Energy & Green Tech

U.S. energy use rises to highest level ever

Americans used more energy in 2018 than in any other year, according to the most recent energy flow charts released by Lawrence Livermore National Laboratory (LLNL). Overall total energy consumption rose to 101.2 quadrillion ...

Energy & Green Tech

Good news for rooftop solar, not for home batteries

The energy produced over the lifetime of typical rooftop solar panels more than makes up for the energy it takes to make, mount and then eventually recycle them. But adding a home battery usually lowers those dividends, according ...

Engineering

Boosting the 'brains' of computers with less wasted energy

Many internal components used in today's computers reach temperatures that are hot enough to cook a Thanksgiving meal. The heat produced by the computations can easily burn human skin and tissue – and much of the heat is ...

Energy & Green Tech

New approach could boost energy capacity of lithium batteries

Researchers around the globe have been on a quest for batteries that pack a punch but are smaller and lighter than today's versions, potentially enabling electric cars to travel further or portable electronics to run for ...

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Energy

In physics, energy (from the Greek ἐνέργεια - energeia, "activity, operation", from ἐνεργός - energos, "active, working") is a scalar physical quantity that describes the amount of work that can be performed by a force, an attribute of objects and systems that is subject to a conservation law. Different forms of energy include kinetic, potential, thermal, gravitational, sound, light, elastic, and electromagnetic energy. The forms of energy are often named after a related force.

Any form of energy can be transformed into another form, but the total energy always remains the same. This principle, the conservation of energy, was first postulated in the early 19th century, and applies to any isolated system. According to Noether's theorem, the conservation of energy is a consequence of the fact that the laws of physics do not change over time.

Although the total energy of a system does not change with time, its value may depend on the frame of reference. For example, a seated passenger in a moving airplane has zero kinetic energy relative to the airplane, but non-zero kinetic energy relative to the Earth.

This text uses material from Wikipedia, licensed under CC BY-SA