NTU Singapore, Surbana Jurong and ENGIE to partner for sustainable liquid air energy storage research

Nanyang Technological University, Singapore (NTU Singapore), Surbana Jurong (SJ), and ENGIE will be collaborating to develop an alternative way of storing energy using liquid air.

Known as liquid air energy storage, this system uses excess energy from the power grid or cold energy harvested from other processes to cool air, turning it from a gaseous state to a liquid state stored at -196 degrees Celsius.

When stored in a liquid state, air is 750 times more compact, having the energy density of a lithium-ion battery but more sustainable due to its smaller carbon footprint. This energy storage concept was developed in the UK over the last decade and is now being studied by the joint team to see if it can be adapted to benefit Singapore and other tropical urban cities.

A liquid air energy plant is estimated to last for 25 years or longer, as it does not have any electrodes, cathodes or anode materials that degrade after hundreds of charge and discharge cycles like a battery, which must be recycled or disposed of. In contrast, it needs only storage containers and generators to harvest its energy potential, making it a greener and more sustainable alternative.

When energy is needed, the liquid air is turned back into a gaseous state, which creates high air pressure that can power a turbine to generate electricity. At the same time, the cold energy from the process could be harvested to chill water for use by chilled water air-conditioning systems in buildings.

The Memorandum of Understanding on the new “Liquid Air Storage Cogeneration System for Cooling and Power Applications” was signed yesterday (8 Dec 2020) on the NTU Smart Campus by NTU Associate Vice President (Strategy and Partnerships), Prof Subodh Mhaisalkar; CEO ASEAN of Surbana Jurong, Mr. Yeo Choon Chong; and Managing Director of ENGIE Lab Singapore, Mr. Loic Villocel.

Prof Mhaisalkar said: “Our collaboration with SJ and ENGIE signifies NTU’s commitment towards developing sustainable energy technologies which aims to help Singapore lower its carbon emissions, in line with the Paris Agreement which it ratified in 2016. The joint project will build upon the university’s strong research focus on energy systems and sustainability and strengthens our existing research partnerships with both SJ and ENGIE. Such partnerships are also an integral part of the NTU Smart Campus vision, which aims to develop technologically advanced solutions for a sustainable future.”

Mr Yeo Choon Chong, Chief Executive Officer, ASEAN Division of Surbana Jurong said, “This collaboration with NTU and ENGIE is another significant milestone in Surbana Jurong’s R&D effort to test and develop cryogenic-related solutions that can help remove carbon emissions and improve energy efficiency. As a multidisciplinary urban and infrastructure consultancy with a wide geographical footprint, we are able to contribute towards decarbonisation targets by driving innovative energy solutions in Singapore and globally through our member companies.”

Highlighting the importance of this partnership, Loic Villocel, Managing Director of ENGIE Lab Singapore said, “ENGIE Research supports ENGIE Group’s strategy to accelerate the transition towards a carbon-neutral economy. This partnership is vital to ENGIE Lab Singapore’s 5-year roadmap, with key areas like cooling technologies and sustainable data centres. We look forward to working with NTU and SJ, sharing our expertise to work towards a common goal.”

Under the joint agreement, the NTU-SJ Corporate Lab together with ENGIE, will look for more partners and support for their plan to develop and showcase the potential of Cryo-Cogeneration for urban cities.

The new research collaboration is based on promising findings from an earlier study conducted by NTU Associate Professor Alessandro Romagnoli, titled “Green Data Centres Through Cryogenic Energy Systems”, which was supported by the Infocomm Media Development Authority and National Research Foundation, Singapore.

In the 2018 study, Assoc Prof Romagnoli and his research team found that by utilising a liquid air storage system to store and generate energy using liquid Nitrogen (which forms 78 per cent of the Earth’s atmosphere), it is possible to provide cooling and power to Data Centres with zero-emissions at point of use, thus offering a valid solution to replace diesel backup power generators.

Data centres in Singapore account for 7 per cent of its annual electricity consumption, with approximately 37 per cent of the energy usage are used for cooling the servers[1].

The new liquid air energy storage project will also serve as a potential test platform for other suitable cryogens like liquefied hydrogen and for identifying synergies with other technologies such as Fuel Cells and other power generation systems.  

The joint project also complements another ongoing pilot testbed by the NTU-SJ Corporate Lab, which is an integrated urban power generation system that can harvest, store and use cold energy from the regasification of Liquefied Natural Gas (LNG).

Called “Cryo-Polygen”, the pilot testbed will harvest the cold energy which is usually wasted when LNG is converted from liquid to gas, and the waste heat from the gas turbine, to enhance the efficiency and power output of the Cryo-Polygeneration Demonstrator.

Assoc Prof Romagnoli, co-director of the NTU-SJ Corporate Lab and the lead investigator for both projects, said their final goal is to develop a high-efficient energy solution that can harvest waste energy, store it sustainably, and to use that to supplement Singapore’s energy needs, thus reducing the overall carbon footprint.