Energy & Green Tech

Developing a digital twin for the electricity grid

The rapid transition to renewable energy threatens to cause major problems to the very expensive electricity grid in the Netherlands. In his quest for solutions, Professor Peter Palensky is now working on a "digital twin" ...

Computer Sciences

All Bitcoin mining should be environmentally friendly

The rise in popularity of cryptocurrencies such as Bitcoin has the potential to change how we view money. At the same time, governments and societies are worried that the anonymity of these cashless transactions could allow ...

Energy & Green Tech

Offshore wind still looks to get a foothold in California

There may be a literal energy windfall off the coast of California but it is still unclear whether the federal government will give approval to specific sites and how long it will take before tall turbines are bobbing on ...

Energy & Green Tech

Up to 30 percent more capacity for lithium-ion batteries

Researchers of Karlsruhe Institute of Technology (KIT) and cooperating institutions studied structural changes during the synthesis of cathode materials for future high-energy lithium-ion batteries and obtained new major ...

Energy & Green Tech

Used electric vehicle batteries charge up the grid

Researchers at Oak Ridge National Laboratory have developed an innovative control system for repurposed electric vehicle battery packs to store electricity for home use and are scaling up the technology to a large, power ...

Engineering

A gnu way to control room temperature

Heating, ventilation, and air conditioning systems—called HVAC systems—can be a delicate balance. There are many factors to consider, from air flow between rooms to the effect of human body heat. In the past decade, researchers ...

Energy & Green Tech

At 50, Europe's oldest nuclear plant not ready to retire

Europe's oldest functioning nuclear reactor, at Switzerland's Beznau plant, will turn 50 next week—a lifespan deemed dangerously long by environmentalists who are demanding that it be shut down immediately.

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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