Giant Ice Trays Cool Buildings Using Green Energy

Summer is almost upon us, and with it, mass use of air conditioning that takes up around 40 percent of all electricity consumption in buildings, something that energy grids simply cannot support.

That’s why one Israeli company is using ice as a cheaper, greener method to cool office blocks at those times of the day when energy is most in demand and most expensive.

Nostromo Energy packs hundreds of water capsules into power cells, which can be installed on the roofs, in basements, or on walls of commercial and industrial buildings.

Company co-founder and CTO Yaron Ben Nun says he “understood that if solar power was going to be the big winner for clean energy, then the next big thing in its technology would be storage because at sunset, the whole system would turn off.”

The IceBrick is a modular thermal cell that utilizes water’s potential for high energy storage as it freezes from liquid into ice. Picture your standard ice tray, but on a massive scale.

The water in the IceBrick is frozen using cheap or surplus electricity from the grid at off-peak hours (like at night, when temperatures are lower) or from renewable sources such as solar and wind power.

The IceBrick’s “dedicated control software” only lets the ice within the capsules thaw during hours of peak energy use, easing the added demand that air conditioning places on electrical infrastructure and thereby lessening the need for the construction of more power plants to meet rising demand. 

The company says that the unique arrangement of the capsules, as well as the combination of coolants within them for uniform and rapid freezing, means less energy is needed to freeze the water.

The water circulating within the building cools down as it passes through the IceBrick, saving energy.

The cooling system also eliminates the need to use chillers – the massive machines that use energy from the grid to cool water and power air conditioners in commercial and industrial buildings during the hottest points of the day. 

Additionally, the energy released from the ice as it melts is used to power the air conditioning system itself – not just cool the water that it uses to chill its rooms.

“When the water freezes, it stores a tremendous amount of electricity – 80 times more than if we just changed the temperature without it freezing,” Yoram Ashery, CEO of Nostromo, tells NoCamels.

“Instead of having the chillers cool the water, we [use our system to] melt the ice, and by that we chill the water.”

A single IceBrick cell can discharge four to eight hours of cooling, and save 7 to 12 kWh (kilowatt hours) of energy every day.

Ashery says that just one installed system can save 300 tons of carbon a year alone – and the company’s overall contribution only continues to grow. 

Israel’s startup sector includes more than 100 companies specializing in energy tech and over 600 working on climate solutions.

The IceBrick systems are already in use in Israel and in the US, cooling office buildings, data centers and medical device manufacturers, the rooms of which must remain chilled to prevent the growth of bacteria.

Nostromo, which is based in Moshav Shdema near the southern Israeli city of Ashdod, will also soon be installing its systems in 120 American buildings – mostly in California – under a scheme by the US Department of Energy to support clean energy use. 

Additional systems are to be placed in Israel’s Soroka Hospital in the desert city of Be’er Sheva, and in a hotel in Los Angeles whose name Ashery cannot disclose, but says is “iconic.”

“Our focus is the commercial buildings, which have high use of air conditioning. From a market perspective, we’re talking about a quarter of a million buildings in the US,” says Ashery.

So what is a company’s incentive to use Nostromo’s system?

When companies shift their energy consumption from the peak hours to the off-peak hours, they’re switching from expensive power to cheap power.

But beyond that, Ashery believes that there are companies that truly want to make a change for the sake of the environment. 

“There are companies that want to do good, and they are investing in various sustainability initiatives because they want to do the right thing,” he says.

“And other times, it’s just good for businesses. Consumers like you and I often have a preference for brands that we know are more environmentally conscious.”

Global temperatures are on the rise, and are likely to reach new records in the next five years, according to the World Meteorological Organization. This will only result in more and more people leaving their air conditioning units on for longer and longer periods of time.

In fact, the use of energy to cool buildings has doubled since 2000, and over the next three decades, the use of air conditioning units is set to become one of the top drivers of global electricity demand. Right now, it’s at 10 percent, according to the International Energy Agency. 

By the peak hours of energy use in the afternoon (from 4PM to 9PM), energy suppliers resort to supplementing the grid with so-called peaker plants – inefficient power plants that quickly supply energy, but at a great cost to the environment… and to our wallets. 

Peaker plants typically emit far more pollution per megawatt-hour than regular power plants because their fuels are often dirtier, and because the quick ramping up and down does not allow pollution controls to effectively capture air pollutants.

Peaker plants in New York City, for example, emit twice as much carbon dioxide per unit of electricity than regular power plants, and 20 times as much nitrogen oxides, according to the nonprofit law organization Earthjustice.

They also cost more per kilowatt hour than baseload power, or the minimum amount of electric power needed to be supplied to the electrical grid at any given time. 

Nostromo, on the other hand, can control its pollutant-free system through the cloud, so that its team can communicate and interact with grid operators, and dispatch systems when the grid needs power reduction the most.

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