What is the capacity of each panel-level energy storage unit, how much does a unit weight and what are the dimensions?
Each unit has 1kWh of capacity, and weighs ~50lb, and 1 SolarLEAF fits easily within the area under standard PV modules to add up to 3 pounds per sq feet. These are beta unit specs and may optimized for production.
What are the advantages of using panel-level storage?
Panel-level storage shares a lot of the advantages that other module-level power electronics — microinverters, DC optimizers, etc. — bring to the industry, such as the simplification of design, power efficiency, and power optimization. Unlike other large stationary ESS systems, the SolarLEAF™ simply integrates with the same racking system as the solar module and uses the same balance of system. This is advantageous in situations with limited space or where the placement of stationary storage may add significant trenching costs. Additionally, the distributed design of the SolarLEAF™ with lithium-iron-phosphate technology is the safest way to integrate storage, as there is no risk of a cascading thermal runaway. In commercial rooftop systems with ballast racking, the SolarLEAF™ offsets the additional weight needed, which is typically accomplished with concrete ballast blocks.
Where are your energy storage units located in relation to the solar panels in a solar power system?
SolarLEAF™ is designed to be mounted directly behind the solar module that is powering it. The SolarLEAF™ can install electrically between the PV modules and the inverter because it can work with microinverters, string inverters, and battery inverters.
Can your storage units be used with ground-mounted solar?
Yes, Yotta is developing attachment brackets for various ground-mount racking solutions.
Could they be used on motorhomes, travel trailers, or mobile homes?
The SolarLEAF™ is generally not recommended for moving vehicles unless the installation is completed via a professional attachment process.
What battery chemistry do your storage units use?
Current generation of SolarLEAF uses Lithium Iron Phosphate. It is one of the Safest and non-toxic types of lithium ion batteries that have minimal to no fire risks. Moreover, LFP has a high cycle life and needs no maintenance over its lifetime.
What is the use life or longevity for your storage units?
SolarLEAF™ uses a premium, high-cycle life lithium-iron-phosphate chemistry and will come with a standard 10-year warranty with an option to extend to 20 years.
If your storage units are located on rooftops, is there any fire or explosion risk?
Lithium-Iron-Phosphate is one of the safest battery chemistries available, as the phosphate-based cathode material is not prone to thermal runaway. Additionally, each battery is housed in a fireproof enclosure. The distributed architecture renders the risk of a cascading thermal effect nearly impossible. Typically distributed with three feet of spacing between units and carrying a 1 kWh nominal capacity, the SolarLEAF™ effectively minimizes and separates components to further curb thermal effects. SolarLEAF™ will meet and exceed the strictest safety regulations for integrating energy storage into the built environment.
What kind of thermal protection do your storage units have and how does it work?
Yotta’s Smart Thermal Protection technology is based on a phase-change heat exchange system. This is commonly used in satellites to protect electronics and batteries from great variability in temperature. Yotta has developed and patented a solid-state design of the system — no moving parts — that works completely passively in protecting batteries in extreme heat and highly efficient protection against freezing temperatures.
What is the cost of one of your storage units and how many can be combined into one storage system?
Yotta has yet to finalize public pricing. However, we will hit the market with a competitive price point that will rival the installed cost of stationary systems in our target market.
When might they be available for purchase?
We are currently rolling out several pilot deployments with strategic partners. We will be releasing products through our Preferred Partner Program next year with plans for a full market launch by Q4 of 2020.