Considering the already 35.000 MW of solar energy capacity in Europe, the high voltage European Network needed a great coordination between all European Transmission Systems Operators (TSO's) previously, and during the eclipse.
As a sample of the reinforcing this European Network, Last February 20th, it was inaugurated - Ree new - one Power Electric Interconnection between Spain and France by the
French Prime Minister, the president of the Spanish government and the presidents of the TSO's from France (RTE) and Spain (REE).
The underground Direct Current High Voltage (HVDC) Power Line of 64,5 km (40 miles), has represented an investment of 700 millions €. With that infrastructure, the electric interconnection between Spain and France is now 2,800 MW, from the 1,400 MW installed before the inauguration of this interconnection. With this underground installation, the capacity of interconnection has passed from 3% to 6%, of course when will be in operation in summer this year 2015.
The infrastructure has cost ten times more than it was expected. The opposition of the french farmers who made the obligation for building the underground line, instead of the overhead power line, it made that the cost has been increased in 10 times more, of course, reducing the environmental impact.
In the same way, it is necessary to remark the cutting edge technology applied to this infrastructure, making it unique in the world for having the capacity to reverse the direction of the energy flow in just 50 milliseconds.
Similarly, it is necessary to remark other projects which are being implemented in other regions of Europe to reinforce the interconnections of all EU members.
The European Transmission System Operators for Electricity (ENTSO-E), an entity for supporting security of supply, sustainability, and the development of the European internal energy market by EU Regulation EC 714/2009, It is the responsible for the assurance of the coordination of all European TSO's, being a great challenge, understanding which European transmission grid is 300.000 Km of transmission lines, 500.000 Km of distributed lines, with 41 TSO's in 34 countries with 534 millions of citizens.
It is well known the challenges for the implementation of a unique European Electric Network, politically; for the necessity to find a common point of understanding of all the energy markets, and technically; with the necessity to implement some solutions in the DC systems, which are going to be the technology for the interconnection to every state of the European Union, for the advantages in transportation of electricity in long distance; losses reduction, possibility to change the power flow of the current, and increasing the power quality, stability and reliability by power electronic systems.
For some professionals in the implementation of this solutions, gathered in a conference of power electronics in the grid, exposed about the main issue for the implementation of this grid, grid called "SuperGrid", see "Friends of Supergrid", is the existing grid, because it needs to be implemented with the high conditioning of having an existing AC power lines.
Regarding the conference mentioned in the previous paragraph; "IX International conference Energy Innovation. Power Electronics in the Grid - HVDC and FACTS", it was exposed the evolution and the state-of-the-art of the power electronic technology applied to HVDC and AC, in concrete to Flexible AC Transmissions Systems (FACTS), and how the technology and investments are helping in its implementation.
HVDC technology is in the market long time ago. In first term applied for connecting islands or Oil & Gas Offshore Rigs. Afterwards, it was implemented in the development of high level of electric yield coming from Wind Offshore Farms to the Mainland transmission lines.
Talking about the history of HVDC, with the first project in Sweden in 1954, by Dr. Uno Lamm, the father of HVDC, by the company ASEA (nowadays ABB: Asea Brown Boberi), which started to connect Gotland island to the Sweden Mainland Electric System. The project of 150 Km of cable of 150 KV, used mercury valves for the power electronic control.
The evolution of the power electronics in those last years have increased rapidly, with the first and second thyristor generation in 1970 and 1980 respectively, and the starting of using Isolated-Gate Bipolar Transistor (IGBT's) in 2000 - see document of ABB of the 60 years of HVDC technology.
It is necessary to mention, the most important challenge for HVDC technology is the Protection Systems.
Protection systems in HVDC - Think Grid article, are still in development phase, because to date no DC circuit breaker is in the field. With the same philosophy and scheme for AC Power systems, and needing to perform in a short tripping time, of course, without losing selectivity, security and sensibility.
Nevertheless, it is necessary to consider that transmission lines in HVDC are longer than the equivalent in AC, then, the communication time delay is longer. Furthermore, is not possible to use Fourier based algorithm for protection systems used in AC Power Systems, for being a DC current.
On the other hand and making a conclusion, besides the technical and economical challenges for the interconnection of different electric systems. It is necessary to think about to establish systems for controlling all the data generated, from the micro grids; from the smart meters or Advance Metering Infrastructure (AMI) in the Smart Homes, even in both direction, consumption and production, with the Distribution Energy Resources (DER), the Electric Vehicle (EV) Chargers, even in the Vehicle to Grid (V2G) systems, the storage systems, in its different technologies, and regarding the situation of the main Bulk Power Flows in the actual AC Power Systems, which will create a system mixed by AC and DC technologies.
Figure 3_In the left, Smart Meterings, in the right, a Trafos in a Hydraulic Power Plant_source: J. Sánchez Ríos
Of course the development in DC technology will change the composition of the network, not only in HV Systems, also in low and medium voltage (LV & MV), it is well know the implementation of DC for supplying Data Centers and other applications, even working in a off-grid solutions.
The restrictions in the future for the integration of DER in the distribution grid in LV by the owners of this Distribution assets, will create microgrids DC systems; with generation, storage, and EV chargers in parallel with conventional AC infrastructure, normally connected to AC systems.
Likewise, Offshore Wind Power has helped in the development of the HVDC technology, with the increasing of the capacity installed, which have brought investments to the rest of technology requirements; cables, substations and power electronics systems.
Furthermore, if Offshore Wind Technology overcomes its primary handicap, being able to establish wind farms in emplacements independently of the deep sea, and knowing the high cost of the construction phase in the implementation of the Offshore Wind Farm project, which in some cases is being the two-third of the lifetime. The projects which will bring alternatives to fixed-bottom foundations, will extend the emplacement of this Wind Technology. Some samples from Hitachi or Alstom, open the possibility for installing Wind Offshore Energy in deeper locations - out of North Sea and North East coast of US.
Other technology which will bring great possibilities in the electricity transmission with applications in cities, despite of the limitation nowadays, in terms of distance, is the superconducting technollogy. Some projects are yet implemented in Europe - "Ampacity" in Essen, Germany. A project of longest superconducting cable installed in the world, and the first to combine a superconducting cable with a resistive for overload protection restructuring of inner-city networks.
Superconducting cables are cables cooled by liquid nitrogen at -200ºC. Apart of the project expose, it is possible to find applications in other emplacements, one is in ITER project, the International Nuclear Fusion project - see new about the instrumentation for the system monitoring, and in the Superstation "Tres Amigas" in New Mexico (US), for connecting the three electric systems in US and Canada, from Texas, Western and Eastern coast respectively (WECC, Eastern, ERCOT).
Accordingly, it is possible to think about the great possibilities of the DC systems, not only in HVDC, and the coexistence with the existing AC Power Systems.
The potential for the management of all this enormous network and data, which at the end, can be extended not only in a continental space, having only the geographical limitation, or may be not.
May be in future, this Supergrid will be bigger than our future expectations nowadays. Some months ago, it was connected by train Beijing and Hamburg, opening the possibility for establishing an electric catenary, which in future brings automated trains, even this catenary can be supplied by Renewable Energies sources in the emplacement or close to the railway, minimizing the greenhouse gas emissions and reducing the cost of the operation.
If is in construction the project "Keystone XL Pipeline", may be US is able to avoid great damages in the Transmission lines in cases of twister or hurricanes with the implementation of one underground HVDC in parallel with the mentioned project "Keystone XL Pipeline" like is implemented in the West Coast from Oregon to California.
Knowing the relevance of the Electric Operation in the social and economical activity, with this article, it is opened the possibilities to the interconnection of the Electric Systems, for having a more flexible, reliable and profitable Electric System for the integration of Renewable Energies and Electric Vehicles.
Notwithstanding having a constant changing perspective in the Electric Systems, which of course, in terms of hardware, is related to great risk for the obsolescence of the technology, in terms of software, with cloud and big data and its possibility for adapting continuously, it opens a great challenge for the companies with are giving services to the control of the complete Electric Systems. Not only for the Utilities or regional markets, also introducing the control of the holistic energy and other resources; Oil & Gas, Telecommunication, Water, etc., and managing this enormous among of data for optimizing and establishing predictive or simulation models for advancing to any situation like the eclipse exposed. As a result, giving better studies of the possible future projects or any possible disaster, and restablishing the resources as soon as possible.
All of that, in Electric Systems which will be more worried about the complete balance - consumption and generation, which will be the main task of the TSO in future, and with an increasing of DER, but of course being the quality of the wave also a great challenge.
The electric grid is like a river: step by step rivers are more and more dirties, but we want it, step by step, cleaners... Ramon Comelles (Circutor owner in a interview in Enginyers Bcn)
Bibliography:
1) Smart Grid: Technology and Applications / Janaka Ednayake, Kithsiri Liyanage, Jianzhong Wu, Akihiko Yokohama, Nich Jenkins
2) IEEE Power & Energy Magazine / Volume 13
