The world's cities are engines for innovation, growth and economic activity, but they are also a key contributor to climate change.

While cities only cover 2 per cent of the world's surface and are home to slightly over half of the world's population, they consume a disproportionate 78 per cent of the world's energy, and produce over 70 per cent of global greenhouse gas emissions. 

By 2050, urban populations are projected to increase to 68 per cent - up from 55 per cent today - with close to 90 per cent of this increase happening in Asia and Africa. Clearly, cities have a major role to play in addressing climate change for the world to have a chance of limiting global warming to within 1.5oC.

How can we reduce carbon emissions from electricity consumption, transportation, buildings and industrial activities in cities, without compromising on continued population and economic growth in our cities? What role does nature and biodiversity play in this balance?

Presented by Temasek's Ecosperity platform, the Sustain-a-City: An Urban Innovation Challenge invites students to put their imagination and creativity to the test!

The Brief

Calling all students! We invite you to reimagine what a sustainable, net-zero city could look like, and to share your innovative solutions around the following key themes:



This is a virtual competition. You will need to submit your proposed solution(s) with the following deliverables:

  1. A video of 3 minutes (or shorter), pitching your innovative solution
  2. A supporting essay in 500 words (or less) describing the solution's key features and design attributes, how it contributes to decarbonisation efforts, and how the solution interplays with other systems within the city to generate positive multiplier effects or tradeoffs



The competition is open to all registered students between the ages 18 and 25 as of registration date. This includes, but is not limited to, students in high school, junior college, polytechnic, design school and universities. 

This is a team challenge. Teams comprising 2 or 3 members should be formed prior to registration and the team leader can register for the competition by filling out the online registration form linked below.

Competition Phases

The campaign includes 3 virtual workshops in April which all participating teams must attend to qualify for judging. Get the full download on the competition and hear from industry experts at these virtual workshops. Participants will also receive one-on-one mentoring with coaches from Arkki Singapore.

The 6 shortlisted finalist teams must attend and present their solutions at the virtual final pitch session in May.

Virtual Workshop Speakers

Prasoon Kumar

CEO & Co-founder

Willy Lee

Senior Aviation Business Manager

Bjorn Low

Executive Director & Co-founder
Edible Garden City

Tanah Sullivan

Group Head of Sustainability

Nina Yang

SJ CityGlobal

What's in it for you?

Besides a fulfilling learning experience and first-hand advice from industry professionals, 6 shortlisted teams will get to advance to the finals, where they'll pitch their ideas live to a panel of judges to win attractive cash prizes and a trip to Heisinki, Finland!

Finalists will also have their work showcased at Temasek's annual flagship sustainability event Ecosperity Week 2023 in June, to a global audience of business leaders, investors, policy makers and more.

Sunset in downtown Helsinki. Image credit: Julius Jansson on Unsplash


Cash prize of S$10,000 and a 5-day learning trip to Finland

Embark on a trip to Helsinki, Finland's capital city that lives and breathes design. Hosted by Arkki International, the Grand Prize and 1st Runner-up teams will get to immerse in the unique Arkki environment of design thinking and innovation, learn about the Nordic approach to sustainability and connect with like-minded youths who are invested in the future of our planet.

1st Runner-up: Cash prize of S$5,000 and a 5-day learning trip to Finland

2nd Runner-up: Cash prize of S$3,000


Director of Conservation
Head, Real Estate
Executive Director, ERI@N
Nanyang Technological University, Singapore
Group Head of Sustainability
SJ CityGlobal

Judging Criteria

Submissions will be judged based on the following criteria, with each carrying equal weight:


How does the solution contribute to a sustainable net-zero city? For example, does it...

  • improve energy efficiency;
  • result in a net zero or even net positive energy building;
  • reduce waste and/or CO2 emissions;
  • protect nature and conserve biodiversity?


How innovative and original is the solution?


How practical and viable is the solution? Is the cost of design and/or implementation realistic? Can it be scaled up to other cities for greater impact? Is the solution lasting?


How well does the solution integrate with and complement other systems in the city? Teams will be scored on the interconnectivity and interdependence of their solutions with other systems, ensuring net positive multiplier effects and reducing trade-offs.


How effectively and coherently does the submission communicate the solution and its potential impact, including audio and visual aids, models and written materials?


Here are the top 3 winning teams and the People's Choice Award winner:

Grand Prize & People's Choice Award: XWater

Yeong Yoong Sze (21), Lau Hiu Naam (21) & Low Thien Shawn (21)

XWater is a smart urban water management system that comprises hexagonal concrete pavement units and a water storage system. The pavement units contain micro detention cylinders that slow down and store rainwater, which can then infiltrate into the ground. This feature allows cities to replenish groundwater and mitigate urban sinking.

1st Runner-up: Intelligent System To Prevent Contamination Of Recyclables

Zhang Yezhou (18), Yu Youyou (19) & Liu Zihao (18) 

This integrated system seeks to tackle waste contamination in Singapore through the implementation of smart dustbins equipped with a lightweight and highly accurate model that can differentiate recyclables from non-recyclables. The prototype utilises Raspberry Pi and computer vision technology, achieving a high accuracy of 82.1% in sorting recyclable and non-recyclable trash.

2nd Runner-up: Super Solar System

Peyton Choo (20), Chua Li-Ann (21) & Ng Kao Jing (21)

Super Solar System uses water cooling to boost solar panel efficiency and generate extra electricity. It diverts water from rooftop tanks to pipes placed beneath the solar panels, creating a continuous flow of water that efficiently cools the system. This approach not only enhances panel efficiency by reducing its temperature but also generates additional electricity through a thermoelectric generator that utilises the waste heat from the panels.

The Top 6 Finalists

Check out the range of innovative solutions from our finalists, who were also showcased at Ecosperity Week 2023 in Singapore.


Sustain-a-City is an initiative by Temasek's Ecosperity platform. The urban innovation challenge is centred on a competition for students aged 18 - 25 years (as of registration date).

The Sustain-a-City campaign begins with the call for applications in March 2023, and culminates in the announcement of winners at Ecosperity Week in June 2023. Participants will need to attend virtual workshops and mentoring sessions in April, and finalists will need to attend the final pitch session in May.

Familiarity with design, sustainability or engineering would be advantageous, but not necessary.

Yes, you may form a team and register for this competition with students from different institutions.

Communication with teams will be via email, through the team leader as indicated on the registration form. The team leader will receive an acknowledgement email and subquently a welcome e-pack with more details on preparing for the competition.

Yes - at least one member from your team must attend each of the three virtual workshops in April, in order to qualify for judging. The final pitch session is compulsory for shortlisted finalists.

For more information, please contact


Click here to read the terms and conditions of entry.