Prospects for Trans-Atlantic Undersea Power Transmission
Submarine Power Cable Precedents:
For several decades, submarine power cables have carried electric power across short distances under bodies of water within the same nation. Some examples include the cable from mainland Italy to the offshore Mediterranean islands of Corsica and Sardinia. Similar cables were installed in Sweden, Denmark and Japan while international submarine cables have been installed between Spain and Morocco as well as between Southern Italy and Northwestern Greece.
For a brief period, the longest submarine cable in the world connected across Bass Strait between mainland Australia and Tasmania. A more ambitious submarine cable of 450-miles length is being installed across the South China Sea to carry power from a recently completed 2400MW hydroelectric power dam in Sarawak province to mainland Malaysia. That development renews interest in a research project that dates from 1989 and pertains to a submarine cable between Scotland and Iceland.
Iceland – Scotland – Germany cable:
Iceland has an abundance of as yet undeveloped potential for geothermal energy, hydroelectricity and ocean tidal energy. The projected power output exceeds Iceland’s domestic needs and opens the door to explore means by which to market Iceland’s renewable energy internationally. Following initial research into installing a submarine undersea power cable between Iceland and Scotland, some follow-up research explored a possible connection between Iceland and Germany where there is a market for clean renewable energy.
As of January 2009, Ambata Capital indicated an interest in investing in the development of geothermal resources in Iceland. Iceland also offers potential for future hydroelectric development and ocean tidal energy development. The comparatively shallow ocean depth from Iceland to the Faroe Islands and on to Northern Scotland and to Northwestern Germany presents little difficulty to installing an undersea power cable between Iceland and Germany. The proximity of Greenland to the geothermal energy of Iceland suggests that there may be hidden geothermal potential in Greenland,
Extension to Greenland:
Like Iceland, Greenland is sparsely populated with potential to generate electric power from renewable energy that far exceed the needs of the local population. The comparatively short distance of shallow ocean water across the Greenland Sea between Iceland and Greenland offers the potential to extend a submarine power cable to include Greenland. Greenland and Faroe Islands are both provinces of Denmark that have potential to develop renewable energy resources.
In 1998, a research team from the Technical University of Denmark measured wind velocities at an elevation of 10-metres (30-feet) at numerous locations around Greenland, with average wind velocities of over 5.44m/s (17.84-ft/sec) at several locations. Wind charts from the Canada wind atlas extend over Davis Strait to include a portion of the Greenland coast and indicated wind velocities of some 10m/s (33-ft/sec) at 80m or 260-ft elevation. Wind research undertaken in California indicates wind velocities at elevations of 1000-metres can be up to 5-times the velocities at 100m elevation. There is greater wind energy potential at higher elevations around Greenland.
Airborne Wind Power:
Companies such as Magenn Wind Power of Canada are developing airborne wind power technology that promises to tap into winds at elevations of up to 1000m. While the Magenn technology carries airborne electrical generators, the Kitelab group from NW USA has build and tested an airborne technology that activates a ground-based electric generator. The Kitelab system involves kite flying back and forth in a sideways direction to the prevailing wind and driving ground level electrical generators. Recent research undertaken by a team in Forsan Province, China, suggests that an installation involving a small number of mega-sized kites activating ground-level generators could produce up to 100MW in a very small area.
Companies such as Skywindpower and Joby Wind Energy are developing airborne wind power technology capable of operating at elevations of 10,000m or 33,000-feet. A research group in NW USA is investigating an ultra high-altitude power conversion technology with a projected potential of several gigawatts of electric power. The southern and southwestern coast of Greenland is located outside of the main designated international commercial flight paths where such technology could operate. There may be scope to designate a no-fly zone off the western coast of Greenland where high-elevation airborne power generation energy technology may operate.
Cable Extension to Canada:
The proximity of Western Greenland to Eastern Canada offers the possibility of extending the submarine power cable to Eastern Canada. There are 2-possibilities by which to connect the power cable between Greenland and Eastern Canada. A shallow-water cable would be routed across Davis Strait to the north of the 60th parallel, while a deep-water cable could be routed across the Labrador Sea between Southern Greenland to Canada’s Labrador province. A technology that involves ballast and buoyancy chambers could carry a shallow-water submarine power cable at shallow depths across the deep Labrador Sea.
A cable across Davis Strait may be routed through Hudson Strait and under Ungava Bay, to connect to the immense hydroelectric generating capacity of Hydro Quebec. To the south of the eastern entrance of Hudson Strait is a channel called Gray Strait. It lies outside of the designated navigation channel and the kinetic energy of the twice-daily tidal current has been calculated in excess of 6000MW. There are evolving technologies that may be able to generate 1000MWe to 1500Mwe at Gray Strait, for 2-cycles of 5-hours duration each every day. A second section of undersea cable from Gray Strait may be routed along the coast of Labrador and through Hamilton Inlet to a point near the Churchill Falls hydroelectric installations and Labrador wind farms.
Trans-Atlantic Power Transmission:
At the present time, Eastern Canada has the capability to generate additional electric power from hydroelectric, ocean tide, ocean current and wind sources. An undersea power cable connection to Europe via Greenland and Iceland can allow for the off-peak export of electric power from Canada to Europe. When the overnight off-peak period for power generation begins at 12:00AM across Labrador and Quebec, the peak period demand for electric power begins at 6:00AM across much of Western Europe. When the decline in the demand for electric power begins at 10:00PM across much of Western Europe, the peak demand for electric power begins at 4:00PM across the northeastern USA and Eastern Canada.
Hydro Quebec’s main power dams are in close proximity to offshore wind energy along the shores of Quebec’s west coast and the 1600-offshore islands on the eastern side of Hudson Bay and James Bay. While there may be potential to install several hundred new-generation tower-mounted turbines at 100m and eventually 120m elevation on those islands, there is also potential to install airborne wind energy along the west coast of Quebec to tap into the winds that blow at some 5-times the velocity at 1000m elevation. Most of the commercial air traffic that flies through this region travels at altitudes of over 3000m and up to 10,000m.
The time frame for an undersea power cable linking Germany to Iceland is as yet unknown. However, the projected growth in demand for electric power across Western Europe suggests that such a cable would likely be installed within the next decade. The efficiency of trans-North Atlantic undersea UHV-DC power transmission would likely exceed the efficiency of compressed air energy storage (CAES) as well as pumped hydraulic storage. In terms of short-term and long-term overall costs, the undersea power cable promises to be competitive with energy storage technology.
At the present time, each UHV-DC power cable can carry up to 2200MW with potential for up to and perhaps exceeding 4000MW within the next decade. There is a convergence of technologies underway that will greatly influence the development of a trans-North Atlantic undersea power cable. UHV-DC power technology is advancing along with power cable technology. There are simultaneous advances underway in airborne wind energy technology, ocean tidal power technology, ocean wave energy technology and hydraulic kinetic turbine technology. The convergence of technologies offers the possibility of the international trans-oceanic transmission of electric power via a trans-North Atlantic undersea power cable system.