ElectriStor™ Core Benefits

WattJoule’s ElectriStor™ product platform has multiple core benefits versus competitive energy storage solutions. Let’s explore each of these benefits in more detail.

 

Durability by Design

A long lifetime of 20 years is a requirement for energy storage systems and is similar to what solar energy systems provide today. Early vanadium flow battery systems have demonstrated well over 10,000 cycles because the fundamental chemistry is highly stable and does not degrade over time. Similarly, ElectriStor™ has been tested thousands of cycles with no degradation in its vanadium electrolyte performance. In contrast, lithium-ion batteries always exhibit a small cycle-by-cycle degradation, limiting their useful lifetime to a maximum of 3,000 cycles with restricted charge/discharge window and temperature range. This means you would need to purchase your lithium-ion battery packs three times to obtain 10,000 cycles. That’s an expensive proposition. ElectriStor™ has been designed with highly durable materials based on engineered plastics and composite materials to give long life and trouble free operation. Key components, such as the electrolyte pumps, can be easily replaced in the field in order to extend system life.

 

Low Capital & Life Cycle Cost

Two important cost metrics used today are the installed capital cost in $/kWh of rated storage capacity and the Levelized Cost of Storage (LCOS) in $/MWh of actual storage supplied over time for a given application scenario. The LCOS metric is becoming a better industry metric for comparison because, unlike installed capital cost, LCOS takes into account all costs over the actual system lifetime, including all operational costs, repair costs, and costs related to system efficiency. These additional factors are significant. ElectriStor™ is very competitive on an LCOS basis because we start with a low installed capital cost and combine that with a 20-year system lifetime and minimal operational and maintenance costs.

 

100% Charge/Discharge Window

The ElectriStor™ system allows the use of up to a 100% charge/discharge window on every cycle, enabling maximum application flexibility. In contrast, lithium-ion use in stationary storage systems strictly limits this window, according to a complex map of power, temperature and cycle count in order to guarantee lifetime. This means that running multiple storage applications simultaneously may become difficult to implement and possibly unfeasible in some situations.

 

Reduced Footprint

Early flow battery systems had quite a large footprint. By significantly improving system energy density and power density, and by eliminating the need for specialized cooling equipment, we significantly reduce the size and weight of our entire system. ElectriStor™ requires less real estate for siting and lowers overall installation costs.

 

System Flexibility & Scalability

WattJoule’s ElectriStor™ product platform enables OEM system integrators to rapidly build and scale large energy storage systems for their end user customer project requirements. Our platform is a modular, scalable system that requires a minimum of non-recurring engineering time for any one project. Since power and energy are fully independent in our system, there is a large range of flexibility based on the application. To obtain higher power levels, you cluster together energy conversion modules. To obtain higher energy levels, you can either increase the size of an individual tank and/or cluster more tanks together. Power can range from 20kW to 200 MW. Energy can range from 100kWh to 1000MWh. The two are completely independent in our platform.

 

No Refrigerated Cooling Required

Many of today’s energy storage systems require refrigerated cooling; otherwise their systems will degrade and fail prematurely. In contrast, ElectriStor™ requires simple air cooling. This means no costly air conditioning equipment and a higher net system efficiency, since we don’t incur an energy loss to run the AC, and there is less equipment to maintain.

 

No Fire or Explosion Hazard

We have all heard about smartphones, laptops, hoverboards, aircraft, electric cars and large storage systems catching on fire due to battery failure. WattJoule electrolyte is over 60% water and contains no flammable materials. Based on this and its inherent design, ElectriStor™ cannot catch fire or explode like conventional lithium-ion and sodium sulfur technology. This is a major benefit when large energy storage systems, containing massive amounts of energy, are sited close to populated buildings. This removes a major concern by system integrators, developers, fire authorities and insurance companies. In fact, no fire suppression equipment is required for our systems.

 

Longer Duration Storage Improves Costs

Let’s say you have two identical energy storage systems with the same power rating. One is a lithium-ion system and the other is an ElectriStor™ system. The cost of the lithium system in terms of $/kWh for the battery packs, for any energy rating in hours, will be essentially constant. In contrast, ElectriStor™ will have a continually declining $/kWh cost because of the independence of the power (energy conversion) and energy components of the system. When storage times become greater than 2–3 hours, ElectriStor™ becomes increasingly competitive to lithium-ion solutions. This is because as we need to increase storage time we only need to add liquid to the system and increase the size of our tanks. All of the other energy conversion hardware remains exactly the same.

 

A Sustainable Solution

ElectriStor™ was built with sustainability in mind. In the first place, our major global mission is to enable the broad use of sustainable renewable energy through the use of energy storage. Secondly, our equipment and materials are designed for durability and simple repair of components. This allows one to continually extend ElectriStor™ useful lifetime to 20 years and beyond. The liquid electrolyte does not degrade, and the vanadium and other chemicals can be easily removed, recycled by simple processes, and reused in the future. All the hardware components we use are made from materials that can be fully recycled.