Old coal power plants – India scenario and overview of Decommissioning process

Old Thermal plants scenario in Indian context and Overview of the Decommissioning Process for Old Thermal Power Plants

Coal plants worldwide are grappling with low-capacity utilization levels and environmental issues; and have not only become unprofitable to utilities, but also uneconomical to customers.
Reducing dependence on coal-fired power generation is also essential to keeping the global temperature increase to 1.5°C between 2030 and 2052 if it continues to increase at the current rate. However, while a reduction of 80% in coal energy is needed to meet this goal, global energy-related CO2 emissions from energy combustion and industrial processes rebounded in 2021 to reach their highest ever annual level. A 6% increase from 2020 pushed emissions to 36.3 gigatonnes (Gt), an estimate based on the IEA’s detailed region-by-region and fuel-by-fuel analysis, drawing on the latest official national data and publicly available energy, economic and weather data.
According to IEA, CO2 emitted from coal combustion was responsible for over 0.3°C of the 1°C increase in global average annual surface temperatures above pre-industrial levels, making coal the single largest source of global temperature increase.
While the rationale for a coal phase out is compelling, the process is slow given
a) large existing stock of coal plants and associated mines (“coal assets”) to be retired;
b) partial replacement with new coal assets often within the same region or on existing sites; and
c) limited economic alternatives to redeploy existing coal and power plant workforce.
The Accelerating Coal Transition (ACT) investment program offers, to both public and private sector entities, a one-of-its-kind, holistic toolkit to tackle three critical challenges associated with a transition away from coal: governance, people and infrastructure.
Renewable energy has been eroding the commercial viability of coal, especially in older, inefficient operations with share of uncompetitive coal plants estimated to rise to over two thirds globally by 2025. The transition to clean energy represents an enormous economic opportunity for developing countries. The advent of low-cost solar wind and (increasingly) battery and other energy storage technologies has offered an opportunity for countries to re-evaluate new coal assets being built, re-purpose existing assets which still have considerable life left, or to decommission existing assets which are near retirement. This is not only expected to save customers money but also offer climate, create jobs, public health and environmental benefits.
India is the world’s second largest coal consumer after China, and the third largest emitter of greenhouse gases. Coal-fired plants currently account for over half (around 237GW) its nearly 417 GW power generating capacity (Source: CEA). India has pledged a 33-35% reduction in the “emissions intensity” of its economy by 2030, compared to 2005 levels.
India has achieved its target of achieving 40% of its installed electricity capacity from non-fossil energy sources by 2030 in November 2021 and further the current share of installed electricity capacity from non-fossil energy sources stands as 42.53 % as per CEA. At the COP26 India is committed to achieving 500 GW of installed electricity capacity from non-fossil fuel sources by the year 2030.
CEA has earmarked around 55 GW capacity of old coal based power plants for retirement in next 3 to 5 years of timeframe considering the Indian power sector planning. It is one of the important aspects that old thermal power plants must get due attention during the course of complete decommissioning process – planning, preparation, site characterization, project management, remediation and reclamation, execution and project closure.
The expected process for decommissioning a fossil-fueled power generating plant is summarized below.
The reason for outlining a specific process is to guide the decommissioning through successive steps of evaluation and decision-making that will ultimately lead to a decommissioned site which
1. Minimizes risk to human health and safety;
2. Minimizes environmental impacts;
3. Complies with all applicable laws and regulations, that is, is consistent with all applicable codes, guidelines and recommended practices, and complies with federal, state and municipal land use requirements
4. Is suitable for post-decommissioning land use objectives, whether this means unrestricted land use or a specific proposed land use
5. Does not represent an unacceptable liability to present and future owners
6. Is aesthetically acceptable

Further, following a specific, proven process allows the Owner / Developer with the added benefits of:
• Cost containment due to a defined scope of work and elimination of variables
• Management of liabilities related waste handling, as the process described herein places boundaries and requirements on how contractors can manage waste streams generated from the decommissioning process.
• Ability for the owner / operator to focus on other important issues not directly related to the decommissioning project, as this process allows other Team members to manage the day to day work elements.
The decommissioning process proceeds through five separate steps, each with specific tasks, team roles, deliverables and completion milestones. The steps are briefly introduced here and described.

In this step procedure, the focus is on decommissioning the infrastructure that is directly involved in the generation of electric power, including main generating structures, support buildings, fuel and process chemical handling and storage facilities, power house and cooling structures (e.g. cooling tower / pond) and waste handling facilities that directly support the generation of power, including wastewater collection and treatment pond and ash storage facility. This document does not discuss the decommissioning of fuel supply (e.g. mines in “mine-mouth” facilities) or fuel transportation facilities (e.g., gas or oil pipelines, belt conveyers for coal), nor does it discuss decommissioning of electricity transmission facilities (e.g. high-voltage power lines). These types of facilities typically have their own operating approvals and therefore require a separate decommissioning process.

Steps in the Decommissioning Process

Step 1 – Project Framing
This step is certainly the most important stage in the decommissioning process. It is in this stage that owner / operator, regulatory authorities and stakeholder expectations are first identified, project management, communication and consultation and technical teams are formed, a process for making site management decisions is developed, project management systems are developed and put in place.
Also preliminary project schedule and funding arrangements are developed in parallel and preliminary post decommissioning land use objectives are defined.
It is our experience that the more effort that is put into Step 1 of the process, the more likely it is that the project will be completed successfully – that is, when the project is finished, the objectives defined during the project are met.

Step 2 – Site Characterization.
This step involves a series of focused site investigations, the findings for which provide an understanding of the potential subsurface environmental issues at the site, a description of hydrological and hydrogeological conditions on the property, an understanding of potential waste streams generated during the abatement and demolition work, and identification of constraints to meeting the preliminary post-decommissioning land use objectives for the site. Various agencies have developed guidance for tiered environmental site investigations; for the purposes of this document, we have elected to use the following nomenclature:

• Phase I Environmental Site Assessment – a non-intrusive study of the historical uses of the property to identify potential environmental concerns.
• Phase II Environmental Site Assessment – typically includes an intrusive sampling and analysis program designed to determine if residual impact is present in the surface or subsurface, and the corresponding magnitudes.
• Phase III Environmental Site Assessment – involves additional sampling and analysis of subsurface media to further identify the magnitude and extent of impact so that strategies for future remedial action options can be developed.

Step 3 – Remediation and Reclamation Planning.
This step includes the development of remediation and reclamation solutions that address the environmental issues, site conditions and constraints identified during Step 2. These solutions must be developed in a manner that is consistent with the post-decommissioning land use objectives for the site. Step 3 consists of two sub-steps:
• The development of a Conceptual Remediation and Reclamation Plan
• The completion of a “pre-demolition” survey to identify environmentally-regulated materials and to confirm underground structures and utilities and
• The development of Detailed Remediation and Reclamation Plans and Contract Documents

Step 4 – Implementation
This step includes the site workings according to plans developed in Stage 3. In this stage, environmental abatement, demolition, and site remediation occurs; the site is reclaimed according to the post-decommissioning land use objectives; and any long-term risk management measures are installed.

Stage 5 – Project Closure
This stage includes those tasks necessary to confirm that the remediation and reclamation of the site has been successfully completed, the site meets the post-decommissioning land use objectives defined in earlier stages of the project, and that owner / operator, community stakeholders and regulatory review agencies have all confirmed their approvals for the project. Closure also prepares the site for ownership transfer, and/or redevelopment consistent with the post-decommissioning land use objectives. Long-term risk management controls (e.g., notification for deed to property, environmental monitoring programs and approvals, institutional access controls) are also put into place during this stage.

Timeline:

The total timeline for this complete activity will take around 14 to 16 months’ time for step-4 Remediation & Reclamation Implementation. This is approximate timing for typical 210 MW unit provided parallel teams are deployed for four units decommissioning activity. Stepwise timeline required for each step is provided in table below: