POWER import from India reached 500 MW on December 3. It may be recalled that Bangladesh started importing 175 MW of electrical power from India through a 100-km 400-kV transmission line from Baharampur in India to Bheramara in Bangladesh on October 3. The import of power from India is a very significant event in the history of power development in Bangladesh. An attempt to import electricity from India was initiated in 1997 but it did not bear any fruit.
The interconnection of electrical grids through high voltage transmission lines across international boundaries is a common practice all over the world. The largest interconnected grid is the synchronous grid of Continental Europe (UCTE) with over 670 Giga Watts (GW) of electrical power. Hundreds of thousands of Mega-Watt-hours (MWh) of electricity are exchanged per day through the European Energy Exchange (EEX). The Eastern Interconnection has a generating capacity of 610 GW and covers eastern US and Canada. The widest area is served by the IPS/UPS system with a generating capacity of 337 GW serving the countries of the former Soviet Union. Other major interconnected grids include the Western Interconnection serving western US, Canada and north western Mexico (160 GW), Nordic countries synchronous zone (93 GW), and Ireland and Great Britain synchronous zone among others.
Efforts are underway to interconnect the US Eastern and the Western Interconnections and form a mega grid. Similarly, the Central and East European countries intend to form another mega grid. European grids operate on a system frequency 50 Hz whereas North American grids operate on 60 Hz. Though grids with the same operating frequency are normally interconnected, it is possible to link systems with different frequencies through DC transmission lines or variable frequency transformers.
Interconnection of regional power grids improves stability and reliability of power supply, reduces the requirement of expensive cold and spinning reserves and allows the construction of larger and more economical central power plants, resulting in overall improvement of economy of the systems.
In our region, discussions were initiated for building a Saarc power grid in 1998. It was reported in December 2011 that Nepal and Bhutan agreed to export 2,000 MW of electricity to Bangladesh, 1,000 MW each from Saptokoshi project in Nepal and Sankosh project in Bhutan. The grids of Nepal and Bhutan are already connected with the Indian grids. India also took initiative to lay an undersea power cable to link its grid with that of Sri Lanka. If both countries agree, it will be possible to interconnect the grids of Pakistan and India also.
“A South Asian power grid that allows free flow of electricity between producers and importing nations in the region is a top priority and will hugely benefit Bangladesh,” said Farooq Abdullah, India’s renewable energy minister, in October. He added: “This regional grid will help Bangladesh import more power, because then it can turn to Bhutan and Nepal apart from India.”
Nepal and Bhutan have huge hydro potentials estimated at 83,000 MW (42,000 MW economically viable) and 30,000 MW of electricity, respectively. At present, only a very small fraction of these potentials are being utilised. According to the Central Electricity Authority, Northeast India has a hydro power potential of 58,971 MW (excluding Sikkim), of which only 2.13% is utilised and another 4.82% is under developed, leaving over 93 % still untapped. Tripura Chief Minister Manik Sarkar said that his government was more than willing to offer 100MW of power from its Palatana plant that was made possible by transportation of heavy equipment through Bangladesh.
If the hydro potentials of the Saarc region are exploited through joint collaboration, a Saarc power grid will be highly rewarding for the participating countries. For this purpose, Bangladesh should build more transmission lines to the north to connect with the grids of Bhutan and Nepal, to the east to connect with the eastern states of India and, if possible, to the south-east to connect with the grid of Myanmar which has good deposits of natural gas, though Myanmar is not a member Saarc as yet. The interconnections will help Bangladesh to import electricity from all the neighbouring countries.
The writer is a former chief engineer of Bangladesh Atomic Energy Commission and author of “Rooppur & the Power Crisis.”
Source : The Daily Star