Cindy Man, an engineering graduate from the Electrical & Mechanical Services Department, never dreamed that one of her inventions could help monitor Hong Kong's sometimes unpredictable weather.

But her new electronic device now helps the Hong Kong Observatory monitor the operation of wind-powered automatic weather stations in remote areas.

The device, put into operation at Ngong Ping on Lantau today, can tell the Observatory whether sufficient electrical energy is generated to support the operation of the station in an instant.

A time to celebrate: Cindy Man opens a bottle of champagne to celebrate the commissioning of her wind-power monitor at Ngong Ping's automatic weather station.  Electricity is supplied to the station with a wind-power generator.

Automatic weather stations provide real-time atmospheric information, such as wind speed and direction, temperature and rainfall, to support the Observatory in monitoring and forecasting weather conditions.

Data is fed back to the Observatory by wireless transmission.

Despite the steep learning curve in constructing the device, Ms Man said she is pleased her work can be used for such an important community task.

"There were difficulties in designing the circuit of the device, and colleagues at the Observatory lent me a helping hand," she said.

"Journeys to inspect the automatic weather station, which is located on a remote hilltop, and to figure out how to install the device were also exhausting because there was no road transport. We had to carry the equipment to the hilltop on foot.

"However, I find the experience very rewarding, in particular that my work can be used to explore the potential of renewable energy in Hong Kong."

Renewable energy used to power remote stations

Solar cells have been used since the 1980s to power some automatic weather stations in remote areas and on islands owing to the lack of electricity supply.

However, inadequate sunshine due to prolonged periods of overcast sky or rainy weather means that occasionally there may not be sufficient power to keep the stations running. To provide an alternative energy source, the Observatory began deploying wind-powered generators at some stations in early 2000.

A typical wind-powered generator consists of three blades, each about a metre long.

The blades require a relatively low wind speed, a little over 10 kilometres per hour, to start turning.

At a wind speed of 20 kilometres per hour commonly experienced at hilltops and open spaces, the generator is capable of generating 50 watts of electrical power, sufficient to support an automatic weather station.

At present, wind-powered generators have been set up at eight automatic weather stations on Lantau and islands near the airport at Chek Lap Kok, and they have been performing well.

The mixed use of wind and solar power has avoided failures at these stations due to insufficient power.

The Observatory has worked with the Electrical & Mechanical Services Department since 1985 to provide engineering graduates with training opportunities.