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sts.components.contact.mr.placeholder Sebastian Webel
Mr. Sebastian Webel

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Pictures of the Future
The Magazine for Research and Innovation
 

Smart Grids and Energy Storage

Helping Grids Withstand Tomorrow’s Storms

In October 2012, Hurricane Sandy swept across the northeastern coast of the United States, crippling the power network. Smart Grid technologies from Siemens are helping to make power networks more robust in the face of hurricanes, heat waves and periods of drought.

Five years ago, at the end of October 2012, Hurricane Sandy swept along the northeastern coast of the U.S. with winds of up to 150 kilometers per hour. Power outages left millions of people in the dark. Recent storms such as Harvey and Irma have once again demonstrated that energy management systems must be able to handle such natural disasters in the face of climate change. With this in mind, Siemens has been using smart grid technologies to help make power networks more robust as an increasing number of hurricanes, heat waves, and droughts challenge infrastructures.

When Hurricane Sandy sped toward the U.S. Atlantic coast five years ago, the storm threatened to carve a swathe of destruction through New York, New Jersey, and Pennsylvania. This posed a huge challenge for America’s biggest grid operator, PJM Interconnection, which manages the power supply for more than 61 million customers in Pennsylvania, New Jersey, Maryland, and ten other states as well as in the District of Columbia. PJM Interconnection distributes the electricity produced by more than 1,300 power plants to regional network operators. If this distribution backbone were to break down, electricity customers would literally be left in the dark.

As people had feared, Sandy caused extensive damage. The lights went out in eight million households, five million of which were in the area served by PJM Interconnection. More than 140 overhead power lines and transformer substations were damaged, and it took weeks of repairs before all of the electricity connections returned to service.

Hurricane Sandy damaged more than 140 overhead power lines and transformer substations. One particularly hard-hit area was Route 35 North in Ortley Beach, New Jersey (image).

Climate Change: A Challenge for Power Grids

Such blackouts could become more frequent in the future. In the United States, climate change will not only produce more storms like Hurricane Sandy, but also more floods, wildfires, heat waves, and droughts. These expectations were supported by the U.S. Department of Energy in a report from October 2015. Climate change is already affecting the nation’s power grid, which encompasses more than 9,200 power plants and almost half a million kilometers of overhead lines.

For example, power plants in the U.S.’s arid Southwest often have to cut back their power production because of a lack of cooling water. From 2011 to 2017, California experienced its most severe drought since meteorological measurements began. According to recent studies of the growth rings of ancient trees, the drought was the most severe in 1,200 years. Global warming is also increasing the risk of severe storms and hurricanes in the Gulf of Mexico and along the Atlantic and Pacific seaboards. In October 2015 Hurricane Patricia, the strongest Pacific hurricane ever recorded, hit the southwestern coast of Mexico with wind speeds of up to 400 kilometers per hour. The storm caused floods that destroyed houses, transformers, and power lines.

In August 2017 hurricane Harvey devastated large areas of the United States along the Atlantic seaboard, causing more than $70 billion in property damage. Harvey was followed in September by Hurricane Irma, which almost completely destroyed some Caribbean islands and left more than 13 million people in the southeastern United States without power. Due in part to such disasters, the U.S. Department of Energy recommends that power grids be protected against extreme weather phenomena.

With wind speeds reaching 400 km/h, Hurricane Patricia in October 2015 was one of the most powerful cyclones ever recorded.

Fighting Weather with High Tech

This assessment is shared by PJM Interconnection. In November 2011 it therefore installed an energy management system from Siemens, which enables it to monitor and control its grid more effectively during power outages. The system encompasses two control centers, which jointly manage the grid during daily operation. If one of the centers should break down in an emergency, the other one can continue to control operations on its own. This is precisely what happened when Hurricane Sandy swept through the area. As a result, PJM was able to monitor the condition of its transmission grid at all times.

The innovative network management system is based on an integrated  platform developed by Siemens and PJM Interconnection. Various applications, such as energy, market, and transmission network management systems can be combined on the platform. “This open architecture is the system’s strength. It makes it possible to integrate not only new but also older existing applications with little effort,” says Ravi Pradhan, Vice President for Technology Strategy at the Siemens Energy Management Division in Minneapolis. “Thus solutions that already exist can be taken over. Moreover, the simultaneous operation of two control centers increases grid reliability, especially during exceptional situations such as hurricanes that affect the entire network.”

Because the damages caused by Hurricanes like Sandy New York is becoming increasingly interested in local microgrids.

Building Systems that Are Smart and Robust

In addition to transregional grids, local power networks, such as the one in New York City, have to be made more robust as well. Because the damage caused by Hurricane Sandy left more than one million people in New York without power for days on end, the city is becoming increasingly interested in local microgrids. One example of this is a pilot project known as the Brooklyn Microgrid, which was launched in the Park Slope neighborhood in 2016. In combination with battery storage units, the system should at least temporarily prevent the lights from going out if there is a citywide power outage. Among other things, the Siemens Digital Grid Division is supplying the project with a microgrid management system.

Con Edison, a power company that serves ten million customers in New York City and nearby Westchester County, has also taken preventive measures since Hurricane Sandy. From 2013 to 2017, the company implemented a billion-dollar plan that protects its entire power grid against extreme weather conditions. Among other things, Con Edison is reinforcing doors and increasing the height of dikes and protective walls in order to protect power plants, transformer substations, switchgear, and other systems. In addition, the company is erecting robust transmission towers, installing surveillance sensors throughout its grid, and replacing overhead power lines for key facilities such as police stations, fire departments, hospitals, pharmacies, and supermarkets with underground facilities.

In the summer of 2015, Siemens helped Con Edison to put new automation technology into operation for two distribution systems in lower Manhattan. If a flood appears imminent, the new technology can split the distribution systems into four sub-grids in a fraction of a second. As a result, disruptions such as the explosion of a transformer substation at the eastern end of East 14th Street during Hurricane Sandy can no longer spread to the rest of the grid.

The sub-grids are separated by a number of centrally controlled switching stations. The two distribution systems have 44 of these switching stations, which have been installed underground. If the separation of the sub-grids is manually triggered at the control center, up to 20 switches have to be simultaneously activated within a few milliseconds. It’s quite a challenge to simultaneously activate such a large number of switches spread across the entire grid. As a result, such commands are now transmitted through a fast and redundant fiber-optic network.

Before installing its controllers, Siemens tested the entire solution to make sure that it can simultaneously activate the switches at the required speeds. The test was successful. “This was the first time that synchronous switching was achieved in a distribution system and the first time that the IEC 61850 Goose standard was used for synchronous switching underground,” says Chief Engineer Andre Smit from Siemens Digital Grid Energy Management Systems in Wendell, North Carolina. When the next storm arrives, the system could, if necessary, instantly isolate the southeastern corner of Manhattan (which includes Wall Street and thus the financial center of the United States) from the rest of New York.

Hubertus Breuer
Picture credits: from top: 2.picture Corbis, 3.dpa/picture alliance; Picture gallery: picture 2: PJM Interconnection