Energy & Green Tech

How West Africa can expand power supply and meet climate goals

Not too long ago, when the idea of solar and wind energy was still hotly debated, critics used to point out the limitations of these energy sources: the sun doesn't always shine and the wind doesn't always blow. But nowadays ...

Robotics

An origami-based robotic structure inspired by ladybird wings

Researchers at Seoul National University have recently developed a compact and lightweight origami structure inspired by ladybird beetles. In a paper published in Science Robotics they show how this structure can be used ...

Energy & Green Tech

DC smart grids for production plants

Most production plants today are still powered by alternating current. In the long term, however, research teams from the Fraunhofer Institutes for Manufacturing Engineering and Automation IPA and Integrated Systems and Device ...

Energy & Green Tech

More efficient biosolar cells modelled on nature

Potential sources of renewable energy include protein complexes that are responsible for photosynthesis. However, their efficiency in technical applications still leaves much to be desired. For example, they cannot convert ...

Energy & Green Tech

Finding balance between green energy storage, harvesting

Generating power through wind or solar energy is dependent on the abundance of the right weather conditions, making finding the optimal strategy for storage crucial to the future of sustainable energy usage.

Energy & Green Tech

Researchers develop viable sodium battery

Washington State University (WSU) and Pacific Northwest National Laboratory (PNNL) researchers have created a sodium-ion battery that holds as much energy and works as well as some commercial lithium-ion battery chemistries, ...

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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