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Power Import Options for a Nuclear-free Germany

Sep 12, 2011 - Harry Valentine - energypulse.net

Germany's influential environmental movement has responded to the fallout of Japan's recent nuclear problems. They successfully lobbied their federal government and Germany's Chancellor has announced the phase-out of nuclear power generating in that country. Germany will seek to use domestic and imported wind, hydroelectric, solar and other forms of renewable power. That choice opens new opportunity for Iceland and also Greenland that urgently seeks foreign investment to build their national economies.

Previous studies have examined the concept of linking a submarine power cable across the relatively shallow waters of the Northeastern Atlantic Ocean, between Germany and Greenland. There is also scope to extend such a cable between Iceland and the eastern coast of Greenland, to the largest fjord in the world called Scoresby Sound with some 38,000 Km2 or 14,700 square-miles of water surface area. The tidal current through the relatively narrow entrance to this inlet is estimated at just over 2m/s, the minimum velocity needed for viable installation of kinetic turbines.

There is scope to slightly reduce the depth and width of that relatively desolate entrance, to slightly raise the velocity of the twice-daily bi-direction tidal current that flows for some 20-hours each day. A Florida-based research group has been developing what may become the world's largest-diameter kinetic turbine, originally intended for installation in the Florida Straits and may also be suitable for installation in the Strait of Gibraltar, the Canary Channel and the entrance to Scoresby Sound. A combination of ballast and a tension cable suspension system may enable turbines to operate below the winter ice at that entrance.

There are several high coastal mountains along Greenland's eastern coast, just across the Greenland from Iceland. Ongoing developments in high elevation, terrain enabled, terrain enhanced and airborne wind energy technologies promise to generate higher output at more competitive costs. There may be future potential to install such technology in high mountains along Greenland's eastern coast, to generate electric power in addition to the possible electrical output from the entrance of Scoresby Sound then export that power to Germany, via Iceland.

Iceland has over 2200MW of undeveloped hydroelectric potential, along with potential to develop geothermal energy resources along with high-elevation and airborne wind energy, plus oceanic tidal energy. The possible presence of on-shore and offshore natural gas at Iceland may include the possible presence of salt caverns in the Icelandic bedrock. Seismic testing would be able to confirm such a possibility along with the location, size and depth below surface of such geological formations.

The possible presence of one or more salt domes located near the Icelandic coast would be a definite plus to enhance the operation of seasonal CAES (compressed air energy storage) installations. A coastal location allows for the use of seawater-displacement in the emptied salt dome to increase seasonal energy storage capacity. However, there would be a need to develop some special light oil that would separate the highly compressed air from seawater inside the salt dome.

During winter, wind energy blowing over eastern Greenland's high mountains and off the Icelandic coast would be at its peak. There may be scope to transfer winter wind energy from Greenland and Icelandic offshore ocean wave energy into seasonal storage at Iceland. Recent developments in high-temperature seasonal thermal energy storage may serve as a basis to develop an expanded version of such storage for the purpose of storing the heat-of-compression produced by the pumping of air into CAES.

Some of this heat could be stored at heat of fusion using molten salt in an adapted salt dome. SENER of Spain is one of the leading companies to have developed molten salt thermal storage for the solar thermal power industry. The volume of some underground salt domes combined with future research may allow for large-volume, seasonal, high-temperature thermal energy storage. Such thermal storage would be used to pre-heat compressed air prior to it being superheated via the combustion of natural gas and subsequent expansion in a multi-stage power turbine system.

There are few countries that have excess electric power for sale, to which Germany can directly link a power line to import electrical energy. Iceland is a prime candidate to sell renewable electric power to Germany, via submarine cable. Given the likelihood of Germany's demand for electric power exceeding Iceland's generating capacity, there is scope to extend the submarine cable across to eastern Greenland for the purpose of importing oceanic tidal energy and high-altitude wind energy. Norway is blessed with many fiords where it may be possible to generate oceanic tidal energy for direct export to Germany.

A future nuclear-free Germany may have to examine the possible import of electric power via power cables that cross several international borders. Several Middle Eastern and North African nations have indicated an interest in exporting solar-thermal electric power to European markets, using UHV-DC power transmission. One power cable could cross the Eastern Mediterranean Sea to Italy, then Austria into Germany.

A precedent from New York State involves installing a submarine power cable under waterways between Montreal and New York City. A waterway that connects Stuttgart in Germany to Marseilles in France may include a future submarine power cable that would connect between Southern France to a point in North Africa. Future developments in more cost-competitive high-altitude wind power, solar-thermal electric power plus oceanic tidal power conversion may provide electric power to a future nuclear-free Germany.