Page 100 - Hong Kong Green School Guide

3. Green School Guide - 3.3 Energy Saving
Hong Kong Green School Guide 98
Benefits
• Utilise wind as a ‘free’ resource to provide energy;
• Visible feature to demonstrate the school’s green initiatives to the public; and
• Practical feature for students to learn about renewable energy, for example,
by observing the energy produced from the system (e.g. via energy meter,
connection to lighting system).
Issues to Consider
a. Opportunities
• Wind turbine can be installed to harvest wind energy for electricity needs.
b. Constraints
• Wind availability to the subject building can be affected by site wind availability,
local topography, vegetation, and surrounding buildings;
• Structural loading of the roof and potential vibration; and
• Water proofing & potential water seepage issue during installation.
c. Solutions
• Wind measurement shall be conducted before installation. Renewable
energy system suppliers shall be consulted;
• Several types of wind turbine available:
Microturbine Horizontal-Axis
Wind Turbine
Vertical-Axis
Wind Turbine
Cost Low High High
Wind Direction
Capture
One direction All horizontal
direction
All horizontal and
inclined direction
Start up wind
speed
Low (>2m/s) Moderate (>3m/s) Moderate (>3m/s)
Energy
generated
Low
(25-Watt light bulb
for 400 hours)
Moderate
(25-Watt light bulb
for 2,500 hours)
Moderate
(25-Watt light bulb
for 2,000 hours)
* Comparison provided above is not exhaustive. Energy generation predicted is
based on wind availability in Kowloon Tong, where there is no wind blockage by
surroundings and is based on these selected wind turbines (12 MicroTurbines,
600 Watt horizontal-axis wind turbine and 1,000 Watt vertical-axis wind turbine).
Please consult registered professional and/or contractor for detailed comparison
and installation options.
3.3.11 Wind Turbine Applies to NS & ES