BE Magazine - Volume 5, Issue 1 - (Page 35) PLANT BE Award Finalist Powered by Renewable Energy Papua New Guinea’s first geothermal power plant replaces heavy fuel oil combustion I nstead of venting steam into the atmosphere, the Lihir Gold Ltd. mine on Lihir Island now redirects the mining co-product to a 56-megawatt geothermal power station. The station generates enough energy for mining operations and the village communities PROJECT OVERVIEW Lihir Geothermal Power Station Organization Snowy Mountains Engineering Corporation (SMEC) BE Awards Category Plant Rookie of the Year Project Objective Design and construct a $10 million 20-megawatt extension for existing 30-megawatt geothermal power plant phases, with a 30-megawatt plant commissioned in June 2005 and an additional 20-megawatt extension completed in December 2006. SMEC also assisted Lihir Gold in the registration of the plant under the Clean Development Mechanism (CDM) of the Kyoto Protocol in 2005. CDM helps countries fulfill their commitments to greenhouse gas reduction by hosting projects that not only reduce emissions, but also helps to transfer new technology and economically benefit both the host country and project participants. The Lihir geothermal power station is Papua New Guinea’s first and, to date, only CDM project—one of just 844 registered projects worldwide. For each megawatt hour of power it produces, 700 kilograms of carbon dioxide emissions are eliminated. In 2004, Lihir Gold burned 88,000 tons of heavy fuel oil—the equivalent of 280,000 tons of carbon dioxide—that produced about 6 percent of Papua New Guinea’s greenhouse gas emissions. It is estimated that the geothermal plant will eventually eliminate the equivalent of 298,000 tons of carbon dioxide per year. By replacing a high-carbon fuel with renewable geothermal energy, Lihir Gold is eligible to trade $3 million a year in carbon credits on the global carbon trading market. Thus, the geothermal power station will not only reduce fuel oil costs, but also generate revenue for the company. Learning curve The power station is designed to collect geothermal steam from three steam wells in the Lihir basin and pipe the two-phase fluids to a separation plant for water removal. The single-phase steam is then transferred to a scrubber for dissolved solids removal. The clean steam is finally delivered to the turbine generators—three on this tiny island in the South Pacific. The model project exemplifies the goals of the United Nations Framework Convention on Climate Change to replace fossil fuels with renewable energy and reducing greenhouse gas emissions. Lihir Gold is a major gold producer in the Pacific Rim, operating one of the world’s largest gold mines and processing facilities on the island of Lihir. It is located 900 kilometers northeast of Port Moresby in the New Ireland province of Papua New Guinea. Lihir has abundant geothermal reserves associated with volcanic and seismic activity in the region’s Ring of Fire, but this energy source was previously unexploited. Instead, electricity on the island was primarily generated by heavy fuel oil combustion. When Papua New Guinea signed the Kyoto Protocol in 2000, committing the country to reduce its greenhouse gas emissions by 2012, the government put a high priority on developing renewable energy technologies. Lihir’s mining operations presented a prime opportunity. During the open-cut mining process, the Lihir gold mine drills geothermal discharge wells and shallow steam-relief wells to vent built-up steam pressure. The company commissioned Australian power-plant designer Snowy Mountains Engineering Corp. (SMEC) in 2003 to build a 6megawatt pilot plant to test the feasibility of harnessing this steam for energy. The proven technology was then scaled up in two v SMEC’s power station demonstrates the viability of geothermal power as a renewable energy source sets in the 30-megawatt plant and an additional two sets in the 20megawatt extension. Design of the 20-megawatt extension involved duplicating parts of the 30-megawatt plant as well as integrating the extension with existing services. SMEC met the challenge by adopting new technology Volume 5, Issue 1 | BE MAGAZINE 35
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