National Mission on Advanced Ultra-Supercritical (AUSC) Technology

The concept of supercritical technology was first introduced in India by the planning commission in its Integrated Energy Policy Report 2006. Consequently, country adopted the supercritical and then ultra-supercritical technology to improve the efficiency of coal power plants. And recently, the Ministry of Science & Technology announced a National Mission on advanced ultra supercritical technologies for cleaner coal utilisation.

What is Advanced Ultra-Supercritical (AUSC) Technology?

The pulverised coal power plants are divided into four categories based on operating temperature, pressure and efficiency of steam cycle. First is subcritical pulverised coal power plant that operates with critical temperature and critical pressure of water below 540 degree and 170-220 bars and has operating efficiency below 38%. Second is supercritical pulverised coal plant that operates with critical temperature and critical pressure above 615 degree and 250 bars and reaches efficiency upto 42%. Third is ultra-supercritical pulverised coal plant that operates with critical temperature and critical pressure of water above 620 degree and 330 bars and reaches efficiency in the range of 42% to 46 %. Fourth is advanced ultra-supercritical pulverised coal technology that operates with critical temperature and critical pressure of water in range of 700-760 degrees and 350 bars and targets operating efficiency greater than 50%.

Salient Features of National Mission on Advanced Ultra-Supercritical (AUSC) Technology

• The mission aims to spend nearly $ 238 million on cleaner coal utilisation technology
• It proposes setting up of two Centres of Excellence on clean coal technologies.
• Government has approved a budget of Rs 1554 crore for the research and development of AUSC technology for thermal power plants
• The design of the 800 MW advanced ultra supercritical (AUSC) boiler for coal power plant is expected to be ready by 2019-2020.
• It aims to construct Smart Grids & and improve Energy Storage facility in the country
• Government has also announced two Mission Innovation-centric funding opportunities in smart grid and off grid access.
• Under the Indo–US Joint Clean Energy Research Programme, a new collaborative public–private programme on Smart Grids & Energy Storage has been approved.

Rationale behind the Mission

Currently, the estimated carbon dioxide pollution from coal based power plants in the country is 38%. The AUSC project is estimated to reduce this carbon dioxide emission by 20% at source. Also, the power plant based on AUSC technology will reduce coal consumption by 20% in comparison to a sub-critical plant and by 11 percent compared to super critical plant. Furthermore, the AUSC operating efficiency is expected to be above 50% which is much higher than sub-critical and super critical technology. Hence, the project would lead to capital cost savings.

Discussion

Currently, nearly 60% of the country’s energy requirement is met through coal. Though central electricity authority has projected to reduce the dependence on coal based power plants and has designed framework to adopt new renewable sources, yet the available renewable resources are not viable enough to meet the increasing domestic demand, and therefore, coal based power plants will continue to be a feature of Indian Power Sector at least for 50-60 more years. Furthermore, the advanced ultra supercritical technology is a pioneering indigenous technology and has potential enough to solve the bottlenecks of coal based power plants. The AUSC project will enable Indian industries to design, manufacture and commission higher-efficiency and low polluting coal-fired power plants. This in turn will also lead to establishment of new industries and generate employment opportunities in the country.