Where does my electricity come from?

Thankfully, it comes from literally hundreds of places.

People who lived in New England back in November of 1965 will never forget the day the lights went out all across the Northeast. It was the largest blackout in U.S. history. Back then there was no unified electric grid to assure that power could be transferred reliably around New England. There was also no way to import additional power from other regions when required.

By 1970, all six New England states had joined together to form the seventh largest grid of the 109 grids in the eastern states. With the new grid in place, New England had hundreds of interconnected power generating plants and a reliable way to exchange power with other grids outside of New England. Today, the New England Grid has more than 350 generators and power plants and 12 interconnections that allow our grid to import or export power with grids in New York, New Brunswick and Quebec.

The Balance of Power

Think of the 8000 miles of transmission lines in our power grid as a huge rechargeable battery. The 350 power plants serve as battery chargers. Draining the battery are 675 115-kilovolt lines from local utilities that feed electricity to substations around New England. The substations, in turn, feed power to homes and businesses in a given area. The 12 interconnections from grids outside of New England can either charge or drain the big battery depending on whether our grid is importing or exporting power.

As you might imagine, controlling the giant battery’s state of charge requires constant vigilance. Charge it too much and the local utilities couldn’t handle the load. Charge it too little and brownouts or rolling blackouts would result.

The job of keeping the grid’s battery in peak condition belongs to ISO New England, Inc. a non-profit independent service operator formed when utilities were deregulated. Walk into their offices in Holyoke Massachusetts and you’ll see a large operations room depicting every single power plant, transmission line and substation in New England.

To a large extent, managers at ISO New England control the big battery’s state of charge by analyzing the historical use of power. When more power is needed, they can order it from suppliers’ generating plants, based on the lowest price, from an auction board where suppliers list their prices hour-by-hour. To lower power, they shut down power plants.

To fine tune the system based on instantaneous demands, dozens of the 350 power plants in New England are equipped with automated controls that allow ISO New England to make second-by-second adjustments to the grid’s balance of power.

Unforeseen circumstances such as a heat wave or one or more power plant shutdowns could wreak havoc with the grid, but managers at ISO New England keep backup power online that is equal to one-and-a-half times the biggest potential failure in the system. This might mean starting up seldom used jet fuel turbine generators or dumping dammed up water to a hydro plant to instantly generate more power.

With New England’s sophisticated grid, a wealth of generation choices and a healthy backup system –all under ISO New England’s watchful eye—New England’s power grid is indeed like a battery…It just keeps going and going.