India's transition towards environmentally sustainable technology has become an increasingly important component of economic policy, energy security, industrial development and climate strategy. Between 2017–18 and 2025–26, public expenditure supporting renewable energy, solar power, wind power, decentralized energy, green hydrogen, energy efficiency, electric mobility, sustainable manufacturing and associated infrastructure underwent substantial structural change. This Research examines the evolution of public financial allocation and expenditure on environmentally sustainable technology in India, with particular emphasis on the Ministry of New and Renewable Energy (MNRE), while situating the expenditure within the wider environmental and energy-policy framework. The analysis demonstrates that India's sustainable-technology transition has moved from a predominantly deployment-oriented renewable-energy model towards a broader industrial and technological transformation involving domestic manufacturing, distributed solar energy, green hydrogen, energy storage, electric mobility, grid modernization and low-carbon industrial systems. MNRE expenditure increased considerably over the Research period, although utilization has not always matched budgetary allocations. The Parliamentary Committee on Energy reported that MNRE utilization during 2020–21 was 86.23 percent of revised estimates, rising to 88.43 percent in 2021–22 and remaining at 81.70 percent in 2022–23; expenditure constraints were associated with the COVID-19 pandemic, delays in fund-flow procedures and insufficient proposals from some North-Eastern states. Digital Sansad  The transformation became especially visible after 2022–23. The National Green Hydrogen Mission introduced an initial outlay of ₹19,744 crore, including ₹17,490 crore for the Strategic Interventions for Green Hydrogen Transition programme, while the mission also incorporated pilot projects, research and development and green-hydrogen hubs. Ministry of New and Renewable Energy By 2025–26, MNRE expenditure had reached ₹24,176.68 crore against a budget estimate of ₹26,549.38 crore and revised estimate of ₹25,301.22 crore, representing approximately 91.0 percent of the budget estimate and 95.5 percent of the revised estimate. Press Information Bureau  At the physical level, the financial transformation has been accompanied by substantial growth in renewable-energy capacity. India's renewable-energy installed capacity excluding large hydro expanded strongly, with solar becoming the principal source of new renewable capacity. By March 2026, renewable-energy capacity had reached approximately 274.68 GW, including 150.26 GW of solar and 56.09 GW of wind capacity. Press Information Bureau The evidence therefore indicates a structural transformation in which public expenditure increasingly functions not merely as direct government spending but as a mechanism for mobilizing private investment, creating domestic manufacturing capacity, reducing technology costs and establishing new low-carbon industrial markets.....