A Q&A with Yotta Energy about its panel-level battery SolarLEAF
While the adoption of energy storage is accelerating in the residential and utility markets, installing batteries on commercial solar projects is not always an easy process. There are usually concerns about space: whether there is enough room to place a large battery on the ground floor or whether it is safe to house sufficient storage capacity in a dedicated room in a building. The ability to add storage as utility programs change is also not that straightforward when it comes to permits and the location of commercial storage projects. The market relies on specialized engineering firms to locate solar and storage projects.
Yotta Energy is trying to change that. The panel-level storage company first made news in 2018, is undergoing field tests and plans to launch its SolarLEAF product in Q2 2022. as ballast. If solar installers are familiar with microinverters, power optimizers, or other module-level power electronics (MLPEs), they can connect a SolarLEAF battery. And since it is a functioning MLPE itself, no additional permit is required to add panel-level energy storage.
With the upcoming product launch, Solar Energy World spoke with Yotta Energy CEO Omeed Badkoobeh about the functionality of the SolarLEAF in the commercial solar market.
SPW: Why did Yotta Energy target the commercial solar energy market?
bath koobe: We have been diving deep into this market for four years now. We understand all the pain points and hurdles. Today’s biggest competition for energy storage is doing nothing. Most customers demand energy storage and most developers and installers want to negotiate energy storage customers. Energy storage is very complex. You now have highly specialized companies that are hyper-focused on energy storage. They’ve moved to only really large systems because of cost factors and because they can’t replicate it from building to building.
Our theory is very similar to module-level power electronics in general. They weren’t less expensive than inverters, they just offered more value because of simplification. We do the same for energy storage. We bring more value through overall simplification. If you are a C&I installer and you can deploy solar energy and you can install a ballast block, now you can install energy storage. We make it that simple.
Why did you choose lithium iron phosphate (LFP) for the SolarLEAF’s battery chemistry?
We’ve been big in LFP from day 1 before it became extremely popular. It is much safer than any other kind of lithium battery and the service life is longer. The drawbacks of LFP compared to NMC or NCA are that it is slightly heavier due to less specific energy, but that was part of our direction to enter the C&I market where our battery serves as the ballast weight.
Why did you choose a standard supply of 1 kWh?
We have our unique thermal technology [which maintains batteries at their preferred working temperature range (70-100°F)], but it does take up some space and bulk, so we wanted the product to be located at a point where it could be easily carried and mounted by a single installer. To do that we had a limit of 1 kWh. It is also very easy to design. When you look at storage design, it’s easy to say you need 50 SolarLEAFs for 50 kWh. We have our roadmap and are working on higher capacity units. We are very aggressive in lowering costs, and one of the fastest ways to do that is to make a higher capacity unit for our next generation products.
You’re offering a Dual Power Inverter with the battery, essentially a white-label APsystems dual-module microinverter.
APsystems is our OEM partner. They build the microinverters for us on their platform, very specific to our needs. We call it the Dual Power Inverter because it is designed to work interchangeably with both any PV module and our storage device. You can implement a project today using only the inverters and we call it storage ready. Then you can come back at any time and add energy storage.
We’re very big on microinverter architecture because it’s also a security issue. Since the whole system is low voltage, it is very safe against high voltage DC string system. The barriers to microinverter access to C&I have always been costs, but we are in the market today with this inverter at a price that we believe is very valuable and offers great value against taking a string inverter and then having to add it of quick shutdown devices.
If you are using a two-module microinverter, will each SolarLEAF battery work with two solar panels?
We design the SolarLEAF to take two inputs from a module. Where it gets tricky is that the landscape of modules is constantly changing – one minute 450W is peak, the next you have 650W. We work with any standard module these days, with the exception of a few high voltage 96 cell modules.
Where is the battery in the project wiring?
It is a DC coupled system. We call it PV coupled. The battery is located between the PV module and the microinverter input. The batteries absorb directly from the PV module. [DC-coupling] is the highest efficiency because you only convert DC to AC once. We use the same inverter as the PV module, while most energy storage today is AC-coupled. You don’t go back and forth between DC and AC and have losses.
Is Yotta Energy a Battery Company or an MLPE Company?
We see ourselves more as a technology company. I think to be successful in today’s market, you have to offer a solution-oriented approach. The days of installers and developers dealing with multiple vendors to solve the same problem or solution are decreasing. They hate to have to buy an inverter from this company, a battery from this company, a quick shutdown device from this company. We see ourselves very much turning into a technology leader in this C&I market.
You are often compared to JLM Energy’s failed panel-level storage product from a few years ago. What makes Yotta Energy more successful?
Tesla was the third company to try electric vehicles. Any new technology requires a well thought out team and careful execution and timing. We had developed our technology long before the announcement of the JLM battery. We always knew you had to prove the physics of how this battery can last on a roof. If you can’t, there’s no point in pushing this product out yet. That is why other MLPE companies may not have tried this format. We have worked very hard over the past three years to perfect this thermal technology that makes this product a reality.