Registration and Welcome Desk (NOVA Rectorate)

Dr. Laura Aelenei, Prof. Daniel Aelenei, Prof. Yupeng (Jack) Wu, Prof. Mattia de Rosa, Prof. Teresa de Ponce Leão, Prof. Júlia Seixas

Net Zero Lisbon: From Buildings to Urban Resilience

Lisbon's path towards climate neutrality demonstrates how ambitious climate targets can be translated into tangible action through building renovation, energy efficiency and urban transformation. Beyond decarbonisation, the city is addressing energy poverty, thermal comfort and social inclusion, ensuring that the transition delivers benefits for all citizens. Through initiatives such as Lisbon Climate Contract 2030, RETIME and City4Climate, Lisbon is combining resilience, digital innovation and data-driven governance to create a city that is better prepared for future climate challenges.

Human Factors in Achieving (or Not) Net Zero Carbon Built Environment

Data from the past few decades show that the proportion of the greenhouse gas emissions produced by the built environment, particularly buildings, from the overall emissions has not decreased, despite the fact that most countries around the globe have set the same goal, that is to achieve net zero emissions by 2050. Studies have demonstrated that socio-economic and cultural issues are among the many barriers in achieving net zero, together with other barriers relating to governance and policies as well as industry readiness. This presentation focuses on the human factors that can influence the success, or failure, to achieve net zero carbon built environment. Using a few case studies, important issues that researchers, scientists, engineers and designers need to consider will be highlighted. The presentation will then offer a number of solutions to be considered in developing ways to achieve net zero emissions.

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Data Centers in a Zero-Carbon Future: Metrics, Physical AI, and Emerging Technologies

Data centers are essential infrastructure for the digital economy, but their rapid growth creates significant energy, carbon, and water challenges. This keynote introduces the role of data centers in the transition toward a zero-carbon built environment and examines key performance metrics, including power usage effectiveness, carbon usage effectiveness, and water usage effectiveness. A Massachusetts data center case study from a U.S. Department of Energy project will demonstrate the potential of advanced cooling and control strategies in reducing data center energy consumption. A Bitcoin-mining case study will further illustrate how Physical AI can improve operational efficiency. The presentation will conclude with emerging trends, including space-based data centers, high-temperature operation, and waste heat recovery.

Registration and Welcome Desk (NOVA Rectorate)

Solar PV-X Technologies: New Frontiers Beyond Electricity

Photovoltaic (PV) panels are typically less than 20% efficient in delivering electricity from the Sun’s energy. The efficiency losses are especially pronounced when PV panels are exposed to high irradiance conditions on warm, sunny days, which lead to higher temperature operation. Of the total amount of sunlight incident on PV panels, over 70% is lost to the environment as waste heat.

This loss has motivated the development of ‘hybrid’ PV-thermal (PV-T) collectors, which combine PV cells with a contacting fluid. The fluid recovers waste heat from the cells, thus delivering a potentially useful thermal output, while simultaneously cooling the cells and increasing their electrical efficiency. Recently, a new concept that we refer to as multifunctional ‘PV-X’ collector technology has emerged, in which secondary processes are integrated synergistically with the PV cells, exploiting the available waste heat to perform additional functions directly within the collector.

In this talk, we will present conventional and advanced PV-T and PV-X collector concepts and designs, along with their underlying operational principles. We will explore opportunities for further developing these technologies and examine how new materials can drive improvements from the component to the system level, while discussing the potential of integrating these technologies into broader solar-energy systems capable of providing cooling, heating, power, fuels or clean water.

Renewable Energy Systems: Current status in the world, prospects and problems

This presentation examines mainly the current status of renewables in the world. The presentation starts with some facts about climate change, global warming, and the effects of human activities, such as the burning of fossil fuels on the climate problem. It then outlines the status of renewables in the world, which includes their shares with respect to conventional fuel use for power and for electricity production alone, and their social dimension in terms of jobs created. Then the basic forms of renewables are examined in some detail, which include solar thermal, both for low and high temperature applications, photovoltaics, hydro power, onshore and offshore wind energy systems and biomass/biofuels. In all these the basic technology is presented followed by the current status, the installed capacity in the last decade, which reveals their upward trend, as well as the prospects of the technology and some new research findings. Problems related to the extensive deployment of RES are identified as system transformation is not progressing so fast. We need to build resilient infrastructure, including mainly grids and storage, to be able to utilise renewable energy more effectively.

Nature-Based Solutions as a Key Driver for a Regenerative Built Environment

There is now a near-universal consensus across research, industry, and policy that the global built environment sector must transition from a sustainable to a regenerative paradigm. Yet challenges remain in the primary mechanisms through which this transition can be effectively delivered. This keynote examines the role of Nature-Based Solutions (NBS) as a key driver of the regenerative built environment, positioning them alongside material efficiency, whole-life carbon reduction, and energy performance as fundamental dimensions of transformation. Drawing on insights from the VARCITIES project, funded under the European Union’s Horizon 2020 programme, the keynote will explore how NBS can move beyond mitigation-based approaches to actively restore ecological functions, improve human well-being, and regenerate urban systems. Through place-based interventions implemented across European cities, the capacity of NBS to support healthier, more inclusive, and more resilient built environments is demonstrated. The keynote will argue that embedding nature within the design, governance, and operation of urban spaces is essential to advancing a regenerative agenda for the built environment.