The electric power grid will gain resiliency the next two decades through the rise of microgrids, which produce electricity and sometimes heat in small areas through some combination of renewable energy and energy storage, Southern Co. Vice President of Corporate Security J. Britt Johnson said at the Marcus JCC on Dec. 7.

A subdivision might have its own microgrid and include the cost of power in homeowner association dues, Johnson said. Microgrids also are widely used at military bases, where the electric supply needs to be self-contained so it isn’t vulnerable to attack.

It was the former FBI special agent’s second appearance at the JCC’s Edgewise Speaker Series; he spoke to the group in 2015 about leading the FBI’s Atlanta Division, as he did from 2014 to 2016.

This time Johnson, who has been with Southern Co. since September 2016, spoke about protecting the electric grid’s resiliency in Georgia and the Southeast. It was the best attended Edgewise session of the year.

Southern Co. uses a threat landscape graph to categorize potential dangers. The Y axis shows the likelihood of an event to occur, and the X axis reflects the potential consequences.

The likelihood of a squirrel chewing through a power line is high, for example, but the consequences are low. On the flip side, a nuclear electromagnetic pulse would be devastating to the power grid but is not likely.

Asked about the threat of a nuclear EMP, Johnson said Southern Co. is somewhat prepared, but a lack of solid information on the effects of such an attack is keeping the company from being fully ready. In addition, he said complete preparations for an EMP attack would be prohibitively expensive.

Johnson said events that are likely and have big consequences, such as natural disasters, are what Southern Co. prepares for most.

Asked why power companies trim or chop down trees that threaten power lines instead of burying cables, Johnson said burying cables is more expensive. He also said that method of power transmission could be different in a few years and might not use power lines at all.