Waterproofing the Underground Smart Grid

S&C Electric Company sells 450 distribution switchgear units to Brazil that can keep running — and communicating — in flooded substations.

Hurricane Sandy has already left about 7.5 million U.S. East Coast residents without power, a number that could climb to 10 million from Maine to North Carolina. Some hard-hit utilities are warning that outages could last more than a week. In the meantime, utilities are scrambling to restore power to centers like downtown Manhattan, or hospitals that are evacuating patients under backup power.

In short, it’s an enormous test of the grid’s ability to handle a major weather disaster, from generation and transmission all the way down to end customer -- and both above and below ground. Much of the power infrastructure of New York and other major cities lies underground, making it particularly susceptible to flooding, as well as difficult and dangerous to operate or repair under flooding conditions.

Distribution automation, fault detection and restoration, circuit monitoring and other such smart grid systems that can stand up to flood conditions could really help in situations like these. In fact, a recent bid by Brazilian utility Cemig Distribuição SA for 450 underground distribution switches -- devices that can shift power from one circuit to another in the medium-voltage grid -- specified that they had to be flood-proof in some fashion.

Last week, Chicago-based S&C Electric Co. announced that it had won that contract, worth 78 million reals ($38.5 million), to install its Vista Underground Distribution Switchgear systems across Cemig’s territory, including the soccer stadium in Belo Horizonte that will host games during the 2014 World Cup, as well as urban and rural territories across the state of Minas Gerais.

Cleverson Takiguchi, general manager of S&C Electric in Brazil, said in a Tuesday interview that Cemig’s bid had included requirements for the ability to keep operating during a flood. The utility has manually operated underground circuit switches in place today, but S&C is adding both automation and sensor capabilities to the vaults where these devices sit, and hooking it up to an existing fiber network, he said.

“In Brazil, the demand for this is growing. Many customers have manual switches that they want to automate,” Takiguchi said. They also want to connect to sensors to track everything from transformer loads and faults to attempted theft, a big problem in Brazil -- S&C’s devices connect to motion detectors to sense intrusion, as well as temperature sensors, power quality monitors and the rest.

Everything -- the switches and power cables that connect to them, the controls and automation and sensors and communications gear -- sits inside a metal box that’s engineered to keep the contents dry in extreme conditions, he said.

“The main substation is still up and running and capable of energizing, our system is able to switch from one feeder to another, even if the vault is completely flooded,” he said. One Brazilian customer who installed the S&C device in a room un-mounted to floor or walls discovered that the gas-filled device was actually floating in that room after it flooded, he said -- still operating via the cables that tethered it like a buoy in a bathtub.

Other grid equipment vendors make gear that can run while submerged in water, Takiguchi said. But most of that equipment requires separate communications connections to make it truly “smart” -- and those control systems are rarely made to run underwater. S&C has put all of it together in a single waterproof package, though it did cost a bit more to make sure the connections to Cemig’s fiber network were leakproof, he noted.  

Takiguchi was quick to add that it’s impossible to say whether or not this kind of waterproofing could have helped reduce power outages in cases like Hurricane Sandy’s widespread destruction. Much of the East Coast’s problems have been caused by wind and rain knocking down power lines, and of course, the entire generation and transmission system is aboveground.

But dense urban environments could be well served by an underground fault detection and circuit switching system that can keep running underwater. S&C has sold about 1,000 of these devices in Brazil over the past fourteen years or so, making the new deal with Cemig an important expansion, Takiguchi said. But it’s anticipating more business as the country gears up to support the upcoming World Cup, as well as the 2016 Olympic Games.

Indeed, Brazil’s smart grid market is expected to continue to grow, despite a recent government decision that significantly reduced forecasts for how many smart meters the country would deploy over the coming decade. Companies like Itron, Landis+Gyr, Elster, Echelon, Sensus, Silver Spring Networks, Trilliant and General Electric are all doing projects in Brazil.

Brazil’s extreme climate and geography both play an important role in the country’s grid plans. Takiguchi said that S&C’s flood-proof system is in demand from many of the ten or so customers it has in Brazil. In Rio de Janeiro, IBM is building a citywide emergency response command center, one of its many “smarter cities” projects, which includes managing the floods that can ravage the city in heavy rains. Global warming is only going to make flooding a more pressing problem for cities and utilities across the globe. Waterproofing one’s smart grid assets seems like a good place to start.