Energiá

Energiá is a fundamental concept in physics and daily life, defined as the capacity to perform work or cause change in a system. It takes many forms and can be transferred or transformed between objects and processes. In physics, energiá is a property that changes with the system’s state.

The standard unit of energy in the International System is the joule (J). Larger quantities are commonly expressed in kilojoules or kilowatt-hours (kWh); power is measured in watts. Energy content of fuels is often given in additional units such as toe.

Key forms of energiá include kinetic (motion), potential (position), thermal (temperature-related), chemical (bonds), electrical, radiant (light), and nuclear energy. Energy can be transformed from one form to another, often with some loss as heat in real processes.

Energy is conserved in isolated systems; the first law of thermodynamics states that energy cannot be created or destroyed, only converted or transferred. Irreversible processes dissipate energy, reducing its availability for performing work.

Sources of primary energiá include fossil fuels, solar, wind, hydro, geothermal, biomass, and nuclear energy. These are converted into final energy forms used by households, industry, and transport. Some sources are renewable; others are finite, influencing sustainability, economics, and policy.

Understanding energiá, efficiency, and supply security is essential for technology, industry, and climate policy. Global trends aim to increase renewable use, reduce emissions, and improve access to reliable energy.