Transcript The Implications of RoHS compliances

Renewable Energy
Professor Y.C. Chan
City University of Hong Kong
Director, EPA Centre
Engineers in Society (EE3014)
Lecture Series
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Renewable Energy:“Renewable Energy is energy that is derived from natural processes that
are replenished constantly. In its various forms, it derives directly or
indirectly from the sun, or from heat generated deep within the earth”
- International Energy Agency (IEA)
- Renewables Information 2003.
Types of Renewable Energy:
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Geothermal (not strictly renewable)
 Solar
Hydro
 Wood fuel
Wind
 Biodiesel
Waves and Tides
 Vegetable oil vehicles
Biomass
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Why renewable energy?
• Growing energy demand.
• Limited reserves of fossil fuels.
• Environmental concerns – CO2 emissions, pollution etc.
• Abundant and available everywhere (different types).
• Causes little if any environmental damage and do not deplete Earth’s natural
resources.
Global Warming !!!!
• The Greenhouse Effect traps heat inside the
Earth’s atmosphere. This causes our climate
increasing in temperature. This is known as
Global Warming.
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Future Green house gas Levels:Increasing Carbon dioxide (CO2), Methane (CH4), Nitrous oxide (N2O),
Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs), Sulphur hexafluoride
(SF6) emissions, especially in China and developing countries
Likely to double within 150 years:
• Increased coal usage.
• Increased natural gas usage.
• Increased petroleum usage.
(increased cost and decreasing supply)
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What does Renewable energy mean?
Solar: Converting the radiant energy of the sun to electrical
energy.
Wind: Converting the force of wind into mechanical or
electrical energy.
Biomass: Burning organic matter such as wood or
agricultural materials to produce heat
energy. Methane gas can be provided
from organic wastes.
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What does Renewable energy mean?
Tidal: Tidal, wave and marine current converting the
movement of water into
mechanical or electrical energy.
Wave Energy: Ocean wave energy is captured
directly from surface waves or from pressure
fluctuations below the surface. Wave power devices
extract energy directly from the surface motion of
ocean waves or from pressure fluctuations below the
surface.
Marine Current Energy: The tide is the source of
"marine current" or "tidal stream" energy. Marine
currents refer to a moving mass of water. Useful
energy can be extracted from marine currents using
completely submerged turbines and hydrofoil devices.
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What does Renewable energy mean?
Geothermal: Extracting natural heat from within
the earth for direct heating and/or to produce
electricity.
Hydropower: Generating electricity from falling
water.
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Renewable Energy in Hong Kong:Solar water heating
 There are a number of installations for low-rise buildings in the New
Territories. The largest system installed so far in Hong Kong is at the Sheung
Shui Slaughterhouse.
Building Integrated Photovoltaic (BIPV) Systems
 A number of BIPV systems have been installed in both public and private
projects, showcasing how photovoltaic and electrical systems can be integrated
to supply power.
 These projects include Wanchai Tower, EMSD Headquarters at Kai Tak, and
Science Park in Shatin.
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Renewable Energy in Hong Kong:Building Integrated Photovoltaic (BIPV) Systems
 A 350kW photovoltaic installation has been installed on the roof of the new
EMSD Headquarters in Kowloon Bay.
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The PV array covers the whole roof of the Building The largest in HK, with
2300 PV modules covering 3,180 square meters.
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Renewable Energy in Hong Kong:Smart Building:
Atrium: A wide, sunlit space
in the center of the building.
The Sun-scoop has 480 glass
mirrors which reflect sunlight
onto the aluminum reflectors at
the top of the atrium.
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Renewable Energy in Hong Kong:Wind Energy:
Lamma Winds:
In Feb 2006, Hongkong Electric launched the city’s first commercial-scale wind
turbine. The wind turbine has a rated capacity of 800 kW. Another to be
commisioned in 2007. 2 offshore wind farms proposed.
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Lamma Winds:-
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Challenges of Renewable Energy:1. It can be unpredictable and unreliable
The availability of wind energy depends on sufficiently high wind speeds, and
the availability of solar energy depends on the presence of clear and sunny
weather conditions.
2. Some applications require lots of land
For example, a wind farm that can generate 400 million units of electricity
(about 1% of HK’s annual electricity consumption) may require a land space of
up to 4,000 hectares.
But HK have a vast ocean and wind farms can be installed in ocean.
Big Building tops, Road barriers and noise barriers can be fitted with PV.
3. More expensive than traditional fuels
Not cost-effective. High investment.
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