Siemens sees growing demand for coal-fired power plants

By virtue of the low-cost availability of coal, Siemens/KWU anticipates increasing growth in the demand for coal-fired steam power plants in the world marketplace, particularly in Asia. In many countries, enhanced efficiency and reduced plant costs are driving the life-cycle costs of coal-fired plants back down to a competitive level with natural gas-fired combined-cycle plants.

Siemens has already booked first market successes with a new coal-fired power plant concept tailored to the needs of the Asian market. Since the late 1980s, the company has almost tripled its business with fossil-fueled power plants. Because Germany is among the classic coal countries, Siemens is one of the leading companies in steam power plant technology.

The new concept considers the requirements of traditional utility customers plus the technology and criteria specified by independent producers and developers in regard to life-cycle costs. The objective is to minimize not only the cost of the investment, but also the cost over the entire service life of the plant.

The build-own-operate and build-own-transfer market in Asia is increasingly calling for financial participation from plant construction companies.

“In many markets the available investment capital and the prices which can be achieved for electrical energy are the factors limiting the further expansion of power supply. This generally results in the need to develop new financing models and to minimize power generating costs,” said Professor Klaus Riedle, executive director. “To date, we have commitments in the Asia-Pacific region for participation in IPP projects with a total investment of (US)$3.8 billion, with our equity share in each case lying between 10 percent and 50 percent.”

Siemens has booked several orders for the new 3A-series gas turbines. The 900-MW Tapada do Outeiro power plant in Portugal will have three of the Model V94.3A machines and is scheduled to be turned over to the operating company in 1988 or 1999. In Altbach-Deizisau, Germany, a Model V64.3A gas turbine with a rating exceeding 65 MW is to be installed as part of the construction of the world`s first parallel-powered combined-cycle block with a total capacity of 41 MW.

British utility National Power plc has ordered two of the machines for the Didcot B combined-cycle power station. Siemens secured the turnkey order for this plant in 1994. The facility will have two 675-MW blocks, scheduled to go on-line in the fall of 1996 and 1997 respectively. Siemens also has an order for the 60-Hz Model V84.3A machine in the United States. The first machine of this type with a rating near 165 MW will be supplied to Kansas City Power & Light for a plant scheduled to enter service in 1996.

Modern coal-fired plants can attain an efficiency of more than 45 percent, despite the high energy consumption necessary to meet pollution control requirements.

“In the development of the Benson boiler, we have combined the positive design features of the drum boiler with the operation advantages of the classic Benson boiler with wound furnace tubing,” Riedle said.

Another innovation at Siemens is the E-series turbine, which has a common casing for the intermediate- and low-pressure turbine. The blading shape was determined using sophisticated three-dimensional flow simulation computer programs, increasing efficiency and steam-flow profile.