The challenges that are faced by individual energy systems vary from region to region. But one thing’s for sure: sustainable energy supplies are needed all over the world. Highly efficient natural gas power plants almost always hold the key to success, as several examples in Asia illustrate.
The H-Class gas turbine is the product of more than ten years of development. Back in October 2000, hundreds of engineers from Siemens’ Energy Sector, Corporate Technology, and about 50 external partner companies began working on the turbine and the concept behind the system. Siemens invested over €500 million in the development, construction, and operation of a prototype facility in Irsching, Germany. The gas turbine underwent a rigorous testing program that included more than 170 starts and over 1,500 operating hours. The facility was then converted into the world’s most efficient combined cycle power plant and handed over in the summer of 2011 to the E.ON power company, which put it into commercial operation. The H-Class turbine has made history with its output of 578 MW and combined efficiency rating of 60.75 percent, as it is the first gas turbine to break the magic 60 percent efficiency mark in combined cycle operation. This exemplary project has even earned an entry in the Guinness book of world records, because the SGT5-8000H turbine in Irsching 4 is the largest operating gas turbine in the world. It has now reached more than 17,800 equivalent operating hours (EOHs), 12,500 of which were in combined cycle operation with more than 400 starts.close
China is hungry – especially for electricity. The world’s second-largest economy consumes 4,000 terawatt-hours (TWh) of power every year. Annual economic growth of roughly ten percent has enabled China to lift hundreds of millions of people out of poverty in recent years, but this development has led to an immense increase in the country’s hunger for consumer goods, resources, and energy. According to the United Nations, the country will have 1.4 billion people by 2025. The International Energy Agency reports that Chinese oil consumption alone is set to rise by 70 percent from 2009 to 2015. By then China will account for 42 percent of global oil demand. The country’s electricity consumption has tripled in the last decade, and it may double again to 8,000 TWh by 2030.
China is therefore looking to make power generation more efficient. Plans call for a radical reduction of CO2 emissions per unit of GDP and the achievement of a much more balanced energy mix by 2030, although coal will then still play the major role in the nation’s energy system. The rated capacity for wind farms will increase from 60 gigawatts today to 150 by 2020. However, expanding the use of energy from renewable sources does pose the risk of fluctuation in the grid, since no power can be generated when there is no wind or the sun has set.
These fluctuations can be offset with combined cycle power plants, which are quick-starting and highly efficient. Shanghai Shenergy Lingang is one such plant. It was honored in October 2012 with the Asian Power Award in the category Best Gas Power Project. Each of Lingang’s four blocks houses an F-series gas turbine from Siemens.
Block 4 has set a new efficiency standard for combined cycle power plants in China with its efficiency rating of 59.7 percent and an output of 430 MW – enough to supply electricity to 300,000 people. The power facility is also very flexible. For example, any of its blocks can begin generating electricity just ten minutes after it’s been started up. This feature is now mainly used to react as quickly as possible to the huge demand fluctuations that can rock Shanghai’s power grid on extremely cold winter days or especially hot ones in the summer. Siemens’ solution may also soon be used to balance out the fluctuations that occur when the share of renewable energy in the grid increases sharply.
Three Months Ahead of Schedule. Combined cycle plants can also support Vietnam’s efforts to increase its electricity production. Vietnam is one of the fastest-growing nations in Southeast Asia, and its electricity demand is increasing by 11 to 13 percent per year. According to the Germany Trade and Invest development agency, which is part of the German Ministry of Economics, Vietnam’s demand for energy is increasing roughly twice as fast as its GDP. Power outages are common. Vietnam’s Energy Master Plan for 2011–2020 calls for a threefold increase in output capacity compared to today’s level. One element of the solution is Nhon Trach 2, a 760 MW combined cycle power plant located around 35 kilometers from Ho Chi Minh City. Siemens supplied the plant with a turnkey power block consisting of two SGT5-4000F gas turbines, two heat-recovery boilers, a steam turbine, three air-cooled generators, and all the electrical, control, auxiliary, and support systems.
“Thanks to excellent cooperation between all the project partners, we were able to launch commercial operations at the plant in just 28 and a half months,” says Lothar Balling, Head of Gas Turbine Power Plant Solutions at Siemens Energy’s Fossil Power Generation Division. “We finished our share of the work three months ahead of schedule. That made it one of the most rapidly built power plants in all of Asia in recent years. What’s more, the facility’s output and efficiency ratings exceed those that were guaranteed before the plant was constructed, and its emission levels are lower as well. The plant is setting new standards for Vietnam.” This achievement was honored at the Asian Power Awards ceremony, where the facility was named an Outstanding Fast-Track Power Project.
Siemens has also added its H-Class to the successful F-Class series. The H-Class includes the gas turbine in the Irsching power plant, which achieved the world record electrical efficiency of 60.75 percent in combined cycle operation with a steam turbine at a total electrical output of more than 580 MW in April 2011. The H-Class reached an efficiency level that was over 1.5 percent above that of the previous F-Class. The greater size of the H-Class also enables further cost savings thanks to economies of scale.
More Power from Natural Gas. The latest series of Siemens gas turbines – the H-Class – is now operating around 3,000 kilometers away, in South Korea. Siemens has already sold eight of these gas turbines in South Korea since they were launched on the market in 2011. This success is due to the fact that South Korea has very low energy reserves itself and is therefore forced to rely on expensive imported fuels such as liquid natural gas (LNG). That’s just one more reason why the power plants need to be so efficient. For example, an increase in electrical efficiency of just one percentage point in an 800 MW facility results in an additional output of 60 million kilowatt-hours per year. That’s enough to supply electricity to some 30,000 more people at the same fuel cost and the same CO2 emission level. The fuel issue is particularly important, since fuel costs account for 75 percent of a power plant operator’s total costs.
“Efficiency is a crucial concern when one is transforming energy, because natural gas prices are so high here,” says Kwang-Jae Yoo, CEO of Posco Engineering & Construction. Posco is responsible for the construction of the Ansan power plant, which is located in the city of the same name southwest of the South Korean capital, Seoul. “Siemens currently has the most efficient power plant technology, which is tried and tested and has been operating for one and a half years now. Siemens is also an experienced and reliable project partner,” Yoo adds.
Siemens is building the plant’s centerpiece – the power island – as a turnkey facility that will include two H-Class gas turbines, a steam turbine, and generators. Ansan will be a combined cycle plant that uses liquefied petroleum gas (LPG) as fuel. When it goes on line in 2014, it will have a rated gross electrical output capacity of 834 megawatts (MW) and will also provide district heating for the residents of the city of Ansan. This technology ensures optimal exploitation of natural gas and will raise the plant’s fuel efficiency rating to more than 75 percent. The facility’s gas consumption and carbon dioxide emissions will also be one third lower than the average values for existing gas power plants around the world.
Siemens built its first-ever combined cycle plant in Bang Pakong, Thailand, in the early 1980s. The plant had an efficiency rating of around 48 percent. In just three decades Siemens has increased the efficiency of its combined cycle plants by over 12 percentage points. That corresponds to a more than a 25 percent increase in fuel conversion.
A further record will be achieved in Germany in 2015. Here, the utility Stadtwerke Düsseldorf recently awarded Siemens a contract for the Lausward power plant, which will feature 595 MW on a single shaft, a net efficiency of over 61 percent, and up to 85 percent fuel conversion. Research in the field continues, as Siemens plans to achieve a combined cycle efficiency rating of over 62 percent by 2020.