Frequently Asked Questions: Voltage Reduction
What is a voltage reduction?
A voltage reduction reduces power demand system wide. The percent of the voltage reduction determines the size of the reduction. For example, a 5% voltage reduction results in a 2% reduction in power demand.
Why do utilities do this?
During peak load periods when electric energy may be in short supply, a voltage reduction reduces customer demand and allows a utility to stretch out its supply. This is one of a series of steps that allows utilities to maintain uninterrupted service to customers
Am I going to see a voltage reduction this summer?
it is possible that there will be voltage reduction this summer. Hot weather, combined with limited availability of generating capacity, could mean utilities need to take these measures to meet demand for power and to continue to provide uninterrupted service to customers.
Will there be any advanced notification of voltage reductions?
When feasible, utilities will alert customers through broadcast media when a potential for voltage reductions exists. In extreme circumstances, however, there may not be time for notice.
What effect will this have on my service?
Generally, a voltage reduction will not have an appreciable effect on your service. Standard household appliances and electrical equipment are manufactured to tolerate a 10% plus/minus change in voltage. A 5% voltage reduction is within that tolerance. In fact, utilities sometimes perform voltage reduction tests with little notice to customers.
Customers with concerns about their electric service or about sensitive electronic equipment should check equipment manuals or their equipment suppliers about potential precautionary measures to protect equipment or data. Computer users should save files and data frequently.
What if I depend on electricity for life–support or other health–related equipment?
People who use electrically powered life–support systems should always have a backup.
How long will the voltage reduction last?
The reduction will last until the New York Independent System Operator (NYISO) or the Long Island Power Authority (LIPA) can achieve a balance between capacity and demand. If voltage reductions are necessary, they will typically be during the period of 12:00PM to 8:00PM, or shorter.
Why do utilities ask customers to avoid using power?
The appeal is made to reduce customer demand, to balance generating capacity and demand on Long Island and to help maintain uninterrupted power for customers.
Heavy electricity use, hot weather, limited available generating capacity, and limited transmission capacity have prompted utilities to issue appeal to customers.
How much difference can turning off lights and appliances really make?
A BIG difference – probably several hundred megawatts statewide. (A megawatt is one million watts and serves roughly 300 single homes.)
How many times will you have to do this?
Public appeals are one of several steps utilities take in times of excess demand to safeguard the electric system. During periods of hot weather and when available generating capacity is limited, appeals may be issued whenever heavy electricity use reduces power reserves to unacceptably low levels. Often an appeal is all that is needed to reduce demand.
What will happen if not enough people pay attention to the appeal to reduce consumption?
Utilities would be forced to reduce voltage, or possibly black out customers in certain areas. Depending on where and what the problem is would determine the extent of the blackouts and who would be blacked out. California is experiencing rolling blackouts due to the lack of available capacity and energy. The electric is turned off to specific areas fo a designated time each day, then the lights are turned back on and another area is blacked out.