SMA America is putting an emphasis on efficiency with its SMA Home Energy Solution for the U.S. home solar + storage market. SMA Home Energy Storage includes the Sunny Boy Smart Energy (SBSE) hybrid inverter, the SMA Energy Meter, optional Backup Secure, the SMA 360° app, SMA ShadeFix and the SMA Energy app. SMA also has partnership with SPAN for circuit-level smarts and load management. We discuss all of it on this episode of The Pitch with Senior Applications Engineer Hasan Taylor.
Watch the full episode above or read part of the transcript below.
Crowell: SMA is known for its inverters, and so I wanted to start there because the U.S. solar market in recent years has gravitated toward microinverters and optimizer-based systems. With where we’re headed now in the current market, why should installers consider switching back to string inverters? And the Sunny Boy in particular.
Taylor: We’re a known quantity in the industry as you already touched on. We’ve been here for over 40 years, so when you see the SMA brand, you think of reliability and stability. We’re not going anywhere, so that’s the first thing.
I think that our approach of reducing complexity is something that installers should take a look at. Reducing complexity and the number of components in a system is going to reduce the overall failure rate, and I think that’s why it’s really important to look at string inverters, and string inverters without module-level optimization. Our inverters have ShadeFix, which provides its own string-level optimization. By putting the optimization technology in the inverter itself, that means the module-level electronics — even in jurisdictions where you have rapid shutdown and you still have to have the module level electronics — that [MLE] is now just doing the one simple job of rapid shutdown. It’s not doing optimization, so that means there’s less components overall still, even with that MLE there.
Something that’s very important compared to microinverters, for instance, is we’re reducing ac losses. When you have microinverters, that means that the dc to ac conversion is happening up on the roof, and now you have a longer ac run from your microinverter going down to the panel. With a string inverter, you’re not doing any that conversion at the panel level. That conversion is happening at the inverter, and that inverter can be placed right next to your panel, which means you have a shorter ac run. There’s no needing to compensate for ac losses – which, you can’t actually compensate for ac losses.
Something related to that is the oversizing capacity. Because we allow for such high dc to ac ratios, even if you do have longer dc runs, you can compensate for that.
Crowell: I wanted to clarify a couple of those points you brought up. When it comes to ShadeFix, explain a little bit more how that compares to module-level optimization.
Taylor: It’s kind of like Google Maps for the inverter — it’s going to get you to the point that you want to get to in the quickest way possible. There was actually a study that was done by the University of Southern Denmark regarding ShadeFix compared to module-level optimizers, and what that study found was that actually, outside of the worst shading possible — severe shading — our inverters with ShadeFix actually outperformed the module-level optimizers. When we’re talking about severe shading, that’s something that best practices say we should be avoiding anyway.
Crowell: When you say partial shading, does that term encompass permanent partial shading of a tree that partially shades the array, or partial shading in terms of cloud cover?
Taylor: It’s actually both.
Crowell: Thinking about the dc to ac equation here, the Sunny Boy has a 200% dc oversized design capability. Why is that important these days? Is that because of higher wattage modules on the market? Is it taking into account the energy storage that you’re thinking is going to be added in later?
Taylor: No. 1, yes, that is compensating for higher wattage modules that we’re seeing in the industry nowadays. But even more importantly, going back to what I mentioned earlier, say it’s a complicated roof where you have a bunch of different arrays facing possibly different orientations. We allow you to really just stack the inverter up on that dc side to compensate for any potential dc losses. Once that is converted the ac, you’re still getting the most you can out of that inverter.
Talking about storage, that’s actually a really important point. Allowing for that high dc to ac ratio means that now you can, if you do have a battery, or say you add a battery at a later date, now you can charge that battery more quickly and more efficiently because we’re going straight dc to dc — no conversion — straight from the array to the battery. You can really charge that battery quickly during the day when the panels are really pumping out energy.
Crowell: That’s part of the equation we were just talking about, in terms of making sure to maximize not just the amount of production of the PV, but the total efficiency of the conversion rates of that PV from beginning to end.
Taylor: That is absolutely correct.
Crowell: Another feature that stood out to me is the SMA Backup Secure option, which allows solar to power the home when the grid goes down even without a battery.
Taylor: This is a huge deal. I live in PG&E territory in Northern California, so we’re experienced when it comes to blackouts, and I have family that says, ‘Hey Hasan, I have solar, why isn’t it powering my home?’ Or where you don’t have the funds to pay for an expensive battery right now. This is attacking that issue head on.
The way it works is you have your switch and outlet. You connect it to our inverter. Say the grid fails. Go outside, turn that switch on, and now the inverter’s in standalone operation. You get up to 2 kW out of that outlet during the day. Once again, this is going to the dc oversizing, if you have an oversized array, then that really is going to help guarantee that you get the max out of that outlet.
Say you do add that battery at a later date, you can still use the outlet now at night. Now you have that battery power available at night, up to 2 kW. No transfer switch necessary or microgrid interruption device. You just have that power available to you 24/7.
Pick up the rest of the conversation right there, as we get into the battery specs (BYD batteries), the SPAN smart panel, and SMA’s added value customer service such as free system monitoring.
- 7:08 – Battery specs: Capacity and Output Power
- 9:29 – Can I use a different battery? (and should you?)
- 10:24 – SPAN smart electric panel partnership
- 11:29 – SMA 360 app and SMA Energy app
- 12:39 – SMA Smart Connected free monitoring service
— Solar Builder magazine
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