Imagine a single integrated plant system that can simultaneously produce four key utilities for daily living — electricity, water, air-conditioning and heat, and in a more environmentally-friendly and cost-effective manner. This novel smart quad-generation plant has been developed by a research team from NUS Mechanical Engineering, led by Associate Professor Ernest Chua.
A significant amount of energy is currently required for the generation of the four utilities. It also gives rise to extensive energy wastage and needs a huge floor area, said Assoc Prof Chua.
“With our smart plant, these processes are carefully integrated together such that waste energy can be harvested for useful output. Overall, this novel approach could cut energy usage by 25 to 30 per cent,” he explained, adding that the plant cuts carbon dioxide emission by about a third and is less bulky.
The utilities plant uses natural gas to power the micro turbines to produce electricity. Waste heat generated can be channelled back to power chillers to produce chilled water, which is then used to cool and dry air for air conditioning. The waste heat can additionally be used to produce hot water or steam.
The plant also recycles non-potable water, like rain water, to produce drinking water with a purity close to bottled mineral water.
A dual-dehumidification system in the plant can remove up to 60 per cent of moisture from the air to enable quicker cooling of the environment. The unique system uses water chilled to 13 to 18 degrees Celsius to cool the air, instead of the usual temperature of 4 to 7 degrees Celsius. Each increase by 1 degree Celsius gives energy savings of about 3.5 to 4 per cent, contributing further to the plant’s overall energy efficiency.
“The tropical climate is hot and humid, and our smart utilities plant is uniquely designed to operate efficiently in such weather conditions. We developed innovative membranes to remove moisture from the air and coupled with a novel method of cooling the air, the plant significantly reduces the amount of energy needed to meet air-conditioning needs. This is unlike existing methods, which are usually very energy intensive,” Assoc Prof Chua elaborated.
Smart features like real-time tracking of power consumption, and remote operating of valves and pumps have been incorporated into the plant. This enables evaluation of energy efficiency, as well as customisation and optimisation of the different processes for various communities. The team is also hoping to transfer this data onto the cloud to enable mobile access and remote operation from other parts of the world.
The research team sees potential for the plant to be used in housing and building clusters, as well as underground and floating cities, especially those in tropical climates.
In the future, the researchers hope to explore opportunities to commercialise and test-bed some of their patented technologies that have been developed from this project.
This project was supported by the National Research Foundation Singapore’s Competitive Research Programme.