111. Japan Offers Ship-Based LNG Power Generation for Islands
The Japanese government is exploring the idea of providing power to islands in Indonesia using ships that generate electricity from LNG.
The concept would be a first for full-scale LNG power generation at sea. LNG would be delivered by tankers from Indonesian terminals to ships equipped with LNG storage tanks and power-generating turbine systems. The strength of the idea comes from their potential for rapid deployment, says Japan’s ministry for Economy, Trade and Industry which hopes other Asian nations will be interested too.
Indonesia has over 13,000 islands, and many rely on diesel generators for power. Initial testing would involve around 10 islands close to East Timor, such as the Maluku Islands, reports The Japan News.
The idea is seen to be a way to counter China’s growing influence through its “One Belt, One Road” initiative. This includes boosting power and transportation infrastructure in the region.
Earlier this year, Japanese LNG infrastructure firm Chiyoda Corporation announced that it has received approval in principle from ABS for a new, unique vessel class: the floating LNG-fueled power plant. The new design would reuse existing ships. Chiyoda proposes to convert surplus LNG carriers into floating electrical generating stations with a capacity of 70 to 400 megawatts. The power would be run onto shore with heavy electrical cables.
Japanese engineering company Modec has also announced the development a power plant ship that uses LNG as the fuel for electricity generation. The FSRU’s came on the market earlier this year.
222. A New Concept for Japan’s Power Needs
One day, combined cycle power plants might float off the coast of Japan. Siemens and the Norwegian company Sevan Marine are working on such a concept for plants that would be unaffected by earthquakes and tsunamis.
In March 2011 the earth quaked in eastern Japan and a tsunami devastated huge swathes of the region’s coast. The disaster caused a meltdown at the Fukushima nuclear power plant, causing Japan to shut off its nuclear reactors, which had until then supplied nearly one-third of the country’s electricity needs. Now, the Japanese government would like to put some of the country’s 48 reactors back online in order to reduce oil and gas imports. However, with mounting resistance in large parts of the Japanese population, a clear schedule for restarting the reactors remains elusive. The country also needs more alternatives to help it maintain a secure energy supply the next time an earthquake hits. Japan therefore needs new ideas for creating a secure and environmentally-compatible electricity supply.
Floating Power Plants
With this in mind, in the fall of 2014, an unusual suggestion was made by Sevan Marine, a Norwegian company that develops offshore platforms for the oil and gas industry. Together with Siemens, Sevan Marine presented a concept for creating floating power plants that could be anchored off the coast. For example, such a power plant would use liquefied natural gas (LNG) to produce 700 megawatts (MW) of electricity for the mainland. The suggestion was well received by the Japanese Ministry of Land, Infrastructure, Transport and Tourism, because the mountainous island nation has few locations for fossil-fuel power plants that are safe against earthquakes and tsunamis. Moreover, many people don’t want to have a power station in their backyards.
“We originally came up with the idea for a floating power plant in 2006,” says Fredrik Major, who is responsible for Business Development at Sevan Marine. “Back then, we were looking for ways in which Norway could reduce the country’s CO2 emission levels by using commercially useless, so-called stranded gas as fuel for a floating power plant with integrated CO2 capture and reinjection. That power plant was intended to feed clean power both to oil and gas installations offshore as well as to the grid onshore, replacing gas-fired power plants without CO2 capture and storage capabilities.” Stranded gas is produced as a byproduct of operations at offshore oil and gas drilling platforms. Siemens has been involved in the project ever since, adds Vemund Kaarstad, Lead Engineer at Siemens’ oil and gas unit in Oslo.
“Tsunamis and earthquakes don’t have destructive effects on the open sea,” says Major. “In fact, the water only has to be over 50 meters deep. How far such a power plant has to be from land is determined by the steepness of the coastal sea floor and the distance that has to be maintained to shipping lanes and inhabited areas.”
Sevan Marine would supply such a power plant’s base, which would consist of a cylindrical hull 106 meters in diameter. This hull would be anchored to the seafloor at three points via chains. The superstructure would consist of several decks and reach about 50 meters above the waterline. The installation would contain a combined cycle power plant — a plant with both a gas and a steam turbine. It would also have quarters for a crew of about 20 people as well as high-voltage transmission technology for transmitting electricity to the mainland. This technology would be identical to that used for offshore wind farms, but it would include additional safety measures due to the fact that the installation would store significant amounts of flammable gas. Depending on the power plant’s location, such a facility would be supplied either with LNG from tankers or with gas through a land-based pipeline. The power station’s seven LNG tanks could hold almost 200,000 cubic meters of fuel, which would enable it to generate 700 MW of electricity for 30 days. The plant would also contain a regasification complex to convert LNG back into a gaseous state for combustion. The platform and the liquefied gas tanks could be manufactured by Japanese shipyards.
Nearly 55 Percent Efficiency
Siemens, meanwhile, would supply the two 350-MW power plant blocks. Each block would be equipped with five SGT 800 gas turbines. This is a proven turbine model that is also used in major industrial facilities, for example. Each turbine would have a Heat Recovery Steam Generator attached in which the turbine’s exhaust would create steam that a steam turbine and its associated generator would use to produce additional electricity. As a result, the power plant would have a total efficiency of almost 55 percent. Electricity production could be regulated in 70-MW steps by shutting individual gas turbines off and on. “All of the technology we use in our concept exists and has demonstrated its worth in practice,” says Johan Hansson, who works for Siemens in Finspång, Sweden, where he and his colleagues are developing the power plant concept for the Japanese project. Siemens would also be responsible for connecting the power plant to the Japanese grid via a high-voltage submarine power line.
One of the concept’s key elements is the platform’s cylindrical design. This round floater moves differently in the waves than does the elongated hull of a ship. Instead of rolling along its longitudinal axis and pitching along its transverse axis, the round floater would move up and down with the waves. “The rolling and pitching movements are much smaller than the critical values for the rapidly rotating turbines,” explains Hansson. “That’s why we were able to use proven power plant components.” Round structures have been demonstrating their suitability for marine use for years in the North Sea and off the cost of Brazil, where they serve as offshore drilling and production platforms. Their circular shape is also a precondition for the use of high-voltage submarine power lines that can transmit large amounts of electricity. While a round hull can be moored in fixed orientation, an elongated hull will have to rotate to keep the bow up against the waves, thus requiring transfer of the power through a swivel system. Available technology for swiveling power is today limited to around 10-20 MW.
But is such a solution cost effective? “The closer it would be located to the coast, the lower the costs would be for power transmission,” says Kaarstad. “However, the selection of the power plant’s location would also have to take other factors such as fishery and main shipping lanes into account.” Japan has to import liquefied gas anyway, and it would be easier to supply this fuel at sea than on land. Another benefit of the offshore power plant is that it wouldn’t need any cooling towers because it would be cooled by the surrounding seawater. The offshore installation would also serve as a valuable backup system if an earthquake were to damage land-based power plants.
More than 60 floating power stations are in operation around the world, deploying some 4 GW at continental shores where electricity is most needed. Though these feature a variety of power sources (including nuclear, gas, and heavy fuels), most are power barges — they do not have their own propulsion systems and would have to be towed to desired locations.
Some are of extraordinary size or feature novel designs. The largest of these, for example, is a 220-MW unit at Mangalore, in southwest India, according to Waller Marine Inc., the project’s designer. The maritime services provider is also currently carrying out design work on an even larger project, a 520-MW combined-cycle facility that will provide power to New York City. And at the same time, it is working on a modularized floating integrated gasification combined-cycle power plant, which would be fueled by petcoke.
More recent examples include the two revolutionary mobile power stations developed separately by companies in Russia and Germany: Russian investment management company United Industrial Corp.’s (Russian acronym OPK) floating nuclear power station and RWE Power’s pilot combined-cycle gas turbine power barge.
Both of these projects are expected to be set afloat within the next two years. About 450 feet long, OPK’s floating nuclear power station is expected to have a total capacity of 70 MW. It will be located in the north of the Russian Federation, where key energy supplies are lacking, OPK said. The reactors’ thermal energy can be sent up to 180 miles away. The plant’s design lifespan is 40 years, with refueling every two to three years. The project is said to have a 12-year payback.
RWE Power’s power barge will feature a combined-cycle gas turbine power station erected on floating pontoons. When deployed, the 98-foot by 328-foot units would be anchored and connected to the gas or electricity grid, providing electricity to shortage-stricken countries on the eastern Mediterranean and on the Black Sea.
This October, meanwhile, German company MAN Diesel announced a new direction in floating power plants, saying it had signed a contract with Turkish company Karadeniz Powership Co. Ltd. for the supply up to 24 large-bore power-generating diesel engines that would be installed on four “power ships” (Figure 4). The contract, which MAN says is worth over €100 million, includes 21 type-18V51/60DF dual-fuel engines and three 14V48/60 HFO engines, with a total output of 400 MW.
4. Floating an idea. Turkish company Karadeniz Powership Co. Ltd. plans to convert former freighters into floating diesel power plants using 24 large-bore power-generating diesel engines made by German company MAN Diesel. The ships will reportedly have an output of up to 400 MW, and they will be used to provide electricity to shortage-stricken countries in Africa, the Middle East, and around the Mediterranean. Courtesy: MAN Diesel
The ships are former freighters that will be converted into floating diesel power plants, which will be connected to local power grids to temporarily cover demand whenever onsite power plants are insufficient or new power plants cannot be built quickly enough. Unlike so-called “power barges,” the “power ships” will be equipped with their own propulsion engines and therefore will not need to be towed. They are expected to be used in Africa, Pakistan, regions in the Middle East, and around the Mediterranean.
According to Turkish newspaper Zaman, the first of these so-called power ships is already in the works: A 125-MW ship ordered by Iraq’s electricity ministry is in the final phase of construction and will soon be dispatched to the country. The 188-meter-long power ship will be docked in the Umm Qasr port in the Persian Gulf to mainly provide energy for the port. The remaining electricity will be diverted to residential areas in Basra, the newspaper reported in November.
—Sonal Patel is POWER’s senior writer.