Energy: a never-ending battle

nergy has been essential to human life since the dawn of time.As early as the Paleolithic era, the production and preservation of fire were crucial for survival.Throughout the development of humanity there has been a constant need to control energy sources.This goes from wood and coal to oil and gas, plus, with the advent of technology in the modern era, chemical, electrical, or nuclear energy.Physics entered the game early enough, behind the technological progresses made in energy generation, storage, and utilisation stands one unifying discipline: physics.Thermodynamics governs every heat engine, power plant, and refrigeration cycle, establishing the efficiency limits that drive innovation in energy conversion.Electromagnetism forms the basis of electrical generation, transmission, and storage, while quantum mechanics explains the behaviour of semiconductors and the operation of photovoltaic cells and LEDs.Advances in plasma physics drive research in nuclear fusion, potentially the most transformative energy source of the 21 st century.Advances in condensed matter physics underpin the search for new battery chemistry and solid-state materials that can store renewable energy safely and efficiently.Meanwhile, progress in nanophotonics and quantum optics continues to improve the light-harvesting efficiency of solar cells.Even classical mechanics continues to guide the optimisation of turbines, fluid systems, and structural designs in renewable energy infrastructure.The importance of physics goes beyond invention: it is vital for sustainability.Physics teaches us that energy can neither be created nor destroyed, only transformed -a principle that urges efficiency and responsibility in every policy and design we adopt.Energy underpins all activities within modern economies and constitutes a fundamental driver of societal development.However, it is a perilous misconception to assume that a society can sustain a high standard of living and the provision of advanced services (digital technology, hyperproduction of data, etc) while simultaneously achieving a drastic reduction in the consumption of energy and natural resources.Consequently, technological innovation plays a pivotal role in enabling the transition from fossil fuels to sustainable, carbon-free energy sources.Sustained investment in fundamental, technological and industrial research is required.