It’s been several years since Superstorm Sandy wreaked havoc on the east coast of the United States in 2012. The economic impact cost the NYC area about $19 billion from issues related to power loss alone. The easiest thing to blame for such a strong hit to the economy is the storm itself—no storm, no damage, no impact. But a storm can’t be controlled, so we look to the next best opportunity to reduce impact to the electrical power grid – resilience.
Large electric power grids deliver electricity across designated paths from the point of origin (where the power is generated) to where it will be consumed (residential, commercial and industrial facilities). If there is an outage anywhere along one of those paths, the delivery of electricity ceases. Sometimes this isn’t a big deal for the consumer—if the customer’s loads can be “islanded” from the system and there are other sources of electricity that can be brought on to balance the system. But if there are no other sources, or all sources are disrupted (like due to a massive superstorm), then the impact can be felt far and wide.
A solution to grid modernization
Today, the central grid has new competition as residential, commercial and industrial buildings and their surrounding infrastructures are pooling their energy resources together to form what are known as microgrids. A microgrid combines rooftop solar, wind, battery, and diesel/natural gas generators to form a shared supply for local demand. As solar power costs continue to decline, microgrids continue to emerge at an ever faster pace.
The appeal of renewable microgrids is founded in the energy independence and security it can provide for a community. Disconnected from the larger central grid, communities are less likely to be impacted by rolling brown outs or cascading black outs, and they’re less likely to feel the hit to their pocketbook when it comes time to pay their electric bill.
Microgrid technology is the key to secure and reliable energy
As part of the NYC Economic Development Corporation’s “Rise NYC” program, developed post Sandy, UGE, a solar commercial developer in NY, is designing a microgrid for small businesses in the coastal areas affected by the Superstorm to provide future resiliency.
The system will have solar, batteries and natural gas generators. When the grid is running, the solar will export power back to the utility to generate revenue and the batteries will charge during grid-tie from the PV and the utility. When the grid is down, the natural gas generator will power the business’ key systems.
In the event of a natural gas outage or generator failure, an inverter controller will switch the battery on to ensure maximum resiliency. The microinverters for the solar will shut off during grid outage to ensure no power from the PV is exported to the grid and to guarantee emergency responders can safely work on distribution lines.
How Fluke tools are used to commission and test the microgrid system
The NYC utility Con-Edison, NYC Fire Department and NYC Department of Buildings require UGE to perform a thorough system commissioning and testing before receiving approval to energize the system. UGE trusts Fluke’s digital multimeters and three-phase power loggers for this job.
“During commissioning, we test for isolation, continuity and performance,” says UGE Director of Development Mateo Chaskel. “At all points where there are terminations, such as switches and transformers, we make sure that each of the phases is isolated from the other using the ohmmeter setting. We make sure there are no shorts and that each phase is 100% isolated from the others.”
While still deenergized, UGE tests for continuity from beginning to end. Then they energize from the grid back to make sure everything is reading properly. “We energize the inverters individually and verify voltage and amperages are reading properly,” says Chaskel.
As required for utility and fire department acceptance, UGE simulates a grid outage to ensure the PV shuts off, the generator automatically turns on and feeds energy to the loads, and if the natural gas service is down, that the batteries switch on to ensure reliable power. Through each step, UGE uses Fluke solutions to make sure power supplied is normal, measuring the voltages, amperages and frequencies of each component.
About the expert
Michael Ginsberg is a solar expert, trainer for the U.S. Department of State, author and Doctor of Engineering Science candidate at Columbia University. He is also chief executive officer of Mastering Green, where he has trained nearly a thousand technicians worldwide in solar PV installation, maintenance, and operation.