Three years after Hurricane Sandy devastated the East Coast, key electrical infrastructure remains vulnerable to flooding in major storms. A study released Tuesday by the Union of Concerned Scientists (UCS) says millions of Americans living along the East and Gulf coasts would likely lose power in a Category 3 hurricane.
Sandy left more than 8 million people across 21 states without power and caused billions of dollars in damage when power plants and major electrical substations were inundated by its storm surge. Hospitals were forced to evacuate patients, gas stations were unusable and sewage treatment plants spewed untreated wastewater into surrounding waterways.
The potential for more severe and more widespread damage will increase in coming decades due to rising sea levels and more intense, more frequent storms, according to a detailed analysis by UCS.
"The East and Gulf coasts are highly vulnerable and exposed to coastal flooding from storm surge and sea level rise today, and that problem is only going to get worse over time because of climate change," said Steve Clemmer, director of energy research at UCS and the report's co-author.
To determine what infrastructure would be most exposed, Clemmer and colleagues used a computer model developed by the National Weather Service to analyze the impact of storm surge. Combining this information with elevation data from the U.S. Geological Survey produced a detailed analysis of the extent and depth of potential flooding in specific areas. Finally, the group used data from Platts, a company that provides information on energy infrastructure, for the exact locations of power plants and substations in the coastal areas they studied.
In all, 68 power plants and 415 major electric power substations are susceptible to flooding in a Category 3 hurricane, a storm with sustained winds up to 130 mph.
The report focused on five metropolitan regions: the Delaware Valley, southeastern Virginia, the South Carolina lowcountry, southeastern Florida and the central Gulf Coast. The proportion of exposed substations ranged from 16 percent in southeastern Florida to nearly 70 percent in the central Gulf Coast. In Norfolk, Va. and Charleston S.C., more than 80 percent of substations would likely be inundated.
Dominion Virginia Power, the utility that operates electric substations in Norfolk, said it continually assesses its substation and transmission facilities for threats.
"As it relates to flooding, Dominion continues to modify existing station designs and future substations based on [National Oceanic and Atmospheric Administration] flood models for outage planning and design," said Dominion Virginia Power spokesperson Dan Genest.
Ginny Jones, a spokesperson for South Carolina Electric and Gas (SCE&G), the utility that provides power in Charleston S.C., said "we do monitor our infrastructure and prepare it for weather."
Jones said only a small percentage of SCE&G customers lost power in the state's recent massive flooding, when nearly 20 inches of rain fell over three days in the area around Charleston. The rain was caused by Hurricane Joaquin, but the storm did not directly hit the East Coast, which would have significantly increased the region's storm surge.
"As far as that event is concerned things went really well, but I don't want to speculate on things that haven't happened," Jones said.
The UCS report does not take into account any protective measures such as elevating or waterproofing equipment or constructing seawalls that power plant operators or utility companies may have taken, but Clemmer said, "in the areas that we analyzed, I think the vast majority of places have not taken those types of actions."
The report recommends that utilities elevate or relocate key infrastructure away from the coast and add redundancies to reduce power interruptions during storms.
Such redundancies are being added to the grid, but their cost has limited the rate of adoption.
"The perfect power system would be a completely redundant system and it would be completely too expensive for any of us to afford," said Clark Gellings of the Electric Power Research Institute (EPRI), a non-profit organization funded by the electric utility industry.
One example of such a system is solar-powered stoplights with energy storage that limit traffic disruptions during power outages. The lights were developed by researchers at Carnegie Mellon University and were funded in part by EPRI.
EPRI is also working to develop water-resistant electrical equipment after hurricane Sandy caused significant damage to substations and switching stations owned by Con Edison in New York City.
"We were amazed with Sandy, with Con Ed's system, with only a few hours in some cases of equipment being underwater that it was essentially destroyed," Gellings said.
Gellings served as a member of the NYS2100 Commission, created after Sandy to ensure future infrastructure resiliency in New York State. He said Con Edison is now building higher seawalls and, in some cases, installing electrical equipment that can be temporarily raised and "de-energized" during floods to avoid damage.
In addition to relocating or strengthening existing infrastructure, the UCS report also endorses clean energy projects that provide emissions-free backup power.
In Massachusetts, for example, the state is providing $40 million for solar and wind energy coupled with battery storage systems to power emergency shelters, police departments, communications facilities and wastewater treatment plants during outages. Similarly, Florida's SunSmart E-Shelters program provides solar power with battery storage to emergency shelters.
"You can keep the power on for critical facilities and, to the extent that you are using a clean energy solution, you can also help reduce greenhouse gas emissions which will help reduce the magnitude of the problem over time," Clemmer said.