Global energy mix by scenario to 2050

Global primary energy consumption by source

Annual change in primary energy consumption
Primary energy consumption, 2023
Energy use per person, 2023
Electricity generation, 2023
Electricity generation, 2023
Per capita Electricity generation, 2023
Indian Power Scenario
Indian Power Scenario
Indian Power Scenario
Indian Power Scenario
Indian Power Sector – At a glance
Indian Power Sector – At a glance
Indian Power Sector – At a glance
Environmental Aspects of
Electric Energy Generation
 Importance of Energy Conversion in Electricity Demand &
Generation
Growing Global Electricity Demand:
➢ Global electricity demand increased by 2.1% per year on average
from 2010 to 2020.
➢ By 2050, global electricity demand is expected to exceed 40,000 TWh
annually (up from 23,000 TWh in 2019) due to urbanization and
electrification of transport.
Diverse Sources of Electricity Generation:
➢ In 2020, Renewables accounted for 29% of global electricity
generation, with wind contributing 5.5% and solar 3.4%.
➢ Coal still produced 38% of global electricity, but the share is
declining as more countries transition to cleaner sources
Importance of Energy Conversion in Electricity Demand &
Generation
Efficient Energy Conversion Technologies:

Renewable Energy:
Solar (photovoltaics) and wind turbines convert natural resources
directly into electricity, avoiding the need for fuel combustion.
Natural Gas:
Combined cycle power plants convert natural gas into electricity at
efficiencies as high as 60%, significantly reducing waste compared to
older coal plants.
Energy Storage:
Technologies like lithium-ion batteries and pumped hydro storage can
store excess renewable energy and release it during peak demand.
Environmental Impact of Fossil Fuels in Electricity Generation:

Traditional fossil fuel-based power generation contributes significantly to air pollution and global warming.
➢ Coal-fired power plants emit around 820 grams of CO2 per kWh, whereas natural gas plants emit around 450 grams
of CO2 per kWh.
➢ In 2020, electricity generation from fossil fuels was responsible for approximately 40% of global carbon emissions.

Transition to Cleaner Energy:

➢ The conversion of energy from fossil fuels to renewables (solar, wind, hydropower) can dramatically reduce
environmental impacts.
Renewables are among the lowest-emission sources of electricity:
➢ wind and solar have CO2 emissions as low as 10-20 grams per kWh.
➢ The International Renewable Energy Agency (IRENA) reports that solar and wind power together avoided
approximately 1.7 billion metric tons of CO2 emissions in 2020.
Environmental Impact of Fossil Fuels in Electricity Generation:

Energy Conversion & Sustainable Development Goals (SDGs):

➢ Reducing carbon emissions and reliance on non-renewable resources is critical for achieving global sustainability
targets.
➢ The United Nations SDG 7 goal aims to ensure access to affordable, reliable, sustainable, and modern energy for
all.
➢ As of 2020, approximately 89% of the global population had access to electricity, but achieving universal access
requires expanding renewable energy generation.
Energy Efficiency & Environmental Benefits:
➢ Improved energy conversion efficiency reduces the need for additional energy generation, conserving resources
and minimizing environmental damage.
➢ Combined heat and power (CHP) plants can achieve up to 85% efficiency by using waste heat for industrial
processes, compared to 33% efficiency in traditional power plants.
Atmospheric Pollution

➢ Oxides of Sulphur SO2, Nitrogen oxides NO2, Cox, hydrocarbons, fly ash and suspended particulates.

➢ Indian coal carries 0.6% to 1% Sulphur and its ash content varies from 30% to 50 %.

Oxides of Sulphur (SO2)

➢ SO2 released during combustion process of coal.

➢ 20 mg/m3 can cause respiratory problems, 400 mg/m3 can be danger to life
➢ Oxidized to H2SO4 and creates acid rain.
➢ Sulphur emissions can be removed from coal by gasification and floatation process
➢ Removal of sulphur oxides from flue gas
➢ Installing limestones scrubbers to reduce sulphur emissions
 Atmospheric Pollution
Oxides of Nitrogen (NOx)
➢ Oxides of nitrogen : NO, NO2, N2O
➢ Nitrogen oxide, NO2 is a major pollutant.
➢ 150- 200 ppm NO2 concentration, when inhaled can cause severe respiratory
problems.
➢ Installing advanced technology burners - to ensure complete combustion.
➢ Providing tall stacks - lower pollution level in ambient air

Oxides of Carbon (CO, CO2)

➢ CO is toxic gas and affects human metabolism.
➢ Concentration of CO2 in air is reduced by natural process of
photosynthesis. Higher concentration of CO2 major cause for global
warming.

Hydrocarbons

➢ Oxidation process results in few hydrocarbons. It can damage the ozone layer.
 Atmospheric Pollution
Particulates fly ash

➢ Contains fine particles of carbon, ash and other inert materials of

size 1µm.
➢ Emitted from chimney in form of fly ash.
➢ Suspended in air with pollution level 300 µg/m3 can cause poor
visibility, lung inflammation and bronchitis.

Control of particulates

➢ Installing Electrostatic precipitators (ESPs) in the path of flue gas.

➢ ESP remove particles from flue gas, before it is released to atmosphere.
➢ The fly ash escaping ESP is smaller than 2 microns in size.
Thermal Pollution
➢ Steam from low-pressure turbine flows into a condenser and gets converter into water.
➢ Steam cycle efficiency is only 40 % which means unused remaining heat of 60% is released to atmosphere.
 Hydroelectric Projects
➢ Large hydroelectric projects generate electricity and maintain ecological balance by channelling surplus water to
irrigation deficit areas.
➢ More food and foliage, check on soil erosion, recharging of underground acquifers and industrial built-up are
the major positive outcomes of these projects.

1. Terrestrial Effects
2. Wild Life
3. Aquatic life
4. Social Problems
5. Submergence of Cultural Heritage
6. Health Concern
7. Economic Aspect
 Operational Phase of Hydroelectric Projects
Sedimentation of Reservoirs

➢ Sediment observations carried out on large dams in UP, AP, Bihar, MP and
Maharashtra.
➢ The survey shows that the average annual percentage loss of water storage lies
between 0.3 and 0.9.
➢ However, the survey also shows that the economic life of a dam reservoir is
about 100 years.
Reservoir induced seismicity
➢ Environmental critics predict disastrous shocks in every dam storage,
irrespective of the fact whether it is located in a seismic zone or not.
➢ To address one such apprehension the behaviour of ‘Nurek’ Dam in
Ukraine, with height of 305 metre, located in the high seismic zone of
6.5–7.0 magnitude on Richter scale.
 Nuclear Power Generation and Environment
Natural Radiation

➢ Natural radiation comes from cosmic rays, and terrestrial

deposits of uranium and thorium.
➢ Man-made radiation comes through X-rays during medical Mining
check-up, from fall-outs of nuclear weapons tests, and use
➢ Uranium ore is obtained from mines at Jaduguda in
of mobile communication sets, etc.
Chotanagpur.

Radioactive Pollution ➢ The safety of workers is ensured by controlling

radon and airborne radioactive dust by proper
➢ Radiations from radio nuclides during uranium mining ventilation.
➢ Processing of uranium ore as fuel for nuclear reactors
➢ Operation of nuclear reactors for power generation
➢ Accidental radiological hazards
➢ Contamination from nuclear waste.
Nuclear Power Generation and Environment
Processing of Ore

Processing of ore is carried out in three stages:

1. Crushing
2. Grinding
3. Leaching
➢ Purified uranium is precipitated as yellow cake.
➢ Uranium forms only 0.5% of the ore and the remaining bulk is rejected as waste called tailings.
➢ The waste contains radio nuclides like radon–222 and emits radiations.
➢ Tailings are neutralized with lime in ponds, whereas solid tailings are retained in ponds.
➢ A typical value of radiation constant in pond measured with a dosemeter is reported to be 0.75 micro gray an hour
[gray (Gy) is the SI unit of absorption dose of ionizing radiation, corresponding to one joule per kg of absorbing
medium].
➢ Radiation constant decreases with the increase in distance which is 0.2 gray an hour on the embankment of the pond.
 Operational Safety in Nuclear Power Plants

➢ Safety considerations for Pressurized Heavy Water Reactors (PHWRs) are:

➢ Control of reactor power during shutdown and maintenance
➢ Providing adequate cooling
➢ Containment of radioactivity.

Containment of Radioactivity

➢ The cladding that surrounds the fuel serves as the

next barrier to the release of radioactivity.
➢ Any release of radioactivity on account of cladding
failure remains confined within the Primary Heat
Transport (PHT) system boundary.
 Global Environmental Awareness
Kyoto Protocol

➢ The agreement intended to limit the world’s carbon emissions, was signed by 84 countries in Kyoto, Japan in 1997.
➢ The international agreement provides three other options to developed countries to earn ‘carbon credits’ towards
reduction in GHG emissions, namely:
1. Clean Development Mechanism (CDM)
2. Joint Implementation (JI)
3. International Emissions Trading (IET)
➢ Kyoto international environmental agreement was to become the international law with two conditions:
1. 55 countries had to approve it by passing through their national legislation.
2. Approving countries necessarily had to be industrial, so as to account for 55% of their global emissions in 1990.
➢ Kyoto Global Warming pact went into force on 17 February, 2005 when Russia accorded its approval. The pact
envisages to achieve the objectives by adopting the following measures:
1. Improving energy efficiency 2. Maximum use of renewable energy 3. Carbon dioxide sequestration
4. Phasing out tax exemptions and subsidies on all GHG emitting commercial energy sources.
 Global Environmental Awareness
Copenhagen Climate Change Summit

➢ Climate change conference was held at Bella Centre in Copenhagen during December 6–18, 2009.
➢ Terms of Kyoto Protocol will be over by 2012. To keep the process on the line, there was a need for a new Climate
Protocol.
➢ The conference in Copenhagen in the Framework Convention on climate change was attended by 193 countries from
all over the world.
➢ Indian delegation expressed ‘At present India’s per capital emission is 1 tonne to 1.2 tonnes with 8.9% yearly GDP
growth.’
➢ Our emission intensity declined by 17.6% between 1990–2005 and futher 20–25 per cent reduction is possible from
2005 to 2020.
➢ India’s eleventh plan includes increasing energy efficiency up to 20% by 2016–17.
➢ Development of science and technology related to mitigation and adoptation to climate change was highlighted.
➢ The summit introduced ‘Copenhagen Accord’ with a new kind of dynamics in global climate policy.
 Impact of Renewable Energy Generation on Environment
Solar Energy

➢ Solar thermal systems use heat transfer fluids like glycol nitrates and sulphates. For high temperature applications,
CFCs and aromatic alcohols are required.
➢ Solar photovoltaic modules pose disposal problems due to the presence of arsenic and cadmium.
➢ Solar power generators need battery banks with inverters for storage capacity to provide power during nights and on
cloudy days, with a back-up diesel generator.
➢ Hazards to eyesight from solar reflectors.
➢ Solar thermal collectors and roof top photovoltaic (PV) systems have now become an integral part of high-rise
buildings in metropolis.
➢ Large-scale use in densely populated cities limits the exposure of people to daylight due to changes in albedo.
 Impact of Renewable Energy Generation on Environment
Wind Energy

➢ Wind power development requires a large land area to keep distance between turbines and turbine rows. Wind farm
development in a forest area needs cutting of trees leading to degradation of environment.
➢ Degrade environment by noise pollution.
➢ Large wind turbines do interfere with television signals through reflection.
➢ Hazardous for birds, especially those in a migration route.

Biomass Energy

➢ Combustion of biomass produces air pollution.

➢ Large-scale production of biomass and its harvesting accelerates soil erosion and nutrient loss.
➢ Energy-crop plantation on a large scale is water consuming with increased use of pesticides and fertilizers. It causes
water pollution and flooding.
➢ Domestic use of biomass in rural areas creates air pollution, a health-hazard for women and children.
 Impact of Renewable Energy Generation on Environment
Geothermal Energy

➢ Gases escape into the atmosphere. Gases containing H2S are oxidized to SO2 and H2SO4 and drop down as acid rain.
➢ Chemicals like sulphates, chlorides and carbonates of lead, boron and arsenic, pollute soil and water.
➢ Discharge of waste hot water infects rivers, adversely affecting drinking water, farming and fisheries.
➢ Noise pollution, caused by exhausts, blow downs and centrifugal separation, is a health hazard. It is controlled by
installation of silencers.
➢ Large-scale withdrawal of underground fluids from geothermal fields may trigger ground subsidence, causing damage
to surface structures. The problem is mitigated by reinjection of spent fluids back into the reservoir.
➢ Existing geothermal electric plants emit an average of 122 kgs of CO2 per MWh of electricity. It is a small fraction of
the emission intensity of conventional thermal plants.