When the New England Patriots take the field in Arizona against the Seattle Seahawks in the Super Bowl this Sunday, millions of football fans across New England will be tuning in to watch the game. ISO New England system operators also will be keeping an eye on the game—not to cheer on the home-town favorite, but to ensure the region’s power grid reliability. What does a football game in Arizona have to do with the New England power grid? A lot: The Super Bowl always has a visible impact on electricity demand—before, during, and after the game. Like players celebrating in the end zone after a touchdown, demand spikes and dips throughout the game. Grid operators must closely monitor the fluctuations and be ready to respond quickly. Electricity supply must be kept in precise balance with consumer demand at all times—and failure to do so could result in grid instability.
Operating the grid
One of ISO New England’s key functions is the daily reliable operation of the high-voltage power system, a six-state network of 8,500 miles of high-voltage transmission lines and more than 350 generators. To do this, the ISO works with generation and transmission companies to make sure that enough electricity is available for New England consumers at all times. ISO Forecasters and other staff work around-the-clock to create and update a variety of demand, or “load,” forecasts. These short-term forecasts help us decide how many megawatts (MW) of electricity will be needed for a given week, day, or hour, and help us to manage the grid reliably through cold temperatures in the winter, high temperatures in the summer, holidays, and even Super Bowl games.
Factors that affect demand
ISO New England forecasters first consider the weather, which is the most significant factor driving demand for electricity. Temperature, dew point, precipitation, cloud cover, and wind can have a dramatic effect on consumer demand for lighting, air conditioning, and heating. The ISO uses outlooks provided by three different weather forecasting organizations to compile its weather forecast.
Historical data are also a factor in determining demand on a given day. This is especially true when forecasting for special holidays or high-profile sporting events that draw a large television viewing crowd. This information is gathered from a database that searches for similar days in operational history. For example, to forecast demand for the big game on Sunday, forecasters look at consumer demand trends from past Super Bowls; this year they’ll be looking closely at the February 5, 2012, electricity demand profile, which is the last time the Patriots played in the Super Bowl, although this year’s weather for the Super bowl is significantly colder in New England.
Comparable days are analyzed and updated to account for factors such as population and economic growth. The day of the week and information regarding the previous day's weather and demand are also taken into account. Once this information is compiled, Forecasters publish the expected hourly system demand for the remainder of the current day and the next two days. The Forecasters monitor the many variables that go into creating the forecast and, as conditions change, update their reports as needed.
Because generators are scheduled to run based on the load forecast, having accurate forecasts is imperative to ensuring that the appropriate amount of generation is online or available to meet the demand at any given second.
Football’s impact on the grid
The graphs below depict electricity demand on the grid during the 2012 Super Bowl (in blue), and for comparison, the load curve from a typical winter day in 2012 (in green). An event as large as the Super Bowl syncs up the actions of a majority of people in New England, and because of this, electricity consumption spikes and dips throughout the game. For example, the 2012 Super Bowl load curve shows an uptick in demand that coincides with half-time, during commercials, and at the end of the game. These spikes are unique to the Super Bowl and happen because people likely are taking actions that increase electricity use, such as using the oven or microwave, opening up refrigerators, and water systems across the six states operating at virtually the same time—for all the obvious reasons! On a typical winter day, as illustrated in the graph, the evening peak usually occurs between 6 and 7 p.m., and demand continues to decrease after the peak, without the same fluctuations.
If you'd like to keep tabs on the load curve in real-time during the big game, download the ISO to Go mobile app! It's free and is available for download by iPhone and Android smartphone users. Once you've downloaded the app, tap the New England icon on the bottom of the screen and then tap "Demand Chart" (see picture at left).
A larger size of this graph is available via ISO Express. The graph compares the ISO’s demand forecast with actual, real-time load.