Transcript Slide 1

Module 05
Renewable Energy (RE) Technologies & Impacts
- Use of RE sources in electricity generation, in transport, and
in other energy consumption modes
- Ecological impacts of RES, and mitigation measures
Prof. R. Shanthini
Jan 21, 2012
Renewable energy
comes from resources that
naturally renew themselves (replenishable),
and practically never runs out (inexhaustible).
Sustainable energy
is replenishable within a human lifetime
and causes no long-term damages to
the environment.
Examples?
Prof. R. Shanthini
Jan 21, 2012
RE technology options:
- Hydroelectric
- Solar Photovoltaics (Solar PVs)
- Solar Thermal (Solar T),
also known as Concentrated Solar Power (CSP)
- Wind
- Geothermal
- Marine (Wave and Tidal)
- Biofuels (Biomass, Bioethanol and Biodiesel)
Prof. R. Shanthini
Jan 21, 2012
RE in global final energy consumption, 2008:
Wind/solar/
biomass power
generation, 0.7%
Nuclear
3%
Fossil
78%
RE
19%
Biofuels, 0.6%
Biomass/solar
/geothermal
hot water/heating,
1.4%
Hydropower, 3.2%
Traditional
biomass, 13%
Prof. R. Shanthini
Jan 21, 2012
RENEWABLES 2010 GLOBAL STATUS REPORT
Electricity from renewable energy sources:
3500
Global Consumption
(Terawatt-hours)
3000
2500
2000
1500
1000
Hydroelectric
Other Renewables
500
0
1990
Prof. R. Shanthini
Jan 21, 2012
1995
2000
2005
2010
Year
Source: BP Statistical Review of World Energy June 2011
Electricity generation by renewable energy source:
Global Consumption Forecast
(Terawatt-hours)
6000
5000
4000
Geothermal
Solar
Other
Wind
Hydroelectric
3000
2000
1000
0
2008
Prof. R. Shanthini
Jan 21, 2012
2015
2020
2025
2030
2035
Year
Source: Table 13, International Energy Outlook 2011
Electricity from renewable energy sources:
RE is given by actual annual energy production/consumption
(in watt-hours).
RE is also given by the installed capacity power rating
(in watts).
A hydro-electric plant, for example, rarely operates at its full
power rating over a full year.
Capacity factor of RE plant =
Prof. R. Shanthini
Jan 21, 2012
Annual average power
Installed capacity rating
Source: BP Statistical Review of World Energy June 2011
Comparison of Technologies:
Technology
Available
energy
(PWh/yr)
Technical
potential
energy
(PWh/yr)
Current
installed
capacity
(GW)
Current
electricity
generation
(TWh/yr)
Hydroelectric
16.5
< 16.5
778
2840
Solar PVs
14900
< 3000
8.7
11.4
Concentrated
Solar Power
(CSP)
9250 –
11800
1.05 – 7.8
0.354
0.4
Prof. R. Shanthini
Jan 21, 2012
Hydroelectric power
Prof. R. Shanthini
Jan 21, 2012
Amount of
electricity
generated
depends
on the
height
difference.
Prof. R. Shanthini
Jan 21, 2012
Prof. R. Shanthini
Jan 21, 2012
http://en.wikipedia.org/wiki/Hydroelectricity
Hydroelectric power
Technological status mature
Average growth
2.2% per year
Total share of global
energy mix
16% of electricity in 2008
16% of electricity in 2035 (potential)
Prof. R. Shanthini
Jan 21, 2012
Source: International Energy Outlook 2011
World hydroelectric power generation projection:
Hydroelectricity generation
(Terawatt-hours)
6000
Average growth is 2.2% per year
5000
4000
3000
2000
1000
0
2008
2015
2020
2025
2030
2035
Year
Prof. R. Shanthini
Jan 21, 2012
Source: International Energy Outlook 2011
World electricity generation projection:
40000
Electricity generation
(Terawatt-hours)
35000
Hydroelectric
Total electricity
30000
25000
20000
15000
10000
5000
0
2008
2015
2020
2025
2030
2035
Year
Prof. R. Shanthini
Jan 21, 2012
Source: International Energy Outlook 2011
World electricity generation projection:
100%
Electricity generation
90%
80%
Rest
Hydroelectric
70%
60%
50%
40%
30%
20%
10%
0%
2008
2015
2020
2025
2030
2035
Year
Prof. R. Shanthini
Jan 21, 2012
Source: International Energy Outlook 2011
Hydroelectric power
Why hydroelectric power?
Once the dam is built, the energy is virtually free.
No waste or pollution produced.
Much more reliable than wind, solar or wave power.
Water can be stored above the dam ready to cope with
peaks in demand.
Hydro-electric power stations can increase to full power
very quickly.
Electricity can be generated constantly.
Dams help preventing flooding (following predicted
climate change induced heavy rains), if built over capacity.
Prof. R. Shanthini
Jan 21, 2012
Hydroelectric power
The Elwha Dam, a 33 m high dam in Washington state, USA,
is one of two huge dams built in the 1910s to power a local
paper mill, under the direction of Thomas Aldwell.
The reservoir
that fills the
valley behind
the dam is now
known as Lake
Aldwell.
Prof. R. Shanthini
Jan 21, 2012
http://en.wikipedia.org/wiki/Elwha_Dam
Hydroelectric power
Effects of dam on river habitat:
 River bed is eroded by lack of sediment needed to create
suitable habitats for spawning (25 million cubic yards of
sediment have piled up behind the dam over time).
 Water stays for so long in the Lake Aldwell and Lake Mills
(created by damming), it warms up to about 16°C (which would
have been 0°C in the absence of dam).
 These high temperatures are unnatural for spawning fish.
 High temperature also increases parasite populations, which
wipe out two thirds of a spawning population.
 Natural flow patterns (which promote the health of native
species and help eliminate non native species) are evened out
by the reservoirs and dams.
Prof. R. Shanthini
Jan 21, 2012
http://en.wikipedia.org/wiki/Elwha_Dam
Hydroelectric power
The Elwha Dam is being dismantled since Sept 2011.
It is a 3-year project costing $351 millions.
Removal of dam
will restore
the fish habitats,
will create an
additional
715 acres of
terrestrial
vegetation, and
improve elk
habitats.
Prof. R. Shanthini
Jan 21, 2012
http://news.nationalgeographic.com/news/2011/09/110923-elwha-dam-removal/
Hydroelectric power
The Three Gorges Dam project in China
Installed capacity: 22,500 MW
Project cost: 39 billion US$
Length: 2.3 km
Height: 101 m
Prof. R. Shanthini
Jan 21, 2012
Hydroelectric power
The Three Gorges Dam project
- has flooded a total of 632 km² area
- displaced 1.24 million people
- washed away 13 major cities (submerging cultural and
archaeological sites)
- causing dramatic ecological changes
- used 27,200,000 m3 of concrete, 463,000 tonnes of steel
and moved about 102,600,000 m3 of earth.
- when the water level is maximum at 175 m over sea level
(110 m above the river level down stream), the reservoir
created is about 660 km in length and 1.12 km in width on
average, and contains 39.3 km3 of water.
Prof. R. Shanthini
Jan 21, 2012
Hydroelectric power
The Twin Aswan Dams of Nile river
Installed capacity of 2100 MW.
Length: 3.8 km
Height: 111 m
Prof. R. Shanthini
Jan 21, 2012
http://en.wikipedia.org/wiki/Aswan_Dam
Hydroelectric power
The Twin Aswan Dams
 provide protection from floods and droughts
 load of rich fertilizing silt are deposited in reservoirs
instead of the delta
 lack of natural fertilizer has resulted in an increase in
erosion of the river and Nile Delta, and an increase in the
use of chemical fertilizers
 chemical fertilizers have to be imported and thus cost
money for the farmers, and it also causes pollution of the
surrounding environment due to runoff.
 chemical fertilizers contain high levels of Nitrogen and
Phosphorous which are harmful to the water resources
Prof. R. Shanthini
Jan 21, 2012
http://en.wikipedia.org/wiki/Aswan_Dam
Hydroelectric power
What are the problems with hydroelectric power?
Barriers in the natural flow of a river prevents fish from
migration, alters ecosystems, and threatens the livelihoods
of local communities.
The world's 52,000 largest dams release 104 million.
metric tons of methane (a greenhouse gas) annually.
Reservoirs fill up with sediment and cost billions to dredge.
Failure of a dam will have catastrophic consequences.
Loss of land as well as flooding of areas such as natural
habitats and existing settlements.
The future generations must pay for destroying dams.
Prof. R. Shanthini
Jan 21, 2012