By Prof. Srinivasan Periaswamy is a Professor of Mechanical Engineering at BITS Pilani, Rajasthan
Impact of global warming on the earth has been realized for quite some time now; accordingly, various stake holders are already talking about the sustainable development goals (SDGs) and their implementation using clean and green technologies. Clean technology refers to the use of conventional energy resources to address the energy demands, without causing environmental damage. And green technology refers to the use of environmentally friendly renewable energy sources.
While such technologies are already mature to a certain extent, there are still many challenges in implementing them. To gain better understanding, it is worthwhile to analyse such challenges and possible solutions by taking Indian Power Sector as an example.
The Indian power scenario
Back in 1950, India only had the installed capacity of 1713MW power plants for population of 36 crores at that time. And then, India had a phenomenal growth of 24,000% to reach 412200MW for just 400% growth of population. Despite this huge addition, per capita electricity consumption in India is just about 1218 units, which is far below most of the developed countries in the world. It is one of the parameters to measure the economic wellbeing of the countries. It is also predicted that the total installed capacity requirements will be about 8,00,000MW by 2030. Hence, it is imperative to double the installed capacity within a span of 7 years to avoid blackouts and ensure quality power supply.
Challenges in implementing clean technologies in Indian power plant.
At present, 53% of electricity in India comes from coal or lignite based power plants resulting in emission of (Carbon dioxide) CO2, (Sulfur dioxide)SO2, (Nitrogen Oxide) NOx and Particulate Matter (PM). Hence, it cannot be considered as clean energy. While PM emission level is under control by installing the Electrostatic Precipitators (ESPs), controlling/abetting gaseous emission is always a challenge. CO2 is responsible for the green house effect and global warming; not much of attention is given worldwide as implementation of carbon capture and storage (CCS) technology in power plants leads to considerable decrease in efficiency of the power plant, resulting in increased cost of power generation from about Rs.3/unit to nearly Rs.10/kWh as per the predictions.
It will be unviable to increase the electricity tariff to compensate the increase in the cost as it will have a huge social impact due to affordability of the customers. As of now, It is almost impossible to implement CO2 free power generation from the coal based power plants, not only in India, but also worldwide. While the CO2 emission is more of a global problem, SO2 emission is a local problem in the vicinity of the power plant leading to problems in the respiratory system and irritation. Realizing the importance of health impact, government of India notified the emission for SO2 emissions in the year 2015 and given time to adhere to the norms by 2017.
However, most of the power plants could adhere to the norms due to many reasons including the cost of installation and operation. It is estimated that almost INR 60 Lakhs needs to be invested per MW of installed capacity for FGD units. In addition to that, implementing the technology also will lead to more auxiliary power consumption and decrease the total electricity available for meeting the demand. Hence, there is always a resistance from the power generation units to install. It is also not possible to shut the units without FGDs as there will be a huge demand and supply gap. Taking this into consideration, the deadline for installation of FGDs are extended till 2024,2025, and 2026, depending upon the severity of the problem and based on the location of the power plants. High cost of installation and operation, increased cost of electricity generation, decrease in the availability of power for consumption when there is increase in demand are the major reasons for the delay in implementing FGD technology towards abetment of SO2 emission, as a part of clean technology initiative.
While we do have the technology developed for the clean power generation popularly known as clean coal technology, at present the economic barrier is the major reason for being unable to implement these technologies in power plants. On the other hand, it is also a concern to implement such technologies in the power plant that is about to retire soon as the value for the invested money is another huge challenge.
Challenges in implementing green technologies
India is blessed with abundant availability of solar energy, crop residue, water and wind potential for power generation in select regions — all that is required for power generation. These are green energy resources. Intermittent availability of these resources, availability of locations much away from the load centers, and lower plant load factor of such power generation, are few of the key challenges in implementing these technologies.
However, solar PV based power plants considered to be green source is dominating among all the green sources of power with about 62000MW of installed capacity. One of the aspects, which is not given due attention as of now is the disposal of vast number of solar PV cells after their predicted life cycle of 25 years. Since these panels are made of lead, Arsenic, and other poisonous materials, disposing will be a challenge in future even though they are considered to be green energy source and cost of electricity is considered to be very less from these sources of energy. Even with the increased capacity, due to lower plant load factor, majority of the power (about 70%) is generated from conventional power plants as the renewable sources of energy are intermittent in nature and needs energy storage. Cost of solar thermal is very high as of now to the tune of RS.13/kWh and economically unviable.
So, what is the way forward?
In order to make clean and green power a reality, the following measures are essential:
a) Developing cost effective technology of emission abetment to make the implementation economically viable. b) Developing cost effective energy storage technologies to ensure continuous quality power from green energy resources. c) Development of proper energy policy to meet the increasing demand from green and clean power source toward sustainability.
Also, as an educator, I do believe that among key factors such as above, we should also aim to leverage synergies among the government, industry, public, and academia effectively. One of the most effective ways to accelerate clean and green power is by empowering environmental engineers and working professionals with knowledge, experience, and expertise in the key areas (such as environmental management systems), with special emphasis on proactive measures to minimize the pollution at the source and reactive measures to control the pollution with best available technologies.