Super grid

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"Supergrid" redirects here. For other uses, see Super grid (disambiguation).

A super grid is a wide area transmission network that makes it possible to trade high volumes of electricity across great distances. It is sometimes also referred to as a "mega grid".


The idea of creating long distance transmission lines in order to take advantage of renewable sources distantly located is not new. In the US in the 1950s, a proposal was made to ship hydroelectric power from dams being constructed in the Pacific Northwest to consumers in Southern California, but it was opposed and scrapped. In 1961, U.S. president John F. Kennedy authorized a large public works project using new HVDC technology from Sweden. The project was undertaken as a close collaboration between General Electric of the U.S. and ASEA of Sweden, and the system was commissioned in 1970. With several upgrades of the converter stations in the intervening decades, the system now has a capacity of 3100 MW and is known as the Pacific DC Intertie.

The concept of a "Super grid" dates back to the 1960s and was used to describe the emerging unification of the Great Britain grid.[1] In the code that governs the British Grid, the Grid Code,[2] the Supergrid is currently defined - and has been since this code was first written, in 1990 - as referring to those parts of the British electricity transmission system that are connected at voltages in excess of 200 kV (200,000 volts). British power system planners and operational staff therefore invariably speak of the Supergrid in this context; in practice the definition used captures all of the equipment owned by the National Grid company in England and Wales, and no other equipment.

What has changed during the past 40 years is the scale of energy and distances that are imagined possible in a super grid. Europe began unifying its grids since the 1950s and its largest unified grid is the synchronous grid of Continental Europe serving 24 countries. Serious work is being conducted on unification of the European UCTE grid with the neighboring IPS/UPS grid. If completed, this massive grid would span 13 time zones stretching from the Atlantic to the Pacific.[3]




Mega grid[edit]

In the "overlay", or "superstructure" meaning, a super grid is a very long distance equivalent of a wide area synchronous network capable of large-scale transmission of renewable electricity. In some conceptions, a transmission grid of HVDC transmission lines forms a layer that is distinctly separate in the way that a superhighway system is separate from the system of city streets and regional highways. In more conventional conceptions such as the proposed unification of the European UCTE and IPS/UPS system of the CIS, such a mega grid is no different from typical wide area synchronous transmission systems where electricity takes an ad-hoc transit route directly through local utility transmission lines or HVDC lines as required.[4] Studies for such continental sized systems report there are scaling problems as a result of network complexity, transmission congestion, and the need for rapid diagnostic, coordination and control systems. Such studies observe that transmission capacity would need to be significantly higher than current transmission systems in order to promote unimpeded energy trading across distances unbounded by state, regional or national, or even continental borders.[5] As a practical matter, it has become necessary to incorporate smart grid features such as wide area sensor networks (WAMS) into even modest sized regional grids in order to avert major power outages such as the Northeast Blackout of 2003. Dynamic interactions between power generation groups are increasingly complex, and transient disturbances that cascade across neighboring utilities can be sudden, large and violent, accompanied by abrupt changes in the network topology as operators attempt to manually stabilize the network.[6]

Superior grid[edit]

In the second sense of an advanced grid, the super grid is superior not only because it is a wide area mega grid, but also because it is highly coordinated from a macro level spanning nations and continents, all the way down to the micro level scheduling low priority loads like water heaters and refrigeration. In the European SuperSmart Grid proposal and the US Unified Smart Grid concept, such super grids have intelligence features in the wide area transmission layer which integrate the local smart grids into a single wide area super grid. This is similar to how the internet bound together small networks into a single ubiquitous network.


A 765 kV AC transmission grid designed to carry 400 GW of wind power to cities from Midwest at a cost of $60 billion.[7][8]

One advantage of such a geographically dispersed and dynamically balanced system is that the need for baseload generation is significantly reduced since intermittency of some sources such as ocean, solar, and wind can be smoothed.[9] A series of detailed modeling studies by Dr. Gregor Czisch, which looked at the European-wide adoption of renewable energy and interlinking power grids using HVDC cables, indicates that Europe's entire power usage could come from renewables, with 70% total energy from wind at the same level of cost or lower as at present.[10][11][12]

To some critics, such a wide area transmission layer is not novel; they point out that the technology has little difference from that used for regional and national power transmission networks. Proponents respond that beyond the qualitative smart grid features that allow instantaneous coordination and balancing of intermittent power sources across international boundaries, the quantitative comprehensiveness has a quality all its own. The claim is made that super grids open up markets.[13] In the same way that freeways revolutionized interstate transport and the internet revolutionized online commerce when comprehensive high capacity networks were built, it is argued that a high capacity super grid must be built in order to provide a distribution network so comprehensive and with such available capacity that energy trading is only limited by how much electricity entrepreneurs can bring to market.


Wide area super grids plans typically call for bulk transmission using high voltage direct current lines. Europe's SuperSmart Grid proposal relies on HVDC, and in the US, key decision makers such as Steven Chu favor a national long distance DC grid system.[14] There are industry advocates of HVAC. Although FACTS alternating current have drawbacks for long distances, American Electric Power has championed a 765 kV super grid they call I-765 that would provide 400 GW of extra transmission capacity required for producing 20% of US energy from wind farms based in the midwest. (See figure above).[8] Advocates of HVAC point out that HVDC systems are oriented for point to point bulk transmission and multiple connections to them would require expensive complex communication and control equipment as opposed to the simple step up transformers needed if AC lines were used. Currently, there is only one multipoint long distance HVDC transmission system.[15] In the more distant future the voltage loss of current methods could be avoided using experimental superconducting "SuperGrid" technology where the transmission cable is cooled by a liquid hydrogen pipeline which is also used to move energy nationwide. The energy losses for creating, containing, and re-cooling liquid hydrogen need to be accounted for.


Government policy[edit]

Significant scale[edit]

One study for a European super grid estimates that as much as 750 GW of extra transmission capacity would be required – capacity that would be accommodated in increments of 5 GW with HVDC lines.[16] A recent proposal by Transcanada priced a 1,600-km, 3-GW HVDC line at $3 billion USD; it would require a corridor 60 meters wide.[17] In India, a recent 6 GW, 1,850-km proposal was priced at $790 million and would require a 69 meter wide right of way.[18] With 750 GW of new HVDC transmission capacity required for a European super grid, the land and money needed for new transmission lines would be considerable.

Energy independence[edit]


Permits for corridors[edit]


Business interests[edit]



Technology preferences[edit]

Energy producers are interested in whether the super grid employs HVDC technology, or uses AC, because the cost of connection to an HVDC line is generally greater than that if the AC is used. The Pickens plan favors 765 kV AC transmission,[8] which is considered to be less efficient for long distance transmission.



See also[edit]


  1. ^ Alan Shaw (29 September 2005). "Issues for Scotland's Energy Supply" (pdf). Edinburgh, Scotland: Royal Society of Edinburgh: 10. Retrieved 2008-12-07. In 1965 the first 400 kV line was inaugurated, running for 150 miles from Sundon, Bedfordshire to West Burton in the Midlands. The two new 275 kV and 400 kV systems running in parallel with each other became known as the Supergrid. 
  2. ^ "the British Grid Code". 
  3. ^ Sergey Kouzmin (5 April 2006). "Synchronous Interconnection of IPS/UPS with UCTE - Study Overview" (pdf). Bucharest, Romania: Black Sea Energy Conference: 2. Retrieved 2008-12-07. 
  4. ^ Sergei Lebed (20 April 2005). "IPS//UPS Overview" (pdf). Brussels: UCTE-IPSUPS Study presentation. Retrieved 2008-11-27. 
  5. ^ UCTE-IPS/UPS Study Group (7 December 2008). "Feasibility Study: Synchronous Interconnection of the IPS/UPS with the UCTE" (pdf). TEN-Energy programme of the European Commission: 15,16. 
  6. ^ John F. Hauer; William Mittelstadt; Ken Martin; Jim Burns; Harry Lee (2007). "Integrated Dynamic Information for the Western Power System: WAMS analysis in 2005". In Leonard L. Grigsby. Power System Stability and Control (Electric Power Engineering Handbook). Boca Raton, FL: CRC Press. pp. 14–4. ISBN 978-0-8493-9291-7. Retrieved 2008-12-06. Lay summary. 
  7. ^ United States Department of Energy Office of Energy Efficiency and Renewable Energy (20 May 2008). "20% Wind Energy by 2030: Increasing Wind Energy's Contribution to US Electrical Supply" (pdf): 15. Retrieved 2008-12-11. 
  8. ^ a b c AEP- American Electric Power Inc. (25 June 2007). "Interstate Transmission Vision for Wind Integration" (pdf): 1. Retrieved 2008-12-11. 
  11. ^ Gregor Czisch (24 October 2008). "Low Cost but Totally Renewable Electricity Supply for a Huge Supply Area – a European/Trans-European Example –" (pdf). 2008 Claverton Energy conference. Bath, UK: University of Kassel. Retrieved 2008-07-16. Lay summary. 
  13. ^ Peter Fairley (15 March 2006). "A Supergrid for Europe". Technology Review. Retrieved 2008-01-20. 
  14. ^ Steven Chu (2008-10-23). "The World's Energy Problem and What We Can Do About It" (PDF). California State Air Pollution Seminar Series. California EPA Air Resources Board: 52. Retrieved 2008-12-12. Lay summary.  A video of the presentation may also be found at the ARB site.
  15. ^ "HVDC multi-terminal system". ABB Asea Brown Boveri. Retrieved 2010-08-20. 
  16. ^ Gregor Czisch (24 October 2008). "Low Cost but Totally Renewable Electricity Supply for a Huge Supply Area – a European/Trans-European Example –" (pd). 2008 Claverton Energy conference. University of Kassel: 12. Retrieved 2008-07-16.  The paper was presented at the Claverton Energy conference in Bath, 24 October 2008. Paper Synopsis
  17. ^ "Zephyr and Chinook Power Transmission Lines". TransCanada Corp. Retrieved 2008-12-27. 
  18. ^ POWERGRID Corporation of India Limited (August 2007). "National Power Grid Development Investment Program (Facility Concept): Resettlement Planning Document" (PDF). Asian Development Bank. Retrieved 2008-12-27.  Projected 38,236 rupee cost = $790 million USD as of 2008-12-27.
  19. ^ David Charter (13 November 2008). "Power supergrid plan to protect Europe from Russian threat to choke off energy". The Times. Retrieved 2008-11-21. 
  20. ^ James E. Hansen (23 June 2008). "Global Warming Twenty Years Later: Tipping Points Near". Testimony to House Committee on Energy Independence and Global Warming. Columbia University. Retrieved 2008-11-17. 
  22. ^ Dori Glanz (29 August 2008). "Meet Pickens' World Wind Capital". News21. Carnegie Foundation and Knight Foundation. Retrieved 2008-12-12. 

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