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Take a look inside Sing Yin Secondary School, one of the world's greenest

For a Kwun Tong school named one of the world's most eco-friendly, the high cost of installing energy-saving devices is money well spent, writes Andrea Chen

PUBLISHED : Thursday, 14 November, 2013, 8:06pm
UPDATED : Thursday, 14 November, 2013, 10:55pm

A pair of structures resembling giant light bulbs are among several devices that catch the eye on the roofs of Sing Yin Secondary School. The clear domes, fitted with a heliostat that tracks the movement of the sun, collect sunlight and direct it via optical fibre to the floor below to illuminate a physics laboratory - a system that requires no electricity.

Essentially a solar light tube system, the "bulbs" are among various advanced energy-saving devices that led to the Kwun Tong school being named one of the 2013 Greenest Schools on Earth at the annual congress of the World Green Building Council last month.

When the devices were installed in 2011, they were the first of their kind in Hong Kong. The two solar tube systems, which cost HK$350,000 each, were imported from Japan as the technology was not yet available here. The illumination they provide, however, is often less than the power from four 40-watt electric bulbs costing no more than HK$35.

All the same, Sing Yin's headmaster, Kwok But, reckons the energy-saving installations are a worthwhile investment.

"I often tell my students: be prepared to pay more if you want to protect the environment," Kwok says. "Someone needs to start using them [energy-saving devices] to bring the cost down."

It has taken a small fortune to put Sing Yin at the forefront of green construction. When the government decided in 2008 to build the city's first environmental demonstration school, Sing Yin, which had been set to move into a new campus, was selected to be the model.

An additional 10 per cent in construction costs was allocated to install green features. These include rooftop solar panels programmed to track the sun's movement, motion sensors in classrooms that turn off the lights when no one is inside, chillers that pump cold water into the central air conditioning system to optimise its cooling effect, and a lift that converts gravitational energy into electricity on its way down.

It cost HK$248 million to build the 30-classroom facility - HK$20 million more than a school of the same size, Kwok says.

The campus on New Clearwater Bay Road has since been awarded a Platinum certificate, the highest in the city's green architecture standards scheme called Beam (now renamed Beam Plus).

According to a Greenpeace report released in March on the use of Beam Plus standards, Hong Kong would slash its electricity use by 9.4 billion kilowatt hours (kWh) each year if all the buildings, which account for about 90 per cent of the city's electricity consumption, adopted Beam standards as Sing Yin has done.

It also said each citizen would save an average of HK$1,500 annually in power bills. But the report did not estimate how much it would cost to make our buildings eco-friendly.

For Sing Yin, the energy-saving devices have yet to make much of a dent in its electricity bill. Project engineers estimate that green features will cut the school's annual energy use by 27.3 per cent. But it would take 18.4 years to cover the cost of installing the devices - more than twice the normal cap of nine years for other projects.

Kwok says energy intensity at the new campus works out at 50 kWh per square metre per year, 9 kWh less than the average for Hong Kong schools. But the HK$132,000 savings in energy payments that this brings each year barely covers the maintenance of the hi-tech devices - the water-cooled air conditioning system alone requires HK$80,000.

"We end up spending even more than before [on the old campus]. But it's worth it," Kwok says. "People pollute air and water but never pay for it. We have to start paying now for our grandchildren."

His green mindset is greatly influenced by Collapse, the book by American scientist Jared Diamond documenting how civilisations collapse as a result of abusing natural resources. "We are doing the same to our environment," Kwok says.

Hong Kong developers, who are intent on maximising profit from every square foot, rarely share such sentiments. They are almost impossible to persuade to adopt similar measures, according to Ricky Chui Kwok-cheung, an architect with Chows Architects, which designed the green features for Sing Yin.

Stephen Lau Siu-yu, associate dean of architecture at the University of Hong Kong, agrees: "Every time I talk to [the developers], they always say let's do the minimum."

When Lau began studying green architecture in 1998, Hong Kong was ahead of most of Asia in the field. But more than a decade on, he says, the city is still stuck at the demonstration stage while neighbouring countries have introduced mandatory green codes for developers. "Everyone else, including the mainland, has started running. But we are still walking."

Hi-tech devices aren't the only way to introduce green architecture. Passive design - which considers factors such as the orientation of a building in relation to the sun and wind patterns, and window-to-wall ratios - is crucial, Lau and Chui say. If the design maximises natural lighting and ventilation, there could be considerable energy savings without spending a cent on advanced technology.

Sing Yin embodies passive design. The buildings are set in a U-shape, which allows winds to blow in from different directions and maximise natural ventilation, while classrooms face south to make the most of sunlight.

It frustrates Chui that most buildings on Hong Kong Island face north to secure a harbour view at the expense of natural light, while expanses of picture windows make for hotter interiors in the summer.

"The [property] market is not mature ... in terms of sustainability," he says. "People lack understanding of the basic principles - that we can achieve the best with the least input."

Yet some buildings win green architecture certification for energy-saving or eco-friendly features that do not necessarily work for Hong Kong.

"We need to re-educate people, especially the younger generation," Lau says.

The school curriculum for Liberal Studies now includes a module on green architecture, but Kwok says textbook knowledge is far from sufficient. He believes the key to instilling eco-consciousness is to let youngsters put theory into practice.

That's why his students are placed in charge of the air conditioning. Instead of automatically setting thermostats at the recommended 25.5 degrees, their air conditioning use is based on a heat index, which takes into account the wind speed and humidity as well as air temperature measured at a rooftop weather station.

Monitors are appointed to check the heat index every two sessions, and turn off the air conditioning if the index falls below the recommended level.

"We can switch off the central air conditioning from the office. But what can our students learn from that?" Kwok says.

Bruce Ng Cheuk-hang, a Form Five student, hears the message loud and clear. "It is hard to bear the heat after PE classes. But why can't we tolerate it for a few minutes and contribute more to the earth?" he says. "I don't want my son and grandson to find the earth in such an awful state that it is not suitable to live in."

Of all the energy-saving measures, Kwok says the first that he would recommend to Hong Kong schools would be to install a weather station. By basing the utilisation of air conditioners strictly on the heat index, his students have reduced energy use by up to 40,000 kWh a year; yet the weather station costs no more than HK$10,000 to install.

However, Kwok reckons few schools would follow suit as most are more preoccupied with helping students do well in public exams. "Environmental education, people would say, is not yet our priority."

andrea.chen@scmp.com

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