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Run on Sun Monthly Newsletter

Fire! Is Solar a Threat?

We saw a piece this month about a fire on a distribution warehouse in New Jersey that was gutted in part because the local fire department was afraid to interact with the solar power system on the warehouse roof. As solar makes greater inroads on commercial buildings, what can we as an industry do to address this concern? (H/T SolarWakeup.com)

The distribution center, owned by Dietz & Watson, was a refrigerated warehouse that supported over 7,000 solar modules according to news reports. From Google we get this image of the center in happier days:

This is a very large commercial array by any measure - even if those are 200 Watt modules you are looking at a 1.4 MW install on the roof, to say nothing of the additional capacity installed in the carports to the west. It is also a very nicely designed array with clear access paths throughout the roof and plenty of potential areas that could be broken open to allow for venting (although I'm sure from a fire fighter's perspective, they would always want more). Sadly, this is how it looked during the fire:

Here is the view of the blaze taken from the raw video recorded by local TV station NBC10:

This image makes clear that the NE quadrant of the building has been extensively damaged - the black area is where the solar panels have been completely destroyed.

The image also makes clear that the fire department chose to fight this fire from the ground, spraying water and foam onto the roof as opposed to going on to the roof itself. (There was no explanation given as to the cause of the fire.)

The local reporting indicated that the fire crews were concerned about possible collapse of the roof due to the amount of water being poured onto the fire. But they also mentioned the concern over possible electrocution:

Firefighters had to pull back at some points because the fully-charged solar panels posed the risk of electrocution.

"With all that power and energy up there, I can't jeopardize a guy's life for that," said [Delanco Fire Chief Ron] Holt.

So what to make of all of this?

There can be no doubt that solar installations have the potential to make the already dangerous business of fighting a fire more hazardous. Strings of solar panels can produce as much as 600 Volts DC and as a general rule, there is no way to shut them off from the ground. While a DC disconnect on the ground could isolate the array from a ground mounted inverter, there is still potential in the conductors leading from the roof to the inverter. If those conductors are shorted together - due to either a fireman's actions or the fire itself - there is the potential for significant arcing and possibly even electrocution.

Of course, one way to reduce that risk is through the use of microinverters or AC modules. With a microinverter, the only conductor runs are AC which can be safely switched off from the ground meaning that any conductors coming from the roof to the ground will be safe. The individual solar modules can still produce power, but there are no strings to slice into or suddenly short to create a dangerous condition on the roof. While microinverter systems are not generally considered on systems of this size, Enphase recently announced the use of their products on a 2.3 MW commercial array - possibly larger than this one.

Which begs the question - would that have mattered here? Maybe, maybe not. The question really is a function of how well would the local fire department understand the difference? When we talk with local fire inspectors, they are always appreciative of the added safety to be found with microinverter systems but how well does the inspector's understanding extend to the fire crews reporting to that fire? Would they have trusted that the claimed safety was real and moved more aggressively to fight the fire on the roof? Or would they have elected to play it safe?

The solar industry can work to develop safer products - which microinverters surely are - but that won't matter if local fire crews aren't educated as to how best to fight these fires. Interestingly, while local codes require solar installers to provide all sorts of largely useless signage on our arrays - for example, specifying the nominal AC voltage and current as if that would make the least bit of difference to anyone - there is no requirement to indicate the type of inverter being used. Absent such signage, how would a local fire crew know what they were facing?

Maybe our friends at Enphase can design a placard to attach to our AC disconnect switches that advises the local fire department that throwing that one switch renders the conductors coming down from the roof safe?

So much of what we must do in the solar industry is education - this appears to be one area where we need to improve our efforts.

Solar Decathlon Update - Coming Together

We spent part of last week with the great group of folks from Team USC working to re-install their solar PV system. Here's our update.

Although the Team had the house entirely complete for the Send-off Celebration, it had to be deconstructed into its three component pieces for the trip down to Irvine. That meant cutting open drywall and unbolting sections from each other before the three sections could be loaded onto trucks. But it also meant that the solar array, which actually consists of four branch circuits, had to be partially disassembled since three of the four cross section boundaries. Yesterday's task was to restore those connections in a manner that was up to code - since these houses need to pass a rigorous inspection process before being hooked up to the local "micro-grid" - and help the Team stay on track. While starting October 3 the Irvine competition site will be a solar village, right now it is very much a construction zone with massive cranes in all directions manipulating the different homes into place. On the left is last week's view to the North from atop fluxHome.

The view to the South featured a similar display of activity - and the Great Park's trademark orange sphere is there in the background: With all of that activity going on, the competition organizers were taking no chances with safety - everyone entering the competition area was required to wear hard hats, eye protection and proper foot protection. When working on the roof - where I spent the most of my day - harnesses and fall protection gear were mandatory. In fact, if a team member is spotted without proper safety gear, the team is docked competition points. A powerful incentive to follow the rules and maximize safety - always a good lesson to learn.

This image shows us fully decked out in all of our safety gear, working on restoring one of the branch circuit connections: As you can probably tell, it was a beautiful day to be working on a solar project, particularly an inspiring gig like USC's fluxHome.

On the left is a view of the roof last week. In the foreground you see the massive, automated skylight that forms the aperture for the "solar chimney" that is an integral part of the home's systems. Behind the skylight is a portion of the solar array.

Support Team USC

It is a privilege to be a part of the Solar Decathlon - but for the teams involved it is also a massive fund raising project and success, or failure, can be tied to that aspect as much as a great design. In fact we learned yesterday that one of the teams from Virginia had to drop out of the contest because they couldn't raise enough money to complete their design and then ship it to California. So sad to think that two years worth of hard work went down the drain because they fell short on their fund raising. (As they said in The Right Stuff, "No bucks, no Buck Rogers.")

While Team USC has not suffered such a depressing fate, they could still use your support. So if you would be interested in contributing to the team, you can jump over to their Support page and make a donation.

A Little Help from Their Friends...

Finally, while we were taking a break on the ground, we came across a film team that was documenting the Team's progress and they told us about this video that was shot while we were doing the initial installation. The entire video is well worth watching as it documents the efforts of the four teams from California that are competing this year. But we have to admit, we are partial to the section that begins around the 35 minute mark - and stick around for the happy conclusion after the break!

Best of luck to all the schools competing, and especially to Team USC - Fight On!

Run on Sun Named One of Top Solar Contractors

Solar Power World, which recently quoted Run on Sun Founder & CEO Jim Jenal at length in a news article, has just announced their annual listing of the Top 250 Solar Contractors in the United States and Run on Sun made the list, coming in at number 234.

From Solar Power World's editorial announcing the list:

These companies have the vision to succeed in an industry dismissed by so many around the world. These companies—these visionaries—are poised to take full advantage of the near-term solar boom that none other than researcher Shayle Kann has predicted for the U.S. industry.

It is these businesses that have fueled the three-year growth of this industry of 227%. The Solar Power World's Top 250 employ 73,068 people and installed 3 GW in 2012 alone. They have installed 7.8 GW overall. They represent the best across all three segments—utility, commercial and residential—that make this industry so vibrant. In an industry now valued at $11.5 billion, these are the companies that have built it.

For a local company like Run on Sun, it is a great honor to be listed among the biggest and best known solar companies in the country. We are proud of our role in building this industry, and proud to be a voice for making the industry live up to its vision. After all, you cannot claim to be part of building a sustainable future if you engage in shoddy business practices or stoop to unsavory marketing tricks.

So congrats to all our colleagues who made the list - here's to continuing to grow an industry we all love!