One approach many electrical utilities have taken to ensure the electrical load is less than what can be generated is to exercise some form of load control. In this case, certain applications are identified as “deferrable” -- to run later in the day, after the peak. These applications will vary by region, but common loads include residential electric hot-water heaters, air conditioners, pool pumps, crop-irrigation pumps, etc. In a distribution network outfitted with load control, these devices are outfitted with communicating controllers that can run a program that limits the duty cycle of the equipment under control. The utility only exercises the equipment when necessary. The consumer is usually rewarded for participating in the optional load control program by paying a reduced rate for energy. Proper
Load managementby the utility allows them to practice Load sheddingon a less drastic scale to avoid Rolling blackouts and penalties by the Public Utility Commission.
Comparisons to Demand Response
When the decision is made to curtail load, it is done so on the basis of system "reliability". The utility (in a sense) “owns the switch” and sheds load only when the stability or reliability of the electrical distribution system is threatened. The utility (being in the business of generating, transporting, and delivering electricity) will not disrupt their business process without due cause. Load Control, when done properly, is non-invasive, and imposes no hardship on the consumer.
Demand responseon the other hand places the “on-off switch” in the hands of the consumer. While many residential consumers pay a flat rate for electricity year-round, the utility’s costs are anything but flat. In a free market, the wholesale price of energy varies widely throughout the day, every day. Demand Response programs attempt to incentivise the consumer to limit usage based upon "cost" concerns. Should a crisis develop in the supply of electricity, a free Market economyshould allow the price to rise. A corresponding drop in demand for the commodity should meet a rise in price. While this works for predictable shortages, many crises develop within seconds due to unforeseen equipment failures. They must be resolved in the same timeframe in order to avoid a Power blackout. Many utilities who are interested in demand response have also expressed an interest in load control capability so that they might be able to operate the “on-off switch” before price updates could be published to the consumers.
Implementations of Load Control systems
Early implementations occurred in WWII in various parts of the world using a system that communicates over the powerline (known as the "Ripple Control" system). The application of load control technology continues to grow today with the sale of both
Radio frequencyand Powerline communicationbased systems. Certain types of AMI systems can also serve as load control systems.
The largest residential load control system in the world is found in the United States, in Florida at FPL [http://tdworld.com/mag/power_mega_load_management/] . It utilizes 800,000 Load Control Transponders (LCT’s) and controls 1,000 MW of electrical power (2,000 MW in an emergency). FPL has been able to avoid the construction of numerous new power plants due to their demand side management programs. [http://www.fpl.com/news/2006/contents/06032.shtml] Smaller utilities which buy power instead of generating their own, find that they can also benefit by installing a load control system. The penalties they must pay to the energy provider for peak usage can be significantly reduced. Many report that a load control system can pay for itself in a single season.
Ripple control for many years in New Zealand
Ripple control can be used to manage electric water heaters, allowing energy tariffs to be switched from daytime to evening, or hot water power supply to be turned off during daytime. Most electricity lines companies set 7:00am–11:00pm for a more costly daytime tariff, and 11:00pm–7:00am for a discounted evening tariff, which favours dairy farmers that complete milking soon after 7:00am. However, some electricity lines companies set 6:00am as the start of the more expensive daytime tariff, which is somewhat less favourable to dairy farmers - the option being to complete morning milking before 6:00am.
Local lines companies benefit from spreading energy demand throughout the evening as well as the daytime. This improves the utilisation of the electricity network and can be used to defer investment in electricity transmission and distribution lines. However, ripple control is often not utilised by the lines company to control water heating, unless periods of peak demand or power shortages occur.
Depending on the difference between day and night tariffs, significant savings may be achieved through simply installing a timer switch with suitably rated contactors to control electric water heaters. The cost of this is estimated in the area of $500 installed.
Automatic Meter Reading
first = Michael
last = Andreolas
title = Mega Load Management System Pays Dividends
publisher = Transmission & Distribution World
date = February 1, 2004
url = http://tdworld.com/mag/power_mega_load_management/
accessdate = 2007-08-30
last = FPL
title = FPL Files Proposal to Enhance Energy Conservation Programs
publisher = Florida Power & Light
date = May 23, 2006
url = http://www.fpl.com/news/2006/contents/06032.shtml
accessdate = 2007-08-29
Wikimedia Foundation. 2010.
Look at other dictionaries:
Load Control — Als Load Control bzw. Ladesteuerung bezeichnet man in der Luftfahrt einen Teilprozess der Flugzeugabfertigung. In der Regel fallen unter den Begriff sämtliche Tätigkeiten zur Ladeplanung, überwachung und dokumentation. Inhaltsverzeichnis 1… … Deutsch Wikipedia
Load control switch — A load control switch is a remotely controlled relay that is placed on home appliances which use a lot of electricity, such as air conditioner units and electric water heaters. A load control switch consist of a communication module and the relay … Wikipedia
load control group — krovos kontrolės grupė statusas T sritis Gynyba apibrėžtis Asmenys, kurie organizuoja ir kontroliuoja krovimą (sodinimą) krovimo rajone. atitikmenys: angl. load control group pranc. équipe de contrôle du chargement … NATO terminų aiškinamasis žodynas
Load control program — A program in which the utility company offers a lower rate in return for having permission to turn off the air conditioner or water heater for short periods of time by remote control. This control allows the utility to reduce peak demand. U.S … Energy terms
load control group — Personnel who are concerned with organization and control of loading within the pick up zone … Military dictionary
Direct Load Control — Activities that can interrupt load at the time of peak by interrupting power supply on consumer premises, usually applied to residential consumers. *** This Demand Side Management category represents the consumer load that can be… … Energy terms
frequency-load control — dažnio ir galios reguliavimas statusas T sritis automatika atitikmenys: angl. frequency load control vok. Frequenz Leistung Regelung, f rus. регулирование частоты и мощности, n pranc. réglage fréquence puissance, m … Automatikos terminų žodynas
automatic frequency-load control — automatinis dažnio ir galios reguliavimas statusas T sritis automatika atitikmenys: angl. automatic frequency load control vok. automatische Frequenz Leistung Regelung, f rus. автоматическое регулирование частоты и мощности, n pranc. réglage… … Automatikos terminų žodynas
line load control — Attendant s ability to temporarily restrict least important stations from initiating outbound calls during excessive traffic load or emergency conditions … IT glossary of terms, acronyms and abbreviations
Direct electricity load control — The utility installs a radio controlled device on the HVAC equipment. During periods of particularly heavy use of electricity, the utility will send a radio signal to the building in its service territory with this device and turn off the HVAC… … Energy terms