Energy Saving Measurements

Lee Woo Sing College is committed to green management and education, and is the leading green College in CUHK. Being a pioneer of implementing green technologies on a university campus, we have invented and installed a number of first-in-Hong Kong energy saving and renewable energy systems, such as the smart meter and high-efficiency CIGS solar energy system, etc.. College management is committed to energy conservation. Our Campus Environment and Sustainability Committee and its energy saving working group are established to oversee the energy usage and solicit resources for energy saving initiatives. College also organize a series of green education campaigns to encourage the students and staff to live a green life.

arrow down arrow down Solar Power System
arrow down arrow down Hostel Smart Meter
arrow down arrow down Energy Dashboard
arrow down arrow down Glass Window Film

Solar Power System:
Department - College Collaboration

A research team led by Prof. Xiao Xudong and Prof. Li Quan of the Department of Physics, who are also affiliated teachers of Lee Woo Sing College, at the Chinese University of Hong Kong successfully developed Cu(InGa)Se2 (CIGS) thin film solar cells that feature low production cost, high efficiency and extensive application prospects in 2011. Its conversion efficiency of 19.4% is the highest among the same kind of solar cells in the greater China region and reaches world-class level, representing a great breakthrough in the development of renewable energy.


Since 2011, Lee Woo Sing College is closely working with Prof Xiao and recruited a team of teachers and honorary consultants to support this project. The project’s first sets of solar PV panels will be installed on the two roofs of the College campus, making it the first-in-Hong Kong educational institute to have the high efficiency CIGS solar PV system installed.

Prof Xiao and Prof Lau, Master of Lee Woo Sing College, consider the installation of CIGS panels on College’s roof tops a good opportunity of technological demonstration of CUHK research output on CUHK’s own campus, as well as good opportunity of green education to College’s students and University community.

The panel system will convert direct current generated by the solar cell to alternating current and input into the electricity grid directly, to minimize transmission loss. The installation of panels as the field demo has been completed at the end of 2016 and the system is now under operation.

Solar System at South Block:

Solar Panels: 112 Units X 95w Solar Panels

Max. Energy Output: 10.7kW

Solar System at North Block:

Solar Panels: 272 Units X 95w Solar Panels

Max. Energy Output: 25kW

The total annual production of the two systems is around 25,000kWh.

The figures of the production is available on the cloud server as below. Please refresh your browser if the graphs are unable to display correctly.

North Block
Dorothy and Ti-Hua KOO Building

Hostel Smart Meter System – WS Power

WS Power User Interface 用戶介面

In order to raise students’ awareness of energy saving and environmental protection, Lee Woo Sing College installed a smart meter system in the hostel. This device is the first smart meter management system for hostels in Hong Kong. At present, nearly all university hostels in Hong Kong provide free electricity (except for air-conditioning). As the electricity is free, many students have relatively low awareness of electricity saving. It is common to not turn off lights, computers, or even high-power appliances before leaving the room. In light of that, Lee Woo Sing College designed an intelligent power reading device.


The smart meter system is able to capture the electricity usage of air conditioning, lighting and electric sockets per bedroom individually. In 2023, the college has revamped the system and migrated it to a brand new mobile app platform – WS Power. Students would have a chance to study their electricity consumption habit, usage pattern via this app, and adjust their habit when necessary. All the electricity usage in each bedroom is counted as a whole. Certain amount of free credit will be allocated to the room account. Students have to conduct top-up with online payment gateway for excessive usage beyond free credit limit, on a progressive scale.


The user guideline of the WS Power can be found at:





Monthly free amount

1st HKD50

2nd HKD50

3rd HKD50

4th HKD50

and thereafter







When the student’s electricity account balance is low (less than 10 units), the reminder light in the room will light up. At this time, students should top-up as soon as possible, otherwise when the electricity is used up, the air-conditioning electricity will be interrupted immediately; due to safety concerns, other electricity will continue to be provided (negative electricity consumption will be deduced from the free electricity consumption next month or from hostel deposit). All free electricity and paid electricity can be accumulated to the next month, and the remaining paid electricity in the account can only be refunded when checking out.


Top-up procedures


  1. Enter the name of block, then enter the room number and press ENTER
  2. Select ADD VALUE or ENQUIRY; you need to enter a password to view the record
  3. If you want to top-up, please select the amount of top-up ($50)
  4. Tap the Octopus card to complete the top-up process (if the card is less than $35 in reserve after deduction, the top-up will not be processed)


If you encounter any problems during the top-up process, please contact the hostel staff or the college office. The smart power reading device of Lee Woo Sing College only accepts octopus card symbol for top-up.

Detailed usage information can be checked at “WS Power”:


  1. Connect to CUHK network (e.g. CUHK VPN/ Campus WiFi/ ResNet)
  2. Visit to
  3. Select “Block”, enter the “Room No” and “Room PIN” and press “Login”
  4. The room usage and the balance can be checked.

If there is any questions to the room usage information, please write to

Energy Dashboard

An energy dashboard is developed to monitor the electricity usage in the College area:

Glass Window Film

In the summer of 2013, the glass curtain wall of LG1 fitness room and LG2 student dining room of Lee Woo Sing College was coated with a layer of infrared heat insulation film. The heat insulation film coating reduces the indoor temperature by 2-5°C, which saves the electricity cost of air-conditioning and the energy.