Hope for the best, plan for the worse...

BB.

Why it is always a good idea to follow code (for construction and fire safety)--Things do go wrong, even for the "big guys":

https://www.sfgate.com/news/article/Walmart-sues-Tesla-over-string-of-solar-panel-14364829.php

"Why were multiple Walmart stores located all over the country suddenly catching fire?" the suit asks. "The answer was obvious and startling: the stores all had Tesla solar panels installed by Tesla on their roofs."
...
Walmart and Tesla had struck a deal for the installation of solar panels at more than 240 stores, according to the lawsuit, and the fires date back to 2012. A more recent string of fires took place beginning in March 2018.

-Bill

Estragon

"Frayed wires arcing"?  Yikes.

Another story I read on the lawsuit asks (but doesn't answer); what ever happened to the solar roof tiles announced with much fanfare quite a while back?

Dave Angelini

Where did you see frayed wires Estragon? Did I miss it? Seems like it would have to be in the design and installation more than a frayed wire from a rodent. Yikes either way for sure.

Bill, did you ever see anything else on the battery fire on the house in fairfield I think?

Dave Angelini

After reviewing the damage caused by fires, Walmart said in some instances it appeared Tesla personnel made cable connections using connectors that were not compatible.

Walmart said its investigations "quickly discovered that Tesla routinely deployed individuals to inspect the solar systems who lacked basic solar training and knowledge."

Tesla has struggled with its solar business, since acquiring SolarCity in 2016, when it was the leading solar installer in the United States. Since the $2.6 billion acquisition, the company has lost market share as installations declined.

On Sunday, the day before the lawsuit was filed, Tesla CEO Elon Musk announced the company had "relaunched" its solar division and will offer to rent rooftop panels to homeowners in six states, starting at $50/month for a 3.8 kW system.

According to Walmart, Tesla last month responded to Walmart's complaint and "admitted that its site inspections to date 'have identified areas for improvement and opportunities for error correction.'"

Walmart asked the court to conclude Tesla breached its solar agreements, require it to "remove the solar panel systems from all Walmart locations," and award damages "in an amount reflecting the outstanding value of out-of-pocket costs and consulting fees in connection with all the fires caused by Tesla's solar panel systems."

The suit also requests the court award damages "reflecting the value of any contractual payments owed to Walmart" under its solar agreements with Tesla.

Follow Robert Walton on Twitter

BB.

Ugly with Walmart...

No, have not seen anymore with the house fire and Li Ion batteries...

-Bill

Estragon

Dave Angelini said:

Where did you see frayed wires Estragon? Did I miss it? Seems like it would have to be in the design and installation more than a frayed wire from a rodent. Yikes either way for sure.

Bill, did you ever see anything else on the battery fire on the house in fairfield I think?

It was in the linked article in the paragraph starting with "In the suit, Walmart attorneys allege...".

It does sound more like shoddy installation and follow-up inspections than rodents.  I'm surprised Tesla/Solarcity has let it get this far.  

Dave Angelini

I am surprised also. This can kill a company. Kind of looks like defective panels in a string being fed by multiple strings without the required OC protection. Probably a few other ways to do this damage. Pretty damning if below is true. Ugly squared.

 "quickly discovered that Tesla routinely deployed individuals to inspect the solar systems who lacked basic solar training and knowledge."

mike95490

Another case of solar done wrong, poisons everyone's well.

Dave Angelini

7 cases of it with Tesla. This was not isolated and so it sounds more like an incompetent wiring connector design/inspection/installation.
 If you think about it,
this is often what we see in residential. Most of the failures even here on this forum are wiring related.

mvas

The two parties plan to "kiss and makeup".
If I was Walmart, I would, at least. demand that ...
all existing systems be re-wired such that when they are "shutdown" they cannot start a fire - like the store in California DID !

A thorough Electrical Inspection, by PV Trained personnel, might be a good idea too 

Dave Angelini

You think so?  Hard to get past "gross incompetence" Not sure how deep a pocket Elon has these days either.

mvas

I know so ...
Tesla / Walmart joint statement "... we are looking forward to re-energizing the solar panels at Walmart stores  ...".

I think - Tesla will be reimbursing Walmart "for damages".

Dave Angelini

https://www.teslarati.com/tesla-walmarts-joint-statement-resolution-talks/

I wish I could be certain of anything involving Lawyers. I wish them both luck, they will need it.

Tesla was very lucky no-one died also.

Dave Angelini

Last week was not a good week, unless you passed the state bar.....

https://gizmodo.com/amazon-echoes-walmarts-claims-that-tesla-solar-panels-s-1837529249

softdown

Dave Angelini said:

Last week was not a good week, unless you passed the state bar.....

https://gizmodo.com/amazon-echoes-walmarts-claims-that-tesla-solar-panels-s-1837529249

That article is very damning to Solar City and Tesla. Losing a WalMart or Amazon location due to some roof top panels is quite difficult to justify. Pretty clear that Solar City has strikingly major issues.

billybob9

Since all racking is grounded for solar then putting a positive wire directly onto it would make it a heater. If a bare dc wire touched the rack it would have to then back away to ark and just weld in one spot. If the Inverter shut down when this happened the over heating or ark would still happen if the sun was out so maybe a thermal device for shutdown will be the next NEC code.

Dave Angelini

I watch Panasonic as I think they are one of the best panel manufacturers out there. Great warranties and watts per square foot. The link below shows the Tesla panels from Buffalo at a cost 20 cents per watt above the industry. This is where Panasonic backed out of the deal with Tesla.

A history of Solar City and Tesla below.

https://www.vanityfair.com/news/2019/08/how-elon-musk-gambled-tesla-to-save-solarcity

BB.

Here is an article that gives some costs for Tesla Roof Tile and Battery Bank products:

https://wattsupwiththat.com/2017/08/08/tesla-solar-roof-deal-or-dud/

And some basic financial calculations (NPV--Net Present Value---I.e., if you spend $20,000 on your system up front, and it takes 20 years to get your $20,000 back, it is not worth the money--Or the risk to your money).

-Bill

billybob9

Bill

I guess that is an 8k system they're trying to sell and I hope things don't work out for them. If the going trend is to give that curb appeal look to houses again then houses with panels on them will be looked down upon. This could happen in even middle class areas as you would be "those people" who bring the area down. I think this might have been the plan all along.

Dave Angelini

Making the connection: Fires & electrical balance of systems

Walmart’s allegation that some of the fires in the solar plants on the roofs of its stores were started by connectors echoes concerns the industry has had for some time. And the problems go far beyond one manufacturer or installer.

Image: Shoals

Much ink has been spilled over the lawsuit filed by Walmart against Tesla, related to the fires at solar installations on the roofs of its stores. But few journalists have asked why these fires happened in the first place, especially with technical literature stating clearly that properly installed solar arrays do not start fires.

And right there is the first clue – that the problems may not be in the arrays themselves, as much as how they were installed. A quick search for “connector” shows that this word appears dozens of times in the summons filed by Walmart on August 20, 2019.

Not only does Walmart allege that the fires at stores in Milpitas and Lakeside, California were started by faulty connectors, but the company also claims that Tesla staff had mated connectors that were incompatible with each other, that they had failed to torque the connectors adequately, and had failed to replace faulty connectors or to properly torque these following inspections, all of which resulted in unsafe conditions.

As revealed in a later report by Business Insider, Tesla had been running an internal program to replace these connectors, which were identified as Amphenol H4 connectors. Amphenol has denied that its connectors had anything to do with the fire, but this latest news is another black eye for the company following SolarWorld’s recall of modules using Amphenol connectors two and a half years ago.

However, pv magazine research indicates that the problems with connectors and their installation is much deeper than any one manufacturer or installer, and that issues with connectors could be a ticking time bomb for the solar industry.

“I would love to say it is a one-off situation, but it is a very prevalent issue in the industry,” notes Brian Mills, product manager – photovoltaics for Stäubli, which under the former name of Multi-Contact supplied connectors for nearly half of the solar online globally.

 

Compatibility?

Stäubli cites a Failure Modes and Effects Analysis (FMEA) by the EU-funded Solar Bankability Project, which identifies using different kinds of connectors – a practice known in the industry as “intermating” – as by far the leading cause of module failure, with various kinds of connector failures identified as the most costly problems.

Graphic: Stäubli

To be clear, this doesn’t mean that every connector issue ends in a blazing roof or field. But it does indicate that connectors have been a source of major problems.

To understand why this is such an issue, certain basic facts about connectors must be understood. Each connector manufacturer makes their product to their own internal standards, and while these products are typically certified by UL or other organizations, there is no single standard for connectors like there is for the electrical plugs that go into wall sockets.

And the differences are not superficial. Connectors are made of many different materials, and Shoals Technologies CEO Dean Solon notes that while many of the high-end connectors have copper contacts, some manufactures use bronze or aluminum alloys, and says that he has even seen steel contacts.

Additionally, there is no one standard for the size or tolerances of connectors, which means that even if two connectors from different manufacturers look like they are the same size and shape, the imperceptible differences can be real – and damning.

Brian Mills of Stäubli states that intermating connectors is a violation of the National Electrical Code (NEC), but says that it hasn’t stopped many installers from doing exactly this.

“We have turned down customers who wanted to intermate connectors,” Shoals CEO Dean Solon told pv magazine. “We tell them we don’t want to part of the lawsuit.”

 

MC-4 compatible?

Given that intermating connectors violates NEC and that different connectors from different manufacturers can have imperceptible differences, you’d think that manufacturers would want to be clear that their product cannot be intermated with a product from a different manufacturer.

But that would be forgetting the human weakness of avarice, and how this can short-term long-term interests. Solon and Mills both note that many connectors are described as “MC-4 compatible” on module maker’s data sheets, suggesting to installers that they can be intermated with Stäubli’s MC-4.

“It’s a load of bull****” comments Solon.

And despite clear statements from Stäubli that its warranty will be violated if its connectors are mated with products from other suppliers, this has not stopped the “MC-4 compatible” label.

Shoals says that module makers need to be addressed here, and that when it supplies packages of materials including modules to customers, that it requires suppliers to list full specifications, including naming the manufacturer who made the connectors that are on the modules.

 

Penny-wise, Pound-foolish

Both Mills and Solon note that the issue with using cheap connectors and/or intermating these to other connectors is somewhat absurd, given how little connectors add to the overall cost of modules.

“You are talking 1% of the total balance of materials for companies to save to go cheap,” says Dean Solon of Shoals. He says that due to what he describes as stupid errors, his team is currently repowering around 800 MW of solar projects that were installed only a few years ago, including swapping out the electrical balance of systems components.

And while not every connector failure results in a fire, there are real hazards – including for installers. “They don’t understand that the interconnections in a PV system are the highest risk points,” points out Mills.

“The amount of energy that exists at that point is tremendous. It’s an order of magnitude higher than anything you are going to encounter in your home, it’s DC connection, and it’s outside.”

Shoals’ Dean Solon notes that this could also lead to major legal issues. “The first time somebody is electrocuted, the lawyers are going to be the happiest people in the room.”

 

Dean Solon, Brian Mills and Jan Mastny of LEONi will be discussing how to avoid fires, including issues with connectors, at pv magazine’s Quality Roundtable at the Solar Power International trade show in Salt Lake City on September 25. Attendance is free to those with SPI passes. Click here to learn more about this event and to register.

BB.

The old MBA solution... If your average Profit margin is 3% (typical for a large market chain like Safeway), and you can reduce the costs by 1%---That is a 33% increase in profits.

Just took my Honda Van in for another Airbag Igniter recall. 17 years after the initial vehicle sale, still having to "Fix" the airbags... Not good for long term profits to go with lowest bit parts:

https://money.cnn.com/2017/06/25/news/companies/takata-bankruptcy/index.html

Japan's Takata was brought down by the huge cost of its exploding airbag crisis. The company's faulty airbag inflators, which can blast shrapnel into drivers and passengers, have resulted in the recall of tens of millions of vehicles and been linked to 11 deaths in the U.S. and several others elsewhere.

With spiraling debts estimated at more than $9 billion, Takata (TKTDY) said Monday it's seeking bankruptcy protection in Japan and the U.S. It's also selling off the lion's share of its business to a U.S.-based rival.

I do have a question.... In the dim past, air bags were installed for people that chose to ride in vehicles and not wear seat belts. And there were even automatic seat belt systems to buckle up (I hated those--Tried to strangle me as I was reaching out a car window and opening/closing the door).

Back then, there were no mandatory seat belt wearing laws (and they said that there never would be--The government promised). Today we have mandatory seat belt laws. Why even have airbags today (seat belts are better in an accident than airbags). Removing airbags reduces new car costs, and accident repairs.

http://freakonomics.com/2005/07/18/which-would-you-rather-have-a-seat-belt-or-an-air-bag/

It turns out the answer is easy, and my views on this one are much less controversial than on car seats. With Jack Porter, a professor at Wisconsin, I wrote a paper published four years ago that looks at the effectiveness of seat belts and air bags for adults. We found that wearing a seat belt reduced the chance of death by 60-70 percent across all crashes. We estimated that air bags reduce the death rate by 15 percent in frontal crashes, but don’t help in partial frontal, side, or rear crashes. (The benefits we found for adults in seat belts were higher than most previous research, and the results on air bags were lower than in most earlier research. But there is nobody who knows the data who would prefer an airbag to a seat belt if it was an either/or choice.)

The bottom line is that to save a life with a seat belt costs $30,000; to save a life with an air bag costs $1.8 mm by our estimates. This makes seat belts an incredibly effective safety innovation. While in comparison, air bags look bad, indeed in the scheme of things $1.8 mm to save a life is pretty good by regulatory standards.

-Bill

Dave Angelini

Seat belts for MC4's ?

I have client who butt spliced all of his panels even though I told him warranty could be denied.

Certainly not a bad Idea to peak at the temps on them in your spare time.

 I just look at the monthly peak output and make sure it is comparable to 4 months back. Not a bad idea and easier than shooting a temp sensor at MC4. Either way if is a a temp based intermittent the guy with the butt splices is better off.

softdown

I know an old solar guy who removes MC4's because he "doesn't like them". Not sure what he uses instead. 

On a related note, I've known a few mechanics who just about hated synthetic oil - a singificantly better lubricant. People don't always make sense. 

billybob9

Looking at all the videos on youtube  " How to DIY a MC4  " you'll see nobody does it the same. Some don't even use a crimper, which is insane. I never did find a video that was put out by a manufacturer that went thru the whole process that I liked. So lets say a crimp is bad and loose. Is this going to create an ark and what will happen next ? If NEC goes with a Temp on the MC4 it's just more stuff to go wrong. One guy was soldering his M&F connectors on and now I think, "maybe not such a bad Idea".

Dave Angelini

Some of my buds are reporting different make connectors on the same panel, some of the MC4 makers claim full compatibility with others. Some are saying no compatibility and they do not want to be in a lawsuit. Some are saying they can "feel" issues when demating. 

All over the map. The quote below is interesting also from Jerry.

"Just to add, l had a lab and l did testing on connectors, we found that most of the aec issues were under low light. This appeared to be when irradiance was low and once the irads went up the issue was less likely, this was because the Male-female contact was not tight enough and under lower power it would arc instead of heating up and expanding. I used a IR Camera but could see little change due to the plastic.

Then l used an IV curve tester and shaded partially shaded the module after several repeat testing the connectors got warm. I would suggest making your own connector pull out tool to check the contact pressures. This is where you may find your problem components. It appears that early am testing had lower volts and the inverter pushed the current up and causes the loose connector to fail due to the lower volts. 

This testing was done both in the field 1/2 meg and lab testing results were very close.

The modules used for testing were Trina and the field inverters were ABB and Fronius"

MarkC

Probably not anything new, however, this recent compilation of Tesla issues in home installs:
https://www.businessinsider.com/tesla-solar-panel-fires-become-nightmare-some-homeowners-2019-10

softdown

Are there only 99 ways to fail in home solar? Or 999? Geez. Roofs catching on fire! I think a couple Walmarts and Amazons actually burned up?

While a volunteer firefighter, the chief once commented that "We save foundations." He was only half serious. I think.

Dave Angelini

Going to have to use this one on the foundations. Our fire guy's always show up. About 24 hours after the fire rolls thru

softdown

Somewhat pertinent I think. I could use this to help explain a lot of phenomena.