The urban energy transition requires innovative heating and cooling systems, as well as enhanced flexibility in electricity usage. This paper explores the theoretical potential for vertical farms to contribute to the energy transition by supplying residual heat to local district heat networks and flexible electricity usage. A stepped approach was used to design energy systems that achieve thermal energy balance through heat and cold exchange between a vertical farm and buildings within a specific Dutch neighbourhood. Furthermore, alternative lighting strategies for vertical farms were explored to reduce grid congestion and to respond to electricity price fluctuations, limiting the mismatch between electricity generation and demand. Compared to the baseline scenario, the energy system with an integrated vertical farm reduces overall energy use by 15 %, even when accounting for the farm's electricity use. By adopting intermittent lighting that is better aligned with electricity price fluctuations, the vertical farm obtained annual cost savings of 14 %. The integration of vertical farms into energy systems can, therefore, contribute to the urban energy transition by producing residual heat to balance thermal energy system and save money for growers by optimising LED operations to align with electricity price fluctuations, whilst producing fresh vegetables for the city.@en

Over the past decades, various farming methods have evolved in response to the global challenges of increasing food demands, decreasing availability of arable land, and climate change. One of these new farming methods is vertical farming. To understand the contribution of vertical farms to future sustainable food production, beyond its efficient land-use and high yields, this paper evaluates the current carbon footprint of lettuce produced in an operational vertical farm in comparison to conventional open-field farming and both soil-based and hydroponic greenhouse cultivation in the Netherlands. The assessment includes the greenhouse gas emissions of the life cycle of the farm and the crop, from cradle-to-grave. An alternative scenario is explored to include the lost carbon sequestration potential by land-use change, identical packaging for all farming methods, and renewable energy usage. The carbon footprint of the vertical farm was 5.6–16.7 times greater than that of the conventional farming methods in the baseline scenario and 2.3 to 3.3 times in the alternative scenario. The electricity demands of the vertical farm represented 85% of the carbon footprint in the baseline scenario and 66% in the alternative scenario, suggesting that a significant reduction in electricity use is required to compete with conventional farming methods from a carbon footprint perspective. If this could be achieved, vertical farming could become a valid component of future sustainable and food secure systems by its efficient use of land, high yields, minimal use of water, nutrients, pesticides and herbicides, and the ability to be located within or adjacent to cities.@en

Vertical farms use some resources very efficiently. However, their electricity use is considerable, and a significant amount of waste heat is produced. This paper investigates how the integration of vertical farms in buildings could reduce the use of energy, water, and nutrients collectively across both entities by leveraging potential resource synergies. The paper considered the integration of vertical farms in apartments, offices, restaurants, swimming pools, and supermarkets located in the Netherlands. For each typology, the floor area heated and the amount of building users fed by one m2 of one production layer within the vertical farm was calculated, along with required outputs of water and nutrients from the building to sustain the vertical farm. The energy savings of different integration strategies were calculated for each building typology in comparison to a non-integrated approach. Results showed that the synergetic integration of vertical farms with buildings reduced the year-round energy use of the climate systems of both entities collectively by between 12 and 51%. The integration of vertical farms with buildings decreases the use of energy, water, and nutrients from external sources and offers great potentials to reduce the environmental impacts of both entities, whilst producing food in urban environments.@en

Purpose: City-zen is an EU-funded interdisciplinary project that aims to develop and demonstrate energy-efficient cities and to build methods and tools for cities, industries and citizens to achieve ambitious sustainability targets. As part of the project, an Urban Energy Transition Methodology is developed, elaborated and used to create Roadmaps, which indicate the interventions needed to get from the current situation to the desired sustainable future state of a city. For one of the partner cities, Amsterdam, such a Roadmap was developed. The paper aims to discuss these issues. Design/methodology/approach: This paper discusses the approach and methodology behind the City-zen Urban Energy Transition Methodology, with its six steps from the initial energy analysis to the roadmap towards a desired future state. The paper will illustrate this by results from the Amsterdam Roadmap study, in numbers and figures. Findings: The Roadmap study of Amsterdam revealed that the city can become energy neutral in its heat demand, but not in the production of sufficient electricity from renewables. Research limitations/implications: Although as yet only applied to the City of Amsterdam, the methodology behind the roadmap can be applied by cities across the world. Practical implications: An enormous effort is required in order to transform, renovate and adapt parts of the city. It was calculated, for instance, how many energy renovation projects, district heating pipes and photovoltaic panels will be annually needed in order to timely become carbon neutral, energy neutral and “fossil free”. Social implications: The technical-spatial content of the Roadmap was presented to stakeholders of the Dutch capital city, such as politicians, energy companies, commercial enterprises, and not least citizens themselves. Although informed by scientific work, the Roadmap appealed too many, demonstrated by the extensive media coverage. Originality/value: The City-zen Methodology builds upon earlier urban energy approaches such as REAP (Tillie et al., 2009), LES (Dobbelsteen et al., 2011) and Energy Potential Mapping (Broersma et al., 2013), but creates a stepped approach that has not been presented and applied to a city as a whole yet. As far as the authors know, so far, an energy transition roadmap has never been developed for an entire city.@en

Purpose: City-zen is an EU-funded interdisciplinary project that aims to develop and demonstrate energy-efficient cities and to build methods and tools for cities, industries and citizens to achieve ambitious sustainability targets. As part of the project, an Urban Energy Transition Methodology is developed, elaborated and used to create Roadmaps, which indicate the interventions needed to get from the current situation to the desired sustainable future state of a city. For one of the partner cities, Amsterdam, such a Roadmap was developed. The paper aims to discuss these issues. Design/methodology/approach: This paper discusses the approach and methodology behind the City-zen Urban Energy Transition Methodology, with its six steps from the initial energy analysis to the roadmap towards a desired future state. The paper will illustrate this by results from the Amsterdam Roadmap study, in numbers and figures. Findings: The Roadmap study of Amsterdam revealed that the city can become energy neutral in its heat demand, but not in the production of sufficient electricity from renewables. Research limitations/implications: Although as yet only applied to the City of Amsterdam, the methodology behind the roadmap can be applied by cities across the world. Practical implications: An enormous effort is required in order to transform, renovate and adapt parts of the city. It was calculated, for instance, how many energy renovation projects, district heating pipes and photovoltaic panels will be annually needed in order to timely become carbon neutral, energy neutral and “fossil free”. Social implications: The technical-spatial content of the Roadmap was presented to stakeholders of the Dutch capital city, such as politicians, energy companies, commercial enterprises, and not least citizens themselves. Although informed by scientific work, the Roadmap appealed too many, demonstrated by the extensive media coverage. Originality/value: The City-zen Methodology builds upon earlier urban energy approaches such as REAP (Tillie et al., 2009), LES (Dobbelsteen et al., 2011) and Energy Potential Mapping (Broersma et al., 2013), but creates a stepped approach that has not been presented and applied to a city as a whole yet. As far as the authors know, so far, an energy transition roadmap has never been developed for an entire city.@en

Following the Paris Climate Agreements, all European cities must undergo a transition towards asustainable, net zero-carbon energy system. This is an unprecedented challenge that will require a lot of knowledge and methodological support.For the City-zen project, under the coordination and execution of TU Delft, chair of Climate Design & Sustainability, as task within City-zen (WP4, T2), the City-zen Urban Energy Transition Methodology (in short: City-zen Methodology) was developed and tested on various Roadshows (WP9, T3.2) and finally used for the Amsterdam Roadmap (WP4, T2 too). The Amsterdam energy transition roadmap was published in 2018.The essence of the City-zen Urban Energy Transition Methodology is as follows: based on extensive research into energy characteristics of the city, planned near-future developments, stakeholder analyses and future scenarios, a sustainable city vision can be elaborated, after which a roadmap with different energy transition paths can be defined.Such a roadmap was already made for the city of Amsterdam; this report uses maps and images of that study to exemplify steps taken in the City-zen Methodology.@en

Following the Paris Climate Agreements, all European cities must undergo a transition towards asustainable, net zero-carbon energy system. This is an unprecedented challenge that will require a lot of knowledge and methodological support.For the City-zen project, under the coordination and execution of TU Delft, chair of Climate Design & Sustainability, as task within City-zen (WP4, T2), the City-zen Urban Energy Transition Methodology (in short: City-zen Methodology) was developed and tested on various Roadshows (WP9, T3.2) and finally used for the Amsterdam Roadmap (WP4, T2 too). The Amsterdam energy transition roadmap was published in 2018.The essence of the City-zen Urban Energy Transition Methodology is as follows: based on extensive research into energy characteristics of the city, planned near-future developments, stakeholder analyses and future scenarios, a sustainable city vision can be elaborated, after which a roadmap with different energy transition paths can be defined.Such a roadmap was already made for the city of Amsterdam; this report uses maps and images of that study to exemplify steps taken in the City-zen Methodology.@en

Following the Paris Climate Agreements, all European cities must undergo a transition towards asustainable, net zero-carbon energy system. This is an unprecedented challenge that will require a lot of knowledge and methodological support.For the City-zen project, under the coordination and execution of TU Delft, chair of Climate Design & Sustainability, as task within City-zen (WP4, T2), the City-zen Urban Energy Transition Methodology (in short: City-zen Methodology) was developed and tested on various Roadshows (WP9, T3.2) and finally used for the Amsterdam Roadmap (WP4, T2 too). The Amsterdam energy transition roadmap was published in 2018.The essence of the City-zen Urban Energy Transition Methodology is as follows: based on extensive research into energy characteristics of the city, planned near-future developments, stakeholder analyses and future scenarios, a sustainable city vision can be elaborated, after which a roadmap with different energy transition paths can be defined.Such a roadmap was already made for the city of Amsterdam; this report uses maps and images of that study to exemplify steps taken in the City-zen Methodology.@en