Solar power pond goes smart

Authorities have turned part of a flood storage pond in San Tin into a floating solar power site to generate 37,000 units of electricity a year, says Secretary for Development Bernadette Linn Hon-ho.

Linn said power generated by the 70 solar panels will be sufficient to operate a rain pump. In a blog post yesterday, Linn said the Drainage Services Department has completed anti-flood works in 27 New Territories villages with 3,500 residents.

Engineer Lai Hong-ho, from the department's special duty division, said a flood protection scheme generally includes an embankment, a storage pond and a stormwater pumping station.

The embankment surrounding the villages can keep floods out. Drainage systems are also provided in village areas to collect and convey stormwater to a pond.

The storage pond is about 16,400 square meters. When its water level reaches a pre-determined level, the pump in the station will automatically start moving water in the pond to the adjacent channel outside the embankment.

And the stormwater storage pond in San Tin is the largest among the schemes and provides a suitable site for the department's first pilot floating solar power site.

The power site was completed this year, and the project team encountered many challenges in both design and construction.

Chim Sai-shing, an engineer from the department's flood control section, said the engineering team needed to consider external factors such as wind, rain and water flow to minimize the weight of each solar panel so that the system can float more easily.

On the other hand, there must be enough tensile force to prevent the system from being blown up by strong winds and deviating from its original design position, Chim said.

In addition, as the San Tin storm water storage pond is close to the Mai Po Nature Reserve, the department has also installed a floating island in the pond to provide a resting place for birds, which not only enriches the ecological environment of the pond, but also enhances biodiversity.

Linn said the department would continue to uphold the principle of sustainable development, actively adopt more renewable energy and reduce carbon emissions.