Glossary: V to Z
A-C | D-F | G-I | J-L | M-O | P-R | S-U | V-Z
V
Volatile Organic Compounds (VOCs): VOCs are found in a wide variety of consumer products from paints, solvents, and adhesives to carpeting, deodorants, and cleaning fluids. When released into the air, they react with other chemicals to create ozone in the lower atmosphere, impacting human health. They can also have direct air quality impacts inside buildings when off-gassed by indoor paints, carpeting, and adhesives. Nonmethane volatile organic compounds (NMVOCs) are a type of VOC.
Volt: A unit of electrical force equal to the amount of electromotive force that will cause a steady current of one ampere to flow through a resistance of one ohm. High-voltage electricity moves faster than low-voltage electricity, as seen in the difference between high-voltage transmission lines used to move electricity quickly throughout a region and lower-voltage distribution lines used to move electricity directly to customers.
Voltage: The amount of electromotive force, measured in volts, that exists between two points. Voltage is used to describe the amount of power produced by a generator.
W
Water efficiency: Water efficiency refers to practices, products, or systems that use less water than traditional products or systems without sacrificing performance. Water-efficient products can include graywater use and low-flow water fixtures (such as toilets or faucets). Water-efficient practices can include landscaping with plants that require less water, use of rainwater for irrigation, and stormwater management.
Watt (W): The rate of energy transfer equivalent to one ampere under an electrical pressure of one volt. One watt equals 1/746 horsepower, or one joule per second. It is the product of voltage and current (amperage). The term "watt" (in addition to the larger measurements of kilowatt and megawatt) is commonly used to describe the capacity of an electric generator. For example, a 1,000-watt photovoltaic system has the capacity to produce 1,000 watts of power at any given time, though it may not consistently produce this much.
Watt-second (Ws): One Joule equals one watt-second.
Watt-hour (Wh): The energy produced by 1 watt of power acting over a period of 1 hour. The Wh is the basis for the more commonly used measurements kilowatt-hour and megawatt-hour.
Whole-building design: Whole-building design is the integration of a building’s elements and systems to maximize its energy, environmental, and financial performance. A critical element of this approach is the integration of energy systems to maximize efficiency and reduce the need for electricity, heating, and cooling technologies. The whole-building approach also considers construction materials, indoor environmental quality, acoustics, and other building factors like design and siting to minimize a building’s impacts on its surroundings and improve its performance for occupants.
Wind power: Wind power uses the kinetic energy of flowing air to create mechanical energy in a wind turbine that can be transformed into pollution-free electricity. Learn more about wind power and wind turbines.
Wind turbine: Wind turbines are structures that use moving air to generate electricity (wind power) through the use of blades that are easily turned by the wind. This rotating motion is translated inside the turbine into an electric current, which is then interconnected via cables to a nearby electric grid. Learn more about wind turbines and wind power.
Work: Work is the transfer of energy to move an object a certain distance, such as a horse pulling a plow from one side of a field to another. Work is expressed in Joules. The rate at which work is performed is power.
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