How Elevated Substations Kick Storm-Hardening Into High Gear

"If you want to see the sunshine, you have to weather the storm.” – Frank Lane, former Major League Baseball executive

With hurricane season upon us, it’s worth considering how electric utilities can protect their substation structures and equipment against hurricane-induced storm surge.

The risks are high. Frank Camus, DIS-TRAN’s Vice President of Engineering and Design, recalls, “We had a customer whose substation was flooded by a hurricane. They thought it was a 100-year storm, but then, just a year or two later, the exact same thing happened.”

But even just a single weather event can be devastating. As these high-magnitude storms hit, they can cause storm surges that range from 10 to 30 feet in height, and the damage can lead to prolonged power outages, dangerous working conditions, costly (sometimes irreparable) property damage, even regulatory concerns.

This puts coastal electric utilities in the difficult position of having to balance competing responsibilities:

  • Deliver highly reliable electric service;
  • Minimize the cost of storm hardening;
  • Increase the resiliency of their linear and discrete assets (T&D lines, substations and control buildings); and
  • Do all of this, all at once.

Meeting that delicate balance is why DIS-TRAN developed elevated substations. In-place structural elevation enables utilities to cost-effectively storm-harden existing substation equipment sensitive to storm surge flooding by elevating structures in-place to 13 feet above sea level (5 feet above the highest flood point and 2 feet above FEMA and insurance recommendations).

We had the idea after the customer mentioned above came to us to figure out how to protect their assets. As Frank says, “They wanted to raise their equipment up but weren't sure how to go about it.”

They also had several requirements:

  • No change in power station performance or system reliability permitted
  • No appreciable change in operational and maintenance practices permitted
  • No service disruption throughout the life of the project permitted
  • No increase in construction safety risk permitted

DIS-TRAN’s engineers engaged closely with the customer through an iterative process designed (1) to develop clear expected outcomes and (2) to ensure that the final system of interconnected elevated platforms would adequately account for the space required to safely operate the equipment as if done at grade level. Step by step, we:

  • Assessed the structural condition of the existing substation to be hoisted;
  • Assessed the structural condition of the existing foundations to be subjected to increased loadings;
  • Established design criteria;
  • Designed the column extensions;
  • Designed the platform for operations and maintenance; and
  • Designed the lifting plan to accommodate existing equipment and site constraints.

Notably, elevated substations also offer many of the same benefits as factory-built substations. “We can assemble it at a facility and then ship it out as components that can fit on a truck,” says Frank. “That means less construction time in the field, so it reduces both risk and service outage time.”

To better understand how DIS-TRAN’s elevated substations stack up against other storm-hardening options, see the comparison chart below.