Abstract

Buildings represent a critical piece of a low-carbon future and their long lifetime necessitates urgent adoption of state-of-the-art performance standards to avoid significant lock-in risk. So far, life-cycle assessment (LCA) studies have assessed buildings (conventional and Zero Emission Building (ZEB)), mobility and energy systems mainly individually. Yet, these elements are closely linked, and to assess the nexus of housing, mobility, and energy associated with human settlements by aiming for Zero Emission Neighborhoods (ZENs) gives a unique chance to contribute to climate change mitigation. ZEBs and ZENs are likely to be critical components in a future climate change mitigation policy.

This study addresses the challenge of how to use LCA when implementing such a policy, in line also with the introduction of the more stringent Energy Performance of Buildings Directive in 2010 that requires new buildings to be built with nearly ZEB standards by the end of 2020. The specific aims of this report are fourfold. First, to develop and apply an LCA model to support the evaluation of ZEN design concepts with respect to greenhouse gas (GHG) emissions and other potential environmental impacts. Second, to clarify important contributing factors as well as revealing criticalities and sensitivities for GHG emission reductions and environmental performance of such ZEN design concepts. Third, to establish a model basis for other LCA studies on a neighbourhood scale, in terms of a high-quality modelling approach regarding consistency, transparency, and flexibility. Fourth, to apply our model on two cases; a hypothetical case of a neighbourhood consisting of single family house of passive house standard and on Zero Emission Village Bergen (ZVB).

For the first case, the neighbourhood consists of single-family houses built according to the Norwegian passive house standard. We designed four scenarios where we tested the impact of the house sizes, household size, energy used and produced in the buildings, and mobility patterns. Also, we ran our scenarios with different levels of decarbonization of the electricity mix over a time period of 60 years.

Our results show the importance of the operational phases of both building and mobility at year 1, and its decline over time induced by the decarbonization of the electricity mix. In year 60, embodied emissions are then responsible for the majority of the emissions when the electricity mix is decarbonized. The most important contributing factors have been identified as the operational phases of the Building and Mobility subsystems when the carbon intensity of the electricity mix is high, and as the embodied emissions in materials when the carbon intensity of the electricity mix becomes low. A reduction of the following factors has been identified as beneficial for the overall GHG emissions of a ZEN: (1) building floor area by house either/or by inhabitants, (2) passenger cars travel distances by household, which can be achieved by several means; e.g. commuting with public transport and/or by carpooling initiatives, (3) energy use in the buildings, which is reduced by the use of the passive house standard, and (4) carbon intensity of the electricity mix.

The second case – ZVB – consists of residential and non-residential buildings, with a total area of 91 891 m2; 695 dwellings and 1 340 inhabitants. The total emissions associated with the physical elements (buildings, mobility, open spaces, networks and on-site energy) and the life cycle stages (A1-A3, B4 and B6) resulted in a total of 117 kton CO2-eq over the lifetime. This equals 1.5 ton CO2-eq/capita/year and 21.2 kg CO2-eq/m2/year, referring to heated building floor area and as yearly average emissions over the 60 year analysis period. The emissions are distributed between the elements and life cycle stages. Buildings stand for the majority of the total emissions, accounting for about 52% of the total emissions over the lifetime. The mobility is the second most contributing element, responsible for 40% of the total emissions. The emissions from the networks and open spaces constitute only 2.3% together. A sensitivity analysis showed the emission intensity for electricity and the assumption of allocating emissions from waste incineration to the waste management system rather than to district heat to have a considerable impact on the results. If an EU28+NO electricity production mix is used instead of the Norwegian electricity production mix, total emissions over the 60 years analysis period will increase with 12.5%. This is despite the fact that also negative emissions from the on-site electricity production will be larger, due to the significant increase in emissions from electricity consumed in mobility. If the emissions from waste incineration is not allocated to the district heating production, the total emissions are decreased with 25.3%. Hence, this is a most critical assumption in the LCA model.

The most important contributing factors have been identified as the operational phases of the Building and Mobility subsystems when the carbon intensity of the electricity mix is high, and as the embodied emissions in materials when the carbon intensity of the electricity mix becomes low. A reduction of the following factors have been identified as beneficial for the overall GHG emissions of a ZEN: (1) building floor area by house or by inhabitants, (2) passenger cars travel distances by household, which can be achieved by several means; e.g. commuting with public transport and/or by carpooling initiatives, (3) energy use in the buildings, which is reduced by the use of the passive house standard, and (4) carbon intensity of the electricity mix.

Introducing passive house standards on buildings has the potential to drastically decrease the overall CO2-eq emissions of a ZEB, but also of a ZEN; up to by 191% when assuming an average European electricity mix. Yet, by using a highly decarbonized electricity mix, such as is the case in Norway, the decrease is much lower, around 12%.

Also, we found the choice of the functional unit to be decisive for the conclusion of the study. When conducting LCAs on a neighbourhood scale, we thus argue for the use of a primary functional unit “per neighbourhood”, and a second “per person”. The use of a “per m2 floor area” unit is misleading as it does not give credits for reducing the total built floor area.

All these findings demonstrate that the model is capable of long-term analyses of both homogenous and complex neighbourhoods, and provides a detailed understanding of possible future development of the different elements of the neighbourhood and their GHG emissions.

This report is a part of FME ZEN Work Package 1 Analytic framework for design and planning of zero emission neighbourhoods (ZEN). The goal for WP 1 is to develop definitions, targets and benchmarking for ZEN, based on customized indicators and quantitative and qualitative data. Additionally, an LCA methodology for energy and emissions at neighbourhood scale is developed, as well as a citizen-centred architectural and urban toolbox for design and planning of ZEN.

Summary

This report on the pilot projects of the Research Centre on Zero Emission Neighbourhoods in Smart Cities will give the reader an overview of eight pilot projects of the Centre, focusing on the challenges to develop or transform the pilot areas into Zero Emission Neighbourhoods.

The objective of the ZEN Centre is to develop products and solutions that will lead to the realization of sustainable neighbourhoods with zero greenhouse gas emissions. These solutions will be tested in the eight real life pilot projects in Norwegian municipalities. When searching for the best solutions, we first need to map the pilot projects and the challenges they are facing on the way to become sustainable zero emission neighbourhoods. This report will therefore serve as an introduction to the eight pilot projects to help the ZEN partners to develop an understanding for the pilot projects and their challenges, as a base for further research and cooperation.

This report will start with a short introduction of the Research Centre and present a working definition for a Zero Emission Neighbourhood. Each of the eight pilot projects are described in detail by their individual characteristics regarding location, stakeholders, goals, measures, status of project development, and challenges. Challenges were identified through qualitative interviews with stakeholders of the pilot projects. These interviews were conducted in 2017.

A systematic documentation of the process and challenges to develop ZENs will help to identify the success factors and best practices that are needed for planning and developing ZENs. This enables the involved partners to learn from the first pilot projects, and to transfer solutions to other neighbourhood developments. This report provides a foundation for further follow-up, documentation, and analysis.

Norwegian Summary

Denne rapporten vil gi leseren en oversikt over de åtte pilotprosjektene i ZEN Forskningssenter, med fokus på utfordringene som ligger i å utvikle og transformere pilotprosjektene til nullutslippsområder.

Målet med forskningssenteret ZEN er å utvikle produkter og løsninger som vil føre til realisering av bærekraftige nabolag med null klimagassutslipp. Disse løsningene blir testet i åtte pilotprosjekter i norske kommuner. Når vi søker etter de beste løsningene, er det viktig å ha kartlagt pilotprosjektene med tanke på de utfordringene de står overfor med tanke på å oppnå bærekraftige nabolag med null utslipp av klimagasser. Denne rapporten vil derfor fungere som en introduksjon til de åtte pilotprosjektene og skal hjelpe ZEN-partnerne til å utvikle en felles forståelse for pilotprosjektene og deres utfordringer som grunnlag for videre forskning og samarbeid.

Rapporten starter med en kort introduksjon av forskningssenteret og en arbeidsdefinisjon av hva som legges i ZEN. Hvert av de åtte pilotprosjektene er beskrevet i detalj med deres individuelle egenskaper som plassering, interessenter, mål, tiltak, status for prosjektutvikling og utfordringer. Utfordringene ble identifisert gjennom kvalitative intervjuer med de involverte aktørene i pilotprosjektene, mange av dem er ZEN partnere. Disse intervjuene ble gjennomført i 2017.

En systematisk dokumentasjon av prosessen og utfordringene med å utvikle ZENs vil bidra til å identifisere suksessfaktorer og beste praksis for å planlegge og utvikle ZEN. Dette gjør det mulig for de involverte partnerne å lære fra de første pilotprosjektene og overføre løsninger til andre byutviklingsprosjekt senere. Denne rapporten danner grunnlaget for videre oppfølging, dokumentasjon og analyse.

Abstract

This report is a part of Work Package 4 Energy Flexible Neighbourhoods. The goal for WP 4 is to develop knowledge, technologies and solutions for design and operation of energy flexible neighbourhoods.

4th generation district heating is evaluated as a sustainable solution for covering the heating demand in Zero Emission Neighbourhoods and reducing the strain on the electricity grid. There are, however, some technical challenges that must be solved before it is introduced. One of them is to determine how low the supply temperature could be in different building types, which again will determine the minimum district heating supply temperature. This report is evaluating the minimum supply temperature in Norwegian apartment blocks based on effects of improving the thermal envelope and reducing the temperature levels for the heating system. The analysis is based on building simulation and focuses on whether the reduced supply temperature guarantees the comfort in the building, considering the coldest room with a heating setpoint of 22 °C and a minimum acceptable indoor temperature of 19,0 °C.

The simulated buildings are based on the data available from the IEE project Tabula. Generic models representative for Norwegian apartment blocks have been developed in IDA ICE. They consist of eight age classes and three levels of energy performance: • Prior to 1956, from 1956-1970, 1971-1980, 1981-1990, 1991-2000, 2001-2010, 2011-2020 and 2020 →. • Original, intermediate renovation and standard renovation For the intermediate renovation level, it is only the windows and infiltration rates that have been changed. Tabula also includes an ambitious renovation, but this has not been modelled as the results are expected to be similar to those for the newest age class. Simulations are performed with two different dimensioning temperature levels for the radiators typical for Norwegian buildings; 80/60 and 60/40 °C. The results showed that it is possible to reduce the supply temperature to the radiators from 80 to 60 °C for buildings from 1971-80 and all newer age classes, even for the non-renovated buildings. This is based on a minimum acceptable indoor temperature of 19.0 °C (according to the Norwegian building regulations, TEK). For the older age classes, an acceptable indoor temperature is not achieved for the non-renovated buildings when reducing the supply temperature. Although it is sufficient to perform the intermediate renovation to maintain temperatures above 19 °C, it is highly recommended to perform the standard renovation for these age classes to reduce the number of hours with a significantly reduced indoor temperature compared to the setpoint temperature. In addition to reduce the heating demand and thus lead to energy savings, this will also ensure that the occupants are satisfied with their thermal environment. It is important to note that the conclusions would be different if the minimum acceptable temperature was set higher, for instance at 20 or 21 °C. The results can be used by district heating companies, building owners, contractors and consulting companies in order to evaluate the introduction of 4th generation district heating in Norwegian apartment blocks. Both the models and excel sheets with hourly results are available for partners and researchers within FME ZEN.

Abstract

eTransport is a linear optimization tool for evaluating energy supply alternatives for building areas. This report describes an improved, more realistic district heating (DH) module that has been developed for eTransport. The new module includes several improvements as compared to the previous module:

• Varying mass flow that depends on the heat load, as opposed to constant mass flow. 
• Pressure included as a variable, with certain limits for minimum pressure and minimum pressure drop at the loads. 
• Calculation of pumping power is included in the module, and pumping power due to pressure losses in pipes and at loads is included in the objective function 
• A more realistic calculation of heat losses included, and the heat losses are included in the heat load 
• The module allows supply flow to both directions in a pipe; a property which is relevant when more heat sources are present in a DH grid. This feature is however yet to be tested properly.

The report presents the main equations required for mathematical description of a district heating system are presented, followed by the approach taken for linear representation of these equations, required for eTransport. The report includes a brief evaluation of the module using a simple test network, and discusses the simplifications and limitations of the present module, giving suggestions for further improvements.

Sammendrag

Fjernvarme er en viktig muliggjørende teknologi i det grønne skiftet. Fjernvarme kan nyttiggjøre energi som ellers ville gått til spille, slik som gjenvunnet varme fra avfallsforbrenning og industriprosesser; eller mindre spillvarmekilder tilgjengelig i byer, slik som datasentre og store matvarebutikker. Ved hjelp av et fjernvarmesystem kan slike kilder anvendes til oppvarming av boliger og næringsbygg. Med et godt samspill med kraftnettet bidrar fjernvarme i tettbygde strøk til å avlaste kraftnettet og tilgjengeliggjøring elektrisitet til andre formål enn til oppvarming. Bygging av et fjernvarmesystem krever store investeringer i startfasen, og dermed er det viktig å vite hvilke energikilder man bør velge til et gitt område for å minimere tilbakebetalingstiden. Det er derfor vanlig å bruke planleggingsverktøy for sammenlikning av ulike energiforsyningsalternativer til området. eTransport er et slikt verktøy, lagd av SINTEF Energi i 2006. Verktøyet skal oppgraderes og videreutvikles i FME ZEN. eTransport omfatter flere energibærere, og finner den optimale måten til å drifte energisystemet, samt en optimal ekspansjonsplan i et geografisk definert område. I mange tilfeller vil det være konkurransen mellom ulike energibærere: behovet for oppvarming kan dekkes av elektrisitet eller av et fjernvarmesystem og varme kan genereres fra kilder. eTransport beregner de årlige driftskostnadene for ulike energisystemdesign, og sender disse til en investeringsmodell som finner en optimal ekspansjonsplan.

Denne rapporten beskriver en oppgradering av fjernvarmemodulen i eTransport. I den tidligere versjonen av eTransport var modulen for beskrivelse av et fjernvarmesystem svært forenklet. Den oppgraderte modulen er mer realistisk i forhold til beregning av massestrøm, varmetap, trykktap og pumpearbeid. Modulen tillater dessuten forsyning av varme i begge retninger i et rør, noe som kan være aktuelt i et varmenett som utnytter flere, distribuerte varmekilder. eTransport et lineært optimalisverktøy, og rapporten presenterer den valgte tilnærmingen for lineær formulering av de viktigste likningene for beskrivelse av et fjernvarmesystem.

This document outlines the definition, key performance indicators (KPI) and assessment criteria for the Research Centre on Zero Emission Neighbourhoods in Smart Cities (ZEN research centre). This first version of the ZEN definition includes contributions from the ZEN partners. In total, around 50 people involved in the ZEN research centre have contributed to this document.

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Denne rapporten beskriver definisjonen, nøkkelindikatorer og vurderingskriterier som benyttes i forskningssenteret for nullutslippsområde i smarte byer (ZEN senteret). Dette er den første utgaven og inkluderer innspill og bidrag fra ZEN partnerne. Til sammen har omkring femti eksperter fra ZEN senteret bidratt til dette dokumentet. Rapporten foreligger både på engelsk og norsk.

M. K. Wiik, S. M. Fufa, J. Krogstie, D. Ahlers, A. Wyckmans, P. Driscoll, H. Brattebø, A. Gustavsen

Abstract

This report describes existing software tools for analysing operation and expansion of local energy systems and is written in WP5 in the Research Centre on Zero Emission Neighbourhoods in Smart Cities (ZEN). WP5 in FME ZEN aims to develop and apply methodologies that identify the socioeconomic optimal operation and expansion of energy systems within demarked areas. The eTransport model is planned to be further developed and used to analyse pilot cases in ZEN. This report provides a brief description of the eTransport model and other alternative models found in the literature or used by partners in FME ZEN. The models are assessed based on their suitability to address the planned research tasks in FEM ZEN WP5. The report also includes a description of models developed for global and international analysis.

We are grateful for views and suggestions provided by Henrik Madsen (professor at DTU), and for comments provided by Anne Grete Hestnes (professor NTNU)

M. L. Kolstad, S. Backe, O. Wolfgang, I. Sartori

Abstract

The increased use of electric vehicles (EVs) calls for new and innovative solutions for charging infrastructure. At the same time, it is desirable to improve the energy flexibility of neighbourhoods. This paper presents state-of-the-art for smart EV charging systems, with focus on Norway.

The aim of the study is to start investigating how smart EV charging systems can improve the energy flexibility in a Zero Emission Neighbourhood (ZEN). The intention is that the study will be useful when evaluating activities and technologies for the ZEN pilot areas.

The paper presents energy demand for EV charging and typical charging profiles. Further, it describes how charging stations can interact also with the energy need in buildings and neighbourhoods, local energy production and local electric and thermal energy storage. Examples of commercial smart EV charging systems are described.

The report lists some opportunities for testing smart EV charging in the ZEN pilot areas. Piloting of new technologies and solutions can provide more knowledge about smart EV charging systems, and how they can participate in matching energy loads in buildings and infrastructure with local electricity generation and energy storage.

Åse Lekang Sørensen, Shanshan Jiang, Bendik Nybakk Torsæter, Steve Völler

Abstract

This report is a part of Work Package 3 Responsive and Energy Efficient buildings. The goal for WP 3 is to create cost effective, responsive, resource and energy efficient buildings by developing low carbon technologies and construction systems based on lifecycle design strategies.

As conventional HVAC systems can only make most users satisfied with their thermal environment, there has recently been a lot of research into personal climatization systems. The aim of this literature study was to investigate whether personal heating and cooling solutions could contribute to make all users satisfied with their thermal environment. Potential energy savings are considered a bonus, but was also included in the evaluation of the literature on the subject.

Almost all of the articles reviewed in this report found that the personal climatization devices significantly improved thermal sensation and thermal comfort for the users. For both heating and cooling it was found that combining personal comfort devices resulted in higher comfort improvement and higher energy saving potential. The devices also made it possible to achieve thermal comfort outside the traditional heating and cooling setpoints, thus making it possible to extend the thermal dead-band of buildings, which could lead to substantial energy savings. There are however still some aspects of personal climatization systems where there is suggested further research, and these personal climatization systems are still not commercially available.

Øystein Rønneseth

This report reviews the state-of-the-art on thermal energy systems for neighbourhoods. Its main focus is on technologies related to 4th generation district heating (4GDH), biomass combined heat and power (CHP) systems, ground source heat pumps (GSHP) and seasonal heat storage.

Harald Taxt Walnum, Eyvind Fredriksen

How should sustainable neighbourhoods be designed to reduce greenhouse gas emissions towards zero? What kind of information do decision makers need to make solid future plans on the neighbourhood level? A dynamic building stock model has been developed for energy- and GHG-emission scenario analyses of neighbourhoods. The model is generic and flexible and can be used to model any neighbourhood where building stock data is available.

Jan Sandstad Næss, Nina Holck Sandberg, Natasa Nord, Magnus Inderberg Vestrum, Carine Lausselet, Aleksandra Woszczek, Øystein Rønneseth, Helge Brattebø

This report presents a plan for the European power market studies to be carried out within the ZEN Research Centre.

Local energy solutions such as the utilization of local renewable energy resources, and increased energy efficiency, are important for being able to reduce European greenhouse gas emissions to amounts that are in line e.g. with a 2 degree global warming. In the long run, emission levels are affected by many factors including energy system operations, investment decisions, policy instruments, social acceptance for environmental policy, amongst others. Thus, it is not trivial to calculate the full impacts of e.g. 1 TWh extra renewable energy produced locally. Still, it is possible to elaborate on and reveal important mechanisms, which will increase our understanding of those. This report present a plan for European power market studies to be carried out within the FME ZEN. The overall intention with the planned studies is not to provide more accurate numerical calculations than in previous studies, but rather to show how numerical results are affected by which economic mechanisms that are included in such studies. Thus, the studies shall be a basis for creating increased mutual understanding of arguments within FME ZEN.

Ove Wolfgang