UA: A measure of the amount of heat that would be transferred through a given surface or enclosure (such as a building envelope) with a one degree Fahrenheit temperature difference between the two sides. The UA is calculated by multiplying the U–Value by the area of the surface (or surfaces).
U-value or U-factor: A measure of how well heat is transferred by the entire window –– the frame, sash and glass –– either into or out of the building. U–value is the opposite of R–value. The lower the U–factor number, the better the window will keep heat inside a home on a cold day.
Unbundling: Disaggregating electric utility service into its basic components and offering each component separately for sale with separate rates for each component. For example, generation, transmission and distribution could be unbundled and offered as discrete services.
Unfinished Oils: All oils requiring further processing, except those requiring only mechanical blending. In most cases, these are produced by partial refining or are purchased in an unfinished state for conversion to finished products by further refining.
Unleaded Gasoline: Gasoline that has had tetraethyl lead removed in conformance with federal and state regulations. It does not contain more than 0.05 gram of lead per gallon and no more than 0.005 gram of phosphorus per gallon. Premium regular and midgrades are included, depending on the octane rating.
Utility: A regulated entity which exhibits the characteristics of a natural monopoly. For the purposes of electric industry restructuring, "utility" refers to the regulated, vertically–integrated electric company. "Transmission utility" refers to the regulated owner/operator of the transmission system only. "Distribution utility" refers to the regulated owner/operator of the distribution system which serves retail customers.