Latest / Clean Power Hour / Rapid Shutdown and Fire Safety in Solar with Jing Tian, Tigo Energy EP 120

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Rapid Shutdown and Fire Safety in Solar with Jing Tian, Tigo Energy EP 120 · Clean Power Hour

• 0:50
  Jing Tian: Most of the products in the market you have a Power line communication. That is for PLC rapid shutdown. In Kaiba. We also have a wireless communication device for that is offering addition to rapid shutdown. Also with the module level monitoring, and optimization.
• 1:12
  Tim Montague: We have this thing called Rapid shutdown in the solar industry with the advent of the NEC 2017. That's the National Electric Code. Some solar arrays are required to incorporate what's called Rapid shutdown. And this is a safe a safety feature for especially first responders. But for for all of the solar industry. This is a safety feature. My guest today is Jing Tian, she is the chief growth officer for a company called Tigo Energy.
• 1:41
  Tim Montague: Welcome to the show, Jing.
• 1:44
  Jing Tian: Yeah. Thanks, Tim. I really appreciate opportunity.
• 1:46
  Jing Tian: Thank you.
• 1:47
  Tim Montague: It's always great to have such industry veterans on the show you have such a wealth of experience. You've been in many aspects of the industry. And so for our listeners, please give us a little background on yourself.
• 2:01
  Tim Montague: How did you get interested in energy? Why did you end up getting a PhD in some exotic science? And then and then get into industry and not academia?
• 2:12
  Jing Tian: Oh, that's very good question. I think I got a PhD in chemistry. But what I really did it was solid state polymer materials. My dissertation was in organic, a conductive materials that's very naturally ties into the application of a batteries, and photovoltaics. So it gets exposed to these aspects of research while I was in graduate school. So I always thought, you know, great, you watching the PV industry growth from the early days of $10 a watt to today's price of less, you know, cost less than 30 cents a watt. So, so this is like really interesting, exciting industry. I just want to see a product or technology or product to translate it into a real application. That's why I pursue the industry rather than academia.
• 3:12
  Tim Montague: Very good. And you've worked at several very noteworthy companies give us a little background on the companies that you've been part of. And, and now with Tiago, so tell us a little bit about that.
• 3:28
  Jing Tian: Yeah, it's a journey, I'll start out with a company called a sole focus that is a Silicon Valley startup, we start out as concentrated photovoltaics. Early days, if those of you remember when the silicon wafer was still very expensive. So one of the way to reduce the PV costs is to use a mirror to replace the circuits.
• 3:52
  Jing Tian: So, that was the premise of the concentrated photovoltaics with three five junction semiconductor. And so, you can use much less areas of semiconductor Concentrated Solar City into five acts of a solar irradiance to produce more energy. So, so, that was early days, I was there for four years, then the silicon silicon wafer prices coming down significantly, then it gets very difficult for the mirror to competing with the silica so scale silicones to scale up faster. So then I you know, then I went to nano solar, so that was a printing thing from technology. The flexible matrix, again, you know, early days, there's a lot of technology, people are looking at different ways to to bring the PV Kosta right. So CPV is concentrated the thin films and the silica I think any any end obviously we all know today silicon steel is the king of the PV industry. So I went to Trina Solar I was there for quite a few years took out different roles global marketing as well as responsible for US business there. Yeah, then yeah, when a few project developers and also went to some help with the inverter companies and then I joined the Tiago.
• 5:36
  Tim Montague: And Togo is a power electronics company. Which is extremely important. Now, when we have this phenomenon called Rapid shutdown. Let's why don't we just start at the top Oh, what is rapid shutdown? And how does it work?
• 5:55
  Jing Tian: Here rapid shutdown is electrical safety requirements, as you mentioned earlier, Tim. So what does is it is de energise the PV array when it's needed, right? So it's mostly accomplished with some sort of module level power electronics, in order to comply with NEC code 2017 and 2020, because it requires at the module level electric voltage should go down less than 80 volts within 30 seconds. So, then typically, the MLP is installed on the back of each module that it communicates with the inverter. So this setup allows the photovoltaic system by using directional communication signal to the inverter than when the presence or loss of those communication signal acting as an off switch.
• 6:56
  Jing Tian: So only when the shutdown initiated in other words, when sending a signal or lost the signal that how the PV array to go under shutdown mode, then the system gets into shutdown. So create a safety for firefighters and the emergency people need to access to roof.
• 7:16
  Tim Montague: So So these, these MLPs module level power electronics are a small box that sit connected to the solar module, they they're typically one to one or one to two, meaning one MLP per two solar modules, depending on the configuration depending on the product, depending on the approach, different manufacturers have different approaches. And but at the end of the day, right, you just set it it's a switch, right? It turns off the solar module and prevents the electricity from running from the solar module to the facility. And and so the entire system gets de energised very quickly. And this makes it safe for things to happen, like access to fly and cut holes in roofs that might be covered with solar arrays so that the firemen can do their job, which is to create event. So they can get smoke out of the building so that they can do their job and save lives and not be in harm's way themselves. Right. We don't want anyone to get hurt when there's an emergency. And so this is a fire safety phenomenon. And technology at the end of the day, first and foremost, and it has pros and cons. It does in theory create a safer solar array, which we're very fond of, we want solar to be a safe technology for everyone involved. And you know, electricity is dangerous. So there's no there's no ands ifs or buts about that right, we have to be honest, electricity is dangerous, potentially. But it is a necessary thing, right?
• 8:59
  Tim Montague: We can't have the modern life that we have without electricity. And we can't have a clean grid without solar. So we need the solar arrays on our rooftops. And so we're grateful for all of the, you know, science scientists and engineers who are inventing these wonderful devices. So let's go a little deeper. And I think I've explained why we have rapid shutdown. But is there anything else you want to say about why?
• 9:24
  Tim Montague: Why rapid shutdown is important?
• 9:26
  Jing Tian: Yes, I think that you cover the very much. I mean, it's really intended to protect the firefighters and the first responders from contact a high voltage electricity. Keep in mind, even the if the PV array under the sun, they are activated. Even if it's now producing, you know, the AC electricity, say for example, you don't have a load, but the PV array is still energised, that is important that to remember. So that's why I need a rapid shutdown to protect them.
• 10:01
  Jing Tian: So they can go in there to to do the job they need to do or do not watch the house on fire because they cannot reach access to the roof. Because the high voltage hazard
• 10:14
  Tim Montague: Yeah. And so what is it that triggers a shutdown event?
• 10:20
  Jing Tian: at the module level, power electronics will usually is two ways that you do usually is either you go through harder button is or what we call the emergency stop button at that point, usually sending the signal to each module level power electronics on the module.
• 10:38
  Jing Tian: And let's say here's the event.
• 10:42
  Jing Tian: So the you going down to the shutdown mode, which technically is to prevent module to continue to all input current and voltage, right? So it's at each module level, do you shut out the current output so that therefore it gets the system safe? Yeah, other mechanism is usually great auto detection, and I see detected great off performing inverter that sends the signal. So oftentimes those two, combined the two use in the post case, especially in the world, as more and more people adopting the battery storage system, right agree off doesn't mean you need to enter rapid shutdown. So oftentimes, in this case, is opposed to physical, as well as auto detection going on.
• 11:30
  Jing Tian: In combination.
• 11:31
  Tim Montague: Yeah. So let's talk about a specific case, let's say that there's a short happening in a solar array, some connection is getting hot, or sparking or doing something it shouldn't do. And the MLP notices this event, and then it sends a signal using the the very wires that are sending the electricity, right, it's this is Power line communication or PLC.
• 12:00
  Tim Montague: Call it right. And how does it how exactly does that work? And is that is that a state of the art technology?
• 12:10
  Jing Tian: I think this is one of the most commonly used a technology called a powerline communication, essentially you sending a signal, I usually say you know, a signal special signal to each module, power level, Paulo module electronics, and what module level power electronics. So, it will does is hear the signal. So it says like, okay, the signals, signals are here. So I'm keeping. So when that signal disappear, they say, oh, signal is not there, I need to enter into shutdown mode. So that's how it's communicated.
• 12:48
  Tim Montague: Everybody, thanks for listening to the Clean Power Hour or viewing it on YouTube, we do have a great YouTube channel. If you're not subscribed, please go to clean power dot group, and hit that YouTube icon and subscribe to our channel. Of course, you can find all of our content on your favourite audio platform as well. So please give us a rating and review back to the show. And what else should we know about rapid shutdown? You know, it is?
• 13:14
  Tim Montague: In my mind, okay, rapid shutdown is a safety feature. And so I immediately go to things that could go wrong with solar arrays, we don't like to talk about this in the solar industry, but solar arrays do catch fire. There are things that go wrong with solar arrays.
• 13:39
  Tim Montague: But what else should people be thinking about when it comes to rapid shutdown? And how is Tygo?
• 13:43
  Tim Montague: I guess, approaching this problem from a high level? And then let's get into some of the nitty gritties? Okay, um,
• 13:56
  Jing Tian: let me just to make sure I understand questions.
• 13:58
  Jing Tian: It's like, really, how can law be shut down technology used? Or if he can clarify the question, if you don't mind?
• 14:07
  Tim Montague: So I mean, we've we've touched on, okay, we have this thing called Rapid shutdown. And the MLP is integral to this. It is the MLP is a technology that allows for rapid shutdown. There are other ways, right? You can, you can put the inverter very close to the array and use the inverter without an MLP. But in large solar arrays, that's not practical sometimes. And so the MLP approach is a widely adopted approach. But if you're a solar installer, or you're doing Oh, NM, or you're a developer, I mean, there are many angles to to the solar industry, but if you're a solar professional, what do you need to know about rapid shutdown that you may not know already?
• 15:02
  Jing Tian: Oh, that's it. Yeah, so rubbish on this, you know, I can't speak for every other product right, but most of the product in the market you have a Power line communication, that is for PLC, rapid shutdown. In cable, we also have a wireless communication device, but that is offering addition to rubbish also with the module level monitoring and the optimization, since we are talking about rubbish specifically today, so I will focus on the PLC communication. So which is really really important as designing the systems to be really aware of the phenomena what we call it is a cost. Right so this is not the not the title product is specific. This is like anyone use a powerline communication, then when you have two conductive wires adjacent to each other, the signal could jump from one wire to the other way. So that's what we call it. Crosstalk. So hypothetically, as we speak earlier, Tim, we say how's the signal is generated, so right signal generated from a transmitter, then sending the signal down one power line, to the module level power electronics. So they hear the signal there, they don't hear the signal, they're off, if you have another line next to each other, but the line is supposed to be down, because it did not hear the signal. But if there's a cross talk, they signal jump into the next slide. So the other array is supposed to be off and up is on or, or some, some off, because crosstalk or the signal integrity is not so great, that will cause some problems for the entire system.
• 17:03
  Tim Montague: Yeah, I'm curious, you know, when when a when a solar array goes into shutdown, then it has to, at some point come back to life, what is the process for, for figuring out what's going on? Do you have to roll a truck? Or is there a is there a remote monitoring feature? Or what walk us through that process? From, you know, when there's a when there's a yellow alert? And the the the MLP goes into shutdown, to then coming back to life? Because there's, there's, you know, there's false positives, there's true positives, and then maybe somewhere in between, but what are some of the scenarios? And how do you? How do you how do you approach this?
• 17:54
  Jing Tian: Yeah, so with the title, Tsa, tsa TS for F family product, right, so as I mentioned that the rapid shutdown is triggered by two things. One is the loss of you, when you detect the AC grid off, then the anti interrupter shut down, then AC grid is back on, then the system will go back into the operation mode. But if it's triggered by the emergency button, then you have to go in there manually, and oftentimes, it's someone there to push the button, then then you'd be at a job site to bring the system back. But oftentimes, if it's a too rapid shutdown, you probably want to inspect the system to bring back up right
• 18:42
  Tim Montague: then and then the the the technician doing the O and M though they would have some specific information about where the problem occurred right within the array, they actually would be able to you know, look on their smart device and identify a specific region of the array and they're not just it's not a needle in the haystack problem really, right it is it is quickly identifiable where the problem occurred, right?
• 19:11
  Jing Tian: Yes, that's where the title tears for a Oh, and as so title that's reason we call it tears for is because we have a very flexible product to offer with a different type of functionality, with the tears for ATF is for rapid shutdown.
• 20:23
  Jing Tian: Only. We don't have that ability to pinpoint where the problem is. But if it were the title tears for ao or AES, they both offer module level monitoring with all adding additional function for optimising, optimising. Then we have a module level monitoring portal, you actually can see details what's going on with each panel, what's going on can very quickly help people identify where the problem is. And then also we talk about the remote access that reduced the truck row significantly. I mean, we can diagnose more than 97% of a problem remotely and resolve those problems remotely.
• 21:10
  Tim Montague: You know, in your materials, you identify that one of the causes of PCB related fires is improper meeting of dissimilar connector types. What are you referring to when you say dissimilar connector types
• 21:26
  Jing Tian: it's a typical as a two different type of connectors say you know, MC four connectors with the h4 connector for example. It's not in obviously this is a pretty lengthy it's pretty passionate topic for me about the industry. needs to standardise rather than each one has a different type of connected with NEC code or require has to be same type of connectors, that, you know, it's very efficient. But that said, because this is different design, right? So could be caused the connection gap and are not connected properly.
• 22:04
  Jing Tian: That's where often time with the Ark of which initiation of the fire happens.
• 22:12
  Tim Montague: Yeah, you know, rooftop fires are no good for anyone. They're not good for the host. They're not good for the solar installer. They're not good for the solar industry, right, we don't like fires. And there have been a number of high profile solar fires in the last couple of years. But we have to remember, they're a tiny fraction of the solar installations. Solar is a very safe technology. Generally speaking, I do want my listeners to understand this. You should, you should not be afraid of installing a rooftop solar array, you want to work with qualified professionals, who are very experienced to use top tier products, right? You don't want Chinse on your solar products in so this, this, this is very important. You don't want to just instal the cheapest equipment possible. And, but, but when it comes to, you know, installers face many challenges, sometimes the modules don't come with long enough leads. And so you have to you have to instal, you have to instal, you know, extra wire and extra connectors to make the solar project work.
• 23:23
  Tim Montague: And sometimes there's a shortage of MC four connectors by a single manufacturer. And so you have to work with multiple manufacturers. I mean, there are these practicalities that you can't just snap your fingers and you know, be done with. So, I you know, it is a slightly complicated situation, but, but anyway, what else should our listeners know about Tiago, you know, you have a family of products, you are making a best of breed technology. But, but it is a you know, it is a there is there's a spectrum. So what do you have to say to you know, those project managers and procurement professionals who are specifying your technology, what do they need to know about Tiago?
• 24:19
  Jing Tian: I think, really, you know, it's a good Very good point. Thank you, Tim, about phi. So we know this. There's a small amount of incidents. But one fire is a fires to your customer. So I think we don't take this very lightly. But in the case of a weather system cause fire it's oftentimes is it's, I don't want to make any assumptions. In a lot of cases, what we see is not a component to from Tigers product perspective, it's not a title component to cause problem, or is it to do with the design and the implementation. And we view it will be a tour industry benefit for everyone to understand ways to instal module level power electronics with PLC communication. So we've taken a multi pronged approach to really to bring the industry forward to get more of educated so. So what we did is we had a quite a few things we've done, we've first is updated the documentation and instalation guidelines to really help people to understand crosstalk and how to avoid it.
• 25:43
  Jing Tian: Right. So what we call the crosstalk avoidance criterias.
• 25:47
  Jing Tian: And so those, and we have lots of white paper available on our website. In addition, this year, we also released the PLC signal integrity tool that is applicable to anyone's inverters, devices. It's really helping people to diagnose potential crosstalk issues either from design phase or from the system you already installed. So if you get a green light, meaning you are okay, if you get yellow or light red, we ask people to contact us we can help you to take a look figure out how to mitigate that. Right then he also early in June this year. We have a release the Tygo tears for certification course to really help eg hearing people's self paced their learning and also has the any snap separate credit as well.
• 26:51
  Jing Tian: And most importantly, the other thing is. Now in addition, we also did, we're about to release, NAB separate cross taco workshop with the Bayfield.
• 27:00
  Jing Tian: Renewable, it's really in the interest of to help the entire solar industry community. So that's what we do for helping people understand the crosstalk.
• 27:14
  Jing Tian: But on the other hand, we also continue our innovation that is rooted in Tigers blood. So we introduced the what we call the pure signal technology transmitted last night's November surgery early in the summer, it's really helped people, if you wanted to put a signal together, this is the technology to help you to mitigate it even further. And so I call the last line of defence for for the combatant the crosstalk phenomena. And when people wants to put a wire together hold on together to help people to simplify the installation.
• 27:57
  Tim Montague: So you mentioned a partnership with Bayfield. I mean, I'm on your website, Tygo energy.com. You go to the Resources tab, where can people find out information about you know, these these webinars that you're giving? I think
• 28:12
  Jing Tian: it's all on the Resources website. And I think the main view is not released yet it will be released as a part of that nap separate curriculum. Yeah, I think gotcha. Gotcha. Yeah. will be delivered in person at a net next next step conference.
• 28:28
  Tim Montague: Okay. Yeah, that's coming up, I think in the spring in St. Louis, if I recall correctly, so great. So anyone pursuing NABCEP certification or recertification just take note that you can learn about Tiago and earn see us, you can find many CEU courses, including my own and heat spring.com. So check out heat spring.com. And I have two courses there on commercial solar one on de risking those leads and projects on the front end, and then a full five hour course on selling and developing commercial solar projects. So check that out.
• 29:14
  Tim Montague: Well, Jean, I don't really have any other questions for you.
• 29:17
  Tim Montague: What else would you like to talk about? If anything, I really appreciate you coming on the show. And this I mean, I know Tiger was really, really really keen on this issue of crosstalk I don't fully understand I guess what the problem is, if you want to say more about that or anything else, feel free?
• 29:38
  Jing Tian: No, I think you covered most of it. I think a you know one last point is I want to in I forgot to mention is Tiago has very rigorous quality control. So we have continued to improve our product. And you know, we have the total improvement over the years. We have a ship the 10 million TEUs for units since 2016 with our return rate of 0.01%. So we are continuing to drive this our products are 100% tested out of factory. And so we you know in the industry people did hear some issues as in I couldn't emphasise this enough is to do with a how we instal how we implemented the system.
• 30:31
  Jing Tian: So if people with any questions, I would love for them to check out our website. Come Contact us to learn more about how to best to instal implemented title devices in the field.
• 30:45
  Tim Montague: Yeah, I love it that you have so much educational content on your website. I really appreciate that. You know, this is a very fast growing industry. We are now growing between 40 and 60% a year right, we were doing about 40% Now we're going to ramp to 60% a year. We're going to triple in the next five years.
• 31:01
  Tim Montague: We're here in 2022. And this is a combination of what's going on globally and clean energy but also the IRA legislation the inflation Reduction Act. You know, I guess that is a question. You know, one of the bottlenecks is supply chain. How is Tygo tackling supply chain issues because you know chips or their chips are in short supply.
• 31:26
  Tim Montague: You you you yourselves are making a computer on you know, a computer on a box that sits on a solar module. So what do you say about the supply change challenges?
• 31:37
  Jing Tian: We fortunately have a managing our supply chain we very strategically We work with our supply partners. We have no issues and to meet the demand in the market will continue to be able to supply supporting the industry growth we have growing the business multi folds and this year's be able to meet the delivery needs. I think we're I'm looking forward to grow with every our partners installers in 2023.
• 32:08
  Tim Montague: Very good. Well check out all of our content at Clean Power hour.com. Please give us a rating and a review.
• 32:14
  Tim Montague: Most importantly, a review on Apple and Spotify. And please subscribe to our YouTube channel. Just click on the YouTube icon there and clean power hour.com And check out my courses on heat spring on Tim Montague. Let's grow solar and storage. Thank you so much Jing.
• 32:29
  Jing Tian: Thank you Tim.