The new Institute of Sciences and Technologies for Sustainable Energy and Mobility (STEMS) of the National Research Council is active since 1 October 2020. The new institute merges the Istituto Motori, The Istituto di Ricerche sulla Combustione and the Istituto per le Macchine Agricole e Movimento Terra. The Institute belongs to the Department of Engineering, ICT and Technologies for Energy and Transport and has offices in Naples, Ferrara and Turin. STEMS represents a research hub for sustainable energy and mobility issues with over one hundred researchers. STEMS research activities are carried out with the aim of giving effective responses to the challenges related to climate, energy and mobility that are closely linked and must be addressed with a holistic approach, also with regard to their implications for citizens and in general for society as a whole. In particular, the Institute addresses issues of primary national and international interest such as in particular the decarbonisation of the energy and mobility sectors, promoting the energy transition towards renewable resources. Another important issue is the improvement of energy efficiency which reference not only to the area of mobility but also to industrial sectors, including the agricultural and off-road sectors. The research also focuses on the use of distributed sensors and advanced data analytics methodologies in the management and optimization of energy systems. The greater penetration of low-carbon renewable sources, the development of sustainable mobility systems, energy networks and their integration, power-to-gas technologies, Carbon Capture Use and Storage (CCUS) technologies, production technologies of clean energy carriers (hydrogen, methane, other gaseous and liquid carriers), implementation of digitalization for the production of databases that allow the development of management, planning and efficient decision support models are fields of primary interest of STEMS in line with the objectives of the Paris Agenda 2030, the European and National Green New Deal for sustainable development and the National Research Plan 2021-2027.