SOLAR RAPID SHUTDOWN – Will it shut you out?

In early November this year,  a small group of folks will cast a vote that will decide the new language in the 2017 National Electrical Code (NEC) for solar Rapid Shutdown. Many feel strongly that, if approved, the new code will lead to higher costs of components, installation and warranty service.  In my opinion, this seemingly well-intentioned proposed code change should be of concern to all solar industry stakeholders. Why?  Because at minimum it seems to point to special interests working to leverage the code, and in the worst case scenario it sets back all our industry efforts to increase solar adoption nationally. 

Over the last 10 years, firefighters have significantly impacted solar rooftop design, mostly by making clearance requirements to have relatively safe and easy access to roof tops.  Those changes have been logical, have proven to be effective, and have met little resistance.

Now the proposed language for the new code presents an elevated and controversial argument that firefighters need the ability to work safely from outside and inside the perimeter of an array (read – to break through the roof without electrocution).  For working outside the array, there seems to be consensus: a maximum of 30 volts in the lines after 10 seconds.  The controversial language revolves specifically around working inside the array.  The current version of the text would require electronic shutoff at the individual panel level when triggered.  The idea is that the array production would be reduced to a non-lethal threshold (80v is proposed).  As written, this code would undeniably provide a competitive advantage to micro-inverter and optimizer manufacturers; it would also arguably increase the cost of purchasing, installing and servicing solar systems, given the additional electronics that would have to be set-up, monitored and serviced by the installer. 

Thus the question: is this really a first responder issue?  Or is it a lobby that favors a segment of the component manufacturing industry? 


Who says we need Panel Level-Shutdown?

I was finally compelled to write about this by a white paper written by SMA.  The company manufactures both central and micro inverters and is the premier provider of inverters in the US market.  The paper makes a series of enlightening arguments against the proposed code change by explaining that it goes beyond establishing a standard; it imposes how to achieve the standard by mandating panel level electronics.

There are at least two problems with this proposed NEC rapid shutdown text:

1-It’s heavy handed.   It’s a bit like saying that a roof-top solar array must be able to withstand 90 mile an hour sustained wind so installers are required to use 3 lag bolts with 1.25 inch coarse penetrating thread for each footing which must be installed 3 feet apart.  That’s not code, it’s dictatorship.  The American way is simply to state the wind tolerance required.  The market, in its incredible inventiveness and effectiveness, finds ways to satisfy and even exceed the requirement.   An informal poll of manufacturers and installers indicates to me that each would attack a rapid shutdown requirement from different angles, and the panel-level shutdown seems to be the most electronically encumbered.

2- As revealed by SMA, there is a question as to whether the need for first responders to chop through a solar panel exists at all; the practice is not established (wisely) in the firefighting community.  So, why the need?

Let’s consider some fundamental arguments surrounding this.   The most vocal firefighter in the country favoring panel-level shutdown is a well-known and respected fire captain from San Jose, Captain Matthew Paiss (“pace”).  He teaches and consults on all things related to firefighting around solar, has been expressive on panel level shutdown on multiple platforms, and is on more than one committee related to this issue (including being a voting member representing the International Association of FireFighters -IAFF- on the panel that decides the fate of rapid shutdown in the NEC).  His thoughts on this subject are easily found via the web (here’s an example).  

Captain Paiss presents the fundamental argument that the lives of firefighters are not to be gambled with and are far more important than the impact of this safety feature on solar industry costs and reliability.  Few would disagree that “safety first” should be the mantra of his trade, and the industry’s record has proven its support. But his argument for adding an additional layer of electronics to solar installations is based on the emotional appeal of the statement, and it steers the discussion away from fundamentals.

The SMA white paper reveals that “According to the National Institute for Occupational Safety and Health database, between 1984 and 2013, there have been seven first responder deaths due to electrocution, and all were related to AC medium-voltage overhead or downed power lines”,…not PV.

Additionally, qualified firefighters I contacted said they would never manage a fire by chopping through solar panels.  I spoke with Los Angeles city firefighter Captain John Green, who is responsible for the guidelines and approval of all solar installations in the city of Los Angeles, the 2nd largest city in the nation, and probably the single busiest fire department solar desk in the nation.  He is adamantly against panel level rapid shutdown and his argument was crisp.  “We don’t want our firefighters messing with the array, no matter what.  Our protocol is a proven operating process, and adding layers of guess work complicates the job.  Some systems might have panel level shutdown, some will not.  Some of those that do will be operative, some will not.  So we do not want that option to even exist; in a situation, there is no time to try to figure out what might work or not on a solar system.  There is enough uncertainty in what we do.  For us, the rule is ‘Do not engage’, period.”  Then I checked with Luke Claus, a 30-year firefighter and Chief Officer of another major Southern California fire department (disclosure – I am indirectly related to Luke).  In turn, he was unequivocal: “We stay away from panels.  We do not want our firefighters messing with them”. 


So then…Why do we need this technology?

I am told that panel-level devices will not be certified to work after exposure to heat, fire or mechanical damage because those conditions are outside the normal operating envelope…That’s when they would be supposed to work!

So…Who really wants this technology?

Germany, the world’s largest solar operator, has determined that their firefighters do not need rapid shutdown at all, per the TUV Rheinland and the Franhofer Institute which both conclude (again, per the SMA white paper) “PV systems do not pose any particular threat to fire department personnel, provided they comply with safety clearances just as with any other voltage-carrying electrical equipment.”  This comes from a country which operates all of their PV systems without grounding.

The SMA paper also brings up salient points about the relative safety of another trade, solar installers and PV service folks.  Installation companies, for whom roof falls is a major concern, will have increase the number of time and trips on the same roof over the life of the system.  That goes totally against the objective of the profession.

So if this technology is not urgently needed, not fail safe, and will increase the cost of solar, then why is it proposed to be included into the 2017 National Electrical Code?


Speaking up to keep component specifications out.

When you look twice at rapid shut down as currently proposed, you see a wolf in sheep’s clothes: specific interests manipulating the electrical code to favor an agenda that will benefit the wrong guys.  Just like you want your Internet and you want it free, you want your solar energy and you want it free of special interests.  Photovoltaics’ greatest strength is their solid-state simplicity: 40 years of productivity, no muss no fuss.   The more unnecessary technology gets forced into compliance, the more solar’s cost will go up, the more its reliability will be questioned by solar naysayers.  

If firefighters really need to work within the array after rapid shutdown, then set the threshold via a dialog with all stakeholders, and let the industry meet it via its own resourcefulness.  Per L.A. Fire Captain John Green, the additional layer of technology is not urgently needed nor wanted by firefighters. So then, increasing the costs of solar through the electrical code seems foolhardy, even more so in the face of the imminent sunset of the federal tax incentive.  I say it’s irresponsible, so irresponsible that it makes me wonder who is responsible for the idea.

All of us stakeholders in the solar industry, in my view, should be concerned about the creeping intrusion of special interests.  Whatever your opinion, let your voice be heard now, before the proposed text becomes law.

You can do so by writing to the Staff Liaison for the National Fire Protection Association,  Mark Earley (mwearley[at]   Also, here are the members of the “Code Making Panel 4″ (the group crafting the questioned section of the 2017 National Electrical Code).

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