Energy Outlook | Summer 2008

Summer brings baseball, ice cream, boating and vacations. It also brings peak power demand in New Hampshire and all of New England. Fortunately, ISO-New England—the independent service operator in charge of gathering up electricity from power plants and then divvying it up throughout New England—is forecasting adequate power for 2008's summer season. If you'd like to read more about this, click here. Despite this, local transmission constraints, extremely hot days or unexpected transmission or generation outages could require the implementation of emergency measures to help maintain power system reliability.

What We're Doing to Help

If you are going to purchase a new air conditioner, PSNH suggests that you consider an energy-efficient model. The NHSaves program even offers a $20 rebate when you do so. Additionally, you can use our energy calculator to estimate how much energy that air conditioner—or any appliance—will use and will cost.

PSNH also works with a number of our larger customers to try to reduce energy use during peak events through the following programs:

• PeakSmart
• PeakSmartPlus

Some Like it Hot | 2007 Peak Demand

In 2007, New Hampshire's electricty demand peaked during the hot month of August. The following chart shows New Hampshire's monthly peak demand for 2007:

New Hampshire's peak power demand was recorded on August 2, 2006. The high temperature in Manchester on that day was 98.1° Fahrenheit.

When the Heat is On | Emergency Measures

On days of a capacity deficiency, a series of actions is implemented to help balance supply and demand and maintain the reliability of the regional power system. For example, one measure allows the ISO to utilize mutual assistance agreements with neighboring power systems to purchase emergency power if the New England power grid’s operating reserve falls below required levels.

Another measure calls upon the public to temporarily conserve its use of electricity and help reduce demand on the power grid. If necessary, ISO New England will use its public appeal program, which is modeled on the National Weather Service's storm advisory system, when issuing requests to conserve.  The emergency warning system has two levels of public appeal: Power Watch and Power Warning.

A Power Watch is invoked to request that customers voluntarily reduce electricity use, in ways consistent with health and safety, when the region's electricity supplies are expected to be tight.  A Power Warning is a more urgent appeal issued when there is a concern that utility companies may have to disconnect customers to reduce local demand on the power grid so that the integrity of the entire power grid is maintained. In the past, these public appeals have been extremely effective in reducing electricity demand.