Can parallel lines meet: Power transmission: How to build a real supergrid by making existing electricity lines more efficient at transmitting power

Can parallel lines meet: Power transmission: How to build a real supergrid by making existing electricity lines more efficient at transmitting power

Mar 8th 2014 | From the print edition

GERMANY has a problem. The decision, taken in 2011, to close down the country’s nuclear-power stations risks leaving parts of the country with insufficient supplies of electricity. This means power will have to be brought in from elsewhere. But to do that seems, on the face of things, to require the building of new transmission lines, which will be unpopular with those they pass by.

One alternative is to make better use of existing lines. In theory, the simplest way of doing so would be to run direct current through them, instead of the existing alternating current. AC transmission has long dominated most grids because the higher voltages needed to boost energy transfer can be more readily stepped up and down again. But AC suffers transmission losses in a way DC does not, which even in efficient euro-zone grids is around 6%. With newer technology, however, the transmission of high-voltage DC would reduce those losses and thus provide more capacity, but it is technically awkward.

Now, however, an experiment by Amprion and TransnetBW, two German electricity-transmission firms, suggests it could be easier than engineers had feared. If true, this not only solves Germany’s local problem, it could also lead to the construction of a European supergrid to carry solar energy from the sunny south, and wind energy from the stormy west, to the continent’s industrial heartlands.

The difficulty the transmission companies face is that they need to have their cake and eat it. They want to transmit power 400km along an existing line from North Rhine-Westphalia, which has a surplus generated by conventional means, to Baden-Württemberg, which relies on Philippsburg 2, a nuclear-power station that will shut, unless there is a change of policy by the end of 2019. Although using DC is the best way of doing so, they also have to keep some AC capacity on the line, since that is more useful for local purposes. This means having parallel cables hanging from the pylons, some carrying AC and some DC.

That does not sound too hard to a layman. But the firms’ engineers feared the electric fields surrounding the adjacent cables might interfere with one another. This could happen in three ways: capacitance, induction and resistance. Calculations suggested the first two should not be problematic, but the third might well be—and might wear out the transformers which are used to step the current down from its transmission value of around 400,000 volts to the more manageable values used in homes and offices. Experiments on an unused line, however, suggested this does not happen. The only things that need be changed are the insulators. Doing that will be much easier than building a whole, new line.

Euro lines

If it were just a question of solving a little local difficulty, this discovery would have limited significance. But that is not the case. It actually opens up the possibility of moving a lot more electricity around as DC, with a resulting increase in grid capacity, in what the engineers refer to as an ultranet. This should reduce the need to build new lines to connect the continent’s burgeoning wind and solar generating plants to the cities. Such connections would also help balance supply, helping to iron out some of the inevitable variation the weather brings to both wind and solar power.

The actual conversion of the North Rhine-Westphalia to Baden-Württemberg line is now scheduled for 2019. Electrical engineers everywhere will be looking on with interest.


About bambooinnovator
Kee Koon Boon (“KB”) is the co-founder and director of HERO Investment Management which provides specialized fund management and investment advisory services to the ARCHEA Asia HERO Innovators Fund (, the only Asian SMID-cap tech-focused fund in the industry. KB is an internationally featured investor rooted in the principles of value investing for over a decade as a fund manager and analyst in the Asian capital markets who started his career at a boutique hedge fund in Singapore where he was with the firm since 2002 and was also part of the core investment committee in significantly outperforming the index in the 10-year-plus-old flagship Asian fund. He was also the portfolio manager for Asia-Pacific equities at Korea’s largest mutual fund company. Prior to setting up the H.E.R.O. Innovators Fund, KB was the Chief Investment Officer & CEO of a Singapore Registered Fund Management Company (RFMC) where he is responsible for listed Asian equity investments. KB had taught accounting at the Singapore Management University (SMU) as a faculty member and also pioneered the 15-week course on Accounting Fraud in Asia as an official module at SMU. KB remains grateful and honored to be invited by Singapore’s financial regulator Monetary Authority of Singapore (MAS) to present to their top management team about implementing a world’s first fact-based forward-looking fraud detection framework to bring about benefits for the capital markets in Singapore and for the public and investment community. KB also served the community in sharing his insights in writing articles about value investing and corporate governance in the media that include Business Times, Straits Times, Jakarta Post, Manual of Ideas, Investopedia, TedXWallStreet. He had also presented in top investment, banking and finance conferences in America, Italy, Sydney, Cape Town, HK, China. He has trained CEOs, entrepreneurs, CFOs, management executives in business strategy & business model innovation in Singapore, HK and China.

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