Solar power trial reduces carbon footprint

PUBLISHED : Monday, 08 August, 2011, 12:00am
UPDATED : Monday, 08 August, 2011, 12:00am


A single public housing block can save up to 8,400kg of carbon emissions a year - the equivalent of planting of 365 trees - by using solar power, a trial by the Housing Department has found.

The project at Lam Tin Estate, the first to be carried out in public rental housing, achieved a total reduction of 22,610kg last year.

Photovoltaic panels were installed on the roofs of three blocks and on top of a covered walkway.

Senior building service engineer Eric Leung Chi-kwong said that as a subtropical region with abundant sunlight throughout the year, Hong Kong was an ideal place for developing solar energy.

He said the energy used to produce the system could be balanced out in the first three years of its 30-year life span. Not every building suits the technology, however. Leung said the rooftop needed enough space with no nearby buildings blocking the light.

The system at Lam Tin Estate provides about 2 per cent of the electricity for elevators, water pumps and lighting in public areas. The rest is bought by CLP Power.

The power company said there are more than 70 small renewable energy projects connected to its grid in government buildings, schools and the offices of non-governmental organisations.

The price of photovoltaic panels has fallen in recent years, but they are still expensive. 'The main drawback in all cases is the same - it is still cheaper to generate electricity using fossil fuels,' Dr Aleksandra Djurisic, of the department of physics at the University of Hong Kong, said.

He said leading countries all had policies to encourage the use of renewable energy and make technologies competitive on the market by various measures such as special tariffs and carbon tax.

'In the absence of those, it is unlikely that there will be a large scale implementation of renewables [in Hong Kong],' he said.

Koo Wai-muk, a campaigner from Greenpeace, said the government should also provide more funding to push forward local research.

The Housing Authority is planning to try out new solar technologies at its Eastern Harbour Crossing and Kai Tak sites, which it expects to cut 112,700kg of carbon emissions.

Both CLP and Hongkong Electric have plans to build wind farms by 2015. CLP said its farm was expected to support 80,000 households.