Definitions - v

Ventilation

Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. There are three naturally occurring isotopes, with 12C and 13C being stable, while 14C is radioactive, decaying with a half-life of about 5730 years. Carbon is one of the few elements known since antiquity. The name "carbon" comes from Latin language carbo, coal.

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Vermicomposting

The process where worms feed slowly on decomposing materials (e.g. vegetable scraps) in a controlled environment to produce nutrient-rich soil.

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Vertical Axis Wind Turbine

Energy obtained from sources that are essentially inexhaustible, unlike, for example, the fossil fuels, of which there is a finite supply. Renewable sources of energy include wood, waste, geothermal, wind, photovoltaic, and solar thermal energy.

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Vertical-axis Wind Turbine

A wind turbine with the axis or main shaft mounted vertically, or perpendicular to the earth's surface. This type of turbine does not need to be turned to face the wind - the wind always blows across it. Types include Savonius and Darrius.

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Vicariance

The evolution of a new species from a group separated from the original species by a geographic barrier.

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Virga

Rain which fall in the sky but evaporates before it reaches the ground.

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Virgin Materials

A Passive House is a house designed to use Passive Solar Design principals to drastically reduce its energy demands by making full use of the energy supplied by the Sun, this thereby reduces ecological footprint of the building.


This can include its orientation, window placement, Trombe Walls, ventilation, thermal mass and living space placement. It also include the adoption of standards on energy efficiency to further reduce energy demands.

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Virgin Paper

Virgin paper is paper that contains no recycled content and is made directly from the pulp of trees or, alternatively, cotton.

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Volatile Organic Compounds

Sustainable energy refers to energy sources which are in themselves sustainable; e.g. they are not considered finite.

Typically these consist of: Hydro, solar, wind, biomass, geothermal and tidal.

Note: it is important when considering the technologies that utilize sustainable energy sources that the total lifetime cost is fully considered (e.g. from manufacturer, deployment, ongoing maintenance, to final disposal). Although the energy source many not be finite, the lifetime of operation of the technology to access them is finite and this should be considered. Basically there is no point in picking a sustainable energy source using a technology which requires constant maintenance or replacement, there is no net benefit to the environment or the consumer of the energy (higher costs and less reliable).

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Voltage Drop

The voltage lost along a length of wire or a conductor due to the internal resistance of that conductor. The voltage drop is calculated using Ohms Law. 

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