A key feature of the transition that we need to recognise is the role of electricity and hydrogen. Electricity, which currently constitutes around 18 per cent share in total energy use, will play a much bigger role not only because of being more efficient and convenient form in terms of end use (such as e-mobility) but also because it would constitute a much larger share at the primary energy production level. For example, major resources like solar, wind, hydro, and nuclear primarily produce electricity as a first step.

Even production of green hydrogen would need electricity if steam electrolysis becomes the production method of choice. There is, of course, the alternative to split water through thermochemical means directly using the high temperature produced using solar, thermal or nuclear technology. These technologies are evolving, but in principle, it seems to me that the thermochemical route would eventually produce cheaper hydrogen. If that becomes a reality, then the increase in share of electricity could get limited to around 35 per cent of the total energy use.

If that is not the case and we need to produce hydrogen using electricity, then the share of electricity could become as large as 80 per cent. Clearly the electric power business would grow both because we need more energy but also because we expect a major transition towards electricity.

With its potential as a feedstock, energy carrier and storage medium, hydrogen offers significant prospects to decarbonise large sectors of the economy, such as transport and industry, particularly in hard-to-abate areas such as energy intensive industries or long-haul transport, where electrification is only partially possible. Hydrogen-powered fuel cells driving electric power transmission for heavy long-distance transportation are soon expected to become popular due to better viability and freedom from range anxiety while battery-powered smaller electric vehicles would become the main choice for short range in-city transportation.

The use of green hydrogen in industries like fertiliser, iron and steel and adoption of carbon capture and utilisation (CCU) as well as carbon capture, utilisation and sequestration (CCUS) where use of fossil carbon or hydrocarbon remains inevitable, would clearly play an important role in the transformation of our industry sector.

Let us now look at the energy resources available to produce energy equivalent to 45,000 billion units. Detailed estimates by Prof Sukhatme suggest the total renewable energy potential (including solar, wind, small and large hydro, biomass and tidal) in the country to be at around 5,855 billion units. Even after accounting for additional biomass potential of 2,500 billion as discussed earlier and likely uncertainties in the estimates, it is clear that the large gap that still exists would have to be bridged by nuclear, the only other available non-fossil energy with high enough potential.

While the bulk of this large energy requirement can only be met by large capacity plants, a decentralised mode of energy production has its own value in terms of local self-reliance, rural economy and livelihood like in the case of biofuels discussed earlier. Local microgrids in the case of electricity production, should also be linked to the main power grid. There is also merit in making local microgrids DC so they are solar panel compatible. This brings in both efficiency and economy. Work done at IIT Bombay for making solar products in cottage industry mode and at IIT Madras for DC microgrids is noteworthy in this regard.

The next big question would be the stability of grids and the additional cost to consumers, depending on the energy mix and related investments. Generation sources like nuclear, hydro and biomass are steady generation sources whereas sources like solar and wind are variable generation sources. The design of the grid and the peak load capacity has to take into account variability in load demand as well as variability in generation.

Studies have shown that as one approaches net zero, a mix relying primarily on nuclear energy is the most cost-effective option to achieve the decarbonisation target. We need similar detailed studies in Indian context to correctly inform our policy making. 

Talking about nuclear, our domestic self-reliant development has enabled the country to deploy Pressurised Heavy Water Reactors (PHWR) with almost 100 per cent value addition within the country. These reactors have demonstrated a world-class performance and have made global records for the longest uninterrupted runs. The specific capital cost of these systems is about half compared to their counterparts in the international market.

It thus makes sense to rapidly scale up nuclear capacity addition through work on several fleets of 700 MWe PHWRs. In addition, we should quickly develop a Small Modular Reactor (SMR) as a new Indian product that can make use of sites vacated by retiring coal power plants and augment nuclear capacity addition. Indian corporates have done well in the manufacture and construction of nuclear power plants. It is time they also develop new products and prepare for participation in the nuclear business in a more holistic manner without losing advantage of ‘make in India’ in a self-reliant manner.

It is thus clear that in India we can create access to clean energy in the required quantities and that planning and implementation for clean energy transition is a highly interconnected process that needs an integrated view and collective action on the policy, technology, and industry front. Doing this should nearly eliminate the need for energy imports.

Most of the necessary technologies are however still under development. Rather than local energy economics being driven by global markets, we should drive development and deployment of technologies and their prices through a policy leveraging Indian needs and size of the Indian market. An integrated approach thus becomes all the more important.