The concept that could put AC on ice

Ice Energy's remarkable storage compound is colourless, odourless and so safe you can drink it. Pic: Pixabay.

Ice Energy’s remarkable storage compound is colourless, odourless and so safe you can drink it. Pic: Pixabay.

By Jason Deign

Thermal energy storage such as that being commercialised by Ice Energy may have a much greater impact than just doing away with the duck curve.

If sold at scale, it could also effectively put traditional air conditioning (AC) out of business in large areas of the world where AC is essential for daytime workplace and home cooling.

Ice Energy is already bracing itself for growing demand in sunny US territories where increasing distributed solar penetration is causing regulators to move away from net metering plans.

In places such as Hawaii, the shift away from net metering is depriving solar-equipped homeowners of electricity bill reductions and forcing them to look at alternative ways to save money with PV. Powering AC units is one option.

AC is one of the biggest daytime and evening energy loads of households in hot locations. With net metering, much of electricity you need to drive AC units can come for free from any excess you have poured into the grid. 

Net metering being replaced by self-supply

This no longer happens in Hawaii, though. There, net metering has been replaced by self-supply, which means the PV owner forfeits any energy they cannot use on the spot.

This can mean the homeowner waves goodbye to up to 40% of their solar generation, according to Ice Energy CEO Mike Hopkins.

Using excess solar production to freeze ice in a thermal storage system such as Ice Energy’s Ice Cub, though, means “there’s no electrical load for cooling at all,” said Hopkins.

AC “would have been your biggest load when you come home,” he said. “It would have been your biggest contribution to peak hour consumption. It would have been the biggest part of your utility bill. Instead, it’s eliminated.”

This makes the Ice Cub “a really elegant, really effective storage solution for solar PV,” Hopkins said. “It’s really an air conditioner integrated with an ice tank.” 

Half the cost of a Powerwall

The AC component of the technology costs the same as its traditional counterpart. The storage system, meanwhile, “costs about half the cost of a Powerwall,” said Hopkins.

Unlike a Powerwall, he said, ice storage can be fully charged and discharged every day for 20 years with no degradation.

While Ice Energy’s products are already attracting interest from utilities in markets such as California, the company believes AC substitution could be attractive as a consumer proposition in Hawaii and elsewhere.

As a result, the company is looking to tie up partnerships with solar installers. “We think that’s the logical partner here,” said Hopkins, because solar firms face rapidly declining sales in regions where net metering is being phased out.

“You replace old air conditioning with new Ice Cubs and you can have all the solar you want,” he said. “You can over-generate and productively use that over-generation.”   

Cutting electricity bills by 40%

As it stands, Ice Energy claims sunbelt US households could cut electricity bills by 40%, just by avoiding peak charges.

And if the business case for solar with ice storage is already good in Hawaii, it could get even better if PV penetration increases to the point where utilities are forced to charge for accepting additional distributed generation onto the grid.

But it’s not just Hawaii where AC could usefully be replaced by ice storage. “Technically it could go into any building and any home that has traditional direct-expansion air conditioning,” said Hopkins.

There were more than 49m of these packaged air conditioning units sold in Asia Pacific alone in 2015, along with 16.1m in the Americas, according to figures from the Global Air Conditioning Study 2016.

“It would be a technical fit for most buildings and all homes,” Hopkins confirmed. Plus “it would be a good idea wherever cooling is an important part of your load.” 

Huge potential for AC replacement

That narrows the market somewhat, although Hopkins observed that climate change is expanding the need for AC generally. In any case, ice storage’s potential for AC replacement is still huge.

Ice Energy only installed its first Ice Cub a few weeks ago and already the company has been approached by several solar players, said Hopkins.

He is now trying to pivot Ice Energy away from being just a utility-focused vendor and towards having additional residential retail sales through appropriate channel partners, most likely solar installers.

As well as the US, Ice Energy is following up approaches from potential channel partners in Saudi Arabia and Australia.

The company’s manufacturing partner, Mercury Corporation, has the capacity to produce 10MW of Ice Bears per month.

“Nowhere near sufficient”

This is “significantly more than we need for our present contracts and pipeline in the US,” Hopkins said, but “nowhere near sufficient for what we are looking at in Saudi Arabia or Australia.”

Exporting the technology should not be a problem, though. “It’s capable of being manufactured by any qualified contract manufacturer,” said Hopkins.

That could become a requirement sooner rather than later. As more and more players wake up to the potential of solar with ice storage, Ice Energy is looking like an increasingly hot property.

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