28, May 2020 / rebound

Refrigeration Cycles with Embedded Thermal Energy Storage

Back in November 2018, Russell Goldfarbmuren, Rebound’s CTO and Co-founder, was invited to speak to the Colorado Renewable Energy Society about embedded thermal energy storage systems and how IcePoint takes advantage of the concept. The presentation was a great opportunity because, as a developer of a novel refrigeration cycle, Rebound rarely gets to discuss how IcePoint also provides energy storage to the grid. Rebound is making this presentation public once again, because the topic is critical.

When Rebound was founded, solving energy storage was the primary team focus. That may come as a surprise seeing as Rebound is an advanced refrigeration engineering company, not an energy storage company. Rebound doesn’t build batteries (thermal or chemical) and IcePoint generates most of its economic value by solving refrigeration constraints, not via energy storage.

This is all intentional. Rebound’s go-to-market customers need IcePoint because it freezes product faster thus generating more revenue for their business. As a bonus, IcePoint also helps them decrease their energy consumption, avoid peak rates, and mitigate demand charges just like a battery. Rebound’s customer traction, however, is driven by the increased revenue delivered by accelerating IQF freezer production lines or decreasing blast cycle times. Interestingly enough, it’s these high value applications that also get additional storage onto the grid.

Economic Benefits of Embedded Systems

Why did Rebound develop IcePoint with a focus on freezing product faster if a company goal was also to solve energy storage? Simple: energy storage is a challenging business. Here is an example: If a typical IcePoint customer, like a food processing facility or cold storage warehouse, uses a battery to provide 100% efficient energy storage by arbitraging time of use rates and mitigating all demand charges, that battery would save about $140k/yr. To accomplish this, an 18 MWh battery system is needed, which would cost approximately $7.2M. That’s a simple payback of 50 years.

If that same customer instead spends $7.2M on IcePoint refrigeration systems, they would generate between $4.5M and $36M per year in revenue by freezing additional product, while still benefiting from the exact same $140k/yr, energy storage enabled savings.

The battery has a 50 year payback and IcePoint has between a 0.2 and 1.6 year payback. That, in a nutshell, is why Rebound developed IcePoint and not a battery.

This dramatic difference in energy storage costs is not unique to IcePoint or even Rebound. Many other stakeholders in the energy industry have noted the economic advantages of embedded energy storage vs. stand-alone energy storage. For those who want to learn more about energy storage concepts like IcePoint, which uses existing infrastructure to deliver inexpensive energy storage, please review the papers referenced below. They provide a great overview of why energy storage doesn’t need to originate from stand-alone systems. Instead, the grid can adapt using less expensive and more reliable methods, like IcePoint:

CPI: Flexibility The Path To Low-Carbon, Low-Cost Electricity Grids

Brattle Group: The Hidden Battery