(TNS) - Northern California communities hit by some of the worst wildfires the state has ever seen are now preparing for another kind of disaster: prolonged power shut-offs caused intentionally by Pacific Gas and Electric Co.

PG&E has used its aggressive new strategy to prevent its equipment from starting another fire only on one weekend so far this year. But the utility is poised to turn off the lights much more in the coming months as hot, dry and windy weather persists during the most dangerous part of wildfire season.

The impacts may be extreme and unprecedented, cutting entire cities off from the electric grid for several days in the worst-case scenarios. In those instances, stoplights and even cell phones could stop working properly, local officials say, snarling traffic and hamstringing residents’ ability to communicate.

Recently, a neighbor asked one of us whether Russia, China, North Korea and Iran really are capable of hacking into the computers that control the U.S. electricity grid. The answer, based on available evidence, is “Yes.” The follow-up question was, “How expensive will it be to prevent, and who will end up paying for it?”

The answers are: Likely tens of billions of dollars, and probably us, the electricity customers. This is a major — and, in our view, vital — investment in community and national security. But as scholars of grid cybersecurity, we understand it’s not very clear what consumers will be getting for their money, nor whether utility companies themselves should bear some share of the cost.