Super grid
Encyclopedia
Grid (electricity)
An electrical grid is a vast, interconnected network for delivering electricity from suppliers to consumers. It consists of three main components: 1) generating plants that produce electricity from combustible fuels or non-combustible fuels ; 2) transmission lines that carry electricity from power...
that makes it possible to trade high volumes of electricity across great distances. It is sometimes also referred to as a "mega grid".
History
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 1930s, a proposal was made to ship hydroelectric power from dams being constructed in the Pacific NorthwestPacific Northwest
The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...
to consumers in Southern California
Southern California
Southern California is a megaregion, or megapolitan area, in the southern area of the U.S. state of California. Large urban areas include Greater Los Angeles and Greater San Diego. The urban area stretches along the coast from Ventura through the Southland and Inland Empire to San Diego...
, but was opposed and scrapped. By 1961, U.S. president John F. Kennedy
John F. Kennedy
John Fitzgerald "Jack" Kennedy , often referred to by his initials JFK, was the 35th President of the United States, serving from 1961 until his assassination in 1963....
authorized a large public works project using new HVDC technology from Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
. The project was undertaken as a close collaboration between General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...
of the U.S. and ASEA
ASEA
Allmänna Svenska Elektriska Aktiebolaget was a Swedish industry company. It merged with the Swiss Brown, Boveri & Cie in 1988 to form Asea Brown Boveri...
of Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
and is now known as the Pacific Intertie
Pacific Intertie
The Pacific DC Intertie is an electric power transmission line that transmits electricity from the Pacific Northwest to the Los Angeles area using high voltage direct current...
.
The concept of a "Super grid" dates back to the 1960s and was used to describe the emerging unification of the Great Britain grid. In the code that governs the British Grid, the Grid Code, 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
Wide area synchronous grid
A wide area synchronous grid, also called an "interconnection" in North America, is a power grid at a regional scale or greater that operates at a synchronized frequency and is electrically tied together during normal system conditions...
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
IPS/UPS
The IPS/UPS is a wide area synchronous transmission grid of some CIS countries with a common mode of operation and centralized supervisory control. It has an installed generation capacity of 300 gigawatts, and produces 1,200 terawatt-hours per year for its 280 million customers...
grid. If completed, this massive grid would span 13 time zones stretching from the Atlantic to the Pacific.
While such grids cover great distances, due to congestion and control issues, the capacity to transmit large volumes of electricity remains limited. The SuperSmart Grid
SuperSmart Grid
The SuperSmart Grid is a hypothetical wide area electricity network connecting Europe with northern Africa, the Middle East, Turkey and the IPS/UPS system of CIS countries. The system would unify super grid and smart grid capabilities into a comprehensive network...
(Europe) and the Unified Smart Grid
Unified Smart Grid
Unified National Smart Grid is a proposal for a United States wide area grid that is a national interconnected network relying on a high capacity backbone of electric power transmission lines linking all the nation's local electrical networks that have been upgraded to smart grids...
(US) specify major technological upgrades that proponents claim are necessary to assure the practical operation and promised benefits of such transcontinental mega grids.
Dr Eddie O’Connor, founder and CEO of Mainstream Renewable Power and formerly founder and CEO of Airtricity, was, in 2001 wrestling with the problem of taking wind energy from the periphery to a central position in meeting future electricity demand. His intuitive knowledge of weather systems from previous work was reinforced by a research article from the University of Kassel in Germany. His reasoning was that if we could build a grid system large enough to capture wind energy over say 5000 km and connect up to large hydro reserves in Scandinavia and central Europe then a firm source of electricity generation, rivalling nuclear in its invariability, would be created using wind energy. This concept Eddie called the Supergrid and the concept was launched at a conference which Airtricity co hosted with the European Wind Energy Association, in Brussels in December 2001.
Concept
In current usage, "super grid" has two senses – one of being a superstructure layer overlaid or super-imposed upon existing regional transmission grid or grids, and the second of having some set of superior abilities exceeding those of even the most advanced grids.Mega grid
In the "overlay", or "superstructure" meaning, a super grid is a very long distance equivalent of a wide area synchronous networkWide area synchronous grid
A wide area synchronous grid, also called an "interconnection" in North America, is a power grid at a regional scale or greater that operates at a synchronized frequency and is electrically tied together during normal system conditions...
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
IPS/UPS
The IPS/UPS is a wide area synchronous transmission grid of some CIS countries with a common mode of operation and centralized supervisory control. It has an installed generation capacity of 300 gigawatts, and produces 1,200 terawatt-hours per year for its 280 million customers...
system of the CIS
CIS
CIS usually refers to the Commonwealth of Independent States, a modern political entity consisting of eleven former Soviet Union republics.The acronym CIS may also refer to:-Organizations:...
, such a mega grid is no different from typical wide area synchronous transmission systems
Wide area synchronous grid
A wide area synchronous grid, also called an "interconnection" in North America, is a power grid at a regional scale or greater that operates at a synchronized frequency and is electrically tied together during normal system conditions...
where electricity takes an ad-hoc transit route directly through local utility transmission lines or HVDC lines as required. 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. 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 outage
Power outage
A power outage is a short- or long-term loss of the electric power to an area.There are many causes of power failures in an electricity network...
s such as the Northeast Blackout of 2003
Northeast Blackout of 2003
The Northeast blackout of 2003 was a widespread power outage that occurred throughout parts of the Northeastern and Midwestern United States and Ontario, Canada on Thursday, August 14, 2003, just before 4:10 p.m....
. 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.
Superior grid
In the second sense of an advanced grid, the "super grid" is not only superior because it is a wide area mega grid, but 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 heater 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 internetInternet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
bound together small networks into single ubiquitous network.
Wide area transmission can be viewed as a horizontal extension of the Smart grid. In a paradigm shift, the distinction between transmission and distribution blurs with the integration as energy flow becomes bidirectional. For example, distribution grids in rural areas might generate more energy than they use turning the local smart grid into a virtual power plant
Virtual power plant
A virtual power plant is a cluster of distributed generation installations which are collectively run by a central control entity....
, or a city's fleet of one million vehicles could be used to trim peaks in transmission supply by integrating them to the smart grid using vehicle to grid technology.
Intermittent power source
An intermittent energy source is any source of energy that is not continuously available due to some factor outside direct control. The intermittent source may be quite predictable, for example, tidal power, but cannot be dispatched to meet the demand of a power system. Examples of intermittent...
such as ocean, solar and wind
Wind energy
Wind energy is the kinetic energy of air in motion; see also wind power.Total wind energy flowing through an imaginary area A during the time t is:E = ½ m v2 = ½ v 2...
can be smoothed. 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 the entire European power usage could come from renewables, with 70% total energy from wind at the same sort of costs or lower than at present.
To some critics, such a wide area transmission layer is not novel – pointing 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. In the same way that freeways revolutionized interstate transport and the internet revolutionized online commerce when comprehensive high capacity networks for them 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 that entrepreneurs can bring to market.
Technology
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 ChuSteven Chu
Steven Chu is an American physicist and the 12th United States Secretary of Energy. Chu is known for his research at Bell Labs in cooling and trapping of atoms with laser light, which won him the Nobel Prize in Physics in 1997, along with his scientific colleagues Claude Cohen-Tannoudji and...
favor a national long distance DC grid system. There are industry advocates of HVAC. Although FACTS
Flexible AC transmission system
A flexible alternating current transmission system is a system composed of static equipment used for the AC transmission of electrical energy. It is meant to enhance controllability and increase power transfer capability of the network...
alternating current
Alternating current
In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....
have drawbacks for long distances, American Electric Power
American Electric Power
American Electric Power is a major investor-owner electric utility in various parts of the United States. AEP ranks among the nation's largest generators of electricity, owning nearly 38,000 megawatts of generating capacity in the U.S...
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). 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.
In the more distant future the voltage loss of current methods could be avoided using experimental superconducting "SuperGrid
SuperGrid
The SuperGrid refers the existing high voltage transmission grid in Great Britain that was constructed in the 1960s, and to various overseas parallels, including the concept, again in the British context, of increased connectivity to our neighbours...
" 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.
Coordination and control of the network would use smart grid technologies such as phasor measurement units to rapidly detect imbalances in the network caused by fluctuating renewable energy
Renewable energy
Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable . About 16% of global final energy consumption comes from renewables, with 10% coming from traditional biomass, which is mainly used for heating, and 3.4% from...
sources and potentially respond instantaneously with programmed automatic protection schemes to reroute, reduce load, or reduce generation in response to network disturbances.
Significant scale
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 HVDC lines. A recent proposal by Transcanada priced a 1,600-km, 3-GW HVDC line at $3 billion USD and would require a corridor 60 meters wide. 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. 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
In Europe, the energy securityEnergy security
Energy security is a term for an association between national security and the availability of natural resources for energy consumption. Access to cheap energy has become essential to the functioning of modern economies. However, the uneven distribution of energy supplies among countries has led...
implication of a super grid has been discussed as a way in part to prevent Russian energy hegemony
Hegemony
Hegemony is an indirect form of imperial dominance in which the hegemon rules sub-ordinate states by the implied means of power rather than direct military force. In Ancient Greece , hegemony denoted the politico–military dominance of a city-state over other city-states...
. In the U.S., advocates such as T. Boone Pickens
Pickens Plan
The Pickens Plan is an energy policy proposal announced July 8, 2008 by American businessman T. Boone Pickens. Pickens wants to reduce American dependence on imported oil by investing approximately $US1 trillion in new wind turbine farms for power generation, which he believes would allow the...
have promoted the idea of a national transmission grid in order to promote United States energy independence. Al Gore
Al Gore
Albert Arnold "Al" Gore, Jr. served as the 45th Vice President of the United States , under President Bill Clinton. He was the Democratic Party's nominee for President in the 2000 U.S. presidential election....
advocates the Unified Smart Grid
Unified Smart Grid
Unified National Smart Grid is a proposal for a United States wide area grid that is a national interconnected network relying on a high capacity backbone of electric power transmission lines linking all the nation's local electrical networks that have been upgraded to smart grids...
which has comprehensive super grid capabilities. Gore and other advocates such as James E. Hansen believe super grids are essential for the eventual complete replacement of the greenhouse gas
Greenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...
producing fossil fuel use that feeds global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
.
Permits for corridors
Large amounts of land would be required for the electricity transmission corridors used by the new transmission lines of a super grid. There can be significant opposition to the siting of power lines out of concerns about visual impact, anxiety over perceived health issues, and environmental concerns. The US has a process of designating National Interest Electric Transmission CorridorNational Interest Electric Transmission Corridor
A National Interest Electric Transmission Corridor corridor is a geographic region designated by the United States Department of Energy where electricity transmission limitations are adversely affecting American citizens...
s, and it is likely that this process would be used to specify the pathways for a super grid in that country. In the EU, permits for new overhead lines can easily reach 10 years. In some cases, this has made underground cable more expedient. Since land required can be one fifth than that for overhead and the permit process can be significantly faster, underground cable can be more attractive despite its weaknesses of being more expensive, lower capacity, shorter lived, and suffers significantly longer downtimes.
Siting
Just as superhighways change valuations of land due to the proximity to the ability to transport valuable commodities, businesses are strongly motivated to influence the siting of a super grid to their benefit. The cost of alternative power is the delivered price of electricity, and if production of electricity from North Dakota wind or Arizona solar is to be competitive, the distance of the connection from the wind farm to the interstate transmission grid must not be great. This is because the feeder line from the generator to the transmission lines is usually paid for by the owner of the generation. Some localities will help pay for the cost of these lines, at the cost of local regulation such as that of a public utilities commissionPublic Utilities Commission
A Utilities commission, Utility Regulatory Commission , Public Utilities Commission or Public Service Commission is a governing body that regulates the rates and services of a public utility...
. T. Boone Pickens' project
Pickens Plan
The Pickens Plan is an energy policy proposal announced July 8, 2008 by American businessman T. Boone Pickens. Pickens wants to reduce American dependence on imported oil by investing approximately $US1 trillion in new wind turbine farms for power generation, which he believes would allow the...
has chosen to pay for the feeder lines privately. Some localities, such as Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
give such projects the power of eminent domain
Eminent domain
Eminent domain , compulsory purchase , resumption/compulsory acquisition , or expropriation is an action of the state to seize a citizen's private property, expropriate property, or seize a citizen's rights in property with due monetary compensation, but without the owner's consent...
which allows companies to seize land in the path of the planned construction.
Technology preferences
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, which is considered to be less efficient for long distance transmission.Competition
In the 1960s, private California power companies opposed the Pacific IntertiePacific Intertie
The Pacific DC Intertie is an electric power transmission line that transmits electricity from the Pacific Northwest to the Los Angeles area using high voltage direct current...
project with a set of technical objections that were overruled. When the project was completed, consumers in Los Angeles
Los Ángeles
Los Ángeles is the capital of the province of Biobío, in the commune of the same name, in Region VIII , in the center-south of Chile. It is located between the Laja and Biobío rivers. The population is 123,445 inhabitants...
saved approximately U.S. $600,000 per day by use of electric power from projects on the Columbia River
Columbia River
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...
rather than local power companies burning more expensive fossil fuel.
See also
- DESERTECDesertecDESERTEC is a concept proposed by the DESERTEC Foundation for making use of solar energy and wind energy. This concept will be implemented in North Africa and the Middle East by the consortium Dii GmbH, formed by a group of European companies and the DESERTEC Foundation...
- Friends of the Supergrid
- Europe:European super gridEuropean super gridThe European super grid is a possible future super grid that would ultimately interconnect the various European countries and the regions around Europe's borders – including North Africa, Kazakhstan, Ukraine, etc...
, SuperSmart GridSuperSmart GridThe SuperSmart Grid is a hypothetical wide area electricity network connecting Europe with northern Africa, the Middle East, Turkey and the IPS/UPS system of CIS countries. The system would unify super grid and smart grid capabilities into a comprehensive network...
, Synchronous grid of Continental Europe - High voltage direct current (HVDC)
- North Sea Offshore GridNorth Sea Offshore GridThe North Sea Offshore Grid, officially the North Seas Countries Offshore Grid Initiative , is a collaboration between EU member-states and Norway to create an integrated offshore energy grid which links wind farms and other renewable energy sources across the northern seas of Europe...
- Pickens planPickens PlanThe Pickens Plan is an energy policy proposal announced July 8, 2008 by American businessman T. Boone Pickens. Pickens wants to reduce American dependence on imported oil by investing approximately $US1 trillion in new wind turbine farms for power generation, which he believes would allow the...
- Smart grid
- Unified Smart GridUnified Smart GridUnified National Smart Grid is a proposal for a United States wide area grid that is a national interconnected network relying on a high capacity backbone of electric power transmission lines linking all the nation's local electrical networks that have been upgraded to smart grids...
- V2G
- Wide area synchronous gridWide area synchronous gridA wide area synchronous grid, also called an "interconnection" in North America, is a power grid at a regional scale or greater that operates at a synchronized frequency and is electrically tied together during normal system conditions...