity generation
M A Islam, EEE, IIUC
Solar water heating
solar air heating
M A Islam, EEE, IIUC
ADVANTGES OF SOLAR ENERGY
1. Solar energy is free although there is a cost in the building of ‘collectors’ and
other equipment required to convert solar energy into electricity or hot water.
2. Solar energy does not cause pollution. However, solar collectors and other
associated equipment / machines are manufactured in factories that in turn cause
some pollution.
3. Solar energy can be used in remote areas where it is too expensive to extend
the electricity power grid.
4. Many everyday items such as calculators and other low power consuming
devices can be powered by solar energy effectively.
5. It is estimated that the worlds oil reserves will last for 30 to 40 years. On the
other hand, solar energy is infinite (forever).
M A Islam, EEE, IIUC
DISADVANTAGES OF SOLAR ENERGY
1. Solar energy can only be harnessed when it is daytime and sunny.
2. Solar collectors, panels and cells are relatively expensive to manufacture although
prices are falling rapidly.
3. Solar power stations can be built but they do not match the power output of similar
sized conventional power stations. They are also very expensive.
4. In countries such as the UK, the unreliable climate means that solar energy is also
unreliable as a source of energy. Cloudy skies reduce its effectiveness.
5. Large areas of land are required to capture the suns energy. Collectors are usually
arranged together especially when electricity is to be produced and used in the same
location.
6. Solar power is used to charge batteries so that solar powered devices can be used
at night. However, the batteries are large and heavy and need storage space. They
also need replacing from time to time.
M A Islam, EEE, IIUC