Pre-monsoon rains boost electricity generation of hydropower plants

Energy: The pre-monsoon rain over the last couple of week enhanced the electricity generation of the hydropower plants, making up for the shortfall in generation from the dry winter the country experienced.

Power generation during the first three months of the year (January-March) was quite low without much precipitation.

“The rains in April have helped us to make up for some of the shortfall in generation,” Druk Green Power corporation’s (DGPC) managing director, Dasho Chhewang Rinzin, said.

However, he said, the additional energy generated cannot be determined exactly, since hydrology keeps changing every year. Additional revenue earned, he said  could be derived at the end of the year.

An official from meteorology department, Sonam Tashi, said the rainfall over the last couple of weeks was triggered by the onset of pre-monsoon. “It’s the wind direction that determines the precipitation,” he said.

The pre-monsoon wind from the west has a good amount of moisture feeding and this is why the country received good amount of rain.  But no analysis had been made to compare it with condition in the last few years.

If monsoon has arrived, he said, wind would flow toward the country from the Bay of Bengal.

But starting today, the meteorology division forecasts less probability of rain for at least a week.  As for monsoon, the official said no forecast could be made, as wind direction kept changing.

In the last two weeks, Thimphu and Paro received precipitation for seven days.  Both dzongkhags received highest precipitation of 19.2mm and 23.6mm respectively on April 18.  On April 28, Thimphu saw 13.6mm rainfall and 18.6mm fell in Paro.

This means that Wangchu that feeds the two hydro plants of capacity more than 1300MW was well fed.

Dasho Chhewang Rinzin said that it appeared that a below average monsoon was forecast by the Indian meteorological department. “While April has been better than average in terms of rains, one really can’t tell what the river discharges will look like for the rest of the year.”

Meanwhile, power is still being imported from India in the eastern grid because of the energy intensive industries of Dungsam.

In 2013, Bhutan exported 5,557 million units (MU) of energy worth about Nu 11 billion, while it has imported 108 MU worth around Nu 222 million.  Last year, exports dropped to 5,044MU and imports increased to 187MU.

By Tshering Dorji