China building super highway for clean power


China likes to do things on a grand scale, which allows it to serve its vast population and brag about its technical advancements. The country is now building a 800-kilovolt transmission line that will ferry wind and solar power over 2,210 kilometers (1,373 miles) and when completed in 2014 could claim a world record for its capacity of 8 GW, according to the Chinese government-run China Daily on Monday.

This isn’t the first project to use ultra high voltage direct current lines at 800 kV, which are state of the art. Both Siemens (s SI) and ABB (s ABB), two powerline equipment makers, previously announced projects selling their 800 kV equipment to China Southern Power Grid and State Grid Corporation of China, respectively.

ABB sold an 800 kV line to State Grid Corporation of China to complete a 2000-kilometer project in 2010 to transport 6.4 GW of hydropower from the Xiangjiaba power plant in southwestern China to Shanghai. ABB said the Shanghai project was the world’s first transmission project to use ultra high voltage direct current equipment, though Siemens has made a similar claim with a project in China.

State Grid will also build the project touted by People’s Daily on Monday. The project will run power lines from the Hami prefecture in the Xinjiang province in the west to Zhengzhou city in Henan province in central China. The equipment will rise up along regions of big solar power development, such as the Gansu and Ningxia provinces. The project will cost 23.39 billion yuan ($3.7 billion), People’s Daily reported.

The use of high voltage direct current (HVDC) technology is gaining popularity in a world dominated by electric grids that run on alternating current. HVDC equipment tends to cost more, but it also can be more efficient at transporting large volumes of electricity over long distances. On Monday, the U.S. Department of Interior said it’s cleared a hurdle for a proposed HVDC transmission project, which counts Google (s GOOG) as an investor, to carry up to 7 GW of wind power off the East Coast. Meanwhile, Tres Amigas is planning a HVDC transmission project to connect the three major power grids of the country. Japanese conglomerate Mitsui has agreed to invest $12 million in the project. Most of the transmission lines in the U.S. run at much lower voltages than 800 kV.

China has massive goals to build and generate more renewable energy, including 15 gigawatts of cumulative solar power generation by 2015 (and it wants its domestic solar industry to help meet that goal). The country installed a few gigawatts of solar power projects in 2011, and estimates from market analysts and Chinese solar companies have varied widely, from 3 GW to 7 GW, on how much China will add in 2012. China also is the world’s largest wind energy generating country. These developments have made the country a magnet for U.S. tech companies.

China is also interested in pairing energy storage with wind and solar farms. The country completed a 36 megawatt-hour energy storage project – the world’s largest lithium-ion battery farm – last year. Battery makers such as A123 Systems, Boston-Power, and PowerGenix all have set up shop in China to target the energy storage and electric car markets. Boston-Power made the bold move of shifting a bulk of its operation to China after lining up hefty funding from Chinese investors.

Photo courtesy of Siemens


Space Time

800,000 volts should be enough to hold Godzilla at bay, should it come for a visit

Grant Allen

ABB actually built the first commercial HVDC system back in the 50s. There are now over 120 HVDC systems in operation in the world, half of which have been supplied by ABB.

Other breakthroughs:

Multi-terminal transmission

Large-scale transmission between more than two converter stations was made possible by ABB. The first multi-terminal HVDC system was built by ABB for the Quebec-New England Phase II HVDC project. The power is generated at La Grande II hydropower station, converted into DC at the Radisson converter station, and transmitted over the multi-terminal system to load centers in Montreal and Boston. ABB is the only company to have developed a multi-terminal HVDC system.

A completely new power transmission technology

The latest groundbreaking innovation in power transmission is ABB’s HVDC Light®, a unique technology that extends the economical power range of HVDC transmission down to a few tens of megawatts. It is particularly suitable for small-scale generation and transmission applications. In its upper range, the technology now reaches 1,200 MW and +/-320 kV.

Following the first commercial installation in Sweden in 1999, HVDC Light has been chosen for a number of underground transmission projects up to 350 MW in the United States, Australia, Europe and Africa.


How does using DC lines with such high voltage (obviously very low amperage) make such a system more effective than “traditional” AC lines?

Ucilia Wang

It all depends on what new technology has come along to better moderate voltages and reduce power losses along the way from a power plant to the distribution network. AC used to be more efficient and incurred lower power losses over long-distance transmission. You can send a lot more power and at a maximum voltage through DC lines, though, and they offer more control over the direction of the power flow. Newer tech as thyristor valves became available in the last several decades to make DC transmission more efficient. Since electricity from solar farms and batteries is in DC, some argue that using DC lines reduces the cost and need of converting DC to AC for transmission, as it’s commonly done now in the U.S.


Hmm, I see. Technology, and innovation I suppose, is what lies behind, then. (:
I reckon HVDC systems can be easier to work with on paper than AC systems, as well?

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