(April 2012) MidAmerican Energy awarded a contract to Siemens Energy to supply wind turbines for its 407-MW project expansion. American Electric Power began operating the 580-...
Demand Response: An Overview of Enabling Technologies
of protecting turf, loosening up the bureaucracy, high tariffs, etc. are fully behind us. This view is reasonable because, once enabling technologies and products are available that make providing an ancillary service as easy as programming a VCR (or easier!), then the pressure will build and remaining bureaucratic barriers will rapidly erode.
As a final note to illustrate the opening markets, it should be mentioned that utility load management programs, such as direct load control, already exist for large blocks of customer loads as system resources. Programs such as this are financially attractive to businesses; otherwise, they would not have signed up! A mention or two was made of "enabling technologies."
Smart Metering: Has its Time Come?
The proof of the service is in the metering-however, not the metering that has been in use for decades, but smarter metering that provides proof of the customer's energy consumption or ancillary service over some period of time. The information gleaned from improved metering may be needed by one or more of several entities including the utility, load aggregator, energy service provider, or customer's central location. The length and number of time periods for which energy transactions must be recorded varies depending on how the customer and the energy supplier choose to interact.
The energy-related information of most common interest includes:
- Energy-record the customer's energy consumption over the billing period.
- Demand-record the highest demand (energy consumption over a 15-, 30-, or 60-minute period)
- Time-of-Use-record energy consumption in set time frames (bins) when the system is typically experiencing high prices (on-peak) and low prices (off-peak). n Interval-record energy consumption every 5, 15, 30, or 60 minutes.
An is one that can provide not just kilowatt (kW) usage, but a kW profile versus time. This type of meter is absolutely necessary for capitalizing on load response opportunities unless there is direct control by the utility. In many areas, interval data meters are required for all loads with demands greater than 20 to 50 kW. Although "real-time" interval data can be made available to the user within seconds, most utilities consider daily, weekly, or monthly communications satisfactory. The meters may communicate the data using a variety of methods such as telephone, cellular phone, radio and fixed network. The data is typically accessible at a password-protected Web site.
The cost of upgrading an existing meter to an interval meter is remarkably inexpensive, $90 to $245, if a phone line is already available. 2 New interval data meters range in cost from $200 to $3,700 depending on sophistication and features, such as true real-time data updated every few seconds, and continuous power quality monitoring. Many new meters are designed to several different modes of communication, such as pagers or cellular phones.
Interval data meters allow energy managers to see an energy profile of a building and to evaluate the effects of operational changes such as control systems and compact fluorescent lamps. If the building demand can be shaped to fit the Energy Service Provider's best rates, large savings can be achieved by negotiating better prices.
Improved metering? The New Approach