villamosenergiahálózatoknál

Electrical energy, or electric energy, is the energy associated with the movement or the potential difference of electric charges. In physics it can be defined as the work required to move a unit of charge between two points in an electric field, and in everyday use it is measured in kilowatt-hours (kWh). It powers devices, machinery, lighting, and transportation systems.

Most electrical energy is produced at generation facilities and delivered to users through transmission and distribution networks. Generation converts various energy sources into electricity, which is then sent via high-voltage transmission lines and stepped down through substations for local distribution. The electrical grid must balance supply and demand in real time to maintain stable voltage and frequency.

Generation sources vary widely by region and over time. Common sources include fossil fuels (coal, oil, natural gas), nuclear, hydroelectric, wind, and solar. The mix influences emissions, fuel security, and costs. In recent decades, efforts to decarbonize electricity have emphasized expanding renewable capacity, improving plant efficiency, and deploying energy storage and smart-grid technologies to accommodate intermittent generation and enhance reliability.

Environmental considerations focus on emissions, resource use, and land impact, all of which depend on the energy source and technology used. Efficiency gains, demand-side management, and electrification of other sectors (such as transport and heating) are central to many energy policies. Electrification and grid modernization continue to shape the growth and sustainability of electrical energy worldwide.