Energy, Environment, EIA and Climate Change for Engineers — ESE

Weightage: The ESE syllabus lists "basics of energy and environment, including conservation, environmental pollution and degradation, climate change and Environmental Impact Assessment" as a Paper I topic. It is conceptual, with definitions, laws and a few unit calculations. It also feeds the Civil, Mechanical and Electrical technical papers.

1. Energy basics engineers must own

Energy is classed as primary (coal, oil, gas, hydro, sun, wind) or secondary (electricity, petrol). It is also conventional (fossil, large hydro, nuclear) or non-conventional (solar, wind, biomass, small hydro, tidal, geothermal).

Keep three unit conversions ready:

• $1\text{kWh}=3.6\text{MJ}$.
• $1\text{MW}\times 1\text{year}$ at full load $\approx 8760\text{MWh}$.
• $1\text{tonne of oil equivalent}\approx 41.87\text{GJ}$.

Capacity is the maximum output, in MW. Generation is the energy produced, in MWh. Plant load factor is the ratio of actual to maximum possible generation:

$\text{PLF}=\frac{\text{actual energy generated}}{\text{capacity}\times \text{hours}}$

Worked example. A 500 MW plant generates 2.19 million MWh in a year. Its PLF is $2.19\times 10^6/(500\times 8760)=0.5$, so it ran at 50 percent of full capacity.

2. Energy sources and their limits

Because solar and wind output varies, the challenge of a high-renewable grid is flexibility: storage, demand response, interconnection and fast-ramping generation. Pumped-storage hydro and batteries are the two storage routes most discussed.

Capacity numbers change every year, so use the latest Ministry data before you quote one.

3. Energy conservation

Saving a unit is cheaper than generating one. In India the Energy Conservation Act, 2001 created the Bureau of Energy Efficiency (BEE), which runs the star-labelling scheme for appliances and the Perform, Achieve and Trade (PAT) scheme for large industries. The Act was amended in 2022 to allow a carbon credit trading scheme and to extend energy-conservation rules to buildings and vehicles.

Typical engineering measures: power-factor correction, variable-speed drives, waste-heat recovery, cogeneration, LED lighting and insulation.

4. Pollution and its control

BOD (biochemical oxygen demand) measures the oxygen consumed by microbes breaking down organic matter, and is the standard test of organic pollution. COD is higher, since it includes chemically oxidisable matter that microbes cannot digest.

India's National Clean Air Programme (2019) sets city targets for cutting PM10 and PM2.5, and the Air Quality Index reports air quality in six bands from "good" to "severe". Check the latest version of the targets before quoting them.

5. Indian environmental law

• Water (Prevention and Control of Pollution) Act, 1974.
• Air (Prevention and Control of Pollution) Act, 1981.
• Environment (Protection) Act, 1986, the umbrella law passed after the Bhopal gas disaster.
• Forest (Conservation) Act, 1980 and the Wildlife (Protection) Act, 1972.
• National Green Tribunal Act, 2010, which created a specialised environmental court.

The polluter pays principle and the precautionary principle have been read into Article 21 by the Supreme Court.

6. Environmental Impact Assessment

EIA is a planning tool that predicts the environmental effects of a project before approval. In India it works through the EIA Notification, 2006, issued under the Environment (Protection) Act.

The stages are:

1. Screening: decide whether the project needs an assessment, and whether it is Category A (central appraisal) or Category B (state level).
2. Scoping: fix the terms of reference.
3. Baseline study and impact prediction.
4. Public consultation: a public hearing near the site.
5. Appraisal by an expert committee.
6. Environmental clearance with conditions, and follow-up monitoring.

The output is an Environmental Management Plan that lists mitigation, monitoring and cost. Remember that EIA predicts and mitigates; it does not by itself stop a project.

7. Climate change

Greenhouse gases trap outgoing heat. The chief ones are carbon dioxide, methane, nitrous oxide and fluorinated gases. Their strength is compared by global warming potential (GWP) over 100 years, with CO2 as 1. Methane is much higher than CO2 per tonne but breaks down faster, and nitrous oxide is far higher still.

Key international steps:

• UNFCCC (1992), the framework treaty.
• Kyoto Protocol (1997), binding targets on developed countries.
• Paris Agreement (2015), which aims to hold warming well below 2 degrees C and pursue 1.5 degrees C, through nationally determined contributions reviewed every five years.

India's stated goals include net-zero emissions by 2070, a target of 500 GW of non-fossil capacity by 2030, and a cut in emissions intensity of GDP. Targets have been updated across submissions, so check the most recent national statement.

8. Adaptation and mitigation

Mitigation reduces emissions: renewables, efficiency, electrified transport, carbon capture. Adaptation prepares for effects: flood defences, heat-resistant design, climate-resilient crops. An engineer designs for both, for example a building that uses less energy and is also built to cope with hotter summers.

Common traps

• Mixing capacity and generation. One is MW, the other MWh.
• Treating COD and BOD as equal. COD is higher.
• Assuming EIA is a veto. It informs the decision.
• Quoting capacity or target numbers as fixed. They change; use the latest source.
• Calling methane a long-lived gas. It is strong but short-lived compared with CO2.

Memory aids

• "Water 74, Air 81, Environment 86": the three pollution laws.
• "Screening, scoping, baseline, hearing, appraisal, clearance": EIA order.
• "PLF is actual over possible": the load factor.

Summary

Energy questions test units, capacity versus generation and the trade-offs between sources. Environment questions test pollutants, controls and the main Acts.

EIA follows a fixed sequence under the 2006 notification, and climate change links the UNFCCC, Kyoto and Paris to India's net-zero and non-fossil targets, whose numbers must be checked for updates.

Exam protocol

• Convert units before comparing options.
• Name the Act and its year when a question asks for law.
• Treat all capacity and target figures as time-sensitive.
• Eliminate the extreme options when unsure of a number.