Page 104 - Hong Kong Green School Guide

3. Green School Guide - 3.3 Energy Saving
Hong Kong Green School Guide 102
• Photovoltaic types:
Mono-crystalline
silicon
Poly-crystalline
silicon
Amorphous silicon
Cost High Moderate Low
Efficiency High
(around 14%-16%)
Moderate
(around 13%-15%)
Low
(around 5%-7%)
Others to
note
Expensive to
manufacture
Less energy intensive
to manufacture
Can use on curved and
flexible surfaces
• Ideal PV panel orientation is tilted at 14-22 degrees latitude angle on a south
facing roof;
• Authorised Person (AP) and Registered Structural Engineer (RSE) shall
be consulted for aspects related to the structural loading capacity of roof,
alterations and additional works to the existing building structure to support
the installation as well as the means of escape in roof area;
• Additional concrete footing for PV mounting can help avoid invasive bolting
on roof surface which might lead to water seepage issue in later stage;
• Structural mounting and PV installation shall be carried out by renewable
energy system suppliers; and
• Electrical components installation (e.g. DC AC converter, transformer,
controls) shall be carried out by Registered Electrical Contractor & Registered
Electrical Worker.
d. Professional Help
• Authorised Person (AP) & Registered Structural Engineer (RSE) – Appendix
A (2)
• Renewable Energy System Suppliers – Appendix B (6) & (7)
• Registered Electrical Contractor & Registered Electrical Worker – Appendix
B (4)
Cost Information
The costs for installation and maintenance vary and depend on:
• Existing electrical system;
• Structural loading;
• Façade finishes (for BIPV);
• Additional mounting frame;
• Capacity;