Economic analysis of the routes for fulfilment of net-zero energy buildings (NZEBs) in the UK

10th International Conference on Applied Energy (ICAE2018), 22-25 August 2018, Hong Kong, China th Available online www.sciencedirect.com Available online atatwww.sciencedirect.com 10 on Applied Energy (ICAE2018), 22-25 August 2018, Hong Kong, th International Conference 10 International Conference on Applied Energy (ICAE2018), 22-25 August 2018, Hong Kong, 10th International Conference on Applied Energy (ICAE2018), 22-25 August 2018, Hong Kong, China th China 10Economic Internationalanalysis Conferenceof on the Applied Energy (ICAE2018), 22-25 August 2018, energy Hong Kong, China routes for fulfilment of net-zero th ScienceDirect 10 International Applied ScienceDirect China(ICAE2018), 10th International Conference Conference on on Applied Energy Energy (ICAE2018), 22-25 22-25 August August 2018, 2018, Hong Hong Kong, Kong, th China 10Economic International Conference on Applied Energy (ICAE2018), 22-25 August 2018, Hong Kong, analysis of the routes for fulfilment of net-zero energy buildings (NZEBs) in the UK China th Energy Procedia 158 3541–3546 the routes for fulfilment of net-zero Energy Procedia 00(2019) (2017) 000–000 10Economic Internationalanalysis Conferenceof on Applied Energy (ICAE2018), 22-25 August 2018, energy Hong Kong, th Economic analysis of the routes for fulfilment of net-zero energy China th 10 International Conference on Applied Energy (ICAE2018), 22-25 August 2018, Hong Kong, th Internationalanalysis 10 on Applied Energy (ICAE2018), 22-25 August 2018, Hong of routes for fulfilment of net-zero buildings (NZEBs) in the UK www.elsevier.com/locate/procedia China 10Economic International Conference Conference on the Applied Energy (ICAE2018), 22-25 August 2018, energy Hong Kong, Kong, th buildings (NZEBs) in the UK China of the routes for fulfilment of net-zero Matthew Dowds, Siming You*UK China 10Economic Internationalanalysis Conference on Applied Energy (ICAE2018), 22-25 August 2018, energy Hong Kong, buildings (NZEBs) in the Economic analysis of the routes for fulfilment of net-zero energy China th buildings (NZEBs) in the UK 10Economic Internationalanalysis Conference on the Applied Energy (ICAE2018), 22-25 August 2018, energy Hong Kong, China of routes for fulfilment of net-zero Matthew Dowds, Siming You* University ofthe Glasgow, University Avenue, Glasgow, G12UK 8QQ, of UK net-zero energy buildings (NZEBs) in the Economic analysis of routes for fulfilment buildings (NZEBs) in the UK China Matthew Dowds, Siming You* Economic analysis ofMatthew the routes for fulfilment Dowds, Siming You* of net-zero energy

Economic analysis of the routes for fulfilment of net-zero energy buildings (NZEBs) in the UK Economic analysis of routes for fulfilment University ofthe Glasgow, University Avenue, Glasgow, G12UK 8QQ, of UK net-zero energy Matthew Dowds, Siming You* buildings (NZEBs) in the Economic analysis of the routes for fulfilment of net-zero energy University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK Matthew Dowds, Siming You* buildings in the University of Glasgow, (NZEBs) University Avenue, Glasgow, G12UK 8QQ, UK Abstract Matthew Dowds, Siming You* EconomicThe analysis of the routes for fulfilment of net-zero buildings (NZEBs) in the UK University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK 15th International Symposium on District Heating and Cooling energy Matthew Dowds,Avenue, Siming You* buildings (NZEBs) in the UK University of Glasgow, University Glasgow, G12 8QQ, UK Abstract Matthew Dowds, Siming You* of Glasgow, University Avenue, Glasgow, G12 8QQ, (NZEBs) UK This paper evaluated the economicUniversity implications of developing net-zero energy buildings for four types of residential buildings (NZEBs) in the UK Abstract Matthew Dowds, Siming You* Matthew Dowds, Siming You* Abstract University of Glasgow, University Avenue, Glasgow, G12 8QQ, Matthew Dowds, You* houses (i.e. flat, terraced house, semi-detached house, and detached Siming house), across differentUK locations in the UK. Models specific of Glasgow, University Avenue, Glasgow, G12 8QQ,demand-outdoor UK Abstract theUniversity feasibility ofcombinations using theYou* heat Matthew Dowds, Siming This paperAssessing evaluated the economic implications ofvarying developing net-zero energy buildings (NZEBs) for fourHouses types of residential to different locations and loads were created of renewable energy further University ofwith Glasgow, University Avenue, Glasgow, Glasgow, G12 8QQ, 8QQ, UKtechnologies. This paper evaluated the economic implications of developing net-zero energy buildings (NZEBs) for four types ofwere residential Abstract University of Glasgow, University Avenue, G12 UK Abstract University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK This paper evaluated the economic implications of developing net-zero energy buildings (NZEBs) for fourUK. types of residential houses (i.e. flat, terraced house, semi-detached house, and detached house), across different locations in the Models specific Matthew Dowds, Siming You* classified as existing ones and new ones, and the latter had an 55% improvement in energy (heat) efficiency compared to the houses (i.e. evaluated flat, terraced semi-detached house, and detached house), across different locations in the Models specific temperature function long-term district heat demand forecast University ofwith Glasgow, University Avenue, Glasgow, G12 8QQ, UK This paper the house, economic implications ofadeveloping net-zero energy buildings (NZEBs) for fourUK. types ofwere residential Abstract houses (i.e. flat, terraced house, semi-detached house, and house), across different locations in the UK. Models specific to different locations and loads were createdfor combinations of renewable energy technologies. Houses further former. A cost-benefit analysis was conducted forvarying each ofdetached the potential NZEB designs. Without energy storage, income from

to different locations and loads were createdofwith varying combinations of renewable energy technologies. Houses further This paper the economic implications of developing net-zero energy buildings (NZEBs) for four types of residential Abstract University Glasgow, University Avenue, Glasgow, G12 8QQ, UK houses (i.e.asevaluated flat, terraced house, semi-detached house, and detached house), across different locations in the UK. Models specific This paper evaluated the economic implications of developing energy buildings (NZEBs) for four types ofwere residential to different locations and loads were created varying combinations of renewable energy Houses were further classified existing ones and new ones, andwith the latter had an net-zero 55% improvement in5-51% (heat) efficiency compared to the Abstract renewable technology ina,b,c existing households can produce aadetached mean nethouse), profit between oftechnologies. the overall expenditure for NZEB Abstract classified as existing ones and new ones, andwith the latter had an net-zero 55% improvement in energy energy (heat) efficiency compared to the houses (i.e. flat, terraced house, semi-detached house, and across different locations in the UK. Models specific a b c c Abstract to different locations and loads were created varying combinations of renewable technologies. Houses were further This paper evaluated the economic implications of developing energy buildings (NZEBs) for four types of residential houses (i.e. flat, terraced house, semi-detached house, and detached house), across different locations in the UK. Models specific classified as existing ones and new ones, and the latter had an Fournier 55% improvement in (heat) efficiency compared tofrom the former. AThe cost-benefit analysis was conducted for each informed of, the potential NZEB designs. Without energy storage, income I. Andrić *, A. Pina , P. Ferrão J. ., B. Lacarrière , O. Le Corre designs. results will enable policymakers to make decisions for the fulfilment of NZEBs in the UK which can former. A cost-benefit analysis was conducted for each of the potential NZEB designs. Without energy storage, income Abstract to different locations and loads were created with varying combinations of renewable energy technologies. Houses were further This paper evaluated the economic implications of developing net-zero energy buildings (NZEBs) for four types of residential classified existing ones and new ones, andwith the latter an net-zero 55% improvement in5-51% (heat) efficiency compared tofrom the houses (i.e. flat, terraced house, semi-detached house, andhad across different locations in the UK. Models to different locations and loads were created varying combinations of renewable energy technologies. Houses were further former. A as cost-benefit was conducted for each of the potential NZEB designs. Without energy storage, income from renewable technology inanalysis existing households can produce adetached mean nethouse), profit between ofthe theUK overall expenditure forspecific NZEB This paper evaluated the economic implications of developing energy buildings (NZEBs) for four types of residential potentially play an important role in mitigating greenhouse gas (GHG) emissions and help achieve its climate change This evaluated the economic implications of developing net-zero energy buildings (NZEBs) for four types of residential renewable technology inanalysis existing households can produce adetached mean nethouse), profit between 5-51% oftechnologies. the overall expenditure forspecific NZEB classified as existing ones and new ones, and the latter had an 55% improvement in energy (heat) efficiency compared to the apaper Abstract houses (i.e. flat, terraced house, semi-detached house, andinformed across different locations in1049-001 the UK. Models This paper evaluated the economic implications of developing net-zero energy buildings (NZEBs) for four types of residential former. A cost-benefit was conducted for each of the potential NZEB designs. Without energy storage, income from to different locations and loads were created with varying combinations of renewable energy Houses were further classified as existing ones and new ones, and the latter had an 55% improvement in (heat) efficiency compared to the IN+ Center for Innovation, Technology and Policy Research Instituto Superior Técnico, Av. Rovisco Pais 1, Lisbon, Portugal renewable technology in existing households can produce a mean net profit between 5-51% of the overall expenditure for NZEB designs. The results will enable policymakers to make decisions for the fulfilment of NZEBs in the UK which can houses (i.e. flat, terraced house, semi-detached house, andinformed detached house), across different locations in the the UK. Models specific targets. houses (i.e. flat, terraced house, semi-detached house, and detached house), across different locations in UK. Models specific b designs. The results will enable policymakers to make decisions for the fulfilment of NZEBs in the UK which can This paper evaluated the economic implications of developing net-zero energy buildings (NZEBs) for four types of residential former. A cost-benefit analysis was conducted for each of the potential NZEB designs. Without energy storage, income from to different locations and loads were created with varying combinations of renewable energy technologies. Houses were further houses (i.e. flat, terraced house, semi-detached house, and detached house), across different locations in the UK. Models specific Veolia Recherche & Innovation, 291 Avenue Dreyfous Daniel, 78520 Limay, France renewable technology in existing households can produce a mean net profit between 5-51% of the overall expenditure for NZEB classified as existing ones and new ones, and the latter had an 55% improvement in energy (heat) efficiency compared to the former. A cost-benefit analysis was conducted for each of the potential NZEB designs. Without energy storage, income from designs. The results will enable policymakers to make informed decisions for the fulfilment of NZEBs in the UK which can potentially play an important role in mitigating greenhouse gas (GHG) emissions and help the UK achieve its climate change to different locations and loadsrole were created with varying combinations of renewable energy technologies. Houses were further c to different locations and loads were created varying combinations of renewable energy technologies. Houses were further potentially play an important inimplications mitigating greenhouse gas (GHG) emissions and help achieve its climate change houses (i.e. flat, terraced house, semi-detached house, andinformed house), across different locations in the UK. Models renewable technology inanalysis existing households can produce mean net profit between 5-51% ofthe the overall expenditure forspecific NZEB This paper evaluated the economic of developing energy (NZEBs) for four types of residential classified as existing ones androle new ones, andwith latter had an-net-zero 55% improvement in (heat) efficiency compared tofrom the Département Systèmes Énergétiques etthe Environnement IMT Atlantique, rue Alfred Kastler, 44300 Nantes, France to different locations and loads were created with varying combinations of renewable energy technologies. Houses were further designs. results will enable policymakers tofor make decisions for4 buildings the fulfilment ofUK NZEBs in the UK which can former. AThe cost-benefit was conducted each of the potential NZEB designs. Without energy storage, income renewable technology in existing households can produce aadetached mean net profit between 5-51% of the overall expenditure for NZEB potentially play anElsevier important inrights mitigating greenhouse gas (GHG) emissions and help the UK achieve its climate change targets. classified as existing ones and new ones, and the latter had an 55% improvement in energy (heat) efficiency compared to the Copyright © 2018 Ltd. All reserved. classified as existing ones and new ones, and the latter had an 55% improvement in (heat) efficiency compared to the targets. to different locations and loads were created varying combinations of renewable energy technologies. Houses were further designs. results will enable policymakers to make decisions for the fulfilment of NZEBs in the UK which can houses (i.e. flat, terraced house, semi-detached house, andinformed detached house), across different locations in theexpenditure UK. Models specific former. AThe cost-benefit analysis was conducted for each of the NZEB designs. Without energy storage, income classified as existing ones androle new ones, andwith the latter had an potential 55% improvement in energy (heat) efficiency compared tofrom the potentially play an important in mitigating greenhouse gas (GHG) emissions and help the UK achieve its climate change renewable technology in existing households can produce a mean net profit between 5-51% of the overall for NZEB designs. The results will enable policymakers to make informed decisions for the fulfilment of NZEBs in the UK which can targets. th former. A cost-benefit analysis was conducted for each of the potential NZEB designs. Without energy storage, income from International Conference on Applied Selection and peer-review under responsibility of the scientific committee of the 10 former. A cost-benefit analysis was conducted for each of the potential NZEB designs. Without energy storage, income from classified as existing ones and new ones, and the latter had an 55% improvement in (heat) efficiency compared to the potentially play an important role in mitigating greenhouse gas (GHG) emissions and help the UK achieve its climate change to different locations and loads were created with varying combinations of renewable energy technologies. Houses were further renewable technology in existing households can produce a mean net profit between 5-51% of the overall expenditure for NZEB former. AThe cost-benefit analysis was conducted for each informed of the potential NZEB designs. Without energy storage, income from targets. designs. results will enable policymakers to make decisions for the fulfilment of NZEBs in the UK which can potentially play an important role in mitigating greenhouse gas (GHG) emissions and help the UK achieve its climate change Copyright © 2018 Elsevier Ltd. All rights reserved. renewable technology inanalysis existing households can produce a mean mean net profit profit between 5-51% of (heat) the overall overall expenditure for NZEB NZEB Energy (ICAE2018). renewable technology in existing households can produce a net between 5-51% of the expenditure for Copyright © 2018 Elsevier Ltd. All rights reserved. former. A cost-benefit was conducted for each of the potential NZEB designs. Without energy storage, income from targets. classified as existing ones and new ones, and the latter had an 55% improvement in energy efficiency compared to the designs. The results will enable policymakers to make informed decisions for the fulfilment of NZEBs in the UK which can th renewable technology in existing households can produce a mean net profit between 5-51% of the overall expenditure for NZEB potentially anElsevier important role inrights mitigating greenhouse gas (GHG) emissions theofUK achieve its climate change targets. Copyright ©play 2018 Ltd. All reserved. Conference onwhich Applied Selection and peer-review under responsibility ofmake the informed scientific committee of the theand 10help designs. The results will enable policymakers tofor decisions for fulfilment NZEBs in the UK can th International designs. The results will enable policymakers to make decisions for fulfilment of NZEBs in the UK can Abstract International Conference onwhich Applied Selection and peer-review under responsibility of the informed scientific committee of the theand 10help renewable technology in existing households can produce a mean net profit between 5-51% of the overall expenditure for NZEB former. A cost-benefit analysis was conducted each of the potential NZEB designs. energy storage, income from potentially play an important role in mitigating greenhouse gas (GHG) emissions the UK achieve its climate change th Without designs. The results will enable policymakers to make informed decisions for the fulfilment of NZEBs in the UK which can Copyright © 2018 Elsevier Ltd. All rights reserved. targets. International Conference on Applied Selection and peer-review under responsibility ofConsumption; the scientific committee of Efficiency; theand 10help Energy (ICAE2018). potentially play an important role in mitigating gas (GHG) emissions achieve its climate change Keywords: Net Zero Energy Buildings; Electric and Gas Renewable Energy; Cost-benefit Analysis; potentially play an important role in mitigating greenhouse gas emissions the UK achieve its change Energy (ICAE2018). th International designs. The results will enable policymakers togreenhouse make decisions for fulfilment ofUK NZEBs in the UKonwhich can Copyright © 2018 Ltd. All reserved. renewable technology in existing households can produce a mean net profit between 5-51% ofthe the overall expenditure forApplied NZEB targets. potentially play anElsevier important role inrights mitigating greenhouse gas (GHG) (GHG) emissions and help the UK achieve its climate climate change Conference Selection and peer-review under responsibility of the informed scientific committee of the theand 10help Copyright © 2018 Elsevier Ltd. All rights reserved. Energy (ICAE2018). targets. th targets. © 2019 The Authors. Published by Elsevier Ltd. District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the potentially play an important role in mitigating greenhouse gas (GHG) emissions and help the UK achieve its climate change International Conference on Applied Selection and peer-review under responsibility of the scientific committee of the 10 designs. The results will enable policymakers to make informed decisions for the fulfilment of NZEBs in the UK which can th targets. Energy (ICAE2018). Copyright © 2018 Elsevier Ltd. Allresponsibility rights reserved. Conference on Applied Selection and peer-review under the scientific committee of Efficiency; the 10 International Keywords: Net Zero Energy Buildings; Electric and Gasof Consumption; Renewable Energy; Cost-benefit Analysis; This is an open access article under the CCreserved. BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Keywords: Net Zero Energy Buildings; Electric and Gasgreenhouse Consumption; Renewable Energy; Efficiency; Cost-benefit Analysis; greenhouse gas emissions from the building sector. These systems require high investments which are returned through the heat targets. Energy (ICAE2018). th International potentially play an important role in mitigating gas (GHG) emissions and help the UK achieve its climate change Copyright © 2018 Elsevier Ltd. All rights Conference on Applied Selection and peer-review under responsibility the scientific committee of Efficiency; the 10 Cost-benefit Analysis; Energy (ICAE2018). Keywords: Net Zero Energy Buildings; and Gasof Consumption; Renewable Copyright ©under 2018 Elsevier Ltd. All rights reserved. Peer-review responsibility of Electric the scientific committee of ICAE2018 –Energy; The Conference on Applied Energy. 1. Introduction Copyright © Elsevier Ltd. All rights reserved. sales. Due to theEnergy changed climate conditions and renovation policies, heat demand in the future could decrease, targets. International Conference on Applied Selection and peer-review under thebuilding scientific committee of10th theInternational 10th Keywords: Net Zero Buildings; Electric and Gasof Consumption; Renewable Energy; Efficiency; Cost-benefit Analysis; Copyright © 2018 2018 Elsevier Ltd. Allresponsibility rights reserved. Energy (ICAE2018). th International th Conference on Applied Selection and peer-review under responsibility of the scientific committee of the 10 Conference on Applied Selection and peer-review under responsibility of the scientific committee of the 10 prolonging the investment return period. th International Keywords: Net Zero Energy Buildings; Electric and Gas Consumption; Renewable Energy; Efficiency; Cost-benefit Analysis; Copyright © 2018 Elsevier Ltd. All rights reserved. Energy (ICAE2018). Conference on Applied Selection andZero peer-review under responsibility the scientific committee of Efficiency; the 10 International Keywords: Net Energy Buildings; Electric and Gasof Consumption; Renewable Energy; Cost-benefit Analysis; 1. Introduction Energy (ICAE2018). Energy (ICAE2018). The main this paper isAll toresponsibility assess the of using the heat demand – outdoor temperature function for on heatclimate demand Getting to2018 netofEnergy zero in domestic dwellings is the considered tocommittee be one ofofthe means to reduce Analysis; the impacts of 1. Introduction Conference Applied Selection and peer-review under scientific the 10th International Copyright ©scope Elsevier Ltd. rights reserved. Energy (ICAE2018). Keywords: Net Zero Buildings; Electric and feasibility Gasof Consumption; Renewable Energy; Efficiency; Cost-benefit 1. Introduction th study. forecast. TheZero district ofBuildings; Alvalade, located Lisbon (Portugal), wascompanies used of asEfficiency; a to case The district is consisted of 665 Energy (ICAE2018). change. There is Energy an increasing for governments and lead the market in modelling Keywords: Net Electric and in Gas Renewable Energy; Cost-benefit Analysis; International Conference on housing Applied Selection and peer-review under motivation responsibility ofConsumption; the scientific committee the 10 1. Introduction Keywords: Net Zero Energy Buildings; Electric and Gas Consumption; Renewable Energy; Efficiency; Cost-benefit Analysis; Getting tocan net zero in domestic dwellings is considered to be weather one of the to discriminate reduce thehigh) impacts ofdifferent climate Keywords: Net Zero Energy Buildings; Electric and Gas Consumption; Energy; Efficiency; Cost-benefit Analysis; buildings that vary in both construction period and typology. Three scenarios medium, and three district Energy (ICAE2018). 1. Introduction designs that become standardized in the 30 years.Renewable These models willmeans need(low, to between Getting to net zero in domestic dwellings is considered to be one of the means to reduce the impacts of climate Keywords: Net Zero Energy Buildings; Electric and Gasnext Consumption; Renewable Energy; Efficiency; Cost-benefit Analysis; 1. Introduction Getting to net zero in domestic dwellings isgovernments considered to beTo one of the means toobtained reduce the impacts of climate change. There is an increasing motivation for and companies to lead the market in modelling housing renovation scenarios were developed (shallow, intermediate, deep). estimate the error, heat demand values were Keywords: Net Zero Energy Buildings; Electric and Gas Consumption; Renewable Energy; Efficiency; Cost-benefit Analysis; regions andto dwelling types tomotivation allow house to fitto variable requirements opportunities. By change. There is an an increasing forisdesigns governments and companies to lead the marketand in impacts modelling housing 1. Introduction Getting net zero in domestic dwellings considered becompanies one ofspecific the means to discriminate reduce the ofdifferent climate change. There is increasing motivation for governments and to lead the market in modelling housing designs that can become standardized in the next 30 years. These models will need to between compared with results from a dynamic heat demand model, previously developed and validated by the authors. Keywords: Net Zero Energy Buildings; Electric and Gas Consumption; Renewable Energy; Efficiency; Cost-benefit Analysis; 1. Introduction Getting to net zero in domestic dwellings is considered to be one of the means to reduce the impacts of climate integrating a combination of renewable technologiescertified by the Microgeneration Certification Scheme (MCS), designs that can become standardized in the next 30 years. These models will need to discriminate between different change. There isbecome an increasing for governments and to lead the market in impacts modelling housing Getting to net zero in domestic dwellings isdesigns considered to becompanies one ofspecific means tobe reduce the climate 1. Introduction designs that can standardized inhouse the next years. models will need to discriminate between different The results showed that when only weather change is30 considered, the margin ofthe error could acceptable for some of applications 1. Introduction regions and dwelling types tomotivation allow to fitThese variable requirements and opportunities. By 1. change. There is an increasing for governments and to lead the market in modelling housing andIntroduction home efficiency improvements, such as insulating windows, roofs, floors and walls, a net-zero energy building regions and dwelling types tomotivation allow house designs to fitThese variable specific requirements and opportunities. By Getting tocan net zero in domestic dwellings isdesigns considered to becompanies one of the means to discriminate reduce the impacts ofdifferent climate designs that become standardized in the next 30 years. models will need to between change. There is an increasing motivation for governments and companies to lead the market in modelling housing regions and dwelling types to allow house to fit variable specific requirements and opportunities. By (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation integrating a combination of renewable technologiescertified by the Microgeneration Certification Scheme (MCS), 1. Introduction Getting to net zero in domestic dwellings is considered to be one of the means to reduce the impacts of climate designs that can become standardized in the next 30 years. These models will need to discriminate between different (NZEB) design can be achieved. Existing studies have introduced a consistent definition framework for NZEBs[1]. integrating a combination of renewable technologiescertified by the Microgeneration Certification Scheme (MCS), change. There is an increasing motivation for governments and companies to lead the market in modelling housing regions and dwelling types allow designs to requirements and opportunities. By designs that become standardized the next 30 years. These models will need to discriminate between different Getting to net zero in domestic dwellings is considered to be one of the means to reduce the impacts of climate scenarios, the error value increased up toinhouse 59.5% (depending onfit thevariable weather and renovation combination considered). integrating acan combination of to renewable technologiescertified by the Microgeneration Certification Scheme (MCS), 1. Introduction and home efficiency improvements, such as insulating windows, roofs, floors and walls, a net-zero energy building Getting to net zero in domestic dwellings is considered to be one ofspecific the means toscenarios reduce the impacts of climate change. There isbecome an increasing motivation for governments and companies to lead the market in impacts modelling housing Getting to net zero in domestic dwellings is considered to be one of the means to reduce the of climate regions and dwelling types to allow designs to fit variable specific requirements and opportunities. By Some ofthat the major challenges that NZEBs face are related to: and home efficiency improvements, such as insulating windows, roofs, floors and walls, a net-zero net-zero energy building designs can standardized inhouse the next 30 years. These models will need to discriminate between different integrating a combination of renewable technologiescertified by the Microgeneration Certification Scheme (MCS), regions and dwelling types to allow house designs to fit variable specific requirements and opportunities. By The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the change. There is an increasing motivation for governments and companies to lead the market in modelling housing and home efficiency improvements, such as insulating windows, roofs, floors and walls, a energy building (NZEB) design can be achieved. Existing studies have introduced a consistent definition framework for NZEBs[1]. change. 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By decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and and home efficiency improvements, such as insulating windows, roofs, floors and walls, a net-zero energy building integrating a combination of renewable technologiescertified by the Microgeneration Certification Scheme (MCS), that can become standardized in the next 30 years. These models will need to discriminate between different (NZEB) design can be achieved. Existing studies have introduced a consistent definition framework for NZEBs[1]. Getting to net zero in domestic dwellings is considered to be one of the means to reduce the impacts of climate Some the major challenges that NZEBs face are30 to: designs that can become standardized inhouse the next 30related years. These models will need to discriminate between different change. 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Existing studies introduced aincreased consistent definition for NZEBs[1]. and home efficiency improvements, such as insulating windows, roofs, floors and walls, net-zero energy building regions and dwelling types to allow house designs to fit variable specific requirements and opportunities. By Some of the major challenges that NZEBs face are related to: change. There is an increasing motivation for governments and companies to lead the market in modelling housing integrating Technical Meeting the annual energy consumption with a diverse renewable energy system to ensure security regions and dwelling types to allow house designs to fit variable specific requirements and opportunities. By designs that can become standardized in the next 30 years. 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Existing studies have introduced a consistent definition framework for NZEBs[1]. combination of renewable technologiescertified by the Microgeneration Certification Scheme (MCS), integrating Technical - can Meeting the annual energy consumption with a diverse renewable energy system to ensure security designs that become standardized inhouse the next years. These models will need to discriminate between different of on cloudy, cold or allow non-windy days. integrating combination ofdemand renewable technologiescertified by the Microgeneration Certification Scheme (MCS), regions and dwelling to designs to fit variable specific requirements and opportunities. 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of supply on cloudy, cold or allow non-windy days. regions and types to house designs to fit specific requirements and opportunities. By and home efficiency improvements, such as insulating windows, roofs, floors and walls, net-zero energy building a dwelling combination of optimum renewable technologiescertified by the Microgeneration Certification Scheme (MCS), integrating Financial –- can Finding the renewable energies andvariable efficiency improvements that minimise costs (NZEB) design be achieved. 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Existing studies have introduced a consistent definition for NZEBs[1]. Some Policy – Ensuring that NZEB designs are in line with government and Ofgem regulations is essential to receive Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Technical Meeting the annual energy consumption with a diverse renewable energy system to ensure security Some of the major challenges that NZEBs face are related to: Financial – Finding the optimum renewable energies and efficiency improvements that minimise capital costs of supply on cloudy, cold or non-windy days. Some Policy – Ensuring that NZEB designs are in line with government and Ofgem regulations is essential to receive Financial – Finding the optimum renewable energies and efficiency improvements that minimise capital costs and maximise income. 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Financial – Finding the optimum renewable energies and efficiency improvements that minimise capital costs and maximise income. maximise income.  Aand Policy – Ensuring that NZEB designs are in line with government and Ofgem regulations is essential to receive For example, targeting at a multi-storey residential property in Denmark, Marszal & Heiselberg [2] found variety of economic analysis has been conducted to evaluate the economic feasibility of NZEBs in different generation export tariffs. countries. For example, targeting atdesigns a multi-storey residential property in Denmark, Marszal Heiselberg [2]receive found Policy – Ensuring that NZEB are in line with government and Ofgem regulations is essential to  Aand Financial –and Finding the optimum renewable energies and efficiency improvements that&of minimise capital costs maximise income. Policy – Ensuring that NZEB designs are in line with government and Ofgem regulations is essential to receive variety of economic analysis has been conducted to evaluate the economic feasibility NZEBs in different generation and export tariffs. countries. – of Ensuring that NZEBatdesigns areconducted in line with and Ofgem feasibility regulations essentialinto receive For example, targeting a multi-storey residential property Denmark, Marszal &ofisHeiselberg [2] found APolicy variety economic analysis has been to government evaluate thein economic NZEBs different generation and export tariffs. and maximise income. countries. Policy – Ensuring that NZEBatdesigns areconducted in line with and Ofgem regulations isNZEBs essentialinto receive generation and export tariffs. For targeting aa multi-storey residential property Denmark, Marszal [2] found *A Corresponding author. Tel.:+44-0141-330-1780. variety economic analysis been to government evaluate thein different generation and export tariffs. countries. Forofexample, example, targeting at has multi-storey residential property ineconomic Denmark,feasibility Marszal & &ofHeiselberg Heiselberg [2] found 1876-6102 ©–2017 Theexport Authors. Publisheddesigns by Elsevier Ltd. countries. Policy Ensuring that NZEB are in line with government and Ofgem regulations is essential to receive A variety of economic analysis has been conducted to evaluate the economic feasibility of NZEBs in different E-mail address: [email protected] generation and tariffs. For example, targeting at a multi-storey residential property in Denmark, Marszal & Heiselberg [2] found A variety ofauthor. economic analysis has been been conducted to evaluate evaluate theSymposium economic feasibility of and NZEBs in different different Peer-review under responsibility of the Scientific Committee of The 15th International on feasibility District Heating Cooling. variety of economic analysis conducted to the NZEBs in *A Corresponding Tel.:+44-0141-330-1780. generation and export tariffs. countries. targeting at has a by multi-storey property Denmark, Marszal &of found 1876-6102 ©For 2019 The Authors. Published Elsevier Ltd.residential A variety ofexample, economic analysis has been conducted to evaluate theineconomic economic feasibility ofHeiselberg NZEBs in[2] different * Corresponding author. Tel.:+44-0141-330-1780. countries. Forof example, targeting atCC multi-storey residential property ineconomic Denmark,feasibility Marszal & &ofHeiselberg Heiselberg [2] found E-mail [email protected] *A Corresponding author. Tel.:+44-0141-330-1780. This isvariety an address: open access article under theat BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) countries. For example, targeting aaa multi-storey residential property Denmark, Marszal found economic analysis has been conducted to evaluate thein NZEBs in[2] different countries. For example, targeting at multi-storey residential property in Denmark, Marszal & Heiselberg [2] found E-mail address: [email protected] *A Corresponding author. Tel.:+44-0141-330-1780. E-mail address: [email protected] Peer-review under responsibility of theatscientific of ICAE2018 – The 10th International Conference on Applied Energy. variety ofexample, economic analysis has beencommittee conducted to evaluate thein economic feasibility ofHeiselberg NZEBs in[2] different countries. For targeting a multi-storey residential property Denmark, Marszal & found * Corresponding author. Tel.:+44-0141-330-1780. address:author. [email protected] 10.1016/j.egypro.2019.01.914 * E-mail Corresponding Tel.:+44-0141-330-1780. countries. For example, targeting at a multi-storey residential property in Denmark, Marszal & Heiselberg [2] found E-mail address: [email protected] address:author. [email protected] * E-mail Corresponding Tel.:+44-0141-330-1780. * E-mail Corresponding Tel.:+44-0141-330-1780. address:author. [email protected] Corresponding author. Tel.:+44-0141-330-1780. *** E-mail Corresponding Tel.:+44-0141-330-1780. address:author. [email protected] Corresponding author. 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that the energy use should be reduced to a minimum to build a cost-effective NZEB, and the district heating grid is more expensive than heat pump use for NZEB. Wang et al. [3] assessed the possibility of NZEB in the UK by specifically looking at the optimal design strategies and feasibility under Cardiff weather conditions. However, this study did not account for the economic feasibility of NZEBs, and the study was only based on Cardiff weather conditions. Realistic energy consumption and production performance of NZEB for other locations throughout the UK are still unknown. This paper will discuss whether NZEBs are currently a practical housing design option across thirteen cities in the UK. A detailed cost-benefit analysis with respect to different loads per region and dwelling type will be carried out for both existing and new houses. Recommendations will be made to identify what is required to make NZEBs a reality. 2. NZEB design methodology 2.1. Site selection, dwelling types, and renewable energy assignment Thirteen sites (Glasgow City, East Dunbartonshire, Shetland Islands, Neath Port Talbot, Monmouthshire, Gwynedd, Islington, Hounslow, Sunderland, Reigate and Banstead, East Northamptonshire, and Cotswold) for NZEB designs were identified depending on locations, population densities and electric and gas consumptions to represent a diverse and substantial energy report [4]. . Four major dwelling types (flat, terraced house , semidetached house, and detached house) were considered [5].. The electricity and heat consumption data of existing dwellings was estimated based on the report from the Department for Business, Energy & Industrial Strategy as shown in Fig. 1 [6]. To ensure the security of energy supply, the energy consumption data was further increased by a weighting factor (WF) of 1.25 (for Monmouthshire, a WF of 1.6 was used due to its low wind speeds). For a new house that uses new materials with lower U-values, the gas consumption required to heat a house can be reduced by 55% (calculation shown in section 2.5) as shown in Fig. 3. The strategy for renewable energy (wind turbines, solar PV, solar thermal, air source heat pump (ASHP), ground source heat pump (GSHP), and bioenergy) assignment is as follows: (1) wind turbines and solar PV panels serve as the source of electricity, while solar thermal panels, ASHP and GSHP supply heat; (2) ASHP and GSHP energy productions were firstly considered to compensate for the gas consumption; (3) three different biomass usage (1, 1.5 and 2kgs per day) were evaluated with the number of solar thermal panels used to compensate for the remaining gas consumption; (4) the maximum energy from a wind turbine was identified and the remaining would be balanced by solar PV panels; (5) the surplus electricity sold to the grid. It was determined that 1kg of biomass per day optimized the energy production for new houses minimizes the capital and material costs. Whereas, existing houses required 1.5kgs of biomass material per day. The renewable energy assignments for existing and new houses are shown in Fig. 2 and Fig. 4, respectively. In Fig. 4, it is evident that by using optimal floor, roof, wall and window insulation this can lead to a large drop in gas consumption, which results in less thermal energy being required for the house. Therefore, as the GSHP has the highest capital costs, it can be removed from the CBA to improve financial results. Fig. 2 and 4 present the varying energy productions for each household and region type. Most systems include roughly the same renewable system, although the Shetland Islands is only powered by electricity. Therefore, there is no requirement for ASHP, GSHP and a biomass boiler in this region. A solar thermal system was provided to produce 1000kWh/year to add some heating diversity. 2.2. Data for analysis Up-to-date data was collected from national government statistics as listed in Table 1. For parameters of different household types (i.e. flats, terraced house, etc), the national average values were used. Regional wind speeds were identified from the national wind speed database [7]. The Met Office provided the yearly sunshine hours and average air temperature (°C) [8]. The average ground temperature was estimated based on the average air temperature. The assumption is that there is a 0.9°C temperature increase at the depth for ground sourced heat pumps [9]. Finally, the yearly global irradiation was estimated using the European Commission Joint Research Centre’s solar statistics [10]. The average wind speed is 4.5m/s, the sunshine duration is 1493 hours per year, the



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yearly global irradiation is 1200kWh/m2, the average air temperature is 10.6°C and the average ground temperature is 12.4°C.

Fig. 1. Electricity and gas consumptions (existing houses).

Fig. 3. Electricity and gas consumptions (New houses).

Data Location Glasgow City East Dunbartonshire Shetland Islands Neath Port Talbot Monmouthshire Gwynedd Islington Hounslow Sunderland Reigate and Banstead East Northamptonshire Cotswold

Wind speed (m/s) 5.6 5.2 7.2 5 2.6 4.1 4.9 4.8 5.2 4.9 5 5.7

Fig. 2. Renewable energy productions (existing houses).

Fig. 4. Renewable energy productions (New houses).

Table 1. Data of wind speeds and sunshine hours per year. Sunshine hours per Yearly global Average air year irradiation (kWh/m2) temperature (°C) 1203.1 1100 8.85 1248.1 1100 8.95 1197.7 916 8 1381.2 1160 11 1571.2 1220 10.5 1442.9 1090 10.65 1540.4 1300 10.65 1653.3 1310 11.05 1515 1180 9.4 1591.6 1290 11.25 1498.9 1270 9.8 1493.2 1220 9.85

Average ground temperature (°C) 9.75 9.85 8.9 11.9 11.4 11.55 11.55 11.95 10.3 12.15 10.7 10.75

2.3. Renewable energy output, costs and tariffs Each renewable energy technology considered has MCS accreditation which makes it eligible for government tariffs. Any surplus electricity will be sold back to the grid at a tariff of 5.24 p/kWh. Generation tariffs are calculated by OFGEM every 3 months depending on market values of the renewable energy. 2.3.1. Wind turbines The XZERES Skystream 3.7 was selected for micro-wind generation [11]. The 2.1 kW rated wind turbine cost is

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approximately £4500 [12] and there is presently a generation tariff of 8.24 p/kWh [13]. The monthly energy output ( P ) depends on the wind speed ( Vw ) as shown in Fig. 5.

Fig. 5. Monthly energy production of wind turbine [11].

2.3.2. Solar PV The SRP-6MB solar panel was selected for the analysis [14]. For a solar PV between 10 kW to 50 kW, it would have a generation tariff of 4.03 p/kWh [13]. The cost of the system was scaled up based on the size in kW [15]. The energy output was calculated based on the solar panel area, rated power, sunshine hours and the system efficiency. P  Rp  Ts s  Ap (1) R A where p is the rated power, Ts is the sunshine hours per year,  s is the efficiency of solar PV, and p is the area of solar PV panel. 2.3.3. Solar thermal The cost of the system was scaled up based on the size in m2 and the generation tariff is 20.66 p/kWh [13]. The energy output was calculated based on the collector area ( Ac ) and efficiency ( c ), yearly irradiation ( I y ) and system efficiency (  s ). Ac P (2) I ycs 2.3.4. ASHP The cost of a heat pump was quoted at £6000 [16] and there is a generation tariff of 10.49 p/kWh [13]. 2.3.5. GSHP The cost of a heat pump is approximately £14000 [16] and the generation tariff is currently at 20.46 p/kWh [13]. 2.3.6. Biomass The estimated cost of a biomass boiler is £4218 and the pellets are approximately £255 per tonne [16]. The generation tariff is 6.74 p/kWh [13]. 2.4. Energy bill savings The annual energy bill savings were also included in the analysis. The average electricity price, 14.4 p/kWh, and gas price, 0.0364 p/kWh, were multiplied by the estimated consumptions [17] as shown in Fig. 1 and 3.



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2.5. Efficiency improvements This study considers a scenario of new houses with reduced dwelling U-values (W/m2/K) by using improved methods of insulation in walls, floors, roofs and windows. By using MacKay’s heating efficiency analysis, it was estimated that gas consumption can be reduced by approximately 55% [18] as shown in Fig. 3. 2.6. Cost-benefit analysis The purpose of the cost-benefit analysis (CBA) is to provide decision makers with a framework for assessing the economic desirability investing in renewable technology and efficiency improvements. Included in the cost benefit analysis is net present value (NPV), benefit-cost ratio (BCR), internal rate of return (IRR) and cash flow balance (CFB) [19]. NPV is the difference between the present value of cash inflows and the present value of cash outflows over a period of time.

 NPV

LT

Cit

 (1  r ) t

t

 C0

(3)

where Cit is the net cash inflow during a year t; Co is the total initial investment (e.g., capital costs); LT denotes the life time of the renewable technologies, which ranges from 15 years for an ASHP to 25 years for a wind turbine; r = 0.07 is the discount rate. BCR shows the relationship between the costs and benefits of the NZEB, in economic terms.  LT Cet   BCR NPV   C0  (4) t    t (1  r )  where Cet is the expenditure cost (e.g., maintenance costs) during a year t. IRR is a discount rate that produces a zero NPV. CFB shows the net cash income and costs without including any discount rates, to indicate whether it is theoretically possible to achieve a profit.



3. Results and discussion

Fig. 6. CBA of existing houses across different regions.

Fig. 7. CBA of new houses across different regions.

The results of CBA on the existing and new house designs across different regions are shown in Fig. 6 and 7. A total of 28 out of 32 NPV calculations produced a net profit, for a discount rate of 0.07 [20]. The CFB results show that all the cases are theoretically profitable. The IRRs vary between 5-18%, although it is the existing houses that generally have higher IRRs. The BCR results show that the income from the use of renewable energy technology for NZEB designs in existing households can produce a mean net profit between 5-51% of the overall expenditure. Whereas, new houses have a BCR that ranges from -12-53%. The results indicate that investing in a new energy efficient household is financially worse off in the long run. This is due to the fact that the capital costs generally remain the same for most regions whereas the generation income is far lower. The Shetland Islands show the most promising CBA because the island houses are powered by electricity only. To match the electricity demand, the solar panel area was increased, which increases the generation tariff income. Additionally, the capital costs of solar thermal GSHP and ASHP were excluded.

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4. Conclusion This paper studied the economic feasibility of the household and regional variations of NZEBs throughout the UK. The technical challenge of supplying sufficient renewable energies to homes to provide all year-round energy can be fulfilled. The NZEB design could potentially be economically viable for most of the cases if the opportunities benefit from bill saving was considered while the expense in energy storage was disregarded. The cost of energy storage is still a critical player for the practical implementation of distributed renewable energy systems. Future work should include the costs and implications of energy storage, and account for the uncertainty and variability in the cost and benefit data. It is also critical to understand how renewable energy generation at different times through the day matches the variation in the energy demand. Acknowledgements This research is partially supported by the University of Glasgow's John Robertson Bequest Award, Number 114035-06.

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