In 2015, India communicated its intended nationally determined contribution (INDC) for the period 2021-30 consisting of eight elements. Of these, two have a direct relationship with nuclear energy: to achieve about 40% cumulative electric power installed capacity from nonfossil fuel-based energy resources by 2030, and to reduce the emissions intensity of its GDP by 33-35% from 2005 levels. To achieve the first target, India also commits to make efforts to achieve 63 GW installed capacity based on nuclear generation by 2032, provided nuclear fuel supply is ensured.GoI clearly indicated its intention to accelerate growth of nuclear energy when in his Budget 2016 speech, finance minister Arun Jaitley announced the need to diversify sources of power generation for longterm stability. He spoke about drawing a comprehensive plan, spanning the next 15-20 years, to augment the investment in nuclear power generation, and budgetary allocation up to Rs 3,000 crore a year. Considering that investments in power in India generally involve a debt-to-equity ratio of 70:30, this means an investment of Rs 10,000 crore a year.
On May 17, 2017, the Cabinet approved the construction of 10 units of indigenous pressurised heavywater reactors (PHWRs) of 700 MW each. This was followed by the landmark event of a general framework agreement signed with Russia on June 1for setting up another two reactors of 1,000 MW each at Kudankulam, Tamil Nadu. The joint declaration reiterated the commitment of both sides to the vision document signed in 2014, which included the construction of six reactors, each of 1,200 MW, at a new site.
Reactors having a total installed capacity of 6,780 MW are in operation. One Prototype Fast Breeder Reactor (PFBR) having a capacity of 500 MW is under commissioning. Four PHWRs, each of 700 MW, are under construction. The foundation stone for two PHWRs of 700 MW rating was laid in 2014, and the Nuclear Power Corporation of India is moving towards first pour of concrete. And agreements for the construction of four reactors of 1,000 MW rating at Kudankulam have been signed.
Negotiations with the US and Franceare ongoing to tie up constructions of more nuclear power plants. Overall, the country is progressing to achieve the target of 63 GW by 2032.
This development should be examined with India’s evolving electricity mix. Fuelled by GDP growth, electricity demand is rising. Aspirational India demands reliable electricity supply. For the year ended March 31, 2017, total electricity generation was 1,242 billion units, with coal contributing 994 billion units. Generation by captive power plants was additional and could be about 170 billion units, mostly from thermal power plants. Nuclear and Variable Renewable Energy (VRE) sources contributed about 40 billion and 81billion units respectively.
VRE sources are intermittent. Therefore, integrating VRE sources in the grid results in high system cost. Two issues regarding energy generation should be highlighted. One, ‘external costs’. The term is used to denote the cost that the party responsible for generating emissions does not account for and, consequently, consumers of electricity do not pay for. They are paid in terms of health effects (deaths, serious and minor illnesses, etc) by those exposed to emissions and may not be even using electricity.
The EU’s ExternE project studied external costs during 1990-2005. It concluded that nuclear has the least health effects among the electricity generation technologies studied: lignite, coal, oil, gas, biomass and nuclear. The EU’s New Energy Externalities Development for Sustainability study also concluded that nuclear has very low external costs as compared to other technology options. It also favours wind and solar, the two also having low external costs, but also low energy density, constraints on their location and being intermittent, resulting in high system cost.
The second issue is the ratio represented by Energy Returned (ER) over Energy Invested (EI). Governments, business houses and individuals are all concerned about energy use efficiency. How about efficiency of energy production? Energy economists have devised a term EROI to represent the ratio of ER over EI in output. Net energy gain, or useful energy available to society, is the difference between ER and EI. EROI’s value depends on factors like system boundary used for analysis, method of handling heat energy and electricity, and how one addresses the dynamic effect. The issue of dynamic effect arises from the fact that the grid has a certain EROI and this could be higher than the EROI of the energy source under evaluation.
For input, one will draw energy from the grid and use it to produce, say, photovoltaic cells, which have a low EROI. A significant amount of energy is used up in building energy infrastructure when energy demand is increasing. To evaluate inherent characteristics of an energy technology, it is appropriate to make adjustments for this factor. This is termed as dynamic effect.
According to a Princeton University study, for a particular electricity growth scenario for the period 2010-2100, dynamic EROI is as follows: nuclear (62), hydro (57), wind (39), coal (38), gas (8) and solar (6). This data does not factor in energy associated with grid integration, which is very high for solar and wind.
Alow value of EROI means more flow of material per unit of electricity generated. Higher the flow of material, larger the ecological footprint. A value less than about 10 raises issues of sustainability. At present, VRE sources contribute a small fraction of energy to the grid. If their share is increased beyond about 10%, they will not only make grid management difficult, but they will also have an adverse effect on the EROI of the grid.
So, as India embraces an ambitious growth path based on low-carbon energy sources, an approach that integrates positive features of all sources needs to be adopted. India must do everything to achieve the target of 63 GW nuclear-installed capacity by 2032 and set an aggressive target of nuclear generation, say, 25% of total generation, to be achieved by the middle of the century.
(The writer is Homi Bhabha Chair, Department of Atomic Energy)