Contours of a Sustainable Green Economic Growth
Part 1: Energy
The last year has been some of the difficult for India since
independence. Urban Indians, used to working hard, and seeing steady
improvements in income, are fearful of heading out of their homes and faced
with an uncertain future. The unorganized sector consisting of an
estimated 100 million people who have moved from impoverished rural hinterlands
to urban clusters across the country are rendered vulnerable to COVID 19
related lockdowns. Consumption has been reduced to the essentials, borne
out by the fact that except for agriculture and its products, and low-cost
fast-moving consumer goods, the rest of the economy is now on a tailspin.
That the pre-COVID19 era was successful in lifting large sections out of
poverty, especially since 2004 cannot be ignored. This has come with
considerable collateral damage in in the form of rampant increase in emissions
greenhouse gases and pollution. At 2650 million tons of CO2 per annum,
India emits 50% more greenhouse gases per unit area compared to US, while the percentage
area under forest cover is 50% lower in India compared to US. India’s
urban spaces are now among the top 10 polluted cities in the world. Much
of its water from rivers and ground are not potable. India’s progress has
come at the cost of sustainability. India’s challenge as and when
it overcomes COVID19 is to mitigate poverty through better livelihoods and
economic growth, in an equitable manner, while veering away from its emissions
and pollution heavy past. To accomplish the above, generating enough
energy, finding sustainable transportation solutions, and generating new green
jobs will be the central challenge.
While renewables constitute nearly 37% of
installed capacity, the percentage of
energy generated in the final mix was lower: about 140,000
gigawatt-hours (GWh) – or only10% - came from the solar and wind plants.
This is primarily because of the dependency of solar and wind on natural
and manmade factors including cloud cover, smog, and wind flow patterns which are
seasonal in nature. While India would have to augment power
generation in manner that is commensurate to the targeted GDP growth, banking
completely on renewables is unviable with the
technology mix available today.
India needs to therefore develop smart strategies which
include generating renewable and thermal power more efficiently while
decarbonizing the energy economy. Fortunately, the technologies required
to make much of this happen is available or within reach. If due
attention is given to improved efficiency and reduced emissions from the power
sector, India can take decisions which will serve to preserve its natural
capital rather than destroy it. The strategies for India to find
solutions in the short and long term to reduce carbon dependence while
augmenting power generated are outlined below:
Short Term:
Improving Efficiency of Power Generation: Most of power plants are
over 20 years old and rely on subcritical steam cycles where the efficiency
entitlement is about 35%, while the realized efficiency is only in the range of 30% realized
efficiency today. This is largely because of degradation in boilers, turbomachinery
and other balance of plant equipment.
The knowhow to fix this exists, and India needs to source the best available
technologies to bring back the efficiency to its entitlement value, which can
help in reducing carbon dioxide emissions by 210000 tons per year from a 100 MW
plant. In the medium term India needs to convert its coal based thermal
plant to super critical and ultra-super critical steam turbines, with the
efficiency ranging from 42 to 46%
Gas turbine based power plants with combined cycle that use the exhaust energy to drive steam
turbines can drive efficiency to 62 to 63% as against the 30-35%
efficiency prevalent today. In other words, thermal power can operate
at half the CO2 emissions per unit power produced with combined cycle gas turbines. Depending on the
technologies used India can generate 5 to 100% more thermal power without
increasing its total emissions footprint. Therefore frenetic pace
with which more coal blocks are being added for mining at the expense of
centuries old forest cover is unwarranted.
While India’s solar power plants are less than a
decade old, the first wave of wind farms that were installed in
Tamil Nadu and Gujarat in the 1990s - amounting
to nearly 14000 MW, uses technology that is now
outdated. New wind turbines with longer blades, shaped to
maximize energy conversion from low wind speeds can improve efficiency by 25%
or more. In addition, data analytics solutions to improve micro siting
within a wind farm can further improve power generation. Repowering
old wind farms needs to be an active strategy.
Improving Availability of Renewable Power: Wind farms lie
idle for months together and operate at their peak only during monsoonal
flows. Most of the wind farms are situated in fallow lands and the space
between wind towers, about 6 acres per MW capacity lies vacant. Targeting
new solar power plants in such locations with the idea of sharing power
electronics and evacuation technologies could make renewable energy a bankable
solution for about 12 to 14 hours per day especially because wind power is
driven by thermal gradients which increase in the evenings. If efficient
aeroderivative or diesel driven internal combustion engines could be added one
could deliver a bankable 24x7 renewable power solution that uses current
infrastructure.
With falling lithium battery prices and availability of offerings that
exceed several MWh for a few hours, battery storage needs to be evaluated as
part of the energy mix. But there are several concerns; rain forests get
decimated to mine lithium and cobalt, and our dependence on imports would
skyrocket There could be other homegrown inclusive solutions that must
be considered.
Longer Term:
Energy security in the long term must to include hydrogen and biofuels from agro waste as key sources of
thermal power. Hydrogen generated through electrolysis, using
energy from offshore windfarms is a vision that finds an echo in many countries. The hydrogen is
burnt in a gas turbine or fed through fuel cells to to generate power.
Gas turbines with hydrogen in the fuel mix have been tried and tested and
the know-how exists among the major OEMs.
However, the greatest opportunity to develop a renewable 24x7 power
source is a hybrid that consists solar and wind farms working in tandem with
biofuel-powered thermal power sources that provide the required base load power
into the grid. These can be micro grid installations or run into 100s of
MW depending on the specific contexts. India
generates more than 10 times more agrowaste than foodgrains. This
translates to 2.70 billion tons of biomass, with a potential of 270 Million MWh
of electricity assuming very conservatively that the heat rate of the
biomass is just one tenth the calorific value of conventional carbon-based
fuels. There are two technology options: digestion and gasification /
combustion-based solutions.
Digestion-based technologies in a silo capable of handling 100 acres of
harvest with the right feed of enzymes and microbes can generate biofuels which
would be refined in a biorefinery with fuels cut for multiple uses including
energy and transportation. The residues from the digestion process are often
rich natural fertilizers. These technologies are not yet on the finish
line and require government support.
Direct combustion and gasification based technologies operate at a
larger scale and require extensive transportation logistics which may prove to
be complex.; however in the short run these technologies are being explored to
redress the endemic stubble burning to produce thermal power in the
country. With the above technologies, the
farmer becomes a part of the energy and fuel supply chain, with an additional
and valuable revenue source. Making the
above happen needs to be India’s vision and mission.
India needs to seize moment; it needs to stop looking at Climate Change
obligations as a drain on the economy. Instead it needs to
understand that opportunities to upgrade technologies in thermal power, and
reconfigure its renewable portfolio in the form of PV-wind hybrids are
opportunities to drive economic growth. In the longer run it
needs to move towards green hydrogen, and biofuels for 24x7 thermal
power based on renewable fuels along with renewable energy to meet its
growing energy needs.
Acknowledgements: Author would like to thank Mr. Gopakumar Menon,
Navgati for his inputs.
Photographs and schematics are courtesy Google.
