Kurukshetra Magazine May 2024 - 2 | Current Affairs & Hindu Analysis: Daily, Weekly & Monthly - UPSC PDF Download

 Page 1


Green Technologies for Clean 
and Renewable Energy
* Dr. Harender Raj Gautam 
* The author is recipient of ‘Earth Care Award’, Former Professor and Head, Dr. Y. S. Parmar University of Horticulture 
and Forestry, Solan, Himachal Pradesh. Email: hrg_mpp@yahoo.com
nergy is vital for development and 
according to ‘Electricity, 2024 Report’ 
from the International Energy Agency 
(IEA), electricity demand worldwide is 
expected to accelerate during the next 
three years. The report found that the global growth of 
demand for electricity is expected to speed up to a 3.4% 
average from this year through 2026 and approximately 
85% of the global increase in demand for electricity is 
predicted to come from India, China and South-East 
Asian countries. Renewable and clean energy sources 
with low-emissions made up only 40% of the planet’s 
electricity generation in 2023. Thus, energy is at the 
heart of the climate challenge because a large chunk of 
the greenhouse gases is generated through the process 
of energy production by burning fossil fuels to generate 
electricity and heat. Energy is the dominant contributor 
to climate change, accounting for around 60 percent of 
total global greenhouse gas emissions. Thus, to avoid 
the worst impacts of climate change, emissions need to 
E
Current reliance on fossil fuels for energy production is  
exacerbating climate change, making it imperative 
to make a rapid transition to renewable and clean 
energy sources. Renewables, including solar, wind, 
hydroelectric, nuclear, and emerging technologies like 
green hydrogen, offer sustainable alternatives. Green 
technology advances in solar power, wind energy, 
hydroelectricity, nuclear power, energy storage, 
bioenergy, geothermal heat, and smart grids are 
reshaping the energy landscape, making clean energy 
more efficient, cost-effective, and scalable. 
Clean energy investment increased nearly 
50% between 2019-2023, reaching USD 1.8 
trillion in 2023. The transition to renewable 
energy is projected to boost global GDP 
and employment. India has a target to 
achieve 50 percent cumulative electric 
power installed by 2030 from renewables 
and achieve net-zero carbon emissions by 2070. 
Clean energy will be key to limiting global warming 
to 1.5 degrees Celsius or as close to that as possible 
compared with the preindustrial era.
Page 2


Green Technologies for Clean 
and Renewable Energy
* Dr. Harender Raj Gautam 
* The author is recipient of ‘Earth Care Award’, Former Professor and Head, Dr. Y. S. Parmar University of Horticulture 
and Forestry, Solan, Himachal Pradesh. Email: hrg_mpp@yahoo.com
nergy is vital for development and 
according to ‘Electricity, 2024 Report’ 
from the International Energy Agency 
(IEA), electricity demand worldwide is 
expected to accelerate during the next 
three years. The report found that the global growth of 
demand for electricity is expected to speed up to a 3.4% 
average from this year through 2026 and approximately 
85% of the global increase in demand for electricity is 
predicted to come from India, China and South-East 
Asian countries. Renewable and clean energy sources 
with low-emissions made up only 40% of the planet’s 
electricity generation in 2023. Thus, energy is at the 
heart of the climate challenge because a large chunk of 
the greenhouse gases is generated through the process 
of energy production by burning fossil fuels to generate 
electricity and heat. Energy is the dominant contributor 
to climate change, accounting for around 60 percent of 
total global greenhouse gas emissions. Thus, to avoid 
the worst impacts of climate change, emissions need to 
E
Current reliance on fossil fuels for energy production is  
exacerbating climate change, making it imperative 
to make a rapid transition to renewable and clean 
energy sources. Renewables, including solar, wind, 
hydroelectric, nuclear, and emerging technologies like 
green hydrogen, offer sustainable alternatives. Green 
technology advances in solar power, wind energy, 
hydroelectricity, nuclear power, energy storage, 
bioenergy, geothermal heat, and smart grids are 
reshaping the energy landscape, making clean energy 
more efficient, cost-effective, and scalable. 
Clean energy investment increased nearly 
50% between 2019-2023, reaching USD 1.8 
trillion in 2023. The transition to renewable 
energy is projected to boost global GDP 
and employment. India has a target to 
achieve 50 percent cumulative electric 
power installed by 2030 from renewables 
and achieve net-zero carbon emissions by 2070. 
Clean energy will be key to limiting global warming 
to 1.5 degrees Celsius or as close to that as possible 
compared with the preindustrial era.
21 Kurukshetra       May  2024
be reduced by almost half by 2030 and reach net-zero 
by 2050. To achieve this, we need to end our reliance on 
fossil fuels and invest in green technologies to develop 
alternative sources of energy that are clean, accessible, 
affordable, sustainable, and reliable. 
Present Renewable Energy Scenario
We need to rely on renewable energy sources which 
are available in abundance all around us, provided by 
the sun, wind, water, waste, and heat from the Earth. 
Cleaner sources of energy are gaining ground and 
about 29 percent of electricity currently comes from 
renewable sources. As per the statistics released by 
the International Renewable Energy Agency (IRENA), 
at the end of 2023, global renewable power capacity 
amounted to 3,870 GW. Solar accounted for the largest 
share of the global total, with a capacity of 1,419 GW. 
The deployment of solar PV, wind power, nuclear power, 
electric cars, and heat pumps from 2019 to 2023 avoids 
around 2.2 billion tonnes (Gt) of emissions annually. 
Without them, the increase in CO2 emissions globally 
over the same period would have been more than three 
times larger. Renewable hydropower and wind energy 
accounted with total capacities of 1,268 GW and 1,017 
GW, respectively. Other renewable capacities included 
150 GW of bioenergy and 15 GW of geothermal, plus 
0.5 GW of marine energy. In India, renewable energy 
sources, including large hydropower, have a combined 
installed capacity of 183.49 GW, and about 13.5 GW 
of renewable energy capacity was added during 
2023. While solar energy maintained its dominance, 
contributing 75.57 GW, wind energy contributed 
44.15 GW. India aims for 500 GW of renewable energy 
installed capacity and five million tonnes of green 
hydrogen by 2030. India has set a target to reduce the 
carbon intensity of the nation’s economy by less than 
45% by the end of the decade, achieve 50 percent 
cumulative electric power installed by 2030 from 
renewables, and achieve net-zero carbon emissions 
by 2070. India aims to produce five million tonnes of 
green hydrogen by 2030. 
Green T echnologies for Clean Energy
Emerging green technologies for clean energy are 
playing a crucial role in shaping the future of renewable 
energy projects, making them more efficient, cost-
effective, and scalable. According to the IEA, from 2019 
to 2023, clean energy investment increased nearly 50%, 
reaching USD 1.8 trillion in 2023 and growing at around 
10% per year across this period. Important innovations 
of green technologies with commercial potential and 
different stages of scalability are as follows: 
Solar Power: Solar energy is an abundant and 
renewable energy resource and the amount of sunlight 
that hits the earth in a single hour contains more 
energy than the world needs in a year. Sunlight can 
be converted directly into electricity with a device 
called a photovoltaic (PV) cell. Photovoltaic solar cells 
have been the backbone of solar power generation. 
However, emerging technologies are revolutionising 
PV technology by enhancing efficiency and reducing 
costs. Innovations such as multi-junction cells, tandem 
cells, and perovskite-silicon hybrid cells are enabling 
higher energy conversion efficiency and making solar 
power more affordable. Concentrated Solar Power 
(CSP) systems utilise mirrors or lenses to focus sunlight 
onto a receiver, generating heat that drives a turbine 
for electricity production. Emerging technologies in CSP , 
such as molten salt storage and advanced heat transfer 
fluids, improve the efficiency and storage capabilities of 
these systems, enabling continuous power generation 
even when the sun is not shining. Tandem solar cell 
technology is more efficient in converting sunlight into 
electricity and achieving power-conversion efficiencies 
of over 30%. Here, an ultrathin perovskite solar cell is 
stacked on top of a standard silicon solar cell. Silicon-
based photovoltaics which are presently in use convert 
only a small range of longer wavelengths of sunlight into 
electricity. However, when combined, an ultrathin layer 
of perovskite on top of a silicon solar cell can convert 
more sunlight into usable electric energy than either 
cell alone. 
Page 3


Green Technologies for Clean 
and Renewable Energy
* Dr. Harender Raj Gautam 
* The author is recipient of ‘Earth Care Award’, Former Professor and Head, Dr. Y. S. Parmar University of Horticulture 
and Forestry, Solan, Himachal Pradesh. Email: hrg_mpp@yahoo.com
nergy is vital for development and 
according to ‘Electricity, 2024 Report’ 
from the International Energy Agency 
(IEA), electricity demand worldwide is 
expected to accelerate during the next 
three years. The report found that the global growth of 
demand for electricity is expected to speed up to a 3.4% 
average from this year through 2026 and approximately 
85% of the global increase in demand for electricity is 
predicted to come from India, China and South-East 
Asian countries. Renewable and clean energy sources 
with low-emissions made up only 40% of the planet’s 
electricity generation in 2023. Thus, energy is at the 
heart of the climate challenge because a large chunk of 
the greenhouse gases is generated through the process 
of energy production by burning fossil fuels to generate 
electricity and heat. Energy is the dominant contributor 
to climate change, accounting for around 60 percent of 
total global greenhouse gas emissions. Thus, to avoid 
the worst impacts of climate change, emissions need to 
E
Current reliance on fossil fuels for energy production is  
exacerbating climate change, making it imperative 
to make a rapid transition to renewable and clean 
energy sources. Renewables, including solar, wind, 
hydroelectric, nuclear, and emerging technologies like 
green hydrogen, offer sustainable alternatives. Green 
technology advances in solar power, wind energy, 
hydroelectricity, nuclear power, energy storage, 
bioenergy, geothermal heat, and smart grids are 
reshaping the energy landscape, making clean energy 
more efficient, cost-effective, and scalable. 
Clean energy investment increased nearly 
50% between 2019-2023, reaching USD 1.8 
trillion in 2023. The transition to renewable 
energy is projected to boost global GDP 
and employment. India has a target to 
achieve 50 percent cumulative electric 
power installed by 2030 from renewables 
and achieve net-zero carbon emissions by 2070. 
Clean energy will be key to limiting global warming 
to 1.5 degrees Celsius or as close to that as possible 
compared with the preindustrial era.
21 Kurukshetra       May  2024
be reduced by almost half by 2030 and reach net-zero 
by 2050. To achieve this, we need to end our reliance on 
fossil fuels and invest in green technologies to develop 
alternative sources of energy that are clean, accessible, 
affordable, sustainable, and reliable. 
Present Renewable Energy Scenario
We need to rely on renewable energy sources which 
are available in abundance all around us, provided by 
the sun, wind, water, waste, and heat from the Earth. 
Cleaner sources of energy are gaining ground and 
about 29 percent of electricity currently comes from 
renewable sources. As per the statistics released by 
the International Renewable Energy Agency (IRENA), 
at the end of 2023, global renewable power capacity 
amounted to 3,870 GW. Solar accounted for the largest 
share of the global total, with a capacity of 1,419 GW. 
The deployment of solar PV, wind power, nuclear power, 
electric cars, and heat pumps from 2019 to 2023 avoids 
around 2.2 billion tonnes (Gt) of emissions annually. 
Without them, the increase in CO2 emissions globally 
over the same period would have been more than three 
times larger. Renewable hydropower and wind energy 
accounted with total capacities of 1,268 GW and 1,017 
GW, respectively. Other renewable capacities included 
150 GW of bioenergy and 15 GW of geothermal, plus 
0.5 GW of marine energy. In India, renewable energy 
sources, including large hydropower, have a combined 
installed capacity of 183.49 GW, and about 13.5 GW 
of renewable energy capacity was added during 
2023. While solar energy maintained its dominance, 
contributing 75.57 GW, wind energy contributed 
44.15 GW. India aims for 500 GW of renewable energy 
installed capacity and five million tonnes of green 
hydrogen by 2030. India has set a target to reduce the 
carbon intensity of the nation’s economy by less than 
45% by the end of the decade, achieve 50 percent 
cumulative electric power installed by 2030 from 
renewables, and achieve net-zero carbon emissions 
by 2070. India aims to produce five million tonnes of 
green hydrogen by 2030. 
Green T echnologies for Clean Energy
Emerging green technologies for clean energy are 
playing a crucial role in shaping the future of renewable 
energy projects, making them more efficient, cost-
effective, and scalable. According to the IEA, from 2019 
to 2023, clean energy investment increased nearly 50%, 
reaching USD 1.8 trillion in 2023 and growing at around 
10% per year across this period. Important innovations 
of green technologies with commercial potential and 
different stages of scalability are as follows: 
Solar Power: Solar energy is an abundant and 
renewable energy resource and the amount of sunlight 
that hits the earth in a single hour contains more 
energy than the world needs in a year. Sunlight can 
be converted directly into electricity with a device 
called a photovoltaic (PV) cell. Photovoltaic solar cells 
have been the backbone of solar power generation. 
However, emerging technologies are revolutionising 
PV technology by enhancing efficiency and reducing 
costs. Innovations such as multi-junction cells, tandem 
cells, and perovskite-silicon hybrid cells are enabling 
higher energy conversion efficiency and making solar 
power more affordable. Concentrated Solar Power 
(CSP) systems utilise mirrors or lenses to focus sunlight 
onto a receiver, generating heat that drives a turbine 
for electricity production. Emerging technologies in CSP , 
such as molten salt storage and advanced heat transfer 
fluids, improve the efficiency and storage capabilities of 
these systems, enabling continuous power generation 
even when the sun is not shining. Tandem solar cell 
technology is more efficient in converting sunlight into 
electricity and achieving power-conversion efficiencies 
of over 30%. Here, an ultrathin perovskite solar cell is 
stacked on top of a standard silicon solar cell. Silicon-
based photovoltaics which are presently in use convert 
only a small range of longer wavelengths of sunlight into 
electricity. However, when combined, an ultrathin layer 
of perovskite on top of a silicon solar cell can convert 
more sunlight into usable electric energy than either 
cell alone. 
22 Kurukshetra       May  2024
At the heart of recent solar innovations is 
‘Passivated Emitter and Rear Contact’ (PERC) solar 
cells technology where PERC solar cells are modified 
conventional cells that enable the cells to produce 6 to 
12 percent more energy than conventional solar panels. 
PERC solar cells have an extra layer within the back side 
of the cell.  Adding to the array of solar innovations 
is Heterojunction (HJT) technology and it combines 
amorphous and crystalline silicon layers, resulting in 
panels with higher efficiency and superior temperature 
performance. Vehicle-integrated photovoltaics is also 
an emerging technology which refers to the integration 
of solar panels into various parts of a vehicle to generate 
electricity from sunlight, reducing reliance of vehicles 
on fossil fuels and lowering greenhouse gas emissions. 
Solar panels on a vehicle could charge the on-board 
battery, increasing the electric range of electric and 
hybrid vehicles and reducing fuel consumption. To widen 
the applicability of solar power, offshore solar power 
by installing solar panels on bodies of water (oceans, 
lakes, reservoirs) allows to convert solar energy into 
electricity. This approach conserves land resources in 
densely populated areas, efficiently uses water bodies, 
and benefits from the cooling effect of water, enhancing 
solar panel efficiency.
Wind Power: The wind power grew at an increased 
rate of 13% in 2023 and total wind capacity reached 
1,017 GW. The generation capacity has increased both 
in on-shore and off-shore wind power installation 
capacity. The wind power industry is witnessing a 
rapid influx of cost-effective and reliable innovations, 
including rooftop bladeless wind turbines, vertical-axis 
turbines, floating multi-turbine technology platforms, 
and more. According to IEA, technology advancements 
could unlock 80% more wind energy potential during 
this decade. Continued turbine scaling, emphasising 
low material use and more efficient manufacturing 
processes, remains a key option, with cost reductions 
estimated at 11-20% by 2030. The development of 
taller wind turbines with longer blades has dramatically 
increased their capacity to capture energy, even in 
areas with less wind. Another area of progress is in 
bladeless wind energy generation, where structures 
use the oscillation of wind to generate power without 
the traditional turbine structure, reducing maintenance 
and potentially mitigating the impact on wildlife. 
Offshore wind is poised for significant growth, with 
floating turbine technology. These innovations not only 
allow for tapping into stronger wind currents but also 
open up new areas for development, promising higher 
energy outputs than ever before. WindFloat is another 
top wind energy trend and unlike traditional offshore 
wind turbines, WindFloat uses a drag-embedment 
anchor that supports the turbine without any 
construction on the seafloor. Vertical axis wind turbines 
(VAWTs) offer a compelling alternative to traditional 
horizontal axis wind turbines. VAWTs are designed to 
capture wind from any direction, making them suitable 
for urban environments and areas with complex 
wind patterns. Kite wind energy systems utilise large 
kites tethered to the ground to capture high-altitude 
winds. The kites generate significant amounts of clean 
energy while requiring fewer resources compared to 
conventional wind turbines. Enabling technologies 
include innovative power electronics, use of permanent 
magnet generators, and super conductor technology. 
Digitalisation, through advanced sensing and controls, 
enables predictive maintenance and is already reducing 
operation and maintenance costs. Artificial Intelligence 
(AI)-Enhanced Turbines, with the use of artificial 
intelligence, is revolutionising how wind turbines 
operate. By analysing data in real-time, AI enables 
turbines to adjust to wind conditions dynamically, 
improving efficiency and reducing wear and tear. This 
leap in technology means wind farms can expect lower 
maintenance costs and higher energy production. 
Hydroelectric Energy: Hydropower remains the 
largest renewable source of electricity, generating more 
than all other renewable technologies combined. In 
the Net Zero Emissions by 2050 Scenario, hydropower 
maintains an average annual generation growth rate 
of close to 4% in 2023-2030 to provide approximately 
5,500 Terawatt hours (TWh) of electricity per year. 
Page 4


Green Technologies for Clean 
and Renewable Energy
* Dr. Harender Raj Gautam 
* The author is recipient of ‘Earth Care Award’, Former Professor and Head, Dr. Y. S. Parmar University of Horticulture 
and Forestry, Solan, Himachal Pradesh. Email: hrg_mpp@yahoo.com
nergy is vital for development and 
according to ‘Electricity, 2024 Report’ 
from the International Energy Agency 
(IEA), electricity demand worldwide is 
expected to accelerate during the next 
three years. The report found that the global growth of 
demand for electricity is expected to speed up to a 3.4% 
average from this year through 2026 and approximately 
85% of the global increase in demand for electricity is 
predicted to come from India, China and South-East 
Asian countries. Renewable and clean energy sources 
with low-emissions made up only 40% of the planet’s 
electricity generation in 2023. Thus, energy is at the 
heart of the climate challenge because a large chunk of 
the greenhouse gases is generated through the process 
of energy production by burning fossil fuels to generate 
electricity and heat. Energy is the dominant contributor 
to climate change, accounting for around 60 percent of 
total global greenhouse gas emissions. Thus, to avoid 
the worst impacts of climate change, emissions need to 
E
Current reliance on fossil fuels for energy production is  
exacerbating climate change, making it imperative 
to make a rapid transition to renewable and clean 
energy sources. Renewables, including solar, wind, 
hydroelectric, nuclear, and emerging technologies like 
green hydrogen, offer sustainable alternatives. Green 
technology advances in solar power, wind energy, 
hydroelectricity, nuclear power, energy storage, 
bioenergy, geothermal heat, and smart grids are 
reshaping the energy landscape, making clean energy 
more efficient, cost-effective, and scalable. 
Clean energy investment increased nearly 
50% between 2019-2023, reaching USD 1.8 
trillion in 2023. The transition to renewable 
energy is projected to boost global GDP 
and employment. India has a target to 
achieve 50 percent cumulative electric 
power installed by 2030 from renewables 
and achieve net-zero carbon emissions by 2070. 
Clean energy will be key to limiting global warming 
to 1.5 degrees Celsius or as close to that as possible 
compared with the preindustrial era.
21 Kurukshetra       May  2024
be reduced by almost half by 2030 and reach net-zero 
by 2050. To achieve this, we need to end our reliance on 
fossil fuels and invest in green technologies to develop 
alternative sources of energy that are clean, accessible, 
affordable, sustainable, and reliable. 
Present Renewable Energy Scenario
We need to rely on renewable energy sources which 
are available in abundance all around us, provided by 
the sun, wind, water, waste, and heat from the Earth. 
Cleaner sources of energy are gaining ground and 
about 29 percent of electricity currently comes from 
renewable sources. As per the statistics released by 
the International Renewable Energy Agency (IRENA), 
at the end of 2023, global renewable power capacity 
amounted to 3,870 GW. Solar accounted for the largest 
share of the global total, with a capacity of 1,419 GW. 
The deployment of solar PV, wind power, nuclear power, 
electric cars, and heat pumps from 2019 to 2023 avoids 
around 2.2 billion tonnes (Gt) of emissions annually. 
Without them, the increase in CO2 emissions globally 
over the same period would have been more than three 
times larger. Renewable hydropower and wind energy 
accounted with total capacities of 1,268 GW and 1,017 
GW, respectively. Other renewable capacities included 
150 GW of bioenergy and 15 GW of geothermal, plus 
0.5 GW of marine energy. In India, renewable energy 
sources, including large hydropower, have a combined 
installed capacity of 183.49 GW, and about 13.5 GW 
of renewable energy capacity was added during 
2023. While solar energy maintained its dominance, 
contributing 75.57 GW, wind energy contributed 
44.15 GW. India aims for 500 GW of renewable energy 
installed capacity and five million tonnes of green 
hydrogen by 2030. India has set a target to reduce the 
carbon intensity of the nation’s economy by less than 
45% by the end of the decade, achieve 50 percent 
cumulative electric power installed by 2030 from 
renewables, and achieve net-zero carbon emissions 
by 2070. India aims to produce five million tonnes of 
green hydrogen by 2030. 
Green T echnologies for Clean Energy
Emerging green technologies for clean energy are 
playing a crucial role in shaping the future of renewable 
energy projects, making them more efficient, cost-
effective, and scalable. According to the IEA, from 2019 
to 2023, clean energy investment increased nearly 50%, 
reaching USD 1.8 trillion in 2023 and growing at around 
10% per year across this period. Important innovations 
of green technologies with commercial potential and 
different stages of scalability are as follows: 
Solar Power: Solar energy is an abundant and 
renewable energy resource and the amount of sunlight 
that hits the earth in a single hour contains more 
energy than the world needs in a year. Sunlight can 
be converted directly into electricity with a device 
called a photovoltaic (PV) cell. Photovoltaic solar cells 
have been the backbone of solar power generation. 
However, emerging technologies are revolutionising 
PV technology by enhancing efficiency and reducing 
costs. Innovations such as multi-junction cells, tandem 
cells, and perovskite-silicon hybrid cells are enabling 
higher energy conversion efficiency and making solar 
power more affordable. Concentrated Solar Power 
(CSP) systems utilise mirrors or lenses to focus sunlight 
onto a receiver, generating heat that drives a turbine 
for electricity production. Emerging technologies in CSP , 
such as molten salt storage and advanced heat transfer 
fluids, improve the efficiency and storage capabilities of 
these systems, enabling continuous power generation 
even when the sun is not shining. Tandem solar cell 
technology is more efficient in converting sunlight into 
electricity and achieving power-conversion efficiencies 
of over 30%. Here, an ultrathin perovskite solar cell is 
stacked on top of a standard silicon solar cell. Silicon-
based photovoltaics which are presently in use convert 
only a small range of longer wavelengths of sunlight into 
electricity. However, when combined, an ultrathin layer 
of perovskite on top of a silicon solar cell can convert 
more sunlight into usable electric energy than either 
cell alone. 
22 Kurukshetra       May  2024
At the heart of recent solar innovations is 
‘Passivated Emitter and Rear Contact’ (PERC) solar 
cells technology where PERC solar cells are modified 
conventional cells that enable the cells to produce 6 to 
12 percent more energy than conventional solar panels. 
PERC solar cells have an extra layer within the back side 
of the cell.  Adding to the array of solar innovations 
is Heterojunction (HJT) technology and it combines 
amorphous and crystalline silicon layers, resulting in 
panels with higher efficiency and superior temperature 
performance. Vehicle-integrated photovoltaics is also 
an emerging technology which refers to the integration 
of solar panels into various parts of a vehicle to generate 
electricity from sunlight, reducing reliance of vehicles 
on fossil fuels and lowering greenhouse gas emissions. 
Solar panels on a vehicle could charge the on-board 
battery, increasing the electric range of electric and 
hybrid vehicles and reducing fuel consumption. To widen 
the applicability of solar power, offshore solar power 
by installing solar panels on bodies of water (oceans, 
lakes, reservoirs) allows to convert solar energy into 
electricity. This approach conserves land resources in 
densely populated areas, efficiently uses water bodies, 
and benefits from the cooling effect of water, enhancing 
solar panel efficiency.
Wind Power: The wind power grew at an increased 
rate of 13% in 2023 and total wind capacity reached 
1,017 GW. The generation capacity has increased both 
in on-shore and off-shore wind power installation 
capacity. The wind power industry is witnessing a 
rapid influx of cost-effective and reliable innovations, 
including rooftop bladeless wind turbines, vertical-axis 
turbines, floating multi-turbine technology platforms, 
and more. According to IEA, technology advancements 
could unlock 80% more wind energy potential during 
this decade. Continued turbine scaling, emphasising 
low material use and more efficient manufacturing 
processes, remains a key option, with cost reductions 
estimated at 11-20% by 2030. The development of 
taller wind turbines with longer blades has dramatically 
increased their capacity to capture energy, even in 
areas with less wind. Another area of progress is in 
bladeless wind energy generation, where structures 
use the oscillation of wind to generate power without 
the traditional turbine structure, reducing maintenance 
and potentially mitigating the impact on wildlife. 
Offshore wind is poised for significant growth, with 
floating turbine technology. These innovations not only 
allow for tapping into stronger wind currents but also 
open up new areas for development, promising higher 
energy outputs than ever before. WindFloat is another 
top wind energy trend and unlike traditional offshore 
wind turbines, WindFloat uses a drag-embedment 
anchor that supports the turbine without any 
construction on the seafloor. Vertical axis wind turbines 
(VAWTs) offer a compelling alternative to traditional 
horizontal axis wind turbines. VAWTs are designed to 
capture wind from any direction, making them suitable 
for urban environments and areas with complex 
wind patterns. Kite wind energy systems utilise large 
kites tethered to the ground to capture high-altitude 
winds. The kites generate significant amounts of clean 
energy while requiring fewer resources compared to 
conventional wind turbines. Enabling technologies 
include innovative power electronics, use of permanent 
magnet generators, and super conductor technology. 
Digitalisation, through advanced sensing and controls, 
enables predictive maintenance and is already reducing 
operation and maintenance costs. Artificial Intelligence 
(AI)-Enhanced Turbines, with the use of artificial 
intelligence, is revolutionising how wind turbines 
operate. By analysing data in real-time, AI enables 
turbines to adjust to wind conditions dynamically, 
improving efficiency and reducing wear and tear. This 
leap in technology means wind farms can expect lower 
maintenance costs and higher energy production. 
Hydroelectric Energy: Hydropower remains the 
largest renewable source of electricity, generating more 
than all other renewable technologies combined. In 
the Net Zero Emissions by 2050 Scenario, hydropower 
maintains an average annual generation growth rate 
of close to 4% in 2023-2030 to provide approximately 
5,500 Terawatt hours (TWh) of electricity per year. 
23 Kurukshetra       May  2024
Hydroelectricity generation increased by almost 
70 TWh (up close to 2%) in 2022, reaching 4,300 TWh. 
Hydroelectric power is experiencing a renaissance with 
advanced turbine designs that are fish-friendly and 
capable of operating efficiently at low water velocities. 
This greatly reduces environmental impact and extends 
hydroelectricity’s viability to previously unsuitable 
locations. Additionally, kinetic hydro turbines, which 
harvest energy from flowing water without the need 
for large dams or reservoirs, are showing promise for 
small-scale power generation in rivers and streams. 
Tidal power generation harnesses the predictable and 
constant movement of ocean tides 
to generate electricity. Innovations 
in tidal power systems include 
underwater turbines and barrages, 
which efficiently convert tidal energy 
into electrical power. Run-of-river 
hydroelectric systems utilise the 
natural flow of rivers to generate 
electricity without the need for large-
scale dams. These systems have 
lower environmental impacts and 
allow for more flexible installation 
and operation. Underwater turbines 
harness the kinetic energy of ocean 
currents to generate renewable 
electricity. These innovative turbines 
can be installed in various locations, including coastal 
areas and ocean currents, providing a consistent and 
reliable source of clean power.
Nuclear Power: Nuclear power is the second-largest 
source of low-carbon electricity today. Nuclear energy, 
with around 413 gigawatts (GW) of capacity operating in 
32 countries, contributes to both goals by avoiding 1.5 
gigatonnes (Gt) of global emissions and 180 billion cubic 
metres (bcm) of global gas demand a year. According to 
the IEA, global nuclear power generation is forecast to 
grow by almost 3% annually on average through 2026. 
As of August 2023, there are 410 nuclear power reactors 
Kameng Dam and Hydro Power Station, Arunachal Pradesh
Rajasthan Atomic Power Station
Page 5


Green Technologies for Clean 
and Renewable Energy
* Dr. Harender Raj Gautam 
* The author is recipient of ‘Earth Care Award’, Former Professor and Head, Dr. Y. S. Parmar University of Horticulture 
and Forestry, Solan, Himachal Pradesh. Email: hrg_mpp@yahoo.com
nergy is vital for development and 
according to ‘Electricity, 2024 Report’ 
from the International Energy Agency 
(IEA), electricity demand worldwide is 
expected to accelerate during the next 
three years. The report found that the global growth of 
demand for electricity is expected to speed up to a 3.4% 
average from this year through 2026 and approximately 
85% of the global increase in demand for electricity is 
predicted to come from India, China and South-East 
Asian countries. Renewable and clean energy sources 
with low-emissions made up only 40% of the planet’s 
electricity generation in 2023. Thus, energy is at the 
heart of the climate challenge because a large chunk of 
the greenhouse gases is generated through the process 
of energy production by burning fossil fuels to generate 
electricity and heat. Energy is the dominant contributor 
to climate change, accounting for around 60 percent of 
total global greenhouse gas emissions. Thus, to avoid 
the worst impacts of climate change, emissions need to 
E
Current reliance on fossil fuels for energy production is  
exacerbating climate change, making it imperative 
to make a rapid transition to renewable and clean 
energy sources. Renewables, including solar, wind, 
hydroelectric, nuclear, and emerging technologies like 
green hydrogen, offer sustainable alternatives. Green 
technology advances in solar power, wind energy, 
hydroelectricity, nuclear power, energy storage, 
bioenergy, geothermal heat, and smart grids are 
reshaping the energy landscape, making clean energy 
more efficient, cost-effective, and scalable. 
Clean energy investment increased nearly 
50% between 2019-2023, reaching USD 1.8 
trillion in 2023. The transition to renewable 
energy is projected to boost global GDP 
and employment. India has a target to 
achieve 50 percent cumulative electric 
power installed by 2030 from renewables 
and achieve net-zero carbon emissions by 2070. 
Clean energy will be key to limiting global warming 
to 1.5 degrees Celsius or as close to that as possible 
compared with the preindustrial era.
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be reduced by almost half by 2030 and reach net-zero 
by 2050. To achieve this, we need to end our reliance on 
fossil fuels and invest in green technologies to develop 
alternative sources of energy that are clean, accessible, 
affordable, sustainable, and reliable. 
Present Renewable Energy Scenario
We need to rely on renewable energy sources which 
are available in abundance all around us, provided by 
the sun, wind, water, waste, and heat from the Earth. 
Cleaner sources of energy are gaining ground and 
about 29 percent of electricity currently comes from 
renewable sources. As per the statistics released by 
the International Renewable Energy Agency (IRENA), 
at the end of 2023, global renewable power capacity 
amounted to 3,870 GW. Solar accounted for the largest 
share of the global total, with a capacity of 1,419 GW. 
The deployment of solar PV, wind power, nuclear power, 
electric cars, and heat pumps from 2019 to 2023 avoids 
around 2.2 billion tonnes (Gt) of emissions annually. 
Without them, the increase in CO2 emissions globally 
over the same period would have been more than three 
times larger. Renewable hydropower and wind energy 
accounted with total capacities of 1,268 GW and 1,017 
GW, respectively. Other renewable capacities included 
150 GW of bioenergy and 15 GW of geothermal, plus 
0.5 GW of marine energy. In India, renewable energy 
sources, including large hydropower, have a combined 
installed capacity of 183.49 GW, and about 13.5 GW 
of renewable energy capacity was added during 
2023. While solar energy maintained its dominance, 
contributing 75.57 GW, wind energy contributed 
44.15 GW. India aims for 500 GW of renewable energy 
installed capacity and five million tonnes of green 
hydrogen by 2030. India has set a target to reduce the 
carbon intensity of the nation’s economy by less than 
45% by the end of the decade, achieve 50 percent 
cumulative electric power installed by 2030 from 
renewables, and achieve net-zero carbon emissions 
by 2070. India aims to produce five million tonnes of 
green hydrogen by 2030. 
Green T echnologies for Clean Energy
Emerging green technologies for clean energy are 
playing a crucial role in shaping the future of renewable 
energy projects, making them more efficient, cost-
effective, and scalable. According to the IEA, from 2019 
to 2023, clean energy investment increased nearly 50%, 
reaching USD 1.8 trillion in 2023 and growing at around 
10% per year across this period. Important innovations 
of green technologies with commercial potential and 
different stages of scalability are as follows: 
Solar Power: Solar energy is an abundant and 
renewable energy resource and the amount of sunlight 
that hits the earth in a single hour contains more 
energy than the world needs in a year. Sunlight can 
be converted directly into electricity with a device 
called a photovoltaic (PV) cell. Photovoltaic solar cells 
have been the backbone of solar power generation. 
However, emerging technologies are revolutionising 
PV technology by enhancing efficiency and reducing 
costs. Innovations such as multi-junction cells, tandem 
cells, and perovskite-silicon hybrid cells are enabling 
higher energy conversion efficiency and making solar 
power more affordable. Concentrated Solar Power 
(CSP) systems utilise mirrors or lenses to focus sunlight 
onto a receiver, generating heat that drives a turbine 
for electricity production. Emerging technologies in CSP , 
such as molten salt storage and advanced heat transfer 
fluids, improve the efficiency and storage capabilities of 
these systems, enabling continuous power generation 
even when the sun is not shining. Tandem solar cell 
technology is more efficient in converting sunlight into 
electricity and achieving power-conversion efficiencies 
of over 30%. Here, an ultrathin perovskite solar cell is 
stacked on top of a standard silicon solar cell. Silicon-
based photovoltaics which are presently in use convert 
only a small range of longer wavelengths of sunlight into 
electricity. However, when combined, an ultrathin layer 
of perovskite on top of a silicon solar cell can convert 
more sunlight into usable electric energy than either 
cell alone. 
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At the heart of recent solar innovations is 
‘Passivated Emitter and Rear Contact’ (PERC) solar 
cells technology where PERC solar cells are modified 
conventional cells that enable the cells to produce 6 to 
12 percent more energy than conventional solar panels. 
PERC solar cells have an extra layer within the back side 
of the cell.  Adding to the array of solar innovations 
is Heterojunction (HJT) technology and it combines 
amorphous and crystalline silicon layers, resulting in 
panels with higher efficiency and superior temperature 
performance. Vehicle-integrated photovoltaics is also 
an emerging technology which refers to the integration 
of solar panels into various parts of a vehicle to generate 
electricity from sunlight, reducing reliance of vehicles 
on fossil fuels and lowering greenhouse gas emissions. 
Solar panels on a vehicle could charge the on-board 
battery, increasing the electric range of electric and 
hybrid vehicles and reducing fuel consumption. To widen 
the applicability of solar power, offshore solar power 
by installing solar panels on bodies of water (oceans, 
lakes, reservoirs) allows to convert solar energy into 
electricity. This approach conserves land resources in 
densely populated areas, efficiently uses water bodies, 
and benefits from the cooling effect of water, enhancing 
solar panel efficiency.
Wind Power: The wind power grew at an increased 
rate of 13% in 2023 and total wind capacity reached 
1,017 GW. The generation capacity has increased both 
in on-shore and off-shore wind power installation 
capacity. The wind power industry is witnessing a 
rapid influx of cost-effective and reliable innovations, 
including rooftop bladeless wind turbines, vertical-axis 
turbines, floating multi-turbine technology platforms, 
and more. According to IEA, technology advancements 
could unlock 80% more wind energy potential during 
this decade. Continued turbine scaling, emphasising 
low material use and more efficient manufacturing 
processes, remains a key option, with cost reductions 
estimated at 11-20% by 2030. The development of 
taller wind turbines with longer blades has dramatically 
increased their capacity to capture energy, even in 
areas with less wind. Another area of progress is in 
bladeless wind energy generation, where structures 
use the oscillation of wind to generate power without 
the traditional turbine structure, reducing maintenance 
and potentially mitigating the impact on wildlife. 
Offshore wind is poised for significant growth, with 
floating turbine technology. These innovations not only 
allow for tapping into stronger wind currents but also 
open up new areas for development, promising higher 
energy outputs than ever before. WindFloat is another 
top wind energy trend and unlike traditional offshore 
wind turbines, WindFloat uses a drag-embedment 
anchor that supports the turbine without any 
construction on the seafloor. Vertical axis wind turbines 
(VAWTs) offer a compelling alternative to traditional 
horizontal axis wind turbines. VAWTs are designed to 
capture wind from any direction, making them suitable 
for urban environments and areas with complex 
wind patterns. Kite wind energy systems utilise large 
kites tethered to the ground to capture high-altitude 
winds. The kites generate significant amounts of clean 
energy while requiring fewer resources compared to 
conventional wind turbines. Enabling technologies 
include innovative power electronics, use of permanent 
magnet generators, and super conductor technology. 
Digitalisation, through advanced sensing and controls, 
enables predictive maintenance and is already reducing 
operation and maintenance costs. Artificial Intelligence 
(AI)-Enhanced Turbines, with the use of artificial 
intelligence, is revolutionising how wind turbines 
operate. By analysing data in real-time, AI enables 
turbines to adjust to wind conditions dynamically, 
improving efficiency and reducing wear and tear. This 
leap in technology means wind farms can expect lower 
maintenance costs and higher energy production. 
Hydroelectric Energy: Hydropower remains the 
largest renewable source of electricity, generating more 
than all other renewable technologies combined. In 
the Net Zero Emissions by 2050 Scenario, hydropower 
maintains an average annual generation growth rate 
of close to 4% in 2023-2030 to provide approximately 
5,500 Terawatt hours (TWh) of electricity per year. 
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Hydroelectricity generation increased by almost 
70 TWh (up close to 2%) in 2022, reaching 4,300 TWh. 
Hydroelectric power is experiencing a renaissance with 
advanced turbine designs that are fish-friendly and 
capable of operating efficiently at low water velocities. 
This greatly reduces environmental impact and extends 
hydroelectricity’s viability to previously unsuitable 
locations. Additionally, kinetic hydro turbines, which 
harvest energy from flowing water without the need 
for large dams or reservoirs, are showing promise for 
small-scale power generation in rivers and streams. 
Tidal power generation harnesses the predictable and 
constant movement of ocean tides 
to generate electricity. Innovations 
in tidal power systems include 
underwater turbines and barrages, 
which efficiently convert tidal energy 
into electrical power. Run-of-river 
hydroelectric systems utilise the 
natural flow of rivers to generate 
electricity without the need for large-
scale dams. These systems have 
lower environmental impacts and 
allow for more flexible installation 
and operation. Underwater turbines 
harness the kinetic energy of ocean 
currents to generate renewable 
electricity. These innovative turbines 
can be installed in various locations, including coastal 
areas and ocean currents, providing a consistent and 
reliable source of clean power.
Nuclear Power: Nuclear power is the second-largest 
source of low-carbon electricity today. Nuclear energy, 
with around 413 gigawatts (GW) of capacity operating in 
32 countries, contributes to both goals by avoiding 1.5 
gigatonnes (Gt) of global emissions and 180 billion cubic 
metres (bcm) of global gas demand a year. According to 
the IEA, global nuclear power generation is forecast to 
grow by almost 3% annually on average through 2026. 
As of August 2023, there are 410 nuclear power reactors 
Kameng Dam and Hydro Power Station, Arunachal Pradesh
Rajasthan Atomic Power Station
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in operation totalling more than 3,68,000 MW(e) 
in installed capacity in 31 countries. Small modular 
reactors (SMRs) are advanced nuclear reactors that 
typically generate up to 300 MW(e). SMRs technology is 
set to broaden global access to nuclear energy because 
they are more suitable for small electricity grids and 
more easily integrated with renewable energy sources. 
There are more than 80 SMR designs in various stages 
of development in 18 countries, with SMR units already 
deployed in China and the Russian Federation, and one 
design under construction in Argentina. While traditional 
reactors and some advanced technology use water as a 
heat transfer medium, some new technologies are using 
other substances like molten salt or liquid metals. This 
allows reactors to run safely at higher temperatures 
and lower pressures while providing lower construction 
and design costs because the materials do not require 
components that can withstand extremely high pressure 
like water reactors. Micro-reactors are named because 
of their size. They are one percent or less of the size 
of traditional reactors operating today. Micro-reactors 
produce approximately 1 to 10 megawatts and are 
mobile, which means they can be moved from location 
to location depending on where they are needed. This 
technology will be crucial in remote areas that currently 
rely on fossil fuels, for example. Micro-reactors are the 
answer to providing these areas with clean, carbon-
free energy as they can easily be 
transported to where they need to be, 
operated for weeks or months, then 
moved to their next location. 
Energy Storage-Advanced 
Technologies in Batteries: Batteries 
are an effective energy storage 
technology, particularly for the 
incorporation of renewable resources, 
due to their compact size and wide 
availability. However, present battery 
technologies have a long way to 
go before meeting the cost criteria 
for stability, extraordinary power 
operation, high energy efficiency, 
and large-scale energy storage. The 
stationary electric energy storage 
market has recently seen the 
introduction of Lithium Ion Batteries 
(LIBs) for use in mobile devices and 
electronic vehicles. The current annual 
demand for lithium-ion batteries (LIB) is around 1 TWh. 
Sodium-ion batteries (SIBs) are currently evolving as a 
viable substitute for lithium-ion batteries (LIBs) because 
of the abundant availability and reasonable cost of 
sodium. Furthermore, sodium-ion batteries can use 
aluminum for the anode current collector instead of 
copper, which is used in lithium-ion cells. Furthermore, 
they can be safer than lithium-ion batteries as they 
can be stored at zero volts in comparison to around 
30% state of charge in LIBs, causing less risk during 
transportation. Conversely, Na-ion batteries do 
not have the same energy density as their Li-ion 
counterpart (respectively 75 to 160 Wh/kg compared 
to 120 to 260 Wh/kg). Aqueous zinc ion batteries have 
also emerged as promising alternatives to lithium-ion 
battery technology for energy storage systems due to 
their inherent safety, environmental friendliness, and 
cost-effectiveness. These use a water-based electrolyte 
and offer several advantages that make them attractive 
for various applications. They are safer compared to 
other chemistries and are cost-effective because zinc 
is abundant and relatively low-cost. Potassium-ion 
batteries use potassium as the anode material and 
are interesting for energy storage applications due 
to potential for high energy density, abundant and 
comparatively low-cost of potassium, high charge and 
discharge rates for rapid energy transfer and high-power