We have reported on the effort being done to develop the A-USC technology in Japan, which features the 700 deg-C steam condition, since the 2007 EPRI conference. Our 9 year project began in 2008. There have been some major changes in the electricity power market in the world recently. At first, the earthquake changed the power system violently in Japan. Almost all nuclear power plants have been shut down and natural gas, oil and coal power plants are working fully to satisfy the market's demands. In the USA, the so called ‘Shale gas revolution’ is going on. In Europe, they are working toward the target of reducing CO 2 emissions by the significant use of renewables with the backup of the fossil fuel power systems and enhancing power grids. A very rapid increase in power generation by coal is being observed in some countries. Despite some major changes in the electric sector in the world and the CO 2 problem, the global need for coal power generation is still high. We can reconfirm that the improvement of the thermal efficiency of coal power plants should be the most fundamental and important measure for the issues we are confronting today, and that continuous effort should be put towards it. Based on the study we showed at the 2007 conference, we developed 700 deg-C class technology mainly focusing on the material and manufacturing technology development and verification tests for key components such as boilers, turbines and valves. Fundamental technology developments have been done during the first half of the project term. Long term material tests such as creep rupture of base materials and welds will be conducted for 100,000hrs continuing after the end of the project with the joint effort of each participating company. Today, we are preparing the plan for the second half of the project, which is made up of boiler components test and the turbine rotating tests. Some boiler superheater panels, large diameter pipes and valves will be tested in a commercially operating boiler from 2015 to 2017. The turbine rotor materials which have the same diameter as commercial rotors will be tested at 700 deg-C and at actual speed.

The “Cool Earth-Innovative Energy Technology Program,” launched by the Japanese government in March 2008, aims to significantly reduce global greenhouse gas emissions. Among the 21 selected technologies is the Advanced Ultra Super Critical (A-USC) pressure power generation, which targets the commercialization of a 700°C class pulverized coal power system with a power generation efficiency of 46% by around 2015. As of 2004, Japan's pulverized coal power plant capacity reached 35 GW, with the latest plants achieving a steam temperature of 600°C and a net thermal efficiency of approximately 42% (HHV). Older plants from the 1970s and early 1980s, with steam temperatures of 538°C or 566°C, are nearing the need for refurbishment or rebuilding. A case study on retrofitting these older plants with A-USC technology, which uses a 700°C class steam temperature, demonstrated that this technology is suitable for such upgrades and can reduce CO 2 emissions by about 15%. Following this study, a large-scale development of A-USC technology began in August 2008, focusing on developing 700°C class boiler, turbine, and valve technologies, including high-temperature material technology. Candidate materials for boilers and turbine rotor and casing materials are being developed and tested. Two years into the project, useful test results regarding these candidate materials have been obtained, contributing to the advancement of A-USC technology.