October 27, 2019

Ask Mayfield Anything Webinar

Full webinar transcript of Ask Mayfield Anything: Tigo Energy's New Integrated Solar-Plus-Storage Solution. Tigo's product experts Jing Tian and Greg Smith joins Ryan Mayfield and Justine Sanchez from Mayfield Renewables to discuss Tigo's new Energy Intelligent (EI) Inverter, Battery, and Automatic Transfer Switch.
Watch the full webinar on demand

Transcript of the Ask Mayfield Anything webinar on October 27, 2021

About the Tigo EI Residential Solution

Ryan (Mayfield): Well, we're going to jump into this and one of the big things, the reasons why we're here talking to Tigo, is of course energy storage systems are proliferating. There are so many systems out there now and we have so many different use cases in ways that we're integrating solar plus storage into our systems now. So, with this new system that Tigo has been bringing out just wanted to get an opportunity to get an idea of the system as a whole and understand it better. So, with that I'll let Jing and Greg do the introduction on the system itself and we can take it from there.  

Jing (Tigo): Yep, thanks, Ryan. So, I'm going to start it with the Tigo Energy Intelligence Solution. It's really built on Tigo's knowledge with the TS4 flexible module level power electronics. The entire system composed of inverters. It's a hybrid inverter DC coupled with the EI battery and ATS. On top of that, everything is communicated, controlled, and monitored by our Energy Intelligence platforms. So, we’re trying to have the integrations all in one. We have all the solutions from Tigo, but you still get maximum flexibility. You have a choice of different TS4, battery — I will go into a little more detail.  

Batteries are also modular, so it gives lots of flexibility on the system design. So, some of the key features; it's a fast install. Our TS4 only takes about 10 seconds to really install on the modules. Most of you are quite familiar with it and the entire system is able to commission in 10 minutes. One of the key features we introduced is the box scanning process. And as some of you are familiar with Tigo's TS4, you need this scan for each TS4-A-O for the system layout monitoring. So, we have the new feature introduced; we can scale over 30 modules at once. That really speeds up the commissioning process.  

The system is very flexible to scale. We use the TS4-A-O or TS4-A-F, depending on what you need. Also, the battery is modular so it's going to go anywhere from 3.3 kilowatt hour, each modular up to 20 kilowatt hours so that is really [going to give] you flexibility on your system.  

Tigo has been an industry leader, so we have the longest warranty in the business. We provide up to 12.8 months of inverter warranties and with the battery up to 11 years. We have our very localized customer satisfaction teams. All the people would be local to support you for installation and we have site specific apps and design support for you.  

I'll go into a little bit of details on the components. As you see here, this is one enclosure of the Tigo EI Battery. Inside of this BMS, there's three battery modules. Each of these components comes with a 10-kilowatt hour, but you can expand all the way up to 40 kilowatt hours; in other words, four enclosures. They can be paired for essential home backup or whole home backup. Then you can also have three different modules to control the battery for time of use, self-consumption, as well as, for backup mode. Let's take a look at the ATS next.  

With the ATS, we have two options: a 50 amp and 200 amp; a 200 amp is coming, 50 amp is shipping right now. 200 amps should be available towards the end of this year. Both the products are outdoor rated so it can support an essential load or home load with 11 years of warranty.

On top of that the whole entire system will have the Energy Intelligence platform. This one software does everything. It can do the commissioning on the app, it can do the monitoring, as well as, the system control. This module shows it's on the website, a web view with a fleet management. It's configurable with the look of the fleet management and you can also configure the alerts with the system depending on your needs. It's really to empower our installers to have an entire view of the system and be able to reduce your OEM cost.

Ryan: Great. Jing, I really appreciate that overview on all the different components. I guess one of the questions that I had immediately is — I'm just thinking about Tigo obviously doing module level power electronics as a primary product. Can you just speak to Tigo jumping into the ESS — it seems like a huge change — how that decision and where that came from and what it is that that Tigo is looking to serve the market with.  

Jing: Yeah. I mean, I think that the key is that we really listen to the market. As you mentioned, Ryan, there's a growing market in storage. People are looking for more solutions and Tigo heard a lot of customers asking, "You know, we're doing module level optimization and matching with the inverters. Why don't you just have an entire solution for us, it'll make our life easier." right? So that's a lot of what we heard from customers. We believe that the market needs more suppliers to meet the 40% year over year growth in the residential market segment. Storage plays a significant role, and we think there's a need in the market. That's where we're leveraging our know how's and providing additional products to the market.

Specific applications for the Tigo solution

Ryan: How is this a system that can be integrated into existing PV systems? What are the limitations or how are you looking to get this integrated into new or existing installations?

Jing: Our design product planning is one system for all; goes back to our ideas being flexible. The system designer for both a new system — or typically people call it DC couples, then we can do the AC couple — but that feature is in development. We expect to introduce to the market in Q1 next year. So that same system should be able to do both.

Justine (Mayfield): So, if you had existing Tigo units in your installation, could you utilize those and just add on the battery, the hybrid inverter, and maybe take out your old inverter if you want it to.  

Jing: Yeah. That's compatible.

Load Management

Justine: Would [load management] be a part of your planning forward with equipment that's integrated already into Tigo or is that something you can't speak about yet?

Jing: No, I think it's on the roadmap. I think you know we really look at autonomous home over time. This is smart home load management. I think that's very much on our roadmap, but we do want to focus on getting the basic system right in the first place rather than trying to add lots of features, right? So that should be coming in the near future.

Justine: That's great to hear. I mean, I guess one code thing, I would say moving into 2023, like right now we can design systems to just have enough capacity to just cover the largest single load. But moving forward into 2020, that's going away. We're going to have to go by the 702 rules, which tells us we have to have load management or enough capacity to carry the full load. So, I'm glad to hear that that's on the roadmap because it's going to be an issue code-wise coming up.  

Greg: Yeah, and that's comes from the generator side of things, right? Like, they're like, “Oh, well we want battery and all that to act like a generator.” It's like, come on, man. Like give us a break. But yeah, whatever, there's always a way around that.  

Code compliance and standards

Ryan: Greg said he was going to talk about code all day long, so I'll bring up the code question here. But Russell did ask the question about sizing backup power based on total load versus largest load, if ever. And the reference is 710.12A. So, I guess Justine, you may have some input on that. And Greg, I know that you probably do as well having been around that and knowing how to size the system properly. And Justine, you had mentioned something about maybe '23 looking down the road.

Justine: I don't know if that's so much a question as a comment. He's right, right now and it's going to get harder. This is actually the easy thing. Power must be equal to or greater than the largest load. You got to look at your panel and because we're allowed to go by 710 rules, if we're operating in an energy storage system in backup mode or island mode, according to the code, we can go by 710 as long as our inverter capacity, amps, is large enough and can supply that single largest load, we're okay by code. Moving forward to 2020, that language about in island mode is going away. So, 710 is just going to be about standalone systems and we're going to be forced over into 702, which changes that to being — and we have to actually have load management or sizing our capacity for the full load of the panel, really. So that's where we're headed, but we're not there and a lot of places won't be there for many, many years.  

Ryan: I remember having challenges with AHJ way back when on standalone systems. There was something in 690 back when battery stuff was in 690, talking about how you didn't have to do that, essentially. So maybe it was the 710 where we were getting anyway with it for years or something. So that seems like that could be a huge challenge coming up.  

Greg: It's a head shaker. Because it makes this  assumption that when the grid goes down, everybody, their first instinct is to run around and start turning all their loads on. Right? And so, I don't know, it will make it harder on us I think if that does go through, but you know, there's always a way around it. It's going to take a little more planning and it may force, as I said earlier, to bust out those essential load panels, which is not a bad thing.  

Justine: Right. Exactly. I mean, they do make sense. So, we don't overtax our batteries. We use a lot more power than we think we did. So, it's the way we've always done it. It does make sense, but with load management coming on, I mean, I think there's a lot of new tech solutions coming along here.  

Module-level monitoring and optimization

Ryan: Another question, when used with the TS4-A-O, does it change the algorithm during the period of peak generation? Given the ability to capture excess DC current to charge the battery versus clipping? So, I guess that's for the new system, are you able to, instead of seeing that your system going to clipping, are you able to capture that?

Jing: Yeah, that's a good question — the short answer is no, it doesn't change the algorithm at all. But you know, just expanding a little bit on that, the TS4-A-O is a module level optimization. It's really if you have a shading, if you have a mismatch in the strings, allowing you to maximize the production of the system. If you actually look into our Tigo monitoring platform, we also capture the information on the reclaimed energy, the energy lost without a TS4-A-O and show you the amount of energy gain with the TS4-A-O. In terms of excess energy production during the day with a battery, that is at the battery operation mode. Then we can use the excess control from inverter and battery to have excess energy charge the battery. So that's, time of use or self-consumption mode.

Ryan: Great. Robert put in the chat, he was asking about having Jing discuss the opportunities around contractors using fleet management to grow service and maintenance business lines. I guess with the Energy Intelligence platform is that something that the contractors could be using for both their PV systems and their storage systems to help that whole service line of business.  

Jing: Yeah, I think it's great. I will welcome Robert to take a look at our platforms. I think Lucas can probably post the links here. What it does actually depends on the system you install, right? It can give you all the module level visibility of each system performance. If you don't have the TS4-A-O installed, it does give you entire system view and gives you an entire fleet view of the system performance. In there you can set up the alerts, how you want to be notified, and also give you additional system performance comparison depending on the level of monitoring subscription you get. If you get a premium, we have the entire lifetime of the system performance allowing you to really get all the data. Then analytics, you are able to look at a history of the system performance in a lot of ways to help you remote diagnose the system because your most cost is a truck roll. If you can reduce your truck roll or you actually know what the problem you're going to deal with is before you send a truck up, that saves you a lot of the time and the service operation costs.  

Energy storage system

Ryan: What about the energy storage system? How much insight do you have on that? In terms of being able to give your customers, remotely give them, some intelligent information on what is going on with that system.  

Jing: Yeah. We have all the information. The energy management system, the battery systems, I think ultimately will provide the current voltage temperature performance of the battery for the installers. So, they should have visibility to all the battery performance.  

Greg: It will be the same stuff that everybody is used to seeing, right? Like we're not going to give you guys access to cell voltages, right? We're not going to get that granular, but we'll give you guys the pertinent information to help you remotely troubleshoot and fine tune and tweak those system. We find out that people want to put their system in time-of-use mode because they just have that one window they want to offset. Just like me. From five to eight here in SMUD territory, Central California, I had it set to five to eight, but I realized that once you start managing your consumption, you can start opening that window up. So, you can start tweaking and playing around with your system to give you more than just what the utility company is going to ding you for in that three- or four-hour window. So, we give you the ability to remotely get in there and do that in the fleet view. We have these intelligent alerts. We totally revamped this.

And you guys know where I come from. Module level stuff is still kind of new to me, but I'm digging it and I'll tell you I'm a big enough man to realize and to admit that I was wrong for a lot of this. Right? And I don't understand why you would put something up on the roof, like that would not give you that visibility. I totally get why you would want to put a TS4-F up there. You want to comply with rapid shutdown, but you don't get any of this cool stuff that you’re look at on the screen; you don't get any of that visibility. And the average truck roll in the United States is $400. So, the guys that are penny pinching and instead of installing an -O, they install an -F so they're saving $15 - $20 bucks a unit. The first time you roll a truck to go look for something because the -F doesn't have this visibility. You just burned up that $400 bucks. You just burned up the savings that you have. By getting this module level monitoring, I don't understand why you would want to do that, right? Because you get so much more visibility and the monitoring platform for the battery includes all of that. You get all of that visibility. I dig it.  

Justine: So Greg, I'll throw you guys a bone here. You know, I had one of the first beta units over on an old house of mine and Tigo came out, installed them, and lo and behold, I had three out of 10 modules, this is a smaller system, I had three modules that were just — you see the screen, you see bright green, bright green, dark like evergreen, dark, bright green, dark evergreen — so the coloring is what the power is. So immediately, like with one shot, I was like, “oh my gosh, I have three modules that are producing a fraction of what my strong modules are producing,” and I would've never known that if I didn't have that side-by-side comparison. And of course, I got — this is way back in the day — I got the modules and for a good deal. There was a reason there was a good deal, but I had no idea why. But I could have gone along for the lifetime of the system having no idea just because all you have to go by is really your bill. And I had one kid, then I had another kid, so our bills were going up anyway. So, it was really crucial for me to go through that to even realize I had problems with my modules. Then I went and I got it replaced, but I would have never known that if without that monitoring.  

Greg: It is so. So cool. And I've seen the system be able to tell you if there's a bad bypass diode, like that blew me away. I'm like, “how can you know that?” You can. And “aw man, modules never go bad.” Yeah, they do. Yeah, they do. It's so cool that system that we showed, and a lot of our presentations is a floating array, which I never even heard of until I started working with Tigo. And there's a lot of them that are like in the ocean, in these big areas and I've seen them over time. You see the power start to degrade because of all the bird poop that gets on those modules from the pelicans and the seagulls and all that stuff. It's so cool.

Battery storage system sizing

Ryan: There's a question. It's definitely not a Tigo specific question, but it's asking about reliable tool to model large PVN energy storage systems for self-consumption. I will throw that over to, Jing and Greg. I’m just curious if you, Tigo, are doing any of that or working with your customers on the modeling side. We can speak to it a little bit ourselves as well.  

Jing: Yeah, sure. I mean, I think I can probably just talk briefly. We do have a system sizing for a string sizing, as well as an estimate on the battery size, but it's pretty preliminary. I think there's obviously lots of tools out there. Ryan, you probably know a little more about it, but we were working on that to provide a Tigo specific design to make a customer's life easier.

Greg: And I think what the question was getting at, do you have something like PVsyst or Helioscope? Then we'll be able to model the energy storage systems along with solar. There's a lot of great tools out there that can model solar. Those tools have a little catching up to do when it comes with adding energy storage systems to have a good predictive model. I talked to Paul Grana every once in a while from Helioscope and I know that they are working to be able to get something done like that. Something that's as accurate with the batteries as it is already with just the solar stuff. So, I don’t know, Justine, Ryan, maybe you guys know of something.  

Justine: Well, in most of our systems, especially when we're looking at resilience projects we're using HOMER Grid. It’s a very complicated tool and it takes a bit of working with, but it does allow us to look into those money savings — if you're using a generator in the system, the fuel savings — and there's a lot of different layers to that program. So that might be something, although they were asking about large-scale. I don't see you guys going up to the large-scale market currently.  

Jing: Yeah, that's a good point.  

Ryan: And I would throw out there too. Energy tool-based is a good tool on the modeling side, especially on some, well, you can use it on the larger scale for sure. The resilience aspect and using multiple power sources is the tricky part there. I would say that the two that we've seen the most are energy tool base and HOMER as those modeling type programs for that.

Greg: And Homer is good. I mean, it is as detailed as that SMA Sunny design, when you start doing off village electrification projects. But man, you need to take their little training classes. Otherwise, you won't know how to do any of it, but it's awesome. Once you learn how to do it, it'll pop them out. So yeah.  

Justine: Absolutely. I like that top question too, about, I mean, are there any plans for three development or are we sticking to the home scale?  

Jing: Tigo has been very successful in the C&I business. So, we're clearly going to continue to evaluate in the market and see if there's a need for us to really have an additional product to support that market segment.

Greg: Yeah. I mean, that's where the money is, right? So, that's where we're going to go eventually. There's a good one here. The minimum ambient temperature for exterior battery install. The battery is NEMA 4, as well as the inverter and the ATS. Even with the most antagonistic, strictest ASJ out there on where you can place these things outside is, for now, against a structure is still okay. We go from minus 14℉ to plus 113℉.  

Additional Q&A from the audience

Justine: Let's read the question. We just got reminded that the participants can't see the question so it's helpful to read them out loud. I'll read this and then you can answer it. From James, it says, I believe Tigo uses the SunSpec open-source communication protocol for rapid shutdown, communications, and control which allows compatibility with other manufacturers equipment. Do you plan to continue to use open-source protocols and work with other vendors on compatibility issues?

Jing: Yes. The answer is yes. I think that is the basis of our business philosophy. We want to be flexible and compatible with all the suppliers. Today, I actually don't have a number off my head, Sarah knows everything. We have literally hundreds of inverters compatible today. We'll continue to do that. For anyone that got new inverters and would like to talk to us about the compatibility, we conduct all those testings for TS4-A-O, as well as with TS4-A-F and will be continuing to support that.

Ryan: Along those same lines, that question made me start thinking about just rapid shutdown in general. Of course, everybody's favorite topic. Can you speak to the rapid shutdown? Like the initiation? Now we're not doing just a grid tied inverter where loss of AC can be the initiator here. Loss of AC for this type of system is what this was built for. Can you speak to what that initiation looks like? Do the installers have to do something separate? Is there a different switch? How do you guys handle that?  

Jing: Yeah, we need to install a different switch. I jokingly call it mushroom button. You put that in the circuits. Depending on which circuit, if it's on the grid mode or the backup mode, the inverter would respond either way and then initiate a rapid shutdown.  

Greg: And we provide that. It's that red push button, we call it chicken switches, but we give you that. You just have to run two wires into the inverter. We give you the little Phoenix, male adapter. Plug it in and good to go.  

Ryan: Okay. So, it's a contactor that tells the inverter, “Hey, I'm actually in a mode that we need to turn off.” Not actually—

Jing: That's right.  

Ryan: Okay, nice.

Justine: I had another code question earlier, the ESS disconnect. That's part of 706 that really points to— I mean, there could be a couple of solutions and I was looking at your gear to see if there was a way because there are some existing DC disconnects it looks like on ones on the battery unit itself. And it looks like there's one on potentially the inverter, but what do you recommend for that external? It has to be outside the home; for one- and two-family dwellings: lockable. So, Greg, what would you recommend? How would someone deal with that?  

Greg: Well, I don't know if you can see it there, but on the left side, there's a little compartment that opens up with two Phillips screws, right? You just open it up and then that's where the battery on/off switch is. That's not lockable it doesn't comply, right? So, you will have to put a separate DC disconnect between the battery and the inverter, and then that will go wherever code compliant, wherever your ASJ — I mean, I don't know how there's thousands, right? Maybe even 10,000 AHJ so I can't keep them all straight, but the code is pretty clear on that. We will always recommend, and our sales engineers recommend putting a lockable blade disconnect between the inverter and the battery.

Using multiple batteries at a site

Ryan: I was actually curious; this may have been said. I’m trying to do multiple things at once. So, somebody else probably missed it. What is the power rating of the inverter? I missed that entirely.  

Jing: We have two versions of the inverter. There’s a 7.6-kilowatt and 11.4-kilowatt power rating.

Greg: Two pole 40, two pole 60, easy peasy.

Justine: And you can stack up to four. Is it four of the units? I'm sorry, the batteries, or is it 40-kilowatt hours?

Jing: It's a 40. Let me just walk you through the steps. Each battery enclosure, you can have three battery modules. So, if people are ordering 10-kilowatt hour, it comes in four boxes and one box is the enclosure. Now you have three battery modules that adds up to a total of two 10-kilowatt hour. Truthfully it is a 9.9-kilowatt hour. We just made the decimal to 10. Then all those are pre-wired, so the installation is super simple. All you do is just click, put it the mechanical screw to put it on, then with the plus, minus, and the communication cable. That's it. It’s super easy.

That makes 10-kilowatt hour. For our system, you can do primary and the expander. You expand the box, then make it into 20-kilowatt hour. Then in December, we're going to have the upgrade with our 200-amp ATS allowing you to do two and two side-by-side. In other words, parallel, that makes it 40. So, the total backup power would be high. At that point it can go up to 10-kilowatt hour backup power. Right now, this is a 5-kilowatt backup power.  

Greg: Yeah. Pretty slick. Good stuff coming and it is no joke. I put this thing together in the Campbell office and it is the easiest battery bank I have ever connected. The wires are labeled exactly on the terminals where they go on the batteries on both ends. It's oh man, it's super cool. Like I wish everybody would be this easy.  

Jing: And our enclosure is IP 56 rated. So, it's auto rated. The system can go outside.  

Virtual power plants & closing

Justine: Yeah. There's another question. Oh, Tor Allen. I remember Tor. I go way back with Tor many years in the industry, and he says, he's getting here late. Well Tor, now, now. He said he’s wondering if anyone has discussed situations yet where the setup is providing grid services in a virtual power plant?  

Greg: Yeah. Tor is good to see you. I know we're connected on LinkedIn. You show up on my feed a lot so thanks for coming in. Right now, we're just focusing on residential applications. There may be virtual power plant stuff in the future. VPP, the company I previously left, was heavy into that area with BPP. So, I don't know, Jing, if you could provide any insight that I may not have.  

Jing: No, I mean, short term we don't have a plan for VPP. But we understand the market is going towards that and the aggregated distributed power. And that VPP is putting out important features, especially for people looking at the additional revenue streams. Yeah. I hear you loud and clear. So definitely, we're putting it on our roadmaps.  

Justine: It was, I think it was just today, Cossa sent something out about something like three quarters of a gigawatt, I believe of energy storage systems in California alone. That they're just saying, “Hey, we could utilize, we could be tapping into these energy storage systems if there was a funding mechanism, some support there, that helped the utilities offset where they need to offset.” But right now, we just don't have the kind of the infrastructure in play to make that happen, but we're starting to get a lot of battery systems out there, especially in California.

Jing: Yeah. Yeah, definitely.

Greg: Yep. And it provides a great resource, right? Instead of having to turn on some dirty peaker plant, we could just yank off of these energy storage systems, but it's a really complicated process, right? You have to have, again, it all comes down to communication, right? And I'm not talking about us to the utility. I'm talking about the actual protocol between the equipment and the protocol the utility wants to use to control all that demand management. It's a huge effort; not impossible. We see places like Germany that are already doing that. But I mean, they're the size of Texas and we're like, that big, so it's a challenge, but it'll probably start in California like these things usually do and then head out.

Ryan: Well, great. I really appreciate it. Jing and Greg, this has been great. It's been a good conversation. I'm glad to see the Tigo solutions and was really happy to learn more about that. So really appreciate you joining us today, everybody out there. Just want to let you all know that Mayfield, we do provide education, design and development, and content development services. So happy to have you come check us out at Mayfield.Energy. There's mine and Justine's information there. Justine does code classes as well, specifically around the ESS. So, some good stuff that we can work with you all on. Jing and Greg, your information is there too. So hopefully people who have specific questions you can reach out. Yeah, thanks. Thanks for everybody and we'll get the recording out to you all. As part of part of our follow-up.  


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