New storage technologies are broadening the appetite for storage beyond lithium ion. I think weve hit the tipping point where the awareness and value of energy storage has gone mainstream.

Ice Energy Storage Explained

Mike Hopkins | Ice Energy


Tell us a little bit about Ice Energy and your products.

We’re a pioneer in distributed thermal energy storage solutions for the electricity grid. Since 2003, our utility customers have been cost-effectively and reliably using our proprietary thermal energy storage products and services to solve grid problems caused by the peak demand of air-conditioning (AC), deferring or eliminating the need for new peaking power plants, transmission lines, substations and distribution feeder upgrades.

Our Ice Bear and Ice Cub line of products, also known as “ice batteries”, enable the utility to transform its most problematic load – the AC load – into a flexible and reliable grid resource.  

Ice Bears share many parts with the most common type of commercial and industrial “package” AC units, and look very similar as well. The Ice Bear is an add-on to such AC units and instead of cooling the air with a compressor/condensor, Ice Bears use electricity (usually at night or during periods of abundant solar energy) to freeze a tank of water. When desired, the Ice Bear turns off the compressor of the AC units to which it is connected and provides the building the same amount of desired cooling by just melting the stored ice. The ice can deliver a 5-ton cooling load for up 6 hours every day, during which time the only electrical load is a small refrigerant pump requiring only 5% of a compressor’s electrical draw.

Ice Cubs are like Ice Bears but are designed for houses and unlike the Ice Bear the Ice Cub integrates the primary AC unit and storage unit into one package.  Thus the Ice Cub fully replaces the home AC outdoor condensor unit, providing 24/7 cooling with up to 4 hours per day of “ice cooling”. The newest model of the Ice Cub is optimized for homes with solar pv, with a “fast-freeze” ability that enables it to make a full tank of ice during narrow periods of excess solar generation, then cool the home with that ice when the solar generation dissipates.

Last but not least, we have successfully prototyped and will soon release our first thermal energy storage product for refrigeration and process cooling. The market for refrigeration and process cooling is  almost as large as air conditioning, so this product will significantly increase our addressable market. The product will have the same reliability as our Ice Bear product line but will be even more cost effective, which is saying a lot as Ice Bears are the lowest cost energy storage currently available.


What differentiates your products from other energy storage products?

Our products are most commonly compared to lithium ion batteries, and have many advantages over chemical batteries, starting with cost.

The life cycle cost of our thermal energy storage systems is less than half that of lithium ion batteries used for comparable applications, and that advantage will be sustained or grow over the next 5 years.

Ice batteries have unparalleled reliability, 98% + over 35 million operating hours.

Ice Bears and Ice Cubs are environmentally friendly with none of the waste heat, thermal runaway, spill, or disposal issues associated with chemical batteries. The storage medium is tap water, with the tank filled once. Our systems are designed for utilities to last 20 years, with no expensive repowers.

Our proprietary technology ensures Ice Bears and Ice Cubs are high-efficiency, with a roundtrip efficiency of 85% and effective efficiency of 100% or better when the ice is made at night.

As part of our mission to produce the lowest-cost, most robust distributed storage system for the grid, Ice Bears and Ice Cubs are designed to use almost entirely commodity, off-the-shelf components without requiring purpose-built manufacturing facilities.  Ice Bears and Ice Cubs can be manufactured by most competent contract manufacturers, and can be installed and maintained by any properly licensed local HVAC contractor, with a small amount of training by Ice Energy.   This not only ensures that our systems can be scaled and maintained in diverse regions, Ice Bear and Ice Cub deployments generate recurring local jobs across manufacturing, engineering, installation, and maintenance.  We’re committed to deploying solutions which help and support all of our utility partners, their commercial and residential customers, and their communities as well.  


Explain the Duck Curve and its ramifications.

The traditional peak is a mid-day peak, that looks like a bell curve and is driven by the AC load. In places where there is significant solar penetration, specifically in residential areas, the traditional mid-day peak changes into a so-called Duck Curve, where the mid-day peak is replaced with an actual dip in net load caused by solar pv generation exceeding demand – also known as solar over-generation, which in terms of its shape looks like the curved back of a duck. The old peak is replaced by a new peak that occurs later in the day as solar generation dissipates and people come home and turn on their air conditioners, and is a steeper ramp that than the traditional mid-day peak, looking like the neck of a duck. The steeper peak is a problem but the over-generation is an even bigger problem threatening grid stability.


How can Energy Storage be a solution to the Duck Curve?

Energy storage can “charge” with the over-generation, eliminating the dip or back of the duck, and “discharge” when the solar dissipates, eliminating what otherwise would have been the steep ramp up, effectively flattening the duck curve.


Describe the costs and benefits of solving the problem with energy storage

The benefit of solving the Duck Curve problem is the continued replacement of fossil fuel generation with renewables. Without solving the Duck Curve, the over-gen problem will stop continued home solar pv growth because the grid simply can’t handle it. Energy storage is the only effective solution, the question is what’s the right kind of energy storage that is cost effective and reliable for this application. Lithium ion batteries aren’t well suited to this application as the regular use of them degrades their capacity and shortens their life. Even that aside, they are expensive to use for this. Flow batteries could be better suited but haven’t really achieved commercial reliability and are even more expensive than lithium ion. Our ice batteries are ideal on all counts – applicability, cost and reliability.


How do you see Ice Energy fitting into this solution?

The Ice Cub was designed to solve the Duck Curve, and does just that. Most of the time it functions like a conventional high efficiency AC unit. But unlike a conventional AC unit, it will use solar over-gen to make its tank of ice, eliminating the dip or “back” of the Duck Curve, and then deliver back cooling when people come home and through the evening for the stored ice, eliminating what would have been the steep ramp, or “neck” of the Duck Curve. It will do this every day, for up to 20 years, for less than half the cost of a chemical battery. And it fixes the problem using tap water in its tank, filled only once in its life, not using chemicals.


Energy Storage is experiencing tremendous growth currently, give us your expert analysis on what the next 5 years might hold for the energy storage industry (costs, mainstream adoption etc.).

I think it’s a safe bet that the growth over the next 5 years will exceed most everyone’s projections. If you look over past research reports, that’s what’s been happening. In part this is dramatically dropping costs, now at grid parity. In part this is new storage technologies broadening the appetite for storage beyond lithium ion. Last but not least, I think we’ve hit the tipping point where the awareness and value of energy storage has gone mainstream. I certainly hadn’t thought we’d be on CBS Sunday Morning but am really encouraged that this mainstream attention is helping energy storage go mainstream in terms of adoption.

The content & opinions in this article are the author’s and do not necessarily represent the views of AltEnergyMag

Comments (2)

Providing alternative energy resources is what consumers need in their households. Energy storage providers are an essential in such a market which is truly increasing in its popularity as the years pass by. We need to take advantage of cheaper energy alternatives as much as possible to our own advantage.
Energy storage is a promising industry that has been showcasing its benefits throughout the decades. Every industry is contributing towards green efforts to catch up on the positive trend that is benefiting mankind. Self storage is saving the world with ecological storage space diversity. We believe every little effort does matter regardless of the platform that you establish it in.

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