Energy

Three-story water battery cuts university's energy usage by 40 percent

Three-story water battery cuts...
A new energy system for the University of the Sunshine Coast is expected to prevent more than 92,000 tonnes of CO2 emissions over the coming 25 years
A new energy system for the University of the Sunshine Coast is expected to prevent more than 92,000 tonnes of CO2 emissions over the coming 25 years
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Render of the new water battery at USC
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Render of the new water battery at USC
In pursuit of its climate-neutral goals the University of the Sunshine Coast (USC) teamed up with private energy company Veolia to draw up a new clean energy solution for its buildings
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In pursuit of its climate-neutral goals the University of the Sunshine Coast (USC) teamed up with private energy company Veolia to draw up a new clean energy solution for its buildings
A new energy system for the University of the Sunshine Coast is expected to prevent more than 92,000 tonnes of CO2 emissions over the coming 25 years
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A new energy system for the University of the Sunshine Coast is expected to prevent more than 92,000 tonnes of CO2 emissions over the coming 25 years
The University of the Sunshine Coast in northern Australia is on a mission to become completely carbon neutral by 2025
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The University of the Sunshine Coast in northern Australia is on a mission to become completely carbon neutral by 2025

The University of the Sunshine Coast (USC) in Queensland, Australia, is on a mission to become completely carbon neutral by 2025, and a huge early addition to its energy systems is boding well for these lofty ambitions. Switched on in September, a new three-story “water battery” is already producing enough juice to power the campus’ air conditioning systems, reducing its reliance on the grid by more than 40 percent.

In pursuit of its climate-neutral goals, USC teamed up with private company Veolia to draw up a new clean energy solution for its buildings. Looking to make the most of the region’s abundant sunshine and take a bite out of the grid energy used for air conditioning, which accounts for 40 percent of its overall usage, the two came up with solution they’ve dubbed the “water battery.”

“Air conditioning accounts for 40 percent of our daily energy usage, so by eliminating this we are taking a major step towards our carbon neutral goal,” Professor Hill said back in August when the system was first announced.

It is in essence a huge thermal energy storage system. It makes use of 6,000 solar panels installed on the campus’ rooftops and carparks that make up a 2.1-megawatt photovoltaic system. The energy generated by this solar system is then used to cool 4.5 megaliters of water resting inside a three-story tank. This cooled water is then used for the campus’ air conditioning systems, and to great effect.

In pursuit of its climate-neutral goals the University of the Sunshine Coast (USC) teamed up with private energy company Veolia to draw up a new clean energy solution for its buildings
In pursuit of its climate-neutral goals the University of the Sunshine Coast (USC) teamed up with private energy company Veolia to draw up a new clean energy solution for its buildings

According to Veolia, the system is reducing the carbon footprint of the university by 42 percent. This rapid and dramatic impact has even earned it and the USC team some international acclaim, with the water battery winning the “Out of the Box” category at Iceland’s 2019 Global District Energy Climate Awards, announced last week.

“The system was switched on in September and is now delivering 2.1 megawatts of power and we estimate that we will save more than AU$100 million (US$69 million) in energy costs over the next 25 years,” says USC Chief Operating Officer Dr Scott Snyder. “Another benefit is that we are able to take our students to visit the system and teach them about innovation and finding cleaner energy solutions for the future.”

Render of the new water battery at USC
Render of the new water battery at USC

Further to these huge cost savings, the system is expected to prevent more than 92,000 tonnes of CO2 emissions over the coming 25 years, the equivalent output of 525 typical Australian homes in the same timeframe, according to USC.

The video below provides an overview of the project.

Changing the way universities do energy

Source: USC, Veolia

15 comments
Jakes B
I'm not sure from the article and video why they decided on the PV to Thermal chiller to Tank to Air conditioning route vs the more conventional PV to Inverter to AC voltage to Air conditioning option. Is the system "energy transfer" more efficient? Does the large thermal mass smooth out input supply variations stretching the cooling effect to after sunset? On colder days the air conditioning isn't using the max power available from the PV panels. With their Tank solution there is no option of using excess PV power in the rest of the facility.
paul314
So how much did this system cost? PV prices look like about $1000/kw or a bit more, so may $3-4M including the water part? Which would put that $2-3M/year anticipated savings in perspective. (By shading the car parks they also likely prolong the lives of faculty and student cars by a fair bit.)
Nestor Patrikios
Very nice! Do we know how much it cost?
John
How is a tank of water being labelled as a battery?
Douglas Rogers
My rooftop solar was $3000/KW and $2100/KW after tax rebate, for rated power of 7.5 KW. Actual peak power is 5.69 KW.
Ima_Cynic
My guess is the campus is already using chilled water cooling, and this addition simply replaces a portion of their cooling infrastructure, such as the cooling towers. A battery is simply an energy storage device. in this case, the tank is storing the solar energy spent to chill the water, and this is used to remove the heat rather than having to rely on other energy consuming devices to do so.
Bazza Dagazza
So let's see here... they save $100m over 25yrs = $4m/yr which represents 40% of their total energy bill which would be $10m/yr otherwise. There's a lot of missing information (intentional) which means you can't make any meaningful analysis of a project like this. A back of the napkin price estimate is at least $10m and probably closer to $15-20m. The estimated saving of $100m over 25 yrs is at a guess an over the top projection to justify the project. SOP for governments and bureaucrats. Interestingly enough you can dissipate heat into the ground. Ground temps often run around 6c year-round at about a 600mm depth. If you google map the site you'll notice there is a substantial area of open space near and around the water tank along with 2 small lakes/dams/ponds. Boondoggle keeps coming to mind for some reason......
J copley
Same here. How much did this cost? No point spending $2 to save $1.
Colt12
I'm sure that the engineers at the university and installation service have this figured out as a savings.
MikeDalton
The equivalent of 525 homes for 25 years. Are citizens really going to pay an average of AU$634 (US$438) per month for electricity over the next 25 years? That's some expensive power.