Consumer & Gadgets

A new non-fullerene acceptor for indoor solar energy applications

Organic photovoltaic (OPV) cells, a third-generation solar cell technology that can convert solar energy into electricity, have been found to be more efficient than silicon cells under low light intensity indoor LED illumination. ...

Energy & Green Tech

Microorganisms in cow manure used to build rechargeable battery

(Tech Xplore)—For the first time, researchers from Wetsus, the European Centre of Excellence for Sustainable Water Technology; and Wageningen University, both in The Netherlands, have combined two microbial processes—microbial ...

Energy & Green Tech

Sunny prospects for start-up's clear solar energy windows

A Redwood City, California-based tech startup has developed a glass window packed with transparent photovoltaic cells that it believes will revolutionize the way solar energy is harnessed.

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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