SIEMENS

Darkness mostly rules the night in the rural regions of India because many villages are not connected to the power grid. Women only have the dim light of kerosene lamps by which to cook the evening meal, and it’s hard for children to do their homework. At the same time, India’s power demand has increased enormously and will continue to rise. According to the International Energy Agency (IEA), India, China, and the Middle East will account for 60 percent of worldwide growth in energy demand by 2035. But 600 million Indians still live without regular access to electricity. Not only is too little energy produced, but as much as 60 percent of that energy is lost in transmission and distribution. And the grid is prone to failure. During the hot summer months, up to ten power outages a day are not uncommon.

Part of the solution could be located in Mohindergarh, a small town near New Delhi. A new high voltage direct current transmission (HVDCT) inverter station is located here. It converts the DC arriving from Mundra, 1,000 kilometers away, into AC and feeds it to the local power grid. The two regions located at either end of the HVDCT line couldn’t be more different. Mohindergarh is the least developed district in this part of northern India. Its residents, who are mostly farmers, live on the edge of poverty, whereas the residents of Mundra, a port city in the western state of Gujarat, are relatively wealthy. In the 1990s Mundra became a production and logistics hub for packaged salt. Today it is India’s biggest private port and has two high-output power plants. One of them, a coal-fired plant with an output of 4,620 megawatts, is the largest in the country.

Adani Power Ltd. is one of India’s largest private electric companies and the country’s largest importer of coal. In 2009 Adani commissioned Siemens AG and its Indian subsidiary Siemens Ltd. to build the longest private HVDCT system in India. The technology makes it possible to transport electricity over many hundreds of kilometers with minimal power loss. The new HVDCT system can carry up to 2,500 megawatts of direct current at 500 kilovolts. That’s enough to supply electricity to over a million Indian households. At times the construction took place under difficult conditions – temperatures of up to 45 degrees Celsius, strong salt-laden winds, and a shortage of qualified personnel. Nevertheless, Siemens and Adani were able to complete the system within the agreed-on two years. This included about 1,000 kilometers of power lines and the two turnkey rectifier and inverter stations in Mundra and Mohindergarh.

HVDCT could revolutionize the Indian power grid. Since the government only opened up electrical transmission to the private energy sector a few years ago, the country is dependent on the active participation of private companies. The HVCDT system between Mundra and Mohindergarh is a champion of efficiency. In traditional three-phase alternating current transmission systems, the power lost during transmission is two to three times higher. This means that the new system will keep around 700,000 tons of CO₂ per year out of the atmosphere. In October 2011 these HVDCT facilities were the first of their kind in the world to be certified as green technology as part of the climate protection measures put in place by the United Nations Framework Convention on Climate Change (UNFCCC). Adani and Siemens were able to document the corresponding CO₂ -reduction effect. As the HVDCT operator, Adani is now authorized to use emissions credits.

Electricity for Bangladesh. India’s neighboring country also intends to have low-loss power flowing in the future. In Bangladesh almost half of the over 160 million residents still live without electricity. Plans call for this country on the Bay of Bengal to connect its power grid with India’s in 2015. As part of the project Siemens is building a 500-megawatt HVDCT back-to-back station in Bheramara in western Bangladesh. The rectifier and the inverter will be directly connected with each other in one facility, thus creating a problem-free connection between these previously separate power grids. India can then supply electricity to its neighbor over a 110-kilometer-long, 400 kilovolt, three-phase power line.

The power grid in India still needs to be greatly expanded. Weak electrical grids have developed independently over the years, and they will have to be connected to one another. Additionally, in many places there are no distribution lines for bringing electricity into people’s homes. The HVDCT systems are an important step toward making it possible for life in India to go on after sundown.