Peak demand

Peak demand is used to refer to a historically high point in the sales record of a particular product. In terms of energy use, peak demand describes a period of simultaneous, strong consumer demand or a period of highest demand in a billing period.

Peak load

Peak demand, peak load or on-peak are terms used in energy demand management describing a period in which electrical power is expected to be provided for a sustained period at a significantly higher than average supply level. Peak demand fluctuations may occur on daily, monthly, seasonal and yearly cycles. For an electric utility company, the actual point of peak demand is a single half hour or hourly period which represents the highest point of customer consumption of electricity. The daily peak demand usually occurs around 5:30 pm. At this time there is a combination of office, domestic demand and at some times of the year, the fall of darkness.

Some utilities will charge customers based on their individual peak demand. The highest demand during each month or even a single 15 to 30 minute period of highest use in the previous year may be used to calculate charges.

Demand response

According to the Federal Energy Regulatory Commission, demand response (DR) is defined as: “Changes in electric usage by end-use customers from their normal consumption patterns in response to changes in the price of electricity over time, or to incentive payments designed to induce lower electricity use at times of high wholesale market prices or when system reliability is jeopardized.” DR includes all intentional modifications to consumption patterns of electricity of induce customers that are intended to alter the timing, level of instantaneous demand, or the total electricity consumption. It is expected that demand response programs will be designed to decrease electricity consumption or shift it from on-peak to off-peak periods depending on consumers’ preferences and lifestyles. Demand Response can be defined as "a wide range of actions which can be taken at the customer side of the electricity meter in response to particular conditions within the electricity system (such as peak period network congestion or high prices)". Demand response is a reduction in demand designed to reduce peak demand or avoid system emergencies. Hence, demand response can be a more cost-effective alternative than adding generation capabilities to meet the peak and or occasional demand spikes. The underlying objective of DR is to actively engage customers in modifying their consumption in response to pricing signals. The goal is to reflect supply expectations through consumer price signals or controls and enable dynamic changes in consumption relative to price.

Off

Off or OFF may refer to:

See also

Off!

Off! is an American hardcore punk supergroup, formed in Los Angeles in 2009.

History

Off! was formed in Los Angeles, California in late 2009 by Circle Jerks/Black Flag singer Keith Morris, Burning Brides frontman Dimitri Coats, Redd Kross bassist Steven Shane McDonald, and Rocket From The Crypt/Hot Snakes drummer Mario Rubalcaba. The idea to form the band came after Coats had worked as producer on a Circle Jerks album which fell apart. During that time, Coats and Morris had written several songs together which they used to start Off!. The group made its live debut at the 2010 South By Southwest Music Festival in Austin, Texas. Off!'s first Los Angeles show featured an original art installation by Raymond Pettibon at a downtown warehouse space.

The first release by Off! is a 7" vinyl EP called 1st EP, which debuted on October 13, 2010. That EP, along with three more EPs, were later released as a four 7" vinyl box set entitled First Four EPs on December 14, 2010. The collection contains sixteen songs and features artwork by Raymond Pettibon.

Environment variable

Environment variables are a set of dynamic named values that can affect the way running processes will behave on a computer.

They are part of the environment in which a process runs. For example, a running process can query the value of the TEMP environment variable to discover a suitable location to store temporary files, or the HOME or USERPROFILE variable to find the directory structure owned by the user running the process.

They were introduced in their modern form in 1979 with Version 7 Unix, so are included in all Unix operating system flavors and variants from that point onward including Linux and OS X. From PC DOS 2.0 in 1982, all succeeding Microsoft operating systems including Microsoft Windows, and OS/2 also have included them as a feature, although with somewhat different syntax, usage and standard variable names.

Details

In all Unix and Unix-like systems, each process has its own separate set of environment variables. By default, when a process is created, it inherits a duplicate environment of its parent process, except for explicit changes made by the parent when it creates the child. At the API level, these changes must be done between running fork and exec. Alternatively, from command shells such as bash, a user can change environment variables for a particular command invocation by indirectly invoking it via env or using the ENVIRONMENT_VARIABLE=VALUE <command> notation. All Unix operating system flavors, DOS, and Windows have environment variables; however, they do not all use the same variable names. A running program can access the values of environment variables for configuration purposes.