Renewable energy and India's demand growth: Benchmarking aggregate energy and time-of-day feasibility under technical and policy variability

India faces rising electricity demand, which the Indian government aims to meet disproportionally with cleaner resources, e.g., with the targeted 500 GW of non-fossil capacity by 2030. However, whether this can balance demand growth or plateau coal remains uncertain. This study evaluates whether incremental RE can meet aggregate demand growth, examining time-of-day variations, asking if this can avoid higher fossil fuel use. We analyse incremental demand growth until 2030 and 2036 under diverse uncertainty, including different demand shapes and energy growth scenarios. We first assess annual energy adequacy, assuming storage shifts surplus energy into deficits, with uncertainty over varying CUFs for solar and wind, planned hydro, nuclear, and coal additions. We also examine the impact of solar-to-wind ratio, wind capacity limits, rooftop solar, and planned coal projects. Sensitivity analysis identifies the influence of demand growth, demand shape, CUFs, under-construction capacities, and solar-to-wind ratio on RE requirements and time-block surpluses/deficits. We then evaluate time-of-day demand and supply variations, analysing daily surpluses and deficits, including the role of under-construction hydro and nuclear in mitigating worst deficit days. Findings show that to meet 2030 demand growth with RE India would need 11.8 % more RE capacity than targeted. Demand growth and solar CUFs have the highest impact on RE requirements and surplus/deficit, with nonlinear effects from multiple variables. Over 100 days of renewable deficits and seasonal mismatches indicate challenges for storage, necessitating either significant RE overbuilding or greater thermal output, underscoring the need for accelerated RE deployment, grid flexibility, and demand-side measures.