[RE-wrenches] RE-wrenches Digest, Vol 7, Issue 29

Thu Jan 23 11:23:35 PST 2014

Jeffrey and Ray,

Batteries can off-gas hydrogen-sulfide gas when under heavy charge or overcharge. It is the nasty rotten egg smelling gas. Definitely not to be inhaled since when it hits your lungs it turns back into sulfuric acid.

To address Ray’s point, the new 690.12 regulation that has been getting a lot of air time on this list does, in fact, address battery circuits for PV systems. Any circuit that is part of a PV system inside a building within 5’ must be controlled to 30V, 240VA within 10 seconds. This includes all the ac output conductors from a backup PV inverter and the battery inverter input circuit as well. This provision matches the new requirement for battery systems in 690.71(H) that requires “A disconnecting means and overcurrent protection shall be provided at the energy storage device end of the circuit. Fused disconnecting means or circuit breakers shall be permitted to be used.” Ideally we try to keep our battery conductors to 5’ or less and that means that no additional disconnecting means would be necessary according to the new 690.71(H). If we have to go longer than 5’ and the conductors are inside the building, a rapid shutdown capability would need to be on that circuit and it would need to have a disconnecting means and overcurrent protection. The best way to meet this requirement would probably be to have a shunt-trip breaker, similar to what Midnite Solar provides with their birdhouse setup.

There are definitely much more discussion going on in the NEC about energy storage now than ever before. This next code cycle will be very busy on the subject. It is likely that article 480 will soon be turned into “Energy Storage” or a new article in Chapter 6 or 7 will cover “Energy Storage Systems.” It was proposed last cycle and failed, but this time there is much more interest in the subject. The solar industry needs to be involved, so it sounds like this is your year for both of you to get involved.

Bill.

From: re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Jeffrey Quackenbush
Sent: Thursday, January 23, 2014 10:28 AM
To: RE-wrenches
Subject: Re: [RE-wrenches] RE-wrenches Digest, Vol 7, Issue 29

Ray--

What poisonous fumes do lead-acid batteries off-gas? I know they off-gas hydrogen, which can be an explosion hazard -- but hydrogen isn't poisonous. Or were you thinking about a different type of battery.

Jeffrey Quackenbush

On Thursday, January 23, 2014 8:19 PM, Ray Walters < <mailto:ray at solarray.com> ray at solarray.com> wrote:

I must jump on my soap box, as I have so many time in the past, and follow up Glenn's comment here.  We worry so much about details of PV arrays, while batteries are serious safety hazards that no one (including the NEC) ever wants to address.  Not only can they not be de-energized, they have amazing short circuit potential (unlike PV) and they can explode as well. Meanwhile in normal operation, they off gas poisonous fumes.   
The whole industry is looking at energy storage now, as well, so this isn't just confined to the off grid fringe anymore.
Further, many industrial complexes have large battery banks for UPS systems and electric forklifts.  
Why is the NEC still not making any real changes on battery storage?  There have been some fairly interesting fires from utility scale battery systems, seems its more than about time.

R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer, 
Licensed Master Electrician
Solar Design Engineer
303 505-8760

On 1/23/2014 5:49 AM, Glenn Burt wrote:

"They can safely shut down any electrical system in a building—except for PV systems."

Not completely true, as batteries are stored energy systems and while they may be disconnected, are still energized regardless of the state of other systems.

  _____  

From:  <mailto:david.brearley at solarprofessional.com> David Brearley
Sent: ‎1/‎22/‎2014 22:48
To:  <mailto:re-wrenches at lists.re-wrenches.org> RE-wrenches
Subject: Re: [RE-wrenches] RE-wrenches Digest, Vol 7, Issue 29

Drake, 

As far I know you are correct. There have not been any firefighter deaths due to solar. 

However, a fire chief in New Jersey did suggest that he let a warehouse burn down due to the presence of a PV system on the roof:

 <http://www.myfoxphilly.com/story/23313172/multiple-alarm-fire> http://www.myfoxphilly.com/story/23313172/multiple-alarm-fire

 <http://www.theatlanticcities.com/technology/2013/09/why-firefighters-are-scared-solar-power/6854/> http://www.theatlanticcities.com/technology/2013/09/why-firefighters-are-scared-solar-power/6854/

That suggests to me that while there is no crisis today, there is certainly the potential for one down the road. Imagine the insurance industry's response if fire fighters make a habit of not responding to structural fires due to the presence of PV systems. Fire fighters want touch-safe PV modules. And they have a reasonable complaint. They can safely shut down any electrical system in a building—except for PV systems.

SEIA and SEPA are the solar industry lobby. Please do engage and support them. SEIA even has a political action committee, the SolarPAC. Part of the way that I try to stay on top of evolving Code issues is by attending SEIA- and SEPA-sponsored events. 

Also, over the past 4 or 5 years, the Solar America Board of Codes and Standards has scheduled annual meetings that coincide with Intersolar. Those are very informative sessions. I think the sessions are even archived online at  <http://solarancs.org/> solarancs.org.

David Brearley

Senior Technical Editor, SolarPro magazine

NABCEP Certified PV Installation Professional

 <mailto:david.brearley at solarprofessional.com> david.brearley at solarprofessional.com

Direct: 541.261.6545

On Jan 22, 2014, at 8:18 PM,  <mailto:re-wrenches-request at lists.re-wrenches.org> re-wrenches-request at lists.re-wrenches.org wrote:

From: Drake < <mailto:drake.chamberlin at redwoodalliance.org> drake.chamberlin at redwoodalliance.org>

Subject: Re: [RE-wrenches] NEC 2014 690.12 Rapid Shutdown

Date: January 22, 2014 2:16:18 PM CST

To: RE-wrenches < <mailto:re-wrenches at lists.re-wrenches.org> re-wrenches at lists.re-wrenches.org>

Reply-To: RE-wrenches < <mailto:re-wrenches at lists.re-wrenches.org> re-wrenches at lists.re-wrenches.org>

David,

My sincere thanks to all of you who worked to keep the module level disconnect requirement out of the 2014 code cycle. That ruling would have amounted to a knockout punch for string and central inverters on buildings. 

What was the driving force behind this push for immediate module level disconnection? There has clearly not been a rash of firefighter deaths due to PV systems. Although PV needs to continue evolving safety standards that take into account the concerns of firefighters, there is no crisis that would justify thwarting one of the few growing sectors of our economy.  

The PV track record has been amazingly good. So far, I've found no accounts of solar related firefighter deaths or injuries. The NFPA statistics show that the highest cause of firefighter death is heart attack.  <http://www.nfpa.org/newsandpublications/nfpa-journal/2013/july-august-2013/features/firefighter-fatalities-in-the-united-states-2012> http://www.nfpa.org/newsandpublications/nfpa-journal/2013/july-august-2013/features/firefighter-fatalities-in-the-united-states-2012 

This push for crippling regulation bears the earmark of ALEC’s extensive and effective war on solar. As you can read in the following links, the massively funded, Koch brothers-linked ALEC is lobbying heavily, on every level, to derail solar. All who are associated with the solar industry need to be aware of this powerful lobbying campaign. 

 <http://www.theguardian.com/world/2013/dec/04/alec-freerider-homeowners-assault-clean-energy> http://www.theguardian.com/world/2013/dec/04/alec-freerider-homeowners-assault-clean-energy 

 <http://www.salon.com/2013/12/05/alec_freeriders_with_solar_panels_must_pay_for_robbing_the_system/> http://www.salon.com/2013/12/05/alec_freeriders_with_solar_panels_must_pay_for_robbing_the_system/ 

 <http://beforeitsnews.com/environment/2014/01/alec-gain-an-inside-track-on-colorado-solar-2490132.html> http://beforeitsnews.com/environment/2014/01/alec-gain-an-inside-track-on-colorado-solar-2490132.html 

Is there any way that the solar community can be alerted when threats to our industry are being put before the NEC? Although few contractors have the time or money to walk away from their businesses and attend code writing committees, a substantial number might have the time to make phone calls and send letters or emails to code writers. 

The solar industry needs a strong lobby of its own. 

Drake 

[The entire original message is not included.]

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