High prices (and dim minds) are keeping Hongkongers from harnessing solar power. Shirley Zhao explores the risks and costs.

If you live in a typical Hong Kong apartment without balconies and suddenly want to give solar electricity a try at home, ask yourself this question: Do you own the roof of your building?

If not, here’s the bad news: You can’t install solar panels on the roof, not unless you convince the developer (or whoever owns the roof) beforehand. Also, if you think you can just build an extended platform out from your windowsill to hold solar panels, well, you could end up in the news for “building illegal structures” – a seriously contentious issue at the moment.

“The countless rooftops on Hong Kong’s skyscrapers are suitable for solar panels,” reckons Sam Hui Chun-man, a teaching consultant for the Department of Mechanical Engineering of the University of Hong Kong, “but because the spaces are limited, the ownerships of the roofs are unclear, and many old buildings were not designed with solar panels in mind, it’s difficult for residents to make use of solar energy, even if they care less about the prices.”

Many believe it would be simpler for government-owned and subsidised public housing estates, where ownerships of roofs are not a problem, to harness accessible sunlight. In 2009, the Housing Authority spent HK$3 million to install 180 solar panels atop three 40-storey apartment buildings on the Lam Tin public housing estate. It was estimated the systems could generate around 34,000 kilowatts per hour a year, saving an annual cost of $34,000.

Gateway Apartments are among the few private estates in Hong Kong which are installed with solar power systems. The 200sqm roofs of the two Gateway Apartments towers have been partially covered with 100 solar panels since 2009, generating 127,384 kilowatts per hour each year to support the water heating systems for 499 apartments. The system cost HK$1.5 million, and it is estimated to save more than $100,000 annually. However, the system will take at least 10 years to break even, without including maintenance costs.

Rene Holenweger, assistant general manager of Gateway Apartments, says the solar systems were carefully designed and tested, so maintenance costs have been minor. He told Time Out the company is also negotiating with China Light and Power about extending the application of solar power systems to its other estates. “A 10-year payback doesn’t sound overly attractive, but we want to make our contribution to Hong Kong’s environment,” says Holenweger.

Eddie Chan Wing-lai, who owns an apartment in a 400-unit building in Tseung Kwan O, says solar projects may be able to run a few elevators during daylight hours, but can do little to cut the residents’ utility bills due to limited roofing space and low energy transfer efficiency. He told Time Out he had installed two solar panels on his windowsill to generate electricity for his living room lights. “It helps, though not much,” he admits. “I’ll have to wait years for the economic benefits. But if every one of us installs at least one solar panel at home, we can reduce a lot of carbon emissions and make a huge difference to the environment.”

According to the Hong Kong Observatory, the city’s average daily solar radiation is about 13 megajoules per square metre, compared to 10 megajoules per square metre in Berlin, one of the world’s leading markets for solar panel energy.

Solar energy currently generates less than one percent of Hong Kong’s total electrical output. Wallace Chan Siu-wai, scientific officer for the Radiation Monitoring and Assessment Branch of the Hong Kong Observatory, says if 10 percent of the city’s 225sqkm allowed for high-rise buildings can be installed with solar technology, it could provide 5 percent of the city’s electricity. “Solar energy is not enough to serve as the major energy resource for Hong Kong,” says Chan, “because Hong Kong is a high-rise and high-density city. But it is a considerable supporting energy resource, and developing solar energy can inspire more discussion.”

High prices, however, seem to have kept Hongkongers from going solar. According to German Pool, a local solar water heater supplier, a 300 litre solar heater costs $22,000, plus $7,000 for rooftop installation, while the average price of a common water heater is $4,000 including installation.

William Leung, an engineer for a local solar panel supplier, says that in order to generate enough electricity for a 1-HP air conditioner, at least 1-kilowatt solar panels are needed, costing $29,000, plus $18,000 for installation. “The price of solar products has been decreasing over the decade due to advancing technologies and the fast developing solar industry in the mainland,” says Chan. “It’s good to think that one day the concrete jungle of Hong Kong can be turned into a huge vertical solar farm.”

W.Y. Ho, an engineer of the Electrical and Mechanical Services Department, says the design of each new government-sponsored building is required to incorporate “green factors, including the possibility of using solar power.”

“Developing solar energy in Hong Kong is a policy decision,” states Peter Wong Yiu-sun, past president of the Hong Kong Institution of Engineers. “The cost is high but the payback is slow, so it all depends on whether the government has the will. The government can encourage citizens to use solar products by cutting tax or subsidizing. It’s more of a commitment than an [investment]. After all, protecting the environment is not about payback.”