Perched high on a roof in Western Hong Kong Island is what at first glance looks like a mirror. It glints in the sun as it reflects two Hong Kong University researchers explaining what it and an odd collection of matt black and coloured versions alongside are made of.
The structures, say Department of Architecture researcher Josie Close and her electrical engineering colleague, Edward Lo Wai-chau, are the sort of solar panels that other countries have used for several years to create electricity direct from sunlight. But they represent Hong Kong's first properly monitored foray into renewable energy and an attempt to demonstrate the technology, not only in the SAR but for the region.
'It's our equivalent of the 1,000-roof programme in Germany, the 70,000-roof programme in Japan and what I hear is the one million-roof project in the US,' says Ms Close, referring to goals to fit panels in countries where they are much more popular.
It is one effort to make Hong Kong buildings 'greener' in the face of increasing world pressure to cut energy use and thereby help slow global warming, slow the build-up of construction waste that otherwise fills landfills and improve or reduce material use in the initial building. The university has set up a Centre of Renewable Energy looking into various forms of natural energy sources.
The team is studying different types of panel, called photovoltaic cells, in which semiconductors absorb light energy and convert it to electric current. They vary from a traditional silicon type to newer versions that incorporate unusual compounds such as cadmium telluride and copper indium diselenide. The silicon versions work well in laboratory conditions - cool temperatures, bright light - but poorly in the high temperatures that Hong Kong roofs experience, while the newer materials absorb light across more of the spectrum and are more robust than silicon in hot, humid conditions.
Initial findings look promising. 'You can get between 100 and 400 Watts per square metre,' says Dr Lo - enough to light and air-condition a room even when it's raining. And they are ideal for Hong Kong and the region, where use of electricity rises to a peak for air-conditioning when the sun shines.