Energy & Green Tech

Energizing buildings

A solar façade developed at ETH Zurich combines electricity production with intelligent shading to achieve optimal energy balance.

Energy & Green Tech

How to have an all-renewable electric grid

The main solution to climate change is well known—stop burning fossil fuels. How to do this is more complicated, but as a scholar who does energy modeling, I and others see the outlines of a post-fossil-fuel future: We ...

Energy & Green Tech

Carbon-neutral fuels from air and green power

Several challenges associated with the energy transition can be managed by coupling the sectors of electric power and mobility. Green power could be stored in the long term, fuels of high energy density could be used in a ...

Consumer & Gadgets

The future of continuously rechargable batteries

University of Canterbury (UC) Associate Professor Aaron Marshall thinks so and is developing redox flow batteries as a viable energy storage system that will never wear.

Energy & Green Tech

California's rooftop-solar boom leaves equity gap

California leads the nation in the adoption of rooftop solar systems, but information on which communities do, and do not, benefit from these installations has been limited to broad income classifications and anecdotal observations. ...

Energy & Green Tech

Field trials validate wind turbine wake steering impact at scale

If every turn of the wheel is a revolution, then every sweep of a wind turbine blade is an opportunity. That's how researchers at the National Renewable Energy Laboratory (NREL) view the potential for wind plant operators ...

Energy & Green Tech

New rechargeable aqueous battery challenges lithium-ion dominance

A new rechargeable high voltage manganese dioxide zinc battery, exceeding the 2 V barrier in aqueous zinc chemistry, is the latest invention by City College of New York researchers. With a voltage of 2.45-2.8V, the alkaline ...

Energy & Green Tech

Pollution-free hydrogen: green energy breakthrough?

Scientists said Tuesday they have developed a way of extracting hydrogen from oil without releasing greenhouse gases—a breakthrough they hailed as a "silver bullet" for cleaner energy and the climate.

Energy & Green Tech

How buildings can cut 80% of their carbon emissions by 2050

Energy use in buildings—from heating and cooling your home to keeping the lights on in the office—is responsible for over one-third of all carbon dioxide (CO2) emissions in the United States. Slashing building CO2 emissions ...

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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