June 1, 2010

Kawasaki Plant Claims Efficiency Record

By Angela Neville, JD

Tokyo Electric Power Co.’s new Kawasaki Thermal Power Plant claims the title of having the highest combined-cycle efficiency in the world: 59.1%. The new gas-fired facility is equipped with three 500-MW single-shaft combined-cycle blocks. Each block is based on the MHI M701G2 gas turbine, which is the largest gas turbine currently in commercial operation.

From lightning-fast bullet trains to sleek electronics, Japan is a country well known for its many technological accomplishments. Therefore, it’s not surprising that Tokyo Electric Power Co. (TEPCO), the largest utility in Japan, is at the forefront of attaining record thermal efficiency at its new Kawasaki Combined Cycle Thermal Power Station.

TEPCO’s Kawasaki Combined Cycle Thermal Power Station was designed to replace an existing 1,050-MW six-unit conventional power station that has supplied power to the Tokyo metropolitan area for more than 40 years, according to Carlos Koeneke, the vice-president of project engineering at Mitsubishi Power Systems. The first phase, which is called Kawasaki Thermal Power Plant Group 1, was completed in February 2009. The first two blocks were completed in 2007 and 2008; the third block was completed in 2009 (Figure 1).

1. Reduced footprint. The new combined-cycle plant that is shown on the left side of this aerial photo occupies only one-third of the facility’s 3,000,000 square feet. The existing six-unit conventional steam plant is shown on the right. Courtesy: Tokyo Electric Power Co.

Group 1 was constructed as a liquefied natural gas (LNG)–fired facility equipped with three 500-MW single-shaft combined-cycle plants, for a total of 1,500 MW. In addition to power generation, this new plant was configured to supply steam from the heat-recovery steam generators (HRSGs) to 10 neighboring industrial facilities. This higher efficiency steam supply allowed the elimination of lower efficiency old boilers, which were located in nearby facilities, resulting in significant energy savings and emissions reductions (Figure 2).

2. Exhausting work. A common exhaust stack is used for the plant’s three combined-cycle blocks. Courtesy: Tokyo Electric Power Co.

This new, more efficient and therefore more environmentally friendly first phase of the facility reduces the utility’s direct impact on the Kawasaki Bay ecosystem, Koeneke said. Using the gas turbines that generate two-thirds of the total power for Group 1 considerably cuts down on the usage of seawater for the steam cycle condensers. This, in turn, substantially reduces the discharge of warm water into the Kawasaki Bay and thereby lessens the plant’s impact on the nearby ecosystem.