Policy Effort to meet Ratcheted Ambitions : The case of Utility-Scale Solar in India

Accelerating the low-carbon energy transition will require rapid deployment of renewable energy technologies, especially in developing countries where energy demand is growing fast. How much of this acceleration can be left to markets, and how much must be driven by policies? On the one hand developing countries can benefit from technology learning and cost declines from the technological pioneers. On the other hand, developing countries typically pose higher risks to investors. In this paper, we argue that understanding the relative role of markets and policies in accelerating renewable energy growth in the future requires looking at how that growth has unfolded in the past. We examine the case of utilityscale solar in India, which has experienced sustained acceleration over the past decade, underpinned by rising political ambition, and favourable market conditions, including sharply falling technology costs, high solar irradiation, growing demand, and benefits from technological and policy learning from solar PV pioneers. We analyse national energy transitions as shaped by the co-evolution of technological innovation, economic development, and policy change, and map India's solar trajectory by diagnosing technological growth phases, cost trends, and policy evolution at both federal and state levels. We address four questions: (i) What is the relative role of cost decline and policy effort in driving solar growth? (ii) How do policies evolve in response to increasing deployment and declining costs? (iii) What barriers emerge at different phases of technology growth in a developing, technology-recipient country? (iv) Do later adopting regions catch up, or do disparities in deployment persist or increase over time? Our findings show that even in a highly favourable market, utility-scale solar in India has been and remains fundamentally policy-driven. As costs declined, more numerous-and more diverse-policies were required to sustain solar PV growth. Policy interventions were often triggered by emergent barriers, and growth pulses coincided with such adjustments. Many barriers mirrored those in developed countries, but emerged at different, often earlier stages, thereby signaling the need for greater policy effort in developing countries and undermining the argument for easy 'leapfrogging'. Finally, solar growth across Indian states has been and continues to be spatially uneven, with no evidence of convergence between earlier and later adopters. Instead, the co-evolution of cost, technology, and policy appears to reinforce the spatial divergence. For policymakers and researchers modelling climate mitigation pathways and seeking to understand the real-world effort needed to accelerate renewable energy deployment, our findings offer a grounded sense of what it may take. Even under favourable market conditions, sustained growth requires persistent, adaptive, and often increasingly intense policy effort.