Latest / Clean Power Hour / Advancements in String Inverter Technology with John Drummond, CPS America | EP204

Transcript

Advancements in String Inverter Technology with John Drummond, CPS America | EP204 · Clean Power Hour

• 0:50
  John Drummond: We tried to make our products as flexible as we could in terms of different applications. So you could do a large multi megawatt ground mount. Or you could do a smaller community solar, which is only maybe a megawatt or so. And we've designed our products with a field wiring box. So that it can be, you know, for our 101 25, you can either use a, what we call a distributed architecture, or as you mentioned, you can do what they refer to as a virtual Central, you're essentially mimicking the architecture of a central inverter, but you're getting the benefit of a string inverter,
• 1:31
  intro: Are you speeding the energy transition? Here at the Clean Power Hour, our hosts, Tim Montague and John Weaver bring you the best in solar batteries and clean technologies every week, I want to go deeper into decarbonisation. We do too.
• 1:47
  intro: We're here to help you understand and command the commercial, residential and utility, solar, wind and storage industries. So let's get to it.
• 1:53
  intro: Together, we can speed the energy transition.
• 2:01
  Tim Montague: Today on the Clean Power Hour, the evolution of the string inverter in solar technology, I'm Tim Montague, your host Welcome to the Clean Power Hour, check out all of our content at cleanpowerhour.com Give us a rating and a review on Apple or Spotify. And please tell a friend about the show.
• 2:18
  Tim Montague: Today, my guest is John Drummond. He is the Senior Applications Engineer at CPS America. And we are going to be talking about how he sees the industry changing how products have evolved over time. And whatever else comes up. Welcome to the show, John.
• 2:37
  John Drummond: Thank you, Tim.
• 2:37
  John Drummond: Nice to be here. Thanks.
• 2:40
  Tim Montague: This has been a long time in the coming. It's it's, it's great to have you here on the Clean Power Hour.
• 2:46
  Tim Montague: We're we're about to spend some time together in Dallas, Texas at your annual events looking forward to that. But give our listeners a little background on yourself. John, when did you get into the solar industry? And how did you come to CPS?
• 3:04
  John Drummond: Yeah, so I kind of fell into the Renewable Energy Energy Industry. by happenstance, I had a friend who worked for a company called kinetic wind power. This was way back in the mid 90s. And they happen to have an opening in their engineering lab for a technician role for for what they refer to as non wind projects. So this was kind of exciting and new. So I took the role and was and was hired. And what they were doing was taking some of the sub assemblies that were designed for the power conversion cabinet for the wind turbine, and taking these you know, IGBT bridges, controller boards and so forth, and applying them for other renewable energy applications.
• 3:52
  John Drummond: You know, one of them being grid tied solar. We also did some adjustable speed drives, we did some converters for flywheels fuel cells, advanced batteries, you name it, I mean, it was just kind of exciting cutting edge stuff. So it was a kind of a great move for me. So I started with kinetic wind power in 1995.
• 4:14
  John Drummond: In this role, and just about a year or two after that, Kenneth Tech had some financial trouble and had to file Chapter 11.
• 4:26
  John Drummond: reorganization and the department head of the engineering department was a gentleman named Bill Erdman.
• 4:35
  John Drummond: Many, many of your listeners may know or hear if you're Bill Erdman. He was one of the founders of btw engineering. It was originally it was excuse me, Mike Denki Bill Erdman and Chuck Whitaker that started that business they were a third party design consulting firm. But anyway, we spun out of out of Kenna tech and started a company partnering with trace engineerings and we called ourselves trace technologies.
• 5:04
  John Drummond: Trace engineering, as you know, later was acquired by Xantrex.
• 5:08
  John Drummond: They designed the X W off grid and we were doing utility scale stuff utility at the time was 100 kilowatt inverter, you know, that was a that was Big time, big deal. kind of exciting stuff. But yeah, so just kind of, uh, you know, fast forward.
• 5:26
  John Drummond: I worked with them. They were absorbed by Xantrex. We did some kind of standard grid type products. Xantrex had their GT series, so some of your listeners may be familiar with his old GT series, and then Schneider Electric, absorb Xantrex and did some further development and then about 2015 I made the transition to CPS and CPS was focused primarily on string inverters, Schneider and Xantrex. Were doing central inverters. So, there was this kind of wave this shift in the industry that happened probably late 2008 2010 timeframe. And that stemmed from a change in the National Electric Code, which allowed for ungrounded PV systems. So essentially a floating array. This happened primarily in Europe was being allowed, but everything in North America here had to be solidly grounded. So these are back in the days when you only had a 600 volt DC array and either, you know, typically the negative pole was grounded. In some cases, like for some power modules, that positive pole was grounded for efficiency. But that allowed a change in the industry to do what we refer to as a Transformerless inverter, or essentially a string inverter. Yeah, where it didn't, it no longer required an isolation transformer, because there was not a DC ground and an AC ground that needed to be galvanically isolated from one another. Because the array was floating, you could you know, no longer require a transformer transformer simply just a step up transformer, if you had a different service voltage, but yeah, that's really how that came about.
• 7:25
  Tim Montague: So why is that?
• 7:25
  Tim Montague: Why is that such a big deal? The transformerless? inverter? Yeah,
• 7:30
  John Drummond: so great question. So one thing it does is it it it makes the inverter much lighter, because you don't have all this fire in copper and inside it, right? Yep, or maybe an associated transformer with it. So that meant that a, say a, you know, 50 kilowatt inverter, instead of being the size of your, you know, home refrigerator, is now you know, the size of a backpack or a small suitcase, right? It doesn't have to have that isolation transformer in it. And then there were some other changes that were happening at the same time. And that was IGBT module technology and, and what was referred to as three level inverters rather than a two level inverter. So many manufacturers took advantage of that, which meant that for a three level inverter, instead of having two IGBTs, in series, one from the neutral point to the positive bus and one from the neutral point to the negative bus, you would have essentially two IGBTs in series, which meant that these IGBTs could be half the rated DC bus voltage and much smaller footprint, much smaller heatsink which also would add weight and efficiency got better in this case for three level inverter. So there were some major changes which allowed for string inverters and primarily the one was allowing for a an ungrounded PV system.
• 9:03
  Tim Montague: Okay. Now, you mentioned Xantrex, a well known name in today there will no name in portable, correct power systems, RVs, sailboats, trucks, etc. But is that is that a subset of like you mentioned that Schneider absorbs and tracks? Did they spin off a portion of that or something like that?
• 9:29
  John Drummond: Yeah, that's exactly what happened to him is they had their, you know, their large inverter line, I guess you want to call it and that these were inverters that were no they're there. As you mentioned, these mobile devices are like for RVs for long haul truck or marine. They're down in like the to, to, you know, less than 10 kilowatt size. Right. And many of them operate off grid, they're a voltage regulated mode. So they sold the the solar line of business over to Xantrex. And those were their again, their, quote, utility scale Xantrex manufactured everything from a 30 kilowatt inverter up to a half a megawatt a 500 kilowatt central inverter.
• 10:17
  John Drummond: Okay.
• 10:18
  Tim Montague: Yeah. Well, I It's a little awkward, I have to say, talking to somebody who's so technical because you use a lot of lingo that I don't truly understand. But, but let's let's go further. And like, you know, the modern the modern PV industry really started in the US in 2010. Of course, there are many people and many segments of the industry started earlier than that. I mean, the technology itself goes back to the 50s. And so much of the image of solar PV technology is truly very mature and now has become quite commoditized. And, you know, solar panels are the greatest example of this.
• 11:07
  Tim Montague: There's probably over 100 solar panel makers. But But anyway, inverters are still a an extremely important part of the array there. They're less recognized. They're behind the scenes more so right then the solar panels. And I like to say they're the heart of the solar array, though. They're doing the heavy lifting, converting the DC power to AC, and which is an essential role. But if you think to 2010 and forward, you know, I, I recall, talking with Mike Hall, about the early 2000s. In I think in 2002, we were doing one megawatt of solar a year in the United States, right. And last year, we did 33 gigawatts, right. So it truly has been a rocket ship. But how have things changed since the since the 2010s? And when did you? When did you join up with CPS?
• 12:19
  John Drummond: Yeah, yeah. Well, I joined up CPS in 2015. That's, that's when I departed from from Schneider Electric. Okay. At Schneider Electric, I wore a few different hats, right at different roles in my career through Xantrex, and Schneider.
• 12:35
  John Drummond: And it was always kind of involved in product development, you know, bringing new products to market, but also compliance and testing, and then sustaining engineering. So I had some experience under my belt when I came to CPS. And the role I took, which I still have is Application Engineering. I was promoted to a senior couple of years after I joined. But back to your point about, you know, what is what is the evolution of string inverters, that's happened over the years is, you know, one big thing is the, the advancement of some of the autonomous functions that inverters can do to help with grid stability. You know, a few years back, there was a committee formed a smart inverter working group, and they came up with these autonomous functions to help with, you know, voltage and frequency stability of the grid. You know, today, we have inverters that are connecting to the grid that are, you know, that are providing all kinds of services like this, you know, they're not just a box that does power conversion there. These are sophisticated computers, essentially, that are tied to the grid and performing the services. You know, they're, they're able to dynamically inject reactive power for voltage stability in what's referred to as a Volt Var mode, where they're monitoring the grid voltage. And if it's either rising or falling, they can inject or absorb reactive power for that stability. I mean, these are great features in terms of string inverters deploy this. There are national standards now that require this.
• 14:25
  John Drummond: Hawaii, you know, the the Hiko utility group was one of the first to require smart inverters on their grid just because the stiffness of the grid in Hawaii.
• 14:36
  John Drummond: So that was a requirement also stem from Germany.
• 14:42
  Tim Montague: What do you mean about that the stiffness of the grid? Well, in
• 14:45
  John Drummond: the terms of, you know, you've got a generation plants, and everyone's expecting their power to be at a nominal voltage and a nominal frequency.
• 15:46
  John Drummond: And when you start putting loads on this grid, it can change the dynamic of that service. In terms of either, you know, if you've got capacitive or inductive loads that can do a frequency shift in terms of a reactive load, it can bounce around, I'll use that term in terms of loads turning on and off, you know, big loads I'm talking about Yeah. And these inverters can help that have these smart grid functions can help stabilize that in terms of a what were referred to as a weak grid.
• 16:33
  Tim Montague: Okay, so I love this expression. You know, the computer grid the grid, it is much more than doing power conversion it is making the grid smarter. And ultimately, we have to remember this that well, solar does present some challenges to grid operators like the duck curve in California which is which is non trivial. It is also a, a tremendous resource and can do smart things and with the advent of, of smart inverters, right.
• 17:14
  Tim Montague: Ul 1741, I believe is the specification, right? That allows the grid operator to you know, control the inverter remotely and throttle it if need be, as it
• 17:37
  John Drummond: used to be so, 1741 is the safety of the product safety standard. And that's the, you know, the go to that everybody that everyone certifies our inverters to then they added what they referred to as supplement a and supplement a where the smart inverter functions and it was basically what they referred to as an SR D, a supplement requirement document that you had to adhere to, in addition to the safety requirements, safety requirements were like, you know, is your gonna catch fire?
• 18:08
  John Drummond: You know, if you introduce an abnormal by, you know, disconnecting a, a gate lead to an IGBT, does it blow up? Or does it just cease operation, those kinds of things. So, with the introduction to supplement a or 7041 S, A, there was these new grid services that came about. And this was really beneficial, because, as I mentioned, a grid aided in grid stability, but it also meant that if there was ever an an abnormal event on the grid, the inverters were required to ride through this event rather than quickly disconnecting. It used to be that if there was an excursion outside of voltage or frequency, you had to disconnect within either seconds or cycles.
• 18:59
  John Drummond: And there's a famous event that happened in Southern California back and I'm trying to remember what year it was, but it's referred to as the blue cut fire. And your listeners can probably go Google that and find out what it blue
• 19:15
  Tim Montague: cut or blue cut blue I'm sorry, B L u e, okay?
• 19:20
  Tim Montague: Fire, okay. And it was
• 19:23
  John Drummond: a vegetation fire that affected some high power tension lines that, in turn caused a frequency dispersion, excuse me, a frequency anomaly.
• 19:31
  John Drummond: And inverters that were large PV plants to multiple point like gig like megawatts, saw this and disconnected. And unfortunately, it started this kind of cascading event, where the the, you know, the next plant saw it, and it made it worse and worse.
• 19:51
  John Drummond: So this was some forethought about uh huh. You know, we, this doesn't make any sense quickly disconnect. We need to allow these smart inverters to be able to ride through these disturbances. And, and so now there are ride through requirements where an inverter must wait so many seconds, and sometimes it's as many as you know, 13 seconds to 20 seconds to ride through an event before it makes a decision to then disconnect.
• 20:23
  Tim Montague: Oh, that's ready.
• 20:23
  Tim Montague: Yeah.
• 20:25
  John Drummond: So I mean, it's all about aiding in the grid stability. So the recent update is 1741 SB, so supplement B. And that added some additional smart inverter features where there are now communication and scheduling requirements included. They updated a interconnect standard that everyone may be familiar with is I Tripoli 1547. And the updated version is the 2018 version. And a company that is a test protocol document of how are you supposed to test to this 1547 document. That one's 5047 about 120 20. So so a lot of utilities now are beginning to adopt these requirements. So they want what they refer to as SB certified inverters. I'll be happy to share that. Kind of put a feather in my cap here that CPS was one of the first inverter manufacturers to receive this certification for all our products. There was a delay in the process for many manufacturers that was affected by COVID. And that was As you know, scheduling with intervals to have these tests performed, and, and being ready with equipment. So, utilities were saying, January 1 of 2023, you have to have this equipment certified and ready to go. And it turned out that there wasn't a lot of equipment on the market available. So the decision was made to push back the deadline and some utilities were changing the requirement where if it was under a megawatt and you didn't, you know, you could use the old SAE certified equipment, and if it was over, then you would adopt it, or vice versa. So those are changes and all changes for the good because these are just making these you know, I mentioned computers just making these computers better and better.
• 22:28
  Tim Montague: Yeah, explain the difference again, sa versus SB.
• 22:32
  Tim Montague: So
• 22:33
  John Drummond: it stands for supplement a, and it's just a supplement D is just an addendum to supplement a. I see. It's an extension of the requirements.
• 22:41
  John Drummond: So yeah, really, SB includes all the requirements of ft s a plus a few extras.
• 22:50
  Tim Montague: So inverters are getting smarter, they're getting smaller, they're getting lighter, more capable. And meanwhile, adoption, the adoption curve is going through the roof. Right. And so there's, you know, there's this intense pressure though, on manufacturers right to evolve their products and come up with new and better designs. Tell us a little bit about that. How does that work at CPS? Because you have a constant flow of new products coming to market? And you've obviously seen quite a quite a lot about in in, what eight years plus you've been SCPs Yeah, yeah.
• 23:35
  John Drummond: So, you know back to the change of ungrounded PV systems, you know, the other change was going from a maximum open circuit voltage of 600 volts 2000 volts used to be back in you know, prior to I want to say like 2005 era, some manufacturers were getting pretty clever with this maximum 600 volt by doing what they called a neutral point. So, on the DC side, and they had a 1200 volt array that was tied into the inverter, so they could get you know, greater voltage. So, simple Watts law, if you increase the voltage for the same power, your current is going to go down, which means your conductors can go down. Or conversely, you can get more power with the same current and higher voltage right. So that started to happen in the string inverter market where many inverters went from a 600 volt DC CPS used to make a 14 and a 20 kilowatt inverter that was a 600 volt DC, it was a ungrounded PV system back then. But then they went to 1000 volt. And again, just Watts law just made sense. 1000 volt DC is the maximum allowed under the NEC for open circuit voltage for PV systems on buildings, right. So on a on a single family dwelling and a two family dwelling, it's 600 volts DC. So that's all residential, on a on a building.
• 25:06
  John Drummond: It's 1000 volts. And then there are other applications over 1000 volts like 1500 volt DC ground mounts. I was just at the NABCEP conference this week, and there's talk of module manufacturers going to a two KV module. So 2000 volts, and there may be some pilot projects coming out soon. So it's interesting to see that keep going and going. So in terms of the DC voltage increasing, you know, as our, as our industry kind of develops. We've also seen that happen on the AC side, you know, predominantly a commercial interconnect our service voltages like 480 volts, but you'll see in some cases 600 volt is available and 600 volt AC is also very common in in Canada. Well we kind of took that a step further with our 275 kilowatt inverter and went to an 800 volt AC inner tie. Okay, and and we also provide balanced system equipment to complement that. One of the things that happened when we launched our 101 25 kilowatt string inverters that are 1500 volt DC 600 volt AC is many of our clients had, well, where did we get equipment rated for 600 volts? You know, I can't just go to a panel board manufacturer and say, I want 600 volt they it's interesting because the equipment is limited to 600 volts, but it's usually under an older you know, enclosure standard like ul 508, or something like that, that dictates what, say a Molded case circuit breaker or an AC disconnect switches tested to.
• 26:57
  John Drummond: And for an inverter, which falls under 1741. And I truly Tripoli 1547. The voltage can go as high as 120%. Right, you've got these voltage descriptions that you must trip to, well, are those panelboards actually tested to that higher voltage? And in some cases, they were they would have a dual UL IEC listing. So they would be 600 volts and then like 690 volts. And some manufacturers were providing letters that said, Yes, you can use our equipment under a, you know, 120% application or, or a one to one 10% application of nominal voltage. Now, when we went to an 800 volt system, again, some of our customers were struggling, I think Eaton makes some equipment at 800 volt. Abb does, we under CIT group, which is a global provider of electrical components, we were able to manufacture our own AC combiners using Molded case circuit breakers that are rated for 800 volts, including disconnect switches that are rated for 800 volt applications. So this really just kind of complements our portfolio. But again, back to it's just common sense that it's simple Watts law, you increase this voltage for the same power rating, your current is going to go down. Or if you you know if you keep the same current and you have a higher voltage, you're gonna get more power.
• 28:36
  Tim Montague: The Clean Power Hour is brought to you by CPS America, the maker of North America's number one three phase string inverter with over six gigawatts shipped in the US. The CPS America product lineup includes three phase string inverters ranging from 25 to 275 kW, their flagship inverter, the CPS 250 to 75 is designed to work with solar plants ranging from two megawatts to two gigawatts, the 250 to 75 pairs well, with CPS America's exceptional data communication controls and energy storage solutions, go to chintpowersystems.com To find out more.
• 29:12
  Tim Montague: Yep. So in the greater scheme of things, though, this this the evolution of the 275 kW inverter and 800 volt AC systems. This is ultimately playing out by reducing the amount of materials in a, you know, say a 10 megawatt solar plant? Is that how it plays out? Exactly,
• 29:47
  John Drummond: because for the raised voltage, the higher voltage, it means your current is is lower for the same power, which means your conductors are smaller because the current is smaller. Yep. So there's a cost savings there in terms of you know, how much you're spending for conductor runs. You know, some of these can be for these large utility scale, you know, these, this can be inverters and equipment displace kind of far away from each other, you've got these longer runs, this can be really helpful advantageous in terms of cost for that.
• 30:24
  Tim Montague: Yep. I'm always curious also about this centralized approach, or distributed, you know, string inverters allow you to put the inverters all throughout the array. But many times you'll see them clustered. And now you even do the skidded approach as well.
• 30:45
  Tim Montague: How is that decision made? How does a company optimize around one or the other?
• 30:57
  John Drummond: Yeah, yeah, good question. So we tried to make our products as flexible as we could in terms of different applications. So you could do a large multi megawatt ground mount. Or you could do a smaller community solar, which is only maybe a megawatt or so. And we've designed our products with a field wiring box. So that it can be, you know, for our 101 25 You can either use a what we call our distributed architecture, which includes fuse holders, and all string wiring to the inverter, or as you mentioned, you can do what they refer to as a virtual central you're essentially mimicking the art architecture of a central inverter, but you're getting the benefit of a string inverter by clustering inverters in a group near the near the skid mount of transformer in or near the transformer itself. Again, just down to flexibility, the one benefit of doing the cluster approach is that you've got longer DC string runs, and you're not doing the power conversion until you're closer to the transformer. So you can think of it as almost like free DC voltage drop, if you were to convert from out within the array. Now you've already done the power conversion and you've got this long AC run to go back, you might have to mitigate that by upsizing your conductors back to the transformer to offset that voltage drop for those long runs. The other benefit about using the string inverter for this virtual central approach is you've got the benefit of the multiple in PPTs. And the string inverters, you know, in our case, our 275 has 12 max power point tracking channels. And they can increase your energy harvest, in terms of reducing the mismatch losses of the number of strings that are connected to an MPPT, where a central inverter might have multiple strings connected, you've got only two or three per MPPT channel and a 275. Another benefit is is uptime, right? So you're you're getting better energy harvest, but then if there is an issue with the inverter, and and you've got a problem where the inverter is either under producing or it's failed all together, it's a fraction of the total, you know, PV plant versus having a big central inverter that might have a problem and go down. You know, just it's a sense of scale. So it's a it's a win win all around. Yep.
• 33:46
  Tim Montague: Yep. I want to go back to this, this question of how products evolve. You mentioned in the pre show that you work closely with your customers to make sure that you're designing and developing products that that meet their needs. Tell us about that process in? What is the life cycle like? Because, you know, it wasn't that long ago that the 125 was a big deal. And, but now it's the 350? And so, yeah, I'm just curious, what is that?
• 34:30
  John Drummond: You know, it's really voice of the customer, right? It's the guys that are designing these systems, feedback from installers about how can we make improvements in terms of, hey, I wish, you know, your AC terminal, would accept a larger conductor, because I you know, have to mitigate voltage drop for this installation, or, you know, something like, Hey, touch a fuse folders are great.
• 34:57
  John Drummond: You know, they allow for easier, oh, nm activity, I don't have to disconnect the wires from the terminal, I can just, you know, turn off the system and open open the DC disconnect, and then open the individual strings to do my own M service. In terms of power levels, I mean, that's just really the future. I mean, everybody wants to go a little bit a little bigger, we try to stay flexible in terms of our power levels for different applications, like I mentioned, you know, community solar versus a large ground mount, that might be multi megawatt. I mean, we're seeing projects now that are like 100 100 megawatts in size.
• 35:35
  John Drummond: And customers are saying, Well, hey, that, you know, it'd be great if I had a, you know, something double the size, you know, instead of a 125? Do you have a 250 or, you know, if your 275 was a 350, that'd be great because I could reap the benefits of a string inverter, you know, approach to architecture when I build these systems, but I don't have to install as many of them, you know, that kind of thing. So that's kind of where that happens. In terms of product evolution, it really comes from Voice of Customer and, and feedback from our customers.
• 36:16
  Tim Montague: And tell me, how do you work with the sales team?
• 36:23
  Tim Montague: What exactly is an applications engineer? And yeah, how does it How does? Yeah, how does it all work?
• 36:33
  John Drummond: Yeah, great question. So So we support all our products going from the CNI products all the way up to the utility scale products and And it's assisting them in product selection, you know, for a CNI application, there might be a particular inverter size, that would be a bit the best fit for their project. I mean, we have customers that are doing projects from 200 kilowatts DC up to, you know, 100 megawatts.
• 37:03
  John Drummond: So it's helping them select products, instructing them on how it should be installed, we get a lot of questions about, you know, do I need the right spacing for ventilation or serviceability? Or can I mount it this way? Or can I bring my conduits in from the side of the box rather than the bottom? Or I mean, you name it, Tim, there can be all these kinds of questions. And that's really kind of the fun part about my job is fielding some of these questions. And then supporting customers in things like, hey, I need this, this this test data for this utility that we're applying for this interconnect with, they want to know, you know, what's the harmonic content of the output current waveform from this inverter, or what's the short circuit current contribution of the inverter, these are all helping in probably pre screening of the, by the utility for projects. In some cases, we provide what's referred to as a dynamic model.
• 38:03
  John Drummond: So that a stability study can be performed, these are PS CAD pssc, sometimes an aspen short circuit model, and they run in the software programs to first simulation. Many your listeners might be familiar with like p li PV cyst, or like designing a system with like Helio scope or something like that. Sure, PV system is really does a system analysis of production performance analysis, these other applications are really kind of introducing anomalies and seeing how the individual inverter or the PV plant might behave. And you know, if there's a voltage short, or there's some kind of voltage excursion or something like that, so yeah, so those are the kind of things that I support our customers with. And then, you know, assisting our salespeople with the right answers, sometimes I sit in a sales call to support them, where they're talking to a customer and doing the same thing. You know, rather than an email or phone call, it might be a person in person meeting.
• 39:07
  Tim Montague: We solar professionals now are all also battery storage professionals.
• 39:11
  Tim Montague: And if you're not installing, or designing and installing solar and storage systems, you will be it batteries are so important for a variety of reasons. They provide grid services, they allow you to attack, you know, charges beyond daylight hours, etc, etc. There's a whole value stack. But what is your experience been? So far, you've seen the industry go from zero to 60, so to speak, really?
• 39:46
  Tim Montague: Right. And I mean, storage was probably prevalent in the very early days of solar, right, because it was mostly for Off Grid applications, and using more traditional lead acid batteries. But now we have, you know, large scale, stationary storage, and ubiquitous residential storage available.
• 40:10
  Tim Montague: And these are mostly grid tied systems, mostly behind the meter, but also front of the meter. Yeah, give her give her listeners a taste of where you see storage having come and where's it going?
• 40:25
  John Drummond: Yeah, yeah. Well, I mean, everyone knows that the utility rates are going up, right. And there can be challenges around you know, when when you have specific loads at your site that you're trying to offset. And solar is not 24/7.
• 40:45
  John Drummond: You know, just like wind is not 24/7, sometimes the wind blows, sometimes it doesn't. sun comes out for 1214 hours a day and then goes down. So what happens otherwise? Well, you might need a PCS, a power conversion system that has energy storage with a battery. And this is typically used, as you mentioned, for demand rate reduction, peak shaving, you know, like, if it's a industrial complex that has, you know, maybe motors have some kind of factory that's turning on a certain time of day, then you know, you can use that battery that stored energy in the battery to to offset the demand rate charge that those motors or you know, machinery might might incur. During the during the day you've got PV but in other times you don't. You can also schedule it so that you're always using PV When the rates are, are, are higher, and you're charging your batteries, and then when that when that rate changes, you can discharge those batteries to offset that demand rate. So yeah, we're gonna see more and more of this same with residential. I mean, you're seeing lots of manufacturers that are offering battery backup systems, it could be used for the same arbitrage or demand rate reduction or peak shaving for a home. But really, I think that those are kind of systems that are using an off grid in terms of an outage.
• 42:18
  John Drummond: That's a lot of advertising I see for residential is, hey, you're gonna have power if the utility goes away, right? And that's either due to an outage that might be from an accident or a failure. Or it might be a planned outage. I mean, here in California, the utilities are doing unplanned outages in terms of, you know, if there's a storm in an area, and they're concerned about, you know, it affecting their, their grid or their or their overhead wires, they often turn off electricity to some communities.
• 42:53
  Tim Montague: Yeah, so solar is wonderful, only works when the sun shines, and it doesn't work.
• 42:57
  Tim Montague: if the grid goes down, right, it is designed by code to disconnect if there's not a hardware to micro grid, and a battery or some other generator to turn on and start providing power, but so So, but in the CNI space, does the advent of batteries change the inverter space at all?
• 43:31
  John Drummond: Well, you may meet see more micro grid applications that are using simply a PCs that operates at as a voltage regulated source, and it is quote the grid, and then you've got PV that is connected to that source. And the you know, the PV inverter is a current source, it's going to look for a stable voltage source and connect to it. So you may see, again, more micro grid applications are our PCs as the champ power system PCS is, will operate in both a grid forming or grid following mode, they can be programmed to do that. So other manufacturers are doing the same thing. But that you'll see that in more cases where there may be different applications using energy storage and batteries. Yeah.
• 44:27
  Tim Montague: And you've made a big splash with this, this utility scale, five megawatt hour 20 foot container. Tell us about that.
• 44:39
  John Drummond: Yeah, so in terms of our large, you know, I mentioned the five megawatt hour battery, we developed a 200 kilowatt PCs. And we're using the same approach to energy storage as we are with PV, we're taking the quote string inverter approach. So we manufacture a skid mounted transformer with up to 12 of these PCs. Essentially racks that can be installed with this five megawatt hour. And the the advantage of doing this string inverter approach again is if one has a failure, your your your whole system is not down. It also reduces the short circuit current of the battery so it can be safer to work on.
• 45:35
  John Drummond: And then in terms of doing a equalization of the battery strings, if you will, you can charge the battery to a an equal state of charge by kind of less strings. If you've got multiple and you've got some mismatch or high resistance between these different battery stacks that can be an issue.
• 45:58
  Tim Montague: I want to talk in our last few minutes together, John about the company. You have such a storied career, you could work for really any solar manufacturer you chose to literally and and yet you choose to stay at CPS America for eight plus years now. Yes. What is it that first in the first place attracted you to CPS and has kept you there so long? Yeah.
• 46:27
  John Drummond: Well, you know, there was a story told to me when I interviewed about an issue that happened with one of our products or one of their products at the time I wasn't working for them, and they were completely trans A parent with their customer to say, We believe we have an issue with this product. And we want to come out and do a repair for you on your product. It hasn't happened yet. But we want to, we want to be proactive, and be transparent, and take care of you as our customer. And I thought, well, that's, that's amazing, where, you know, some, some other manufacturer might want to just sweep it under the rug, like, oh my gosh, we can't, this is bad news. We can't tell this to you know, our clients, they're gonna go nuts and we're going to lose business. It actually was just the opposite.
• 47:16
  John Drummond: So CPS really prides themselves on customer service and being transparent about issues that happen. And we know that, you know, not every product is failsafe. It's, it's, the things are gonna break, something's gonna happen. And we will make improvements over time. So that initially drew me to the company. And then I think just the company culture in, in, in the sense of community, of working together and being collaborative. On on like this, there wasn't this mentality of like, Oh, you've got to stay in your lane. That's not your job.
• 47:57
  John Drummond: We kind of have this this. This term, we that Brian Wagner's, as coined, called the triangle offense, or the Lightspeed system is another one, where we are working together as a team in different departments to support our customer. And do it quickly. So there's no, there's really gray areas between our lanes? Probably a good analogy.
• 48:23
  John Drummond: Yeah, where we can easily pass information to support this, this client quickly and easily.
• 48:27
  John Drummond: So to answer your question, I think it was really open transparency. That serving our customer was a priority. picking up the phone answering, you know, being a live person and not just getting recording all the time. The culture of team building team working together, it's not an us and them. I mean, we do many events together as a company. And it's everybody, it's upper management, it's, you know, it's people of all roles together. There's no like, oh, that's the, you know, so and so I can't talk to him, because, you know, I don't know.
• 49:11
  Tim Montague: Yeah, you know, these things sound. So, common sense. And yet many companies do not follow these, these these ways. And it it definitely makes CPS stand out. And I, you know, as I've gotten to know, the company, and more and more of the employees. It, it really is striking how you have this very collegial culture, it is not one of have winners and losers.
• 49:50
  Tim Montague: You're all there to ultimately win and bring your customers along with you. And, you know, you fully acknowledge that the products are not perfect. And but you're committed to fixing whatever problems exist. And we stand behind it, of course, yes.
• 50:10
  Tim Montague: Yeah. And that is, and that goes a long way. So Well, John, I want to thank you for coming on the show. I really appreciate your time. And to our listeners.
• 50:25
  John Drummond: Thank you, Tim.
• 50:25
  John Drummond: Appreciate it.
• 50:27
  Tim Montague: Oh, you're welcome. To our listeners, thank you for being here. Please check out all of our content at cleanpowerhour.com. Give us a rating and a review on Apple or Spotify. And please tell a friend about the show. That is the best way you can help others learn about this. And there's an amazing knowledge base here at the Clean Power Hour. We also have a healthy roster of events.
• 50:49
  Tim Montague: So check out the Events tab. I look forward to connecting with you by listener contact me on LinkedIn or via the website.
• 50:57
  Tim Montague: John, how can our listeners find you? Yeah, so
• 51:04
  John Drummond: my email is John with an H J O H N . Drummond D R U M M O N D @ chintpowersystems.com or our website is which is chimp our systems.com. I can I'm usually at every trade show. I was just at NAB set this week. So please feel free to reach out to me and happy to help work work with you on your next project.
• 51:31
  Tim Montague: Without I'll say let's grow solar and storage.
• 51:33
  Tim Montague: I'm Tim Montague. Take care of John. Thank you, Tim. Hey, listeners. This is Tim I want to Give a shout out to all of you.
• 51:44
  Tim Montague: I do this for you twice a week.
• 51:44
  Tim Montague: Thank you for being here. Thank you for giving us your time. I really appreciate you and what you're all about. You are part and parcel of the energy transition, whether you're an energy professional today, or an aspiring energy professional. So thank you. I want to let you know that the Clean Power Hour has launched a listener survey.
• 52:11
  Tim Montague: And it would mean so much to me.
• 52:11
  Tim Montague: If you would go to cleanpowerhour.com. Click on the About Us link right there on the main navigation that takes you to the about page, and you'll see a big graphic listener survey, just click on that graphic, and it takes just a couple of minutes. If you fill out the survey, I will send you a lovely baseball cap with our logo on it. The other thing I want our listeners to know is that this podcast is made possible by corporate sponsors.
• 52:50
  Tim Montague: We have chin power systems, the leading three phase string inverter manufacturer in North America. So check out CPS America. But we are very actively looking for additional support to make this show work.
• 53:02
  Tim Montague: And you see here our media kit.
• 53:08
  Tim Montague: With all the sponsor benefits and statistics about the show, you know, we're dropping two episodes a week. We have now over 320,000 downloads on YouTube. And we're getting about 45,000 downloads per month. So this is a great way to bring your brand to our listeners and our listeners are decision makers in clean energy. This includes projects executives, engineers, finance, project management, and many other professionals who are making decisions about and developing, designing, installing and making possible clean energy projects.
• 53:47
  Tim Montague: So check out cleanpowerhour.com both our listener survey on the about us and our media kit and become a sponsor today. Thank you so much. Let's go solar and storage.