In July, an enormous slab of rock broke off from the Eiger massif in the Swiss Alps and thundered into the valley below. Geologists attribute this dramatic show of nature to the retreating Grindelwald Glacier.

Researchers in Zurich also fear that the alpine glaciers will shrink to one fifth of their original size by the end of the century, or even disappear entirely, just like the glaciers in the Rocky Mountains, the Andes and the Himalayas.

If this happens, there will be nothing left of the "snows of Kilimanjaro" except the Ernest Hemingway novel of the same name.

This far-reaching change is caused by continuous heating of the earth.

The average global temperature has risen by more than half a degree Celsius over the last 150 years, and experts anticipate another substantial rise in the coming 100 years.

Extreme weather events such as cyclones, heavy rainfall and flooding will increase. However, prolonged periods of drought and desertification are also likely.

Most experts now believe that the greenhouse effect accounts for the lion's share of this temperature increase. Along with the greenhouse gases of methane, nitrous oxide and water vapour, carbon dioxide (CO2) is a major factor preventing heat from radiating into space.

Large amounts of carbon dioxide are produced by burning fossil fuels such as coal, natural gas and petroleum.

Although these reserves are clearly limited, and countries low in natural resources are trying to reduce their dependence on oil and gas, fossil fuels will remain the primary sources for the rapidly growing demand for energy in the foreseeable future, accounting for around 70 per cent of power production.

Economical bituminous coal is even enjoying a renaissance. "While oil is becoming scarce and more expensive, there is still plenty of coal throughout the world," says energy expert Harald Bradke of the Fraunhofer Institute for Systems and Innovation Research in explaining the trends.

While the global climate is becoming warmer, power demand will experience the greatest percentage increases between 2000 and 2020 in the Middle East, the Asia-Pacific region, and Latin America.

Today hardly any subject is publicly discussed as much as clean power in China. Megatrends, such as urbanization and industrialization, have brought a significant power demand increase in China.

To meet the rising power demand in China and to supply continuous energy in a friendly enough way with the climate and environment has risen as a big challenge.

How to meet these challenges? The answer lies in improvement of energy efficiency.

China's energy goal includes increasing overall energy efficiency by 20 per cent by 2010, encouraging innovations for saving energy and resources and aggressively enforcing pollution laws.

As in other places in the world, in China coal will continue to be the country's backbone.

China is the world's greatest coal producer and consumer. The country has huge reserves to satisfy its domestic demands. Right now coal fuels around 70 per cent of China's power generation, 75 per cent of the energy used in industry, and 80 per cent of the household energy.

The use of natural gas, liquefied natural gas (LNG), nuclear power, hydro power and renewable energy, in particular wind, will obviously grow. But coal will remain the major component of China's energy mix.

Among the fossil power sources, coal offers two fundamental advantages: it is inexpensive and available worldwide.

In comparison with natural gas, coal offers greater price stability. And because of these advantages, coal-fired power plants will continue to play an important role in the future.

Under this situation, the efficiency of power plants already in operation or still under construction must be increased and the rate of emissions reduced.

Expertise

The completion of the 2X900 megawatt (MW) Waigaoqiao Phase II coal fired plant in Shanghai marks a further key step in China's adoption of highly efficient clean coal technology.

The Waigaoqiao supercritical plant is one of the most advanced power plants in operation in China and far more efficient than a typical coal-fired power plant in China.

It has a net efficiency of a little over 42 per cent, which compares with a worldwide average of 31 per cent and a German average of 37 per cent for hard coal-fired units.

In comparison to the average power plant of the same size in the Chinese fleet, it saves 1 million metric tons of coal a year, slashes fuel costs by 32 million euros (US$40.6 million) a year, and cuts CO2 emissions by around 2.1 million metric tons a year.

Germany's Power Generation Group of Siemens AG supplied the turbine island and other components for both units. A key role was also played by local equipment manufactures, notably Shanghai Electric Group (SEG).

Its three subsidiaries, Shanghai Turbine Co (STC), Shanghai Turbine Generator Co (STGC) and Shanghai Power Equipment Co (SPEC) provided components for both units. SEG and Siemens will also provide the most advanced ultra-supercritical steam turbines and generators for Waigaoqiao Phase III 2X1000 MW project.

SEG-Siemens co-operation continues to contribute to the development of Chinese high-efficiency clean coal power plants.

The Yuhuan 4X1000 MW ultra-supercritical power plant is another Chinese milestone project and will be able to claim new world records in terms of unit output, steam conditions and efficiency.

SEG secured the main contract to supply four 1,000 MW ultra-supercritical steam turbines and the matching generators.

The main equipment, including components, is based on Siemens' proven technology for supercritical plants and Siemens will support this project by providing certain components.

The first unit of Yuhuan project is expected to start up by the end of 2006.

It is seen as a major step forward for clean coal technology in China and it helps to address two issues facing the country: the need to increase power generation capacity in the East China grid and alleviate the severe capacity shortage in that region; and the need to reduce pollution.

Besides development and improvement of conventional coal-fired power plants, innovative ideas are needed. Completely new kinds of coal-fired power plants are being designed which convert coal into gas before being used for power generation, thereby lowering harmful emissions.

Efficient high-performance power plants like these are the wave of the future.

IGCC (integrated gasification combined cycle) is a promising technology in this area. In this process, the coal is first gasified. The resulting synthesis gas is purified and burned in a combined cycle power plant with adapted gas turbines.

The amount of emissions released is significantly lower than traditional steam power plants. In addition, in a next development step, the CO2 can be separated from the synthesis gas, and the hydrogen-rich gas left over can be used in the gas turbine for combustion.

The coal gasification process and the storage of the CO2 can reduce the emissions to a near zero level but increases the investment costs and decreases efficiency.

By optimizing the entire system, the goal is to improve the efficiencies and costs of both gasification and the power plant in the medium to long term.

Two conditions are necessary for building IGCC power plants: first, the manufacturer needs combined cycle power plant technology with adapted gas turbines.

Siemens has acquired extensive expertise in this field over many years.

And second, it is necessary to fuel such power plants with the gasification technology for various types of coal, biomass and chemical waste. As one of the leading players in this field Siemens has recently taken over the coal gasification business of the Swiss Sustec Group.

With this technology, combined with Siemens' expertise, and together with selected partners, Siemens is in a position to offer turnkey IGCC plants and thus make an important contribution to power generation that is compatible with the environment.

Energy is the driving force behind any society. It is not enough to just have a sufficient amount of energy available.

More importantly, the energy must be best used with full consideration of the environment. Improvement of energy efficiency will continue to be a never-ending topic around the world.

With the joint efforts and strengths of Germany and China, the goal of providing clean energy for China can be achieved.

Siemens Ltd China provides the story

(China Daily 09/13/2006 page23)