This article is part of the series Comprehensive Energy Monitor: India and the World
Energy transitions in the last hundred years were
slow processes that were market driven. Markets, by definition,
ignore negative externalities of energy production and energy use that include local pollution and emission of carbon dioxide (“carbon”). The current global energy transition is different from earlier transitions as it is
driven primarily by policy to counter market failure in limiting pollution and carbon emissions. The policy-driven energy transition has thus far focused almost
exclusively on renewable energy (RE) to limit carbon emissions with electricity as the primary carrier. The highly
diffused nature of RE requires elaborate installations such as solar panels and wind turbines that capture the light energy of the sun and the kinetic energy of wind and convert it into usable quantities of electricity. This means that the
material and natural resource (primarily land) costs to generate one unit of electricity are substantially higher for RE compared to the generation of one unit of electricity from fossil fuels. This increased
demand for land for RE projects has not been reconciled with land demand from
India’s reforestation pledge in its updated nationally determined contribution (NDC).
Renewables and Land
The past energy transitions involved a substantial improvement in energy released on combustion (oxidation) and a reduction in carbon emissions on account of the increase in hydrogen content in each step forward. Starting with wood whose
hydrogen to carbon ratio (H/C) was about 0.1, the market moved to coal which had a H/C ratio of 1, then to oil which had a ratio of 2 and then to natural gas which had a hydrogen to carbon ratio of 4. The
systematic increase in the H/C ratio led to the view that hydrogen was “winning” over the energy market and would eventually become the sole carrier of energy. The policy-driven transition towards RE initiated in the last two decades has, in some sense, interrupted the market-based transition with electricity as the primary energy carrier rather than hydrogen.
Each energy transition of the past also involved an increase in the gravimetric energy density (energy content per unit weight) or the volumetric energy density (energy content per unit volume) of the dominant fuel. For example, the
energy density of dry-wood was about 17 million joules per kilogram (MJ/kg) compared to 22-25 MJ/kg for coal and 42 MJ/kg for oil products. Natural gas has an energy density of 35MJ/cubic metre (m
3) compared to
45 GJ (giga joules)/m3 for crude oil, almost 1000 times greater which is why transporting oil is much cheaper than transporting natural gas. Hydrogen is an energy carrier with a gravimetric energy density of
143 MJ/kg, one of the highest, but its
volumetric energy density of 0.01 MJ/litre (l) compared to
33 MJ/l for jet fuel (kerosene) is more than 3000 times higher, presents challenges in using hydrogen as a fuel for aviation.
Vaclav Smil, an influential environmental scientist uses
power density expressed as energy flux per unit surface (water or land) in watts per square metre (W/m
2) to compare a variety of energy sources. His detailed calculations for power density include land required for upstream operations like mining and drilling as well as land required for storage (especially coal) and downstream activities like waste disposal. Smil calculated the maximum power density of crude oil to be
65,000 W/m2 for oil extraction in oil-rich countries like Saudi Arabia and about
500 W/m2 in less well-endowed regions. For natural gas, the power density ranges from
200 W/m2 to 2000 W/m2 and for coal from
100 W/m2 to 1000 W/m2. The power density of REsources is orders of magnitude lower at
4-10 W/m2 for solar (both photovoltaic and concentrated solar power),
0.5-1.5 W/m2 for wind and 0.5-0.6 W/m
2 for biomass. While past energy transitions moved towards energy sources with higher power densities, the energy transition currently underway is an attempt to shift the global energy system towards fuels with
power densities that are orders of magnitude lower. This means that the new infrastructure for a RE-based energy system would not only be much larger but also preempt any other forms of land use in India, especially land required for reforestation.
Issues
Empirical studies suggest that most of the
areas favourable to solar radiation throughout the year coincide with wasteland in India. But most projections locate only 11-12 percent of solar projects in deserts and dry shrublands in India in most scenarios. Wasteland is also not favoured by project developers. Developing projects in
wastelands increases costs partly because of the inhospitable terrain and partly because of the lack of supporting infrastructure. Transmission infrastructure required to move power generated to consuming centres also increases cost. But when wasteland is used, the socio-economic costs imposed on small landholders as well as the ecological costs involved in diverting agricultural land for RE projects are lower. A widely quoted figure for land required for India to meet the goal of 175 GW (gigawatts) of RE is
55,000 square kilometres (km2) to 125,000 km2 based on a power density of 2 MWp (megawatt peak)/km
2 for wind projects and 26 MWp/km
2 for solar photovoltaic projects. The projected area is not large as it accounts for only 1-3 percent of the total surface area of the country, but it is almost 50 to 100 percent of waste land. Another study concludes that if
78 percent of electricity generation in India is accounted for by solar PV, and about 3 percent is derived from rooftop solar PV in 2050, the land area required would be more than
137-182 percent of urban land area in 2010 and a maximum of
2 percent of crop area in 2050. The study finds that for every 100 ha (hectare) of solar PV panels, 31 to 43 ha of unmanaged forest may be cleared throughout the world. The same amount of land for solar projects in India would clear
27 to 30 ha of unmanaged forest. If this materialises, it will go against one of the less discussed NDC pledges of India which is to create an “
additional carbon sink” of 2.5 to 3 billion tonnes (3 BT) of carbon dioxide equivalent (CO
2eq) through new forest and tree cover by 2030.
According to the
land gap report 2022, meeting India’s reforestation pledge will require 56 percent of India’s land area to be dedicated for creating new forests. This is an order of magnitude higher than land required for the forest cover pledges of
large countries like the USA (14 percent) and
China (2 percent). Other estimates put the land required for reforestation at 30-40 Million ha (M ha) equal to the area of Bihar, Jharkhand and West Bengal combined. The reforestation pledge is clearly not well thought through and reconciled with India’s RE installation targets. The competition for land between RE installations and forest cover may invariably favour RE installations that are backed by large industrial and economic interests. But the rush to install RE capacity could come at the expense of forest cover that could, in theory, prove to be a sink for almost all of India’s annual carbon emissions
of about 3 BT.
Source: World Bank Database
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