14 April 2025; 13:00-14:00 GMT+1
Presenter: Dr Emmanuel Essah
Biography
Dr. Essah, is the head of Sustainable Energy, Environment, and Engineering department within the School of the Built Environment. His professional journey reflects a significant dedication to advancing the application of sustainable energy practices and fostering interdisciplinary collaboration between academia and industry. His research interests encompass optimizing the application of Photovoltaic systems in the built environment, energy management in buildings, indoor environmental quality, and the impact of Biophilia on occupants’ wellbeing. His research projects investigate various aspects of buildings, including the design performance, effects of air movement and condensation formation risk. He employs a combination of building simulation modelling methods; including computational fluid dynamics (CFD), integrated environmental solutions (IES), and experimental methods in his research.
Dr. Essah is a member of the editorial board for the Journal of Building Engineering and a guest editor for the Air Quality and Healthy Buildings special issue of the journal. Additionally, he serves as a reviewer for several journals, including Energy Policy, Sustainable Cities and Society, Building Research Information, Energy Transitions, Building and Environment, among others. In addition to his research contributions, he has assumed leadership positions in academic program development serving as Undergraduate Programme Director and later as Programme Director of the MSc in Design and Management of Sustainable Built Environments.
Papers to be presented
- Title: “Experimental and numerical studies to assess the energy performance of naturally ventilated PV façade systems” and “Assessing the performance of a building integrated BP c-Si PV system”
Authors: Mehdi Shahrestani, Runming Yao, Emmanuel Essah, Li Shao, Armando C. Oliveira, Arif Hepbasli, Emrah Biyik, Teodosio del Caño, Elena Rico, Juan Luis Lechón
Link to paper: Experimental and numerical studies to assess the energy performance of naturally ventilated PV façade systems
2. Title: “Assessing the performance of a building integrated BP c-Si PV system”
Authors: Emmanuel A. Essah, Ana Rodriguez Arguelles, Neil Glover
Link to paper: Assessing the performance of a building integrated BP c-Si PV system – ScienceDirect
Session Highlights:
Emmanuel raised a series of important and challenging questions in his presentation.
- For example, while solar energy offers significant potential to reduce carbon emissions and combat climate change, the efficiency of solar panels falls at temperatures over 25 degrees. So solutions are needed that mitigate this impact if solar power is to continue to play a leading role in the global energy transition.
- Photovoltaic (PV) modules are typically designed with an expected lifespan of around 25 years, during which time their efficiency declines gradually. It is generally expected that PV systems will lose about 3.3% of their efficiency after 10 years and up to 6.3% after 25 years.
- The University of Reading has made important contributions to global solar energy research due to its unique copper-based photovoltaic (PV) system installed on the Edith Morley building. This system, owned by SBE, was originally installed in 1998 as a Building Integrated PV (BIPV) on the engineering building’s roof and remains one of the rare examples of such technology.
- Observations of the SBE solar array over time reveal that as global temperatures continue to rise, solar panel efficiency is decreasing at a rate that is inconsistent with the performance outlined in manufacturer datasheets. This trend mirrors the behaviour observed under standard test conditions, where temperature increases adversely affect PV module performance.
- As global temperatures continue to rise due to climate change, the efficiency of solar panels is likely to decrease further. This would affect long-term energy output, reducing their ability to generate power and, by extension, diminishing the expected environmental benefits of solar energy. This presents a key challenge: if solar power is to maintain its role in mitigating climate change, the infrastructure must evolve. This requires the development of materials and designs that can better withstand heat stress and minimize efficiency losses. Furthermore, higher temperatures could necessitate more frequent maintenance and monitoring of solar arrays, potentially adding to both the complexity and costs of solar energy systems.
- Despite these challenges, the impact of climate change on solar technology is likely to drive further innovation. Ongoing research may lead to the development of more heat-resistant materials and more efficient solar cells, which would ensure that solar power remains a viable and sustainable energy solution, even in a warming world.
- In addition to these technical problems, Emmanuel highlighted the widely overlooked problem of how to safely dispose of old or broken solar panels, which contain highly toxic elements. Illegal dumping in the global south has already been reported and without proper regulation and oversight this problem is likely to increase.
Q&A Highlights
It is important to think about whole systems when we introduce any new technology.
Is solar technology already becoming obsolete?
There are still innovations going on. Companies are looking at ways to optimise the technology The biggest challenge is the impact of heat mostly because of the base product, silicon. Some industries are looking at Gallium Arsenide (GaAs), but it is too expensive. We still need solar panels but rising temperatures due to climate change has become a factor to consider.
What can be done to avoid solar panel degradation? And is research in solar technology developing to improve efficiency?
Nanotechnologies are coming onboard, and researchers are also experimenting with gallium, cadmium and other materials.
Given the cost and scarcity of mining the resources for building the solar panels, do you believe it is ethical (as well as efficient) to continue making solar panels that are becoming less effective due to climate change?
Ethical questions are always very tricky. When we look back on COP28, COP29 the reply was yes. Yes but we should also find alternative source to fossil fuels. If we can extend the solar panel lifespan to 10-20 years then it is worth it. The storage is the biggest problem, because of the mining of lithium and the danger its mining is causing.
PV modules contain some valuable metals that is unfair to landfill if we are not able to recycle them. And what about the toxicity they emit when their life span has ended?
We do not have the infrastructure to recycle solar panels.
There is also the question of disconnect between science and policy. Do you think there is a role within the international framework to put a higher profile in the question of regulation and perhaps it is directly attributable and climate relatable a Loss and Damage case.
Just transition from fossil fuel is not happening as we had planed in the case of solar panels. UNFCCC need to integrate policy and it should start from the IPCC.