Iceland has abundant renewable energy sources such as hydropower and geothermal power. According to a paper1 published by the Icelandic Ministry of Energy and Commerce, the usable potential for hydropower in Iceland is about 35-40 TWh per year and for geothermal power it is about 15 TWh per year. At present, 25% of potential hydropower is harnessed and about 8% of geothermal power.
This 8.5 TWh per year energy is used in Iceland now in various ways. Domestically, 99% of the Icelandic population has connection to the public electrical network, most houses are heated by geothermal power, and a large part of electricity is used in heavy industry such as aluminum processing, Ferro-silicon production and a large diatomite processing plant at Myvatn. Today, the aluminum industry in Iceland produces some 270.000 tons of aluminum ingots from bauxite that is being transported from places as far away as New Zealand. New plants and plant expansions will bring the aluminum production in Iceland to over one million tons per year in the next decade. Even then, the potential renewable energy resources will not be exhausted for this industry.
The reasons for the success and growth of this power-hungry industry in Iceland are simple: the costs of generating large amounts of clean electricity in Iceland are low and the end-user markets (where the aluminum is used for end-products) are fairly near: the USA and Europe.
Transport of electricity from Iceland to Europe
The Icelandic government has made it a national priority to make electricity production and exploitation a large factor for its economy. Until recently, Iceland’s main exports came from the fish industry. The production of aluminum ingots frombauxite ore by way of an electrochemical process using large amounts of electricity and the transport of these aluminum ingots to the end-user markets was the first step to export electricity abroad, as aluminum has a high electricity equivalent: each kilogram of aluminum produced represents about 14 KWh of electricity. This means that if we ship 20,000 Tons of aluminum, we would be transporting the equivalent of 20,000,000 * 14 KWh of electricity. This is 280 GWh of electricity, enough to power 500,000 households for a year.
The transportation of electricity from Iceland to end-user markets such as the USA and Europe can be done in different ways, directly – as electrical current or as stored electrical energy- or indirectly – as a fuel of some kind.
Indirect transport of electricity
The indirect way: Hydrogen could be generated from water by electrolysis, requiring large amounts of electricity. However, the electrolysis process itself is about 70% efficient, and to transport hydrogen, it would require high pressurization or liquefaction to be able to transport this fuel. This would require additional energy. Finally, the generation of electricity back from the hydrogen by way of fuel cells would have, at best, an efficiency of 60%. Transporting electricity via the hydrogen/fuel cell route would have a total efficiency of 35% at best, but probably less. Further unsolved problems at the moment are: the safety of transporting pressurized or liquefied hydrogen over the North Atlantic ocean by ship and the current lack of reliable and low-cost fuel cells.
There may be another way to transport electricity indirectly, using the aluminum as a fuel. As stated above, if we ship 20,000 tons of aluminum, we would be transporting the equivalent of 280 GWh of electricity, enough to power 500,000 households for a year. Contrary to liquid hydrogen, aluminum ingots can be shipped safely and easily. The question, of course, is how can we free this electricity from the aluminum transported.
This can be done in an aluminum battery. Using aluminum electrodes in a simple electrochemical cell, filled with seawater or sodium hydroxide solution and using a nickel-manganese counter electrode, the aluminum will be oxidized to Al(OH)3 (aluminum hydroxide) and give off 3 electrons per aluminum atom used up in the reaction. A large part of the electricitystored in the above 20,000 tons of aluminum can in this way be released, generating about 280 GWh of electricity and about 60,000 tons of Al(OH)3 sludge. This sludge could be recycled back to Iceland to generate again 20,000 tons of aluminum to start the process of electricity generation anew.
Technically, this should all be very possible to do, but there is a snag. The average price for aluminum is 1350 Euro/ton (March 2004), so the electricity generated in this way would be minimal 10 Eurocent/KWh but probably twice as much as cost for aluminum transport and costs for the batteries, upkeep, personnel, etc. are not included. So, simply burning aluminum is an economically unfeasible option.
Direct transport of electricity
In 2001, the Icelandic government announced a project called Icelandic Submarine Cable Project. The idea was to export 25% of the nation’s electricity generation potential to Europe via electrical cables. Hydro- and geothermal power stations would be built (up to 30 facilities), requiring a 4,140 million Euros investment (including infrastructure). Two 1200 km long submarine high Voltage cables would be laid between East Iceland and Germany at a total cost of 3,500 million Euros. Each cable would have a transport capacity of 550 MW of high Voltage DC current. On each end of the cable, special converter stations would change the high Voltage DC current in 50 Hz AC 3-phase current, suitable for the national electrical grid. This would require an additional 500 million Euros investment. So, for a total investment of about 8 billion Euros, a net transport of 8 TWhr annually could be realized. However, also here simple economics pose a snag: amortizing the investment over 40 years and requiring an average Return On Investment (ROI) of 6 % (a very modest profit for the investors), the electricity price on the point of delivery would be at least 65 Euro/MWh, but probably more. This exceeds the current wholesale price of electricity in Germany by a factor of 1.5, so it is too expensive, just as the simple Aluminum battery is too expensive.
However, instead of “burning’’ the aluminum in simple electrochemical cells, a rechargeable Aluminum battery can be used. Such batteries are being developed by Europositron2 in Finland. They claim the following specifications for their technology:
Energy density: 2100 Wh/litre or 1330 Wh/kg
Cycle times: 3000+ cycles
Working temperatures: –40 C to +70 C
Lifetime of battery: 10 to 30 years
Exact details of the Europositron technology are not known, but from literature of similar designs it is clear that the claimed energy density represents a breakthrough. As a reference, look at US Patent 6,482,548 (Nov 2002), issued to Glenn Amatucci of Telcordia Technologies in Morristown, N.J. In that patent, a Lithium-Aluminum dual-cation rechargeable battery cell is described with vanadium pentoxide and lithium-silicide electrodes separated by a nonaqueous electrolyte. Charge capacities of up to 525 mAh/g are reported for this battery. At a Voltage of 1.4 V per cell, this comes close to the claimed 1330 mWh/g for the Europositron battery.
If Europositrons claims are correct and long lived giant aluminum batteries can be made with low self-discharge and at reasonable cost (about 15-20 Euro/Kg), ‘shipping’ electricity from Iceland to mainland Europe or the East coast of the USA can be a viable way to import electrical energy from places where electricity can be cheaply made to places where a huge demand exists for clean energy.
About the author
Dr. Pieter van Pelt is a retired chemical scientist from Philips Electronics and recently interested in energy matters. He is not affiliated with Europositron nor endorses their specific technology of which he has no in-depth know-how. He lives in Best (near Eindhoven) in the South of The Netherlands.
1 Address delivered by the Icelandic Minister of Energy and Commerce at “Hydroforum 2000” in München, September 12, 2000.