The recent G20 declaration gives much guidance on agreed positions on clean energy transition. For example, the nations could have “net zero pathways of their own choice” depending on their “national circumstances” while “ensuring uninterrupted power supply” are some of the guarded positions negotiated. For India, the coal sector is the largest one to undergo a massive transition over the next two decades. India is in its growth phase, with per capita electricity consumption of 1,200 units, when the world average is 4,000. Considering the expected economic growth over the coming decades, more than three times additional electricity may be needed around 2050; of course, with the maximum growth of non-fossil sources and efforts for energy efficiency. Therefore, some growth of new coal plants is unavoidable.
India has nearly 600 coal power generation units of varying vintage, size and location that are operating currently. India is also building new units for reliable delivery of power supply. They use more than 800 million tonnes of coal and generate nearly 212 GW, providing 70% of the power generated in the country. While China increased coal capacity from 580 GW in 2009 to 1,100 GW in 2019, India might barely go from 212 GW to 280 GW in the next 10 years, due to timely decarbonisation efforts and commitment to a net zero pathway. Given the magnitude of the problem and the concern of ensuring reliable power supply that is critical for a growing economy, how do we navigate the gradual closing down the plants while ensuring reliability and also growth? How do we gradually transit to the renewable energy (RE) future, given RE cannot deliver continuously and uniformly, even as we move to shut down coal-based generating units? We examine some criteria here.
Age of plants
Closing down old plants, say, above 25 years or 30 years, has become an oft-repeated suggestion. But this is a simplistic solution, often suggested by activists. At present, 52% of the plants in operation have been built in the last 15 years. They usually have a lifetime of 40 years at least. But they often recover capital deployed only in 20-25 years. Thereafter, they give power at competitive prices, challenging even renewables. Moreover, some coal plants would be needed to provide flexible power, when RE is not available—at least for some time. Therefore, they are valuable and may provide an alternative to expensive storage solutions, if flexibility is assured.
The quantum of kwh/kw delivered by a plant can decide its productivity and also its economic competitiveness. However, this often depends on other factors such as proximity to high demand centres and not necessarily technical efficiency alone.
CO2 coefficients of the power plants
Typically, they range from 0.7-1.2 kg/kwh. However, the high values are for older plants, which are fewer and may be used for flexible power on a temporary basis.
During 2016- 2019 period, the Central Electricity Authority issued closure instructions for plants totalling a production capacity of nearly 9,000 MW, mostly coal-based, on the basis of the lack/concern over availability of land, water and coal. The land-use issues for highly urbanised locations are important, mainly due to the resulting air pollution and forgone value of expensive land. Water near some areas also is increasingly getting scarce.
Distance from coal mines
Retiring those plants that are quite far from the mines earlier may avoid transport costs as well as CO2 emissions.
Thus, the conventional thinking of closing because of age, technical efficiency and CO2 coefficients has limited validity.
As mentioned, the coal sector also has to grow, though guardedly. The new coal plants can be located near the coal mines (or the coast, if the coal is imported), to reduce additional costs and CO2 emissions from its transport. The new plants can mainly come up near coal mines (except a few), as not all locations can satisfy their demand with RE in the immediate future.
In conclusion, India would need a roadmap for growth and decarbonisation that considers granularity at the plant level. Although micromanagement using any single criterion should be avoided, a broad set of criteria could be made clear. Location-wise exercises may be needed, but these should, again, be at the regional level without rigid rules, not at the state level. The criteria for closure should focus on requiring less new plants and maintaining reliable supply rather than aiming for minor CO2 gains. Adding more transmission links would be a very effective way to manage the demand due to scattered RE sources. Even connecting with hydro power from Nepal, Bhutan, and Arunachal Pradesh may be perhaps the first level of defence to avoid new coal-based capacity. A new Irade study shows that it could save several hundred million tonnes of CO2, depending on various scenarios.
Source: The Financial Express