Utilities: Why you and your customers want grid-resilient solar


By: SGN Staff


It was one of the ultimate frustrations during the aftermath of Hurricane Sandy. Owners of rooftop solar could not use their systems to power their own premises, even during the day when the sun was shining. They sat without power for days, while their panels generated electricity no one could use.


With a few simple changes, the solar systems in your service territory can add to your region's resilience. I asked DNV KEMA's Richard Fioravanti to explain. For additional information on solar's costs, benefits and challenges, download the executive summary  of a storage study from the New York State Energy Research and Development Authority (NYSERDA). - Jesse Berst


By Richard Fioravanti


As the cost of solar systems continues to decline and adoption rapidly increases, efforts are being made to extract greater value from the systems. The cumulative installed base of PV in the U.S. is doubling every two years, and is growing even faster for residential systems.


Most individuals are attracted to solar due to the ability to generate power from the sun and the relative "independence” this provides them.  The seemingly obvious benefit of being able to produce power absent of the electricity and natural gas infrastructure overcomes the limitation that the device simply can’t operate once the sun fades into night. This is a limitation most owners readily accept because of the belief that no matter the manner of disruption, as long as the sun is shining, an owner of solar would be able to at least produce power at some point of the day.


The importance of grid-resilient solar

Though the thought process seems sound, most solar system owners realize too late that --without the proper equipment -- this may not be the case. Without the extra equipment to isolate the home or business from the grid during an outage, the solar device simply disconnects and renders itself inert until the electricity infrastructure is restored. This would be perceived as a minor inconvenience during short term outages but the full extent of this limitation came to bear after Hurricane Sandy - where the storm delivered a harsh lesson for those who owned solar systems.  


As most home owners do not install the necessary components to make their solar systems "grid resilient,” it has been estimated that 95% of the homes with solar that lost power due to the storm were unable to use the generated solar power during the outage.  An inconvenience for short-term outages, but for some home owners the outage lasted 4-5 days, leaving them to only gaze at their solar panels on their roofs while their homes sat without the power to run even their basic loads.  

The hurdles in the way

Why is this not a standard design for all solar?  The two main hurdles are 1) simple education on the requirements for operation during outages and 2) of course cost.  Hurricane Sandy has quickly educated many on the need and means to isolate and operate a solar solution during outages. 


Advancements in technologies and decreasing cost of storage systems are solving the second hurdle.  Advanced storage systems are now allowing a "ride-through capability” to carry the home through the evening until the process of simultaneously supplying the home with critical loads and charging the battery can be repeated the next day. The solutions themselves do add extra costs, but as the solar and storage systems continue to decrease in cost and align themselves to such a solution, the perceived hurdles to adoption will recede as well. 


It seems that with each significant weather event we are taught a new lesson on how our electricity and gas infrastructure can go away for a substantial period of time.  However, we are also learning that the means to insulate and protect ourselves from such occurrences are getting easier and easier to attain.


Richard Fioravanti has over 18 years of experience working with emerging technologies in commercial and consulting roles. In his current post at DNV KEMA’s Energy Advisory group, his efforts are directed on distributed energy resources such as advanced storage technologies, microgrids, device testing, application modeling, and electric vehicles. He also serves on the board for the New York Battery and Energy Storage Technology consortium


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