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Terms        Voluntary Load Curtailment        Power System Conditions - ISO

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What happens when Power Shortages are predicted!

There are many steps the Independent Systems Operator of New England (ISO) orders electric utilities in New England to take in order to "stretch" electric power supplies. Most of these are indiscernible to electric customers, such as running all engines and reducing voltage. Others involve customers, such as requests for conservation. When shortages are predicted, the Hudson Light and Power Department prepares its customers for what to expect.

The monthly Customer Newsline is used to advise all customers of what might happen during a shortage. Notices are sent to Medical Emergency Customers to ensure that the Department's information on these special accounts is as up to date as possible. Larger industries are contacted to participate in the Voluntary Load Curtailment program involving fax and or telephone notification of power supply conditions in return for voluntary electric use reduction upon request. The local media is supplied with the various terms New England's utilities use if the power supply situation becomes seriously tight.

Prime periods for emergency situations are weekdays, between noon and 8 p.m., during periods of extended heat waves and unhealthy air quality. Historically, this weather usually occurs in July and August. Following are some of the terms electric customers may hear broadcast by the media, or see flashed on the Department’s Web Page, during emergency situations. These terms are not unique to the Hudson Light and Power Department, but would be used across the region. For more information on New England's power status, see www.iso-ne.com/index.html.





Normal - The current electricity capacity status in New England is NORMAL. Conditions are considered normal when there is an ample supply of electricity to meet the region's expected demand.

Power Caution - ISO-New England may issue a "Power Caution" to warn that supplies are tight and further actions may be necessary. This is a term used to notify utilities and does not require public action.

Power Watch - ISO-New England will declare a "Power Watch" when a high demand for electricity in the region creates the need to conserve electricity. Customers can help by minimizing the use of air conditioners, turning off unnecessary lights and electrical appliances and doing laundry in the late evening or early morning hours. Businesses can help by shutting off unnecessary lights and office equipment, such as computers, when not in use. Your cooperation is appreciated.

Power Warning - ISO-New England will declare a "Power Warning" when action is necessary to avoid the collapse of New England's electric system. ISO will order utilities to make a public appeal for conservation. Customers will be asked to immediately reduce their electric use. Simply turning off lights and appliances can make a big difference - as much as 400 to 450 megawatt (mw) region-wide. (One megawatt serves roughly 300 single homes.for today, and is expected to remain in effect throughout this evening. ISO New England, the operator of the region's power grid, is urging customers to take steps to conserve electricity.

One of the steps utilities may be ordered to take during a Power Watch is a Voltage Reduction. ISO may order utilities to reduce voltage on their systems by five percent. Indiscernible to the average customer, voltage reductions have occurred in the past. Customers concerned about sensitive appliances should check with instruction pamphlets or with their suppliers. It is recommended that customers check sensitive electronic equipment and back up computer data more frequently.

When the demand for electricity becomes extremely high and there are insufficient supplies to meet the demand, ISO may order a Voluntary Load Curtailments. Utilities are told to ask their larger businesses to voluntarily reduce their electric consumption. A number of larger industries worked with the Hudson Light and Power Department in the late 1980's on voluntary load curtailments. Upon request of the HL&PD these companies helped avert the need for more stringent measures by using emergency generators, reducing electric use, and/or shutting down operations when possible.

Power Interruption Alert: When utilities have enough advanced notice that rolling blackouts are required, a "Power Interruption Alert" will be issued to notify electric customers that interruption of electric service is imminent. Rolling Blackouts are one of the rare and final steps taken to avoid collapse of an electric system. One has never been issued in New England. When ordered to implement a Rolling Blackouts, utilities shut down various circuits in a rotating pattern until the crisis eases.

During rolling blackouts, customers should not be without power for more than a few hours at a time. When service is interrupted, major appliances should be turned off to avoid damage when service is restored. This is especially important of industrial equipment. If such equipment is left on, the surge to restart the machinery when power is restored could trip circuit breakers and delay the orderly restoration of power to the area.

It is important to note that utilities may not have advanced notice of a Rolling Blackout or Voltage Reduction. The Department's Web Page will be used as one means of notification. While voltage reductions have occurred in the past, Rolling Blackouts have never been ordered by ISO. As a result, utilities are trying to prepare now for any eventuality this Summer. Hudson Light and Power Department Customers with questions or concerns should feel free to call the Hudson Light and Power Department at 978-568-8736. Customers of other utilities should contact their own electric companies.


HL&PD sets up Voluntary Load Reduction Program with Industries!

HUDSON -- When four of the region's major power plants were out of commission one Summer, utilities were warned that power supplies might be stretched to the limit, especially during an extended heat wave. In preparation, the Hudson Light and Power Department put together a Voluntary Load Curtailment program with its industrial customers.

There are many steps ISO orders utilities to take in order to "stretch" electric power supplies. One is an order to ask large industrial users to voluntarily reduce their electric usage. In the 1980's, many of Hudson's industries helped ISO avoid the need for more drastic measures by using emergency generators, reducing electric use and/or shutting down operations when possible.

The Department established a fax/telephone notification program whereby participating industries are alerted to the various steps ordered by ISO, including system-wide voltage reductions and rolling blackouts. The Department's Web Page is also used during emergency situations.

It is important to note that utilities may not have enough advanced warning of the orders to notify any customers. Use of the program has been successful.

Customers interested in the program should contact the Hudson Light and Power Department at 978-568-8736 with the following information: Company name, service location, contact person, alternate contact person, telephone number and fax number. 


This website has been created and is maintained by the Hudson Light and Power Department. Any discrepancy between information provided on this website and the actual practices, policies, rate schedules charges, etc. is unintended. In all such cases, the actual practices, policies, rate schedules, charges, etc. of the Hudson Light and Power Department shall prevail.