IPRs, in particular Patents, can be hurdle or opportunity based on the situation. Integrated factors other than strictness of Patent Regime are also important in Diffusion of ESTs which have been discussed in detail in the present research. International Legal framework plays a crucial role in ESTs diffusion into India. Major legal frameworks relevant for present research include Paris Convention for the Protection of Industrial Property, 1883; Patent Cooperation Treaty, 1970; WTO framework; TRIPS; UNFCCC; WIPO Green and SDGs. Policy and Legal framework of India are also closely intertwined with diffusion of ESTs, their relationship is discussed in the present research. Policy related to climate change and renewable energy is also discussed. In Indian Legal Dimension, Strict Criteria of Patentability, Compulsory Licensing, Patent Prosecution Highway, Commercial Working Data and Renewable Energy is discussed. Thereafter, detailed empirical research is carried out wherein, search query is determined for wind and solar power generation technologies, yearly trends are studied, and nationality of applicants are determined. Towards the end of this research, summary of the research work carried out has been stated and suggestions have been described.