Welcome to the ECOCITY 2022 Interactive Programme

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Plastic waste is a systemic problem impacting everything on the planet. This is acknowledged the world over. The problem won’t be solved by better recycling programs alone. Globally less than 10% of plastic produced has been recycled, and production has increased nearly 200-fold since the 1950s. The issue is not as much about improving recycling as it is about reducing the use of virgin plastic.

Little attention has been paid to the continuing rise in new plastic production. Society has grown comfortable with plastic. We believe, most often mistakenly, that our waste plastic will be redirected away from landfills and recycled into new products. Plastic bags are not recycled into new plastic bags, plastic bottles don’t become new bottles, nor plastic containers new containers. Plastics are recycled into secondary products which at end-of-life go to waste. Plastic products are often processed for recycling only to be incinerated or shipped overseas to end up as waste. Effective recycling programs require circular systems.

The very recycling programs intended to deal with the plastic waste problem may in fact be exacerbating it. We investigate consumers’ attitudes to using plastic given the presence of recycling programs. We discuss whether access to such programs contributes to a sense of ease and acceptance of plastics. We analyse the attitudes and conditions that support the increasing production of plastic, and the potential for alternative materials to be used.

Looking at recycling programs in Vancouver, Canada, with the objective of reducing new plastic production, we assess coordinated cross-cutting solutions in terms of changes to regulatory frameworks, funding research for alternative materials, and disrupting the sense of consumer ease around the use of plastic.

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This research explores the implementation of large-scale district heating (DH) networks in Copenhagen, Stockholm, and Helsinki in order to draw lessons on how to implement efficient DH networks at scale. The heating sector has the largest share of energy consumption globally, which accounts for a third of global carbon emissions. Due to its strong dependency on fossil fuels and the low cost of implementing individual heating systems, such as gas boilers, it is considered to be one of the most difficult sectors to decarbonise.

DH has the potential to deliver on decarbonisation and renewable energy targets in the heating sector. Its capacity to use a wide variety of low carbon heat sources, such as industrial waste heat, ocean and river source heat, solar thermal and geothermal heat, is seen as a major advantage in increasing supply diversity and reducing reliance on fossil fuels. It contributes to more efficient energy use, reduces carbon emissions and is the cheapest method of providing heat in many high-density cities.

This research seeks to provide insights into how cities implement large scale DH networks with a view to finding best practices and effective measures that can overcome the main barriers limiting the uptake of DH networks. The implementation strategies of DH networks in the case study cities are described and key success factors as well as weaknesses are examined. Drawing on socio-technical transitions literature, this research analyses the institutional, political and implementation strategies integral to the delivery of efficient DH networks. It employs a multi-case study approach using qualitative methods to explore DH network implementation from a socio-technical perspective.

The findings revealed that the implementation of efficient DH networks can be achieved through certain key success factors which include various organisational, technical, social, political and design considerations. Also, heat networks will only deliver increased energy efficiency and climate mitigation objectives if properly designed, implemented and managed. This research will be useful for actors seeking to implement DH to identify strategic directions towards the implementation of efficient DH networks.

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The aim is to advance highly circular built cities. This is achieved by attaining the five sub-aims. (1) Redefining a city into multiple sets of eight arenas. A built city consists of buildings and infrastructures that are divided into residential, commercial, industrial, and public sectors according to purposes and types. In turn, Porter’s (1979, 2008) five forces framework is extended into a set of eight arenas that accommodate buildings and infrastructures within each sector or one sub-sector. In Arena 1, users are exploiting buildings and infrastructures. In Arena 2, owners are managing buildings and infrastructures over periods of ownership. In Arena 3, providers offer services for managing the life-cycles of buildings and infrastructures. In Arena 4, investors are realizing (renewing) new (old) buildings and infrastructures. Arena 5, wholes contractors are realizing complete buildings and infrastructures, and in Arena 6, designers are crafting solutions for and contractors are realizing parts. In Arena 7, manufacturers are delivering products, sub-structures, and construction machinery. In Arena 8, suppliers are producing materials. The transformation is required by city governments and authorities under legislation on circular cities. The transformation is enabled by innovation, technologies, and funding. (2) Designing alternative routes that causally connect backward and forward each arena with the other ones. Backward, the procurers of inputs set highly circular objectives and specify procurement criteria. Forward, the marketers of outputs set highly circular objectives and specify fact-based arguments. (3) Assessing the effectiveness of each route for the boosting of high circularity. The criteria of effectiveness are specified, coupled with benchmarks for highly effective routes coupling arenas. (4) Planning a transformation program, jointly by stakeholders. The phases include (i) the assessment of the current degrees of circularity, (ii) the setting of the timeline and goals, (iii) the motivation of owners and users to develop buildings and infrastructures into the circular ones, and (iv) to motivation of developers, contractors, designers, and other stakeholders to offer solutions for the development of the same. (5) Discussing this transformation and putting conclusions on the realization of 8-arena transformations within cities across the globe.

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Germany's material building stock has grown steadily in recent decades. At the same time, enormous amounts of construction waste are being produced. In this way, the opportunity arises to use these anthropogenic resources and develop cities into circular systems. This requires suitable information with the help of which corresponding business models can be developed. Regional material cadastres (MC) provide a basis for this.

MC are instruments that can be used to describe size and composition of material stocks in building inventories and their changes over time. They refer to material quantities and qualities in regions or cities. MC based on methods of continuous material flow analysis describe building material stocks and their dynamics, but can also describe upstream and downstream stages of these materials: Raw material requirements, waste categories. Furthermore, along the processing stages of materials, material-induced “grey” emissions are integrated by coupling with LCA datasets. MC designed in this way provide a solid basis to specify concepts of closed-loop recycling.

The proposed paper introduces the concept of regional MC. On basis of the case study city "Hamburg" an application of the MC is presented, in which the question is pursued whether and how accumulating construction waste quantities can be completely locally circulated. The case study shows: Information generated in the MC allows content-related differentiations of flows and stocks of construction waste in such a way that specific strategies for recycling can be aligned with them. It is possible to focus on topics (concrete recycling), local planning data/experience (building dynamics) and the degree of influence (public/private buildings). Development variants illustrate that, in medium-term, 75% of the concrete aggregate for public construction can be covered from local concrete quarry if ambitious recycling behavior is adopted. In long-term, complete coverage of this demand from public construction is possible and further substitutions are possible in privately financed construction (housing, non-residential buildings). An essential prerequisite for realizing this is suitable implementation strategies, which can be promoted in a focused manner by municipal construction policy, among other things. MC support the design of correspondingly tailored solutions.

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Broad use of photo-voltaic (PV) energy for individual home owners is constrained by perceived high costs, complexity, utility net-metering limitations, and perceived waste in over-generation. This paper proposes an alternative application of PV in an urban setting that addresses these challenges and may open a path to adoption.

The concept involves a system configuration that is small scale and designed to match the energy generation during summer months to expected demand, with on-site battery storage to balance daily requirements. For most of the year the energy produced would be less than the demand. The intent would be to make use of all the PV energy produced when it is available and to make use of grid energy when it is not. The system would be independent of the grid and net-metering would not be considered. The system would be intended to maximize the use of the PV energy generation with no waste.

This concept is applied to an urban setting in Vancouver Canada. The British Columbia grid energy mix is considered to be relatively “green” with 85% produced by hydroelectric generating stations. The electricity tariff is considered to be “low” with the average cost of energy being the third lowest in Canada. Vancouver is a mature built environment with relatively older homes on small lots. If a case can be made for PV in these circumstances then it should be considerably more attractive in other situations.

A system is sized by assuming an average household demand with expected generation based on actual PV arrays in the Vancouver region. Costs are assessed for commercial installation. Requirements for switching between PV and grid energy is defined. Energy cost is estimated over an assumed system lifetime of 25 years and this is compared to the current effective energy tariff. The effectiveness of the concept to provide broad energy generation is defined in terms of the number of such installations that would be required to replace the energy produced by a new currently being considered hydro generating station and comparing the costs involved.