Urban Albedo Computation in High Latitude Locations: An Experimental Approach

Lead Research Organisation: University of Kent
Department Name: Kent Sch of Architecture

Abstract

The proposed research will develop a novel experimental and modelling study for the computation of urban albedo in high latitude locations, using London as a representative urban environment in the UK. This work is primarily motivated by the need to provide accurate albedo estimates for urban configurations, as such calculations are lacking in most Urban Heat Island (UHI) models used to mitigate its effects.

The research will investigate the seasonal effects of albedo on urban temperature. Albedo intervention can bring substantial positive effects during the summer while marginal negative effects are expected in winter. In mild climates such a negative effect might out-weigh summer benefits. It is possible that seasonal intervention on the urban fabric could give an overall positive impact but for this, accurate computation of urban albedo is required at urban design or intervention stage. These issues will be investigated in the proposed study which has three aims; (a) to investigate experimentally the impact of urban fabric on urban albedo; (b) to develop a catalogue of urban albedo for various material and geometrical combinations and (c) to develop an empirical model to predict changes in urban albedo in relation to changes in urban fabric and solar altitude with a specific focus on advanced materials. This aim will be achieved through an extensive experimental study that includes field and laboratory scale measurements, computer modelling, and followed by the development of an urban albedo calculator that is able to explore seasonal variations. The Urban Albedo Calculator values could be used to predict the urban heat island with greater confidence.

Planned Impact

The urban albedo project will lead to a step-change advancement in the understanding of the photometric phenomena of urban surfaces in the context of complex urban geometries. The research will have an impact on UK policy makers in DBEIS, DCLG, DEFRA, GLA and in many local authorities. The policy makers in these organisations can develop urban environment related guidelines that have an impact on façade characteristics more confidently, especially guide lines to mitigate the UHI. Advanced knowledge of urban albedo will lead to better management of UHI. The research will help designers to ensure that new and refurbished façades will have a low impact on outdoor overheating in the summer, which is likely to become more prevalent with future climate change. Planning, urban design, architecture, civil engineering and environmental practices could use the research findings as well as the urban albedo calculator in their day to day consultancy work. Planners and designers could use the urban albedo values from the catalogue to evaluate alternative schemes at early stages. Currently, planners and designers on most occasions carry out urban albedo evaluations based on subjective judgement. Overall the urban albedo calculator will reduce the uncertainties associated with reflective radiation in predicting urban heat island intensity (UHII) and building energy performance. Public understanding of the impact of infrared radiation in the urban environment will be enhanced, through the involvement of school children with the experiments, inspiring students to study STEM subjects. The findings could point the façade material manufacturers towards new directions especially in terms of high urban albedo materials. Further, manufacturers could test these products in different urban geometries using the Urban Albedo Calculator, as well as through the test site which will be set up at University of Kent. Developers of free-ware software focusing on urban climate will have opportunity to integrate the Urban Albedo Calculator into their model.

Publications

10 25 50
 
Description The award is still ongoing, but so far the early results highlight the effect of different materials on albedo. E.g. concrete paving at street level leads to an increase of the street gorge albedo by an average of 9%, with a similar effect found from application of façade colour -street gorge albedo increased by 10%. The combined effect of both strategies contribute to an average albedo increase of 20%. Under wet conditions, however, a consistent reduction of the street gorge albedo is noted, which varies by 20-33%.
Exploitation Route Design Stretegies
Planning guidance
Integration with professional guidance and standards
Guidabce and characterisation of contrsuction materials
Sectors Construction,Education,Energy,Other

 
Description CIBSE Resilient Cities Special Interest Group 
Organisation Chartered Institution of Building Services Engineers (CIBSE)
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution Given the interest of the CIBSE Resilient Cities Group on the importance of urban form and characteristics on the energy and thermal performance of buildings, the potential advances the project will make on better characterisation of urban albedo on urban microclimate and implications for overheating of urban buildings and the development of modelling tools will be relevant.
Collaborator Contribution CIBSE has worked with us in meetings and workshops to inform the development of the project
Impact The collaboration has supported the development of an important workshop on 'Urban Albedo: Digital tools for urban resilience and growth' (October 2018) which reached different audiences and informed the development of the project. Eventually, CIBSE will be able to publish the key results from the project, incorporating guidance material arising from the project into their publications.
Start Year 2017
 
Description Ibstock-Brick supplies for development of 1:10 models 
Organisation Ibstock Brick Limited
Country United Kingdom 
Sector Private 
PI Contribution As clay bricks account for over 50% of all the facades built in the UK today our project is of interest to Ibstock; particularly (i) identifying the role of brick materials on urban albedo, (ii) ways to characterise the materials for inclusion in an Urban Albedo Calculator, and (iii) inclusion of bricks in a catalogue of urban albedo for various materials and geometrical configurations
Collaborator Contribution Brick materials for developing the 3D 1:10 scale model of areas of London, to be used for testing and experimentation in calculating urban albedo of real sites. This was essential to be able to study the material in urban developments. The materilas provided saved teh project around £7500 in direct costs, which would have been spent to purchase the bricks otherwise.
Impact The bricks have been used for buidling the models. The monitoring work is ongoing and the results from the experiments pending.
Start Year 2017
 
Description Marley Ltd Roof specialists supplies for development of 1:10 models 
Organisation Marley Building Materials Ltd
Country United Kingdom 
Sector Private 
PI Contribution As roof tiles are one of the most important roofing materials in the domestic sector in the UK today our project is of interest to Marley; particularly in the role of roof tiles in characterizing the urban albedo more generally and predominately the assessment and characterization and inclusion of the roof tiles in the catalogue of urban albedo for various materials to be developed.
Collaborator Contribution Provision of the roof tiles for the development of the 1:10 scale model. The contribution included £700 of materials we would have purhcased otherwise
Impact The tiles have been used for building the models. The monitoring work is ongoing and the results from the experiments pending. Their acknowledgment is also highlighted in the publications presented
Start Year 2018
 
Description 'Urban Albedo: Digital tools for urban resilience and growth' workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact The project team along with the Greater London Authority and the London Climate Change Partnership (LCCP) organised a very successful workshop at London's Living Room, City Hall on Monday 15th October 2018, marking the beginning of Green GB week. The workshop 'Urban Albedo: Digital tools for urban resilience and growth', which was chaired by the former President of the Urban Design Group, Colin Pullan, brought together leading urban and building scientists, as well as practitioners from different backgrounds, to inform the impact of urban morphology and materials on urban albedo and its importance for health and well-being.
The presentations from the speakers included:
- Urban albedo - state of knowledge and project overview - Prof. Marialena Nikolopoulou, University of Kent
- London's heat risk in a changing climate - Kristen Guida, LCCP
- Insights from practice panel:
The Concrete Centre (Guy Thompson)
Fosters + Partners (Stefano Capra)
SWECO (Gabriela Costa)
IESVE (Dr Khan Naghman)
CIBSE Resilient Cities (Dr Anastasia Mylona)
Year(s) Of Engagement Activity 2018
URL https://research.kent.ac.uk/urbanalbedo/news-and-meetings/workshop-1-importance-of-urban-albedo-the-...
 
Description City STEM speed dating 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact The after-school STEM speed dating event took place at the City of London School for Girls on 21st January. Prof. Nikolopoulou provided an overview of careers in architecture - civil engineering-built environment, while also highlighting careers I research and how careers in practice, industry, consultancy as well as academia can intertwine. The Urban Albedo project was used as one of the case studies.
The audience was secondary school students asking questions to find out more about this line of work, along with the qualifications and experience they would need to be able to enter this field.
Year(s) Of Engagement Activity 2019
 
Description Experimental approach to urban albedo calculation: methodological challenges 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Talk was delivered to Faculty of Architecture (faculty members only), Karpagam University, Coimbatore, India. The talk highlighted the challenges in developing physical experimental model and how those challenges were addressed taking into account the contextual constraints.
Year(s) Of Engagement Activity 2019
URL https://www.kent.ac.uk/architecture-planning/news/2885/dr-giridharan-renganathan-invited-to-speak-in...
 
Description Importance of studying urban albedo experimentally 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Talk was delivered to post graduate students and selected faculty members at National Institute of Technology, Trichy, India. Talk focused on how radiance could be used to fill the gap generated in the physical model developed for the urban albedo study, and how the physical model results could be used to validate the Radiance model.
Year(s) Of Engagement Activity 2019
 
Description MSc dissertations 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact Educational - Four MSc dissertations on different aspects of urban albedo
Year(s) Of Engagement Activity 2018,2019,2020
 
Description Panel participation at the EDGE debate 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Professor Marialena Nikolopoulou at the Edge debate titled, 'Climate Responsive Urbanism: How can professionals meet the challenge of urban densification in a time of climate change?' on 9th January 2020. The title of the talk was "Climate responsive urbanism; opportunities and conflicts"
The event was jointly hosted with The Urban Design Group, the first in a series of debates entitled Cities, Climate and Critical Urban Infrastructure. The series looks to explore the 'consequences of current practices in building, urban design, planning, regulation and policy on critical urban infrastructure'. The event will be convened by Richard Lorch, Editor, Buildings & Cities, hosted by Robert Huxford, the Director of The Urban Design Group and chaired by Professor Rohinton Emmanuel, Glasgow Caledonian University. Professor Nikolopoulou will be joined by Gerald Mills, University College Dublin, Asaf Din, Perkins &Will, Rachel Toms, Public Health England, and Nicola Bacon, Founding Director of Social-Life.
A lively debate followed after the talks for addressing the issues and highlighting the existing gaps for policy and regulation. Participants expressed strong interest on the work and highlighted the lack of knowledge for interventions and implications at the scale of urban block
Year(s) Of Engagement Activity 2020
URL https://www.eventbrite.co.uk/e/edge-debate-96-climate-responsive-urbanism-tickets-86329735563#
 
Description Participation in LCCP 'Heat Risk in London' meeting (June 2018) 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact Prof. Marialena Nikolopoulou attended the LCCP meeting on 23rd June 2018 to establish discussions on the Urban Albedo Project and collaborations with the range participants in the group.
Year(s) Of Engagement Activity 2018
URL http://climatelondon.org/heat-risk-in-london-group-previous-meetings/
 
Description Participation in LCCP 'Heat Risk in London' meeting (September 2017) 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact Dr Giridharan Renganathan attended the meeting on 19th September 2017 to initiate discussions on the Urban Albedo Project and collaborations with the participants in the group.
Year(s) Of Engagement Activity 2017
 
Description Participation in LCCP 'Observing London' meeting (March 2019) 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact Prof. Marialena Nikolopoulou attended the LCCP meeting on 29th March 2019, on the Observing London project with the focus on 'Improving weather monitoring in London'. She represented the views and needs of the Urban albedo project, regarding data and measurements for London.

Collaboration was enabled with the King's College NASA-ESA project which was organising a flight with infra-red cameras over London. Their flight path included our main case study, Stanley Terrace and it was discussed that arrange of data for the specific sites would be provided.
Year(s) Of Engagement Activity 2019
 
Description Research methods for performance analysis 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact A talk was delivered to Postgraduate students of Faculty of Architecture, University of Moratuwa, Sri Lanka. Talk focused on various research methods to assess built environment performance. The albedo project was cited to discuss the how building material performance could be studied scaled down experimental models.
Year(s) Of Engagement Activity 2019
URL https://www.kent.ac.uk/architecture-planning/news/2873/case-director-giridharan-renganathan-gives-le...
 
Description Stakeholder Engagement Planning Workshop 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact An intensive workshop with ARCC/Space4Climate and LCCP on developing extended communication and engagement pathways to help enhance and broaden the pathways to impact work for the project.
Year(s) Of Engagement Activity 2018
URL https://research.kent.ac.uk/urbanalbedo/news-and-meetings/
 
Description TV interview 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Media (as a channel to the public)
Results and Impact Dr Richard Watkins was interviewed live on Euronews, on 2nd July 2019, to discuss the European heatwave, and to understand what is being done to control the temperatures in cities, and prospective future proposals.
Year(s) Of Engagement Activity 2019
URL https://research.kent.ac.uk/case/news/?article=2848
 
Description Urban Albedo present at CIBSE Build2Perform Live 2019 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact The Urban Albedo formed the basis of a workshop organised by Prof. Nikolopoulou and Prof. Kolokotroni on 'Urban Design' at the CIBSE Build2Perform Live 2019 at Olympia in London on Wednesday 27th November 2019. The session ran through how the Urban Albedo collaborative research project is looking at the impacts of the urban fabric to the urban temperatures and how new material can improve urban climate.
Year(s) Of Engagement Activity 2019
URL https://www.build2perform.co.uk/seminar-programme
 
Description Workshop on APEC Cooperative Network of Sustainable Cities - Integrated Urban Planning and Low-carbon Energy Systems 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Prof Nikolopoulou presented the work of the project focusing on "Developing An Urban Albedo Calculator; An Empirical Model to Predict Changes in Relation to Urban Fabric and Solar Altitude in London", in the Workshop of the Asia-Pacific Economic Cooperation (APEC) Cooperative Network of Sustainable Cities - Integrated Urban Planning and Low-carbon Energy Systems, on 19th September, 2019, in Tianjin, China

The workshop was chaired by Tianjin University of Science & Technology, China, along with the APEC Expert Group of Energy Efficiency and Conservation (EGEE&C). The spekaers included talks from:
- China Chief Representative, C40
- Program Officer / China Chief Representative Assistant, ICLEI Beijing Office
- President Assistant, APSEC
- Assistant Director, Electrical and Mechanical Services Department, Hong Kong
- The University of Adelaide, Australia
- Chief / Planning Officer, Metropolitan Development Planning Service, Metropolitan Manila Development Authority, Philippines

Separate workshop followed and the project was presented in the framework of 'Low-carbon Energy Systems for Sustainable Urban Development'
Year(s) Of Engagement Activity 2019
URL https://research.kent.ac.uk/case/news/?article=2942