A full
court press to reduce emissions.
Dr. K.
Anand
Today, April 22nd is earth day. The CO2 emissions level stands at 420.87 ppm. It
was 395 ppm a decade ago in 2013. We are registering an annual
increase of 2.5 ppm per year. The median CO2 ppm for the scary 1.5 deg
rise is 520 ppm - we are just 4 decades away that milestone if not sooner. Power generation is the biggest
contributor to emissions, accounting for more than 50% of green-house gas emissions
in India.
Climate change, along with the urban heat island
effects have pushed energy consumption to record levels For example peak power demand has gone up by
50% in Tamil Nadu in less than a decade, and well before summer. Despite the growing footprint of Renewables
(RE), about 75% of the energy on tap comes from fossil fuel in India. Given that wind energy is seasonal and feasible
only in pockets, and solar energy is subject to variability in weather (smog,
clouds, dust), this should come as no surprise.
With the country recovering from
COVID the last two years have seen some of the highest offtake of coal in
recent times. Coal – freight trains now
clog the tracks dispatching fuel to thermal power plants cranking at full
capacity. Given that the energy demand
continues to be met through increased use of fossil fuels one needs to be
honest in facing these facts and ask where the solution for the energy sector
is, develop technologies and invest accordingly.
Fossil fuel-based power comprises of more than 75%
of the delivered energy
Electricity
sector in India - Wikipedia
An
interesting question is can nature-based approaches such as afforestation and
rapid increase in green cover provide a solution. It would be interesting to take data from one
state to explore this further. Tamil
nadu consumed forty-one crore units of power in one day on April 20th
according to The Hindu. With 75% of the power
coming from thermal power, this translates into thirty crore units of power from
thermal power or close to fifty crore Kg
of coal burnt per day, resulting in 125 crore Kg or 1.25 million tons of CO2
in a day. To sequester this back
through forest-based solutions is a
daunting task. . Tamil Nadu’s standing forests of about 26000 sq km (20% of area) –
six million acres would redress sixty million tons of CO2 or 60 days of emissions. To sequester a year’s worth of emissions about
120000 sq.km of land area – or over 90% of the state needs to have green cover,
which is impossible. However, there are opportunities to
mitigate this further, by converting lower carbon per hectare monoculture plantations
to six hundred Tons / Hectare rain forests and sholas where possible, by regenerating
mangroves across the coast, by converting barren coastal regions to dry
evergreen forests such as those seen in Guindy and Point Calimere. However one needs to be honest in acknowledging
that these are mitigative steps and not the sole pathway to reach Nett Zero
emissions.
A six hundred Tons / Hectare Shola Forest in
Nilgiris
.
Clearly nature-based approaches
are only part of the puzzle. One needs to redress emissions footprint for the different
power generation modalities, at source. Potential
solutions for include:
Technologies to Reduce Emissions from Power Generation by 5 to 30%:
·
More efficient thermal power. ultra super critical
thermal for coal, coal gasification. And combined cycle gas turbines powered by
syn-gas for reduced emissions even at higher cost. This would reduce emissions from existing thermal
power plants by about 20%
·
Combined cycle gas turbines at 64% efficiency as
against 36% to 42% for new coal-based power plants. This can reduce emissions by 30%
·
Carbon capture at an industrial scale. While this would increase energy demand by 5 to
10%, all of CO2 in principle can be captured
- and could be part of a nett zero emissions play,
·
Thermal power augmented with biofuel – includes agro-residues,
municipal waste. Agro-waste is a
renewable resource, and it contributes to reduced emissions to about 10 to 15%
maximum.
Technologies for Zero Emissions
·
More renewables , offshore wind to address peak
power demand in the evening. (5 to 10% of local energy demand).. Of shore wind can generate up to three
times the energy per acre compared to on-shore
installations
·
More Solar and wind energy, rooftop solar and wind, Irrigation pumps powered by solar contributing
to zero emissions.
·
Nuclear.- despite risks this is a mature technology
capable of delivering 24 x 7 power.
Counties such as France had shown clear thinking by resorting nuclear energy
to meet 68% of its energy requirements through nuclear power. Small nuclear power plants are an alternative
that reduce risks of catastrophic exposure of population to radiation leaks
should there be an accident.
·
Small Hydro –
these runs of the river installations amounting to less than a MW of power can
harness energy from flowing streams.
·
Agro-waste driven distributed power can unlock more
revenue streams for farmers. Crop waste,
excreta from cattle could be used to generate either liquid fuel, methane,
natural gas, or hydrogen to generate power, making farmers nett suppliers of
energy. Since any form of agro-waste or
residue is a renewable resource these sources of energy are nett zero in emissions,
·
Green Hydrogen and ammonia – derived from renewable
sources.
We have a plethora of technologies to reduce
emissions. Among these the only ones
that are deployed at a mass scale accounting to a significant proportion of the
energy mix are solar and wind energy.
The country requires a full court press – including technologies to reduce
emissions from fossil fuel-based power, all renewable or Nett zero emissions
energy sources, and nature-based solutions to sequester back greenhouse gases.
The country can clearly do more than what is being
done now. These tangible steps to
maintain energy security while reducing emissions footprint could be the driver
for future economic growth,
References
1 Electricity sector in India - Wikipedia
2. Natural Resources Research (
2019) https://doi.org/10.1007/s11053-019-095
TV Ramchandra et. Al. “Carbon Sequestration Potential of the Forest Ecosystems in the Western Ghats, a Global Biodiversity Hotspot”
