Digitisation of power plant operations, overhaul of old plants and optimisation of the energy mix are some of the steps needed to ensure power sector growth. This is relevant owing to the large-scale penetration of renewable energy, the growing focus on lowering power plant emissions, and the need for flexible operations of coal-based plants. In a recent interview with Power Line, Ashok Ganesan, Senior Executive in Charge of Global Steam Plant Services, GE Power, shared his views on key technology solutions for improving plant efficiency and the future of coal-based power in the country. Excerpts…
What is the outlook for coal-based power plants in India? How can they remain relevant in India’s energy mix in light of significant competition from renewable energy?
Renewable energy is here to stay. However, the role of fossil fuels is still relevant; in fact, it has actually increased with the proliferation of renewable energy. Energy demand has been steadily increasing globally; however, renewable energy capacity additions are yet to keep pace with it. Moreover, owing to the intermittent nature of renewable energy, fossil fuels have become important for grid stability.
Currently, India has 50-60 GW of coal-based capacity under construction. Going forward, the share of coal-based power generation is not likely to decline. In the next 15-20 years, coal is expected to play an important role in the country’s energy mix with 50-60 per cent share, considering factors such as energy security, grid stability and gas shortage. However, coal-based power generation comes with a number of challenges. Although coal availability is not an issue, there are concerns about energy efficiency and the environmental implications of coal-based generation.
What are the key technology solutions for improving the efficiency of power plants? What are the outputs achievable through digitisation?
Hardware solutions for efficiency improvement are important in the Indian context as most of the plants have been operational for 20-30 years. Significant advancements have been achieved with regard to material and power plant design. It is actually easier to implement these technology solutions to a brand new turbine. In the case of an older plant, one cannot change the foundation, wiring, piping, etc. and new solutions need to be incorporated into the existing set-up. For instance, almost the entire steam turbine was changed at the Ukai power plant. We managed to improve the plant’s overall efficiency by 5.5 per cent and the efficiency of its steam turbine by about half a per cent. This would result in significant savings in coal consumption at the power plant, thus lowering the fuel cost and reducing the greenhouse gas emissions from the plant. Overall, this is expected to translate into savings of more than $7 million per year.
Digitisation of power plants will play a critical role in the emerging power scenario. It helps in reducing emissions and enhancing plant efficiency. In addition, digitisation helps in managing grid stability in light of the growing renewable energy capacity.
Currently, many power plants in the country are operated manually, based on the procedures written in rulebooks 20-30 years ago. Over the years, there have been many technological developments and by using a new sensor/existing sensor, plant data can be captured and processed to derive meaningful results. Besides, if the temperature and pressure of coal are constantly monitored, they help in managing emissions and improving efficiency.
Another key advantage of digitisation of power plants is with regard to managing the operations of the flue gas desulphuriser system or any other secondary emission control equipment. In addition, digital plants help monitor the emissions of a power plant on a real-time basis. This helps in saving reagent costs, while keeping a check on the pollution level.
Another benefit of digitisation is flexible operations of the plant. Typically, coal-based plants in India were designed to operate at a plant load factor (PLF) of 50-60 per cent; however, with the penetration of renewables into the grid, these plants are running at an average PLF of 50 per cent and are operating at fluctuating load. Under these circumstances, the benefits of a supercritical plant are actually lost. Digitisation helps in taking decisions regarding power evacuation from a renewable source versus a fossil source taking into account projections on generation from wind energy, solar energy, etc.
What has been the uptake of emission control systems so far by the thermal power industry following the environmental regulations? What are some of the promising technologies in this regard?
The uptake of emission control systems in the thermal power industry has been very slow. There is a lot of confusion among customers regarding the implementation of emission control systems. However, of late, there has been some activity in this space on the commercial and implementation fronts, which is likely to increase uptake in the future.
The new regulations have made the norms for particulate matter emissions more stringent. Technology is available to meet these norms and it works well for Indian coal. However, most of our customers believe that this is nothing more than a tax on power generation, which they cannot pass on to the consumers. Therefore, there is no incentive other than regulatory compliance for installing the system. In order to increase the uptake of emission control systems there has to be a carrot-and-stick approach, and the stick has to be very strong.
NOx emissions are controlled in boilers through efficient burning. These are further reduced through non-catalytic reduction (NCR). However, NCR involves significant capex. Therefore, using low NOx burners and undertaking burner modifications are affordable solutions for managing NOx emissions.
What are the biggest challenges faced by gas-based power plants and how can these be resolved?
The positive sentiment in the gas-based power industry during 2009-12 was based on the expectation of gas availability beyond what domestic sources could provide. Gas-based power generation plays a significant role in India’s energy mix. However, owing to the lack of gas availability and low coal prices, coal-based power generation is a preferred choice. Gas-based power generation, however, has many advantages and it is being used the world over. It is naturally cleaner and, therefore, requires lower investment in cleaning technologies. The savings can thus be used for efficiency improvement and cost-saving technologies. Besides, gas-based plants offer great flexibility in plant operations. These plants can start functioning within 20-25 minutes and can shut down quickly.
At present, the share of gas-based generation in the country’s energy mix is 3-4 per cent. It is expected to increase to 10 per cent within four to five years in order to balance the grid and mitigate environmental pollution. To this end, it is required that domestic gas is available at cheaper rates.
What is your outlook for the Indian power sector?
India is one of the largest power markets in the world with a population of 1.2 billion. Currently, the country’s per capita electricity consumption is one of the lowest in the world. In spite of this, a large portion of our population needs to be given access to electricity; how that happens is going to be an exciting journey. Apart from this, with the increase in per capita income, energy consumption and demand are expected to grow in the country. Further, there is a growing focus on improving efficiency in electricity consumption and using energy-saving appliances. Power demand will definitely pick up in the future, although it is difficult to say when.