Embedding resilience in energy system deep decarbonisation pathways for emerging economies: The case of India

The technical feasibility of 100% renewable energy (RE) pathways in electricity systems depends on enabling conditions such as modern, fast-response grid infrastructure, mature demand response, large-scale storage deployment, the availability of non-variable renewable resources and adequate governance capacity. These conditions may be difficult to realise in many countries in the Global South that face structural transition uncertainties, including infrastructure gaps, renewable resource limitations, and governance issues. This creates a need to embed resilience into the long-term planning frameworks for increasing the likelihood of achieving deep decarbonisation. The study proposes a modelling approach that limits the impact of the above uncertainties by operationalising resilience through the imposition of minimum firm and dispatchable capacity (FDC) requirements within a long-term energy system optimisation model. The framework is applied to India’s electricity sector through a time horizon until 2050, employing six different scenarios. The results demonstrate that deep decarbonisation under realistic Indian conditions requires a diversified portfolio of low-carbon technology alongside RE. The key finding is that a 20% FDC requirement reduces renewable penetration by only ~1% relative to the unconstrained scenario, with a minimal cumulative investment premium of 2.7% (USD 39 billion), largely because hydropower can satisfy the constraint at low cost. However, under higher FDC requirements of 40% and 60%, hydropower and biomass potentials are exhausted, favouring the introduction of low-carbon firm resources such as coal with carbon capture and nuclear into the capacity mix. These additions reduce the storage requirements by 51% and 84%, respectively.