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The purpose of this paper is to analyse altering energy demand patterns and energy factor substitution possibilities over time in the pulp and paper industry in order to increase our understanding of suitable policy options for increasing energy efficiency. The investigation employs a flexible translog cost function and an unbalanced panel data set covering 32 pulp and paper mills over the time period 1974-2005 in Sweden. Specifically, we test whether energy factor demand patterns in the industry for the period 1974-1990 differ from those during the latter period, 1991-2005. The empirical results reveal that even though the Swedish pulp and paper industry is relatively insensitive to changes in energy factor input prices in the short run, we find evidence of significant changes over time. According to the results, the own-price sensitivity of fuel has increased since the 1970s and the 1980s, thus indicating that fuel demand has become more sensitive to short-run changes in relative prices. The estimated cross-price elasticities between electricity and fuel also support the hypothesis of increased substitutability over time. However, the null hypothesis of an equal own-price elasticity of electricity demand across the two time periods cannot be rejected. [ABSTRACT FROM AUTHOR]

Based on a study of policy-induced changes in the Swedish pulp and paper industry, this paper follows a process of socio-technical regime destabilisation. Results from the study show that in industries where established firms have significant power, processes of endogenous renewal are more likely to destabilise established regimes than processes based on niche solutions. Further, the study shows how policy measures aimed to destabilise the current regime may result in different responses, owing to the different capabilities of individual firms. The analysis suggests that heterogeneous capabilities within established industries provide possibilities for policy makers to initiate change. [ABSTRACT FROM AUTHOR]

The pulp and paper industry faces several challenges linked to climate and environmental impact, resource efficiency, rising energy prices, increased competition for biomass resources, and declining demand for traditional printed paper products. However, these challenges also offer strategic opportunities for the industry to develop into a competitive, resource-efficient, and low-carbon industry in line with a biobased economy. Against this background, this paper aims to analyse current energy strategies in the pulp and paper industry in Sweden. Specifically, the paper analyses how companies combine continuous process efficiency to reduce energy costs with activities that could be developed into new energy-related products to increase revenue. Most of the analysed companies work to various degrees with both these strategies, employing methods that include improving energy efficiency, energy security, and energy conversion, as well as developing a wide range of biobased energy products. However, our study indicates that there is an untapped potential associated with energy product development, and we conclude that energy efficiency measures can free up resources, enabling the development of new energy products. Finally, several potential managerial outcomes and implications are outlined. • The paper analyses the energy strategies in the pulp and paper industry in Sweden. • Energy strategies focus both to improve energy efficiency and develop new energy-products. • The companies' energy strategies combined exploitation and exploration. • A number of managerial implications are presented. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to estimate industry-specific direct rebound effects and to relate these effects to industry energy efficiency programs. The rebound effect represents economic behavior that will offset energy savings from energy efficiency improvements. The paper focuses on four energy intense sectors in Sweden; pulp and paper, iron and steel, chemical, and mining, during 2001-2012. We apply a factor demand model that allows for asymmetric energy price responses, i.e. that firms respond differently to increasing and decreasing energy prices. The results show considerable rebound effects. For electricity and non-fossil fuels, efficiency improvements could even 'backfire'. To mitigate this effect, policies, such as voluntary energy efficiency programs, should be combined with an increase in energy taxes if the ambition is to reduce overall energy use. [ABSTRACT FROM AUTHOR]

Extended-Range Electric Vehicles (EREVs) are intended to improve the range of battery electric vehicles and thus eliminate drivers' concerns about running out of energy before reaching the desired destination. This paper gives an insight into EREV's performance operating according to the proposed control strategy over various driving cycles, including the Worldwide Harmonized Light-duty Test Cycle Class 3b (WLTC 3b), Federal Test Procedure (FTP-75), and China Light-Duty Vehicle Test Cycle (CLTC-P). Simulation runs were performed in Matlab-Simulink® for different cases of drive range, electricity mix, and vehicle mass. The control strategy goal was to aim at a specified value of battery state of charge at the targeted range value. The obtained test results included: pure electric drive range, acceleration times, EREV range tests, control strategy range errors, Range Extender (REX) utilization metric and distribution of its engagement instances, fuel consumption, total equivalent CO2 emission, powertrain efficiency, and specific energy consumption. The control strategy operated on average with a range error of −1.04% and a range mean square error of 2.13%. Fuel consumption (in range extension mode) varied between 1.37 dm3/100 km (FTP-75) and 6.85 dm3/100 km (WLTC 3b Extra-High 3). CO2eq emission was 95.3–244.2 g/km for Poland, 31.0–160.5 g/km for EU-27, and 1.2–147.6 g/km for Sweden. This paper is a valuable source of information for scientists and engineers seeking to learn the advantages and shortcomings of EREV drives with a proposed control strategy, based on various sets of results. [ABSTRACT FROM AUTHOR]

The implementation of electricity-charged thermochemical energy storage (TCES) using high-temperature solid cycles would benefit the energy system by enabling the absorption of variable renewable energy (VRE) and its conversion into dispatchable heat and power. Using a Swedish case study, this paper presents a process for TCES-integrated district heating (DH) production, assesses its technical suitability, and discusses some practical implications and additional implementation options. The mass and energy flows of a biomass plant retrofitted with an iron-based redox loop are calculated for nine specific scenarios that exemplify its operation under electricity generation mixes that differ with respect to variability and price. In addition, the use of two types of electrolyzers (low-temperature and high-temperature versions) is investigated. The results show that for the Swedish case, the proposed scheme is technically feasible and capable of covering the national DH demand by making use of the existing DH plants, with an estimated process energy efficiency (electricity to heat) of 90%. The results also show that for a retrofit of the entire Swedish DH fleet, the required inventories of iron are approximately 2.8 Mt for the intermediate scenario, which represents 0.3% and 11.0% of the national reserves and annual metallurgical production rates of the national industry, respectively. In addition to the dispatchable heat, the process generates a significant amount of nondispatchable heat, especially for the case that employs low-temperature electrolyzers. This added generation capacity allows the process to cover the heat demand while decreasing the maximum capacity of the charging side computed herein. [ABSTRACT FROM AUTHOR]

The energy transition towards sustainable resources is more urgent than ever given the environmental and geopolitical challenges. Being one of the major energy users, cities need to understand their energy sector to accomplish its transition, by means of data. However, data are not easily accessible and have their own challenges. This paper presents a joint effort between researchers, city representatives and industry to provide an urban system service that supports research, accelerates urban innovation, and involves the community. An energy data portal, "NRGYHUB", has been developed, where hourly data from thousands of energy meters are available. These meters were collected from neighborhoods in the city of Västerås, Sweden, and they measure electrical and heating energy. In addition, the data are complemented by geometrical and non-geometrical information of the buildings, as well as demographic statistics of the areas. The paper describes the process of data collection, preprocessing, and visualization, in addition to the main challenges and limitations of the project. This dataset can be used for energy use benchmarking, prediction, and analysis. • The creation and implementation of an energy data portal is detailed and made available on nrgyhub.mdu.se. • Legal and licensing issues in data sharing are explored, offering insights for those interested in Sweden and beyond • By showcasing real-world problems, the impact and role of this data sharing initiative are demonstrated. [ABSTRACT FROM AUTHOR]

The energy demand in Sweden is increasing due to the growing electrification, and to meet this need, the generation must be expanded. Wind power generation is a very attractive renewable power production alternative for Sweden because of the favorable weather conditions. Research looks at how much wind energy may be deemed sustainable. Increased energy demand puts pressure on the government and industry to build more wind farms and, as a result, produce more wind turbines. Raw materials are necessary for wind turbines to provide a secure transition to green energy technologies. To meet these demands, the materials from various countries should efficiently contribute towards the Sustainable Development Goals (SDGs). This paper gathers information about raw resources from diverse nations worldwide. All materials are mapped to the country where they are produced using social science criteria. A few nations are chosen based on a sample approach for further analysis, and the implications of mining operations are investigated. Finally, the direct and indirect effects of the SDGs are considered. Based on the data gathered, recommendations and considerations are given to avoid or mitigate the repercussions of raw materials mining and make wind power generation more socially and environmentally sustainable. • Evaluation of side effects of wind turbine raw materials. • The extraction of raw materials often violates human rights. • Mining of raw materials for wind turbines negatively affects the environment. • Extraction of wind turbine materials affects several Sustainable Development Goals. [ABSTRACT FROM AUTHOR]

This paper investigates the dynamic between protection of the historic environment and the application of solar energy technology on 1- or 2-family houses in Sweden. More specifically, the building code relating to the installation of photovoltaic (PV) panels on house roofs and how existing policies are implemented in Stockholm City is investigated in order to better understand the challenges in reconciling renewables and the conservation of built heritage. Especially when applied in urban areas PV panels may have a large impact on socio-cultural values, making them difficult to insta where the historic environment is to be protected from large changes. By using a mix of methods (policy analysis, case studies, and interviews) we come to the conclusion that municipalities should develop routines and guidelines that offer homeowners precise information on the potential of solar energy and requirements motivated by concern for the historic environment. Guidelines that are well-known, clear and also require homeowners to dismount exhausted panels could work both to protect built heritage and to promote more use of solar energy in some small house areas. [ABSTRACT FROM AUTHOR]

If resource intensive practices are regularly represented as conventional, these potentially become naturalised and inconspicuous consumption will increase. Understanding how representations, conventions and everyday practices interact is thus fundamental in tackling unsustainable consumption. To gain new insights into how representations, conventions and practices interact, this paper explores how people respond to cleanliness representations in Swedish media. Cleanliness is chosen as a case for its role in accelerating water and energy consumption (Shove, 2003), and Sweden where cleanliness activities are in line with upward trends (Jack, 2017). Focus-group participants read magazines, discuss content and how it relates to their lives. Cleanliness is perceived as being intertwined with a host of co-conventions such as freshness, health, femininity, masculinity, sustainability, et cetera. Participants have strategies to receive and resist representations, and are especially averse to representations that they suspect are meant to increase consumerism. Dilemmas for participants do not arise from deciding when or how to receive or resist representations. The real dilemmas arise when integrating meanings into everyday life practices given the multiplicity of meanings. Participants see conventions as influencing wider society, but see themselves as individuals critically interacting with representations, a sovereign dupe 1 juxtaposition. [ABSTRACT FROM AUTHOR]

This paper presents an economic assessment of two different policies – both implying an increased demand for forest ecosystem services – and how these could affect the competition for forest raw materials. A forest sector trade model is updated to a new base year (2016), and then employed to analyze the consequences of a more intense use of bioenergy and increased forest conservation in Sweden. These scenarios are assessed individually and in combination. A particularly interesting market impact is that bioenergy promotion and forest conservation tend to have opposite effects on forest industry by-product prices. Moreover, combining the two policies mitigates the forest industry by-product price increase compared to the case where only the bioenergy-promoting policy is implemented. Namely, the energy using sector (heat and power) is less negatively affected in terms of increased feedstock prices if bioenergy demand targets are accompanied by increased forest conservation. This effect is due to increasing pulpwood prices, which reduces pulp, paper and board production, and in turn mitigates the competition for the associated by-products. Overall, the paper illustrates the complexity of the forest raw material market, and the importance of considering demand and supply responses within and between sectors in energy and forest policy decision-making. [ABSTRACT FROM AUTHOR]

• Affordable and adaptable VIP based internal and external retrofitting solutions. • Implementation of VIP based integral retrofitting solutions in two tertiary buildings. • Space heating energy saving analysis before and after VIP based retrofit. • Envelope heat loss coefficient reduction analysis before and after retrofitting. Vacuum insulation panels (VIPs) represent a huge opportunity to achieve nearly zero energy buildings, especially in the retrofitting of existing buildings. VIPs can be applied in conjunction with façade cladding elements, considerably reducing the heat losses or gains from the building by means of very slim wall construction systems or retrofit solutions. However, the fact that VIPs cannot be cut on-site, can be easily damaged during their handling, installation and use and have an envelope that can cause thermal bridging in the junction between panels or when combined with other materials, has hindered their penetration in the construction market. This paper presents two innovative façade retrofitting solutions, a rear ventilated façade and a stud mounted internal solution, that have tackled all these issues and provide thermal transmittances of 0.28 and 0.14 W/m2 K in relatively slim insulation systems of 10 cm widths. Solutions have been installed on the entire façade of two existing buildings located in Bilbao (Spain) and Malmö (Sweden) subjected to an integral rehabilitation process, covering 2100 m2. Buildings energy use have been monitored before and after the renovation, showing energy cuts of around 35% from pre-intervention status. This paper presents the lessons learnt during the design and installation process of the vacuum insulation integrating solutions in the façade of two existing buildings and the thermal performance results achieved after their retrofitting. [ABSTRACT FROM AUTHOR]

Improving energy efficiency in industry is recognized as one of the most vital activities for the mitigation of climate change. Consequently, policy initiatives from governments addressing both energy-intensive and small and medium-sized industry have been enacted. In this paper, the energy end-use and the energy efficiency potential among industrial small and medium-sized companies participating in the Swedish Energy Audit Program are reviewed. The three manufacturing industries of wood and cork, food products and metal products (excluding machinery and equipment) are studied. A unique categorization of their production processes’ energy end-use is presented, the results of which show that the amount of energy used in various categories of production processes differ between these industries. This applies to support processes as well, highlighting the problem of generalizing results without available bottom-up energy end-use data. In addition, a calculation of conservation supply curves for measures related to production processes is presented, showing that there still remains energy saving potential among companies participating in the Swedish Energy Audit Program. However, relevant data in the database used from the Swedish Energy Audit Program is lacking which limits the conclusions that can be drawn from the conservation supply curves. This study highlights the need to develop energy policy programs delivering high-quality data. This paper contributes to a further understanding of the intricate matters of industrial energy end-use and energy efficiency measures. [ABSTRACT FROM AUTHOR]

• A probabilistic model for energy estimation with Bayesian machine learning is pro- posed. • A two stage time-dependent EVRP with chance-constrained partial recharging is pre- sented. • Realistic simulations and experiments with data from electric vehicles are performed. • Results indicate high accuracy, reliability and potential for energy savings. Routing electric commercial vehicles requires taking into account their limited driving range, which is affected by several uncertain factors such as traffic conditions. This paper presents the time-dependent Electric Vehicle Routing Problem with Chance-Constraints (EVRP-CC) and partial recharging. The routing method is divided into two stages, where the first finds the best paths and the second optimizes the routes. A probabilistic Bayesian machine learning approach is proposed for predicting the expected energy consumption and variance for the road links, paths and routes. Hence it is possible to consider the uncertainty in energy demand by planning charging within a confidence interval. The energy estimation is validated with data from electric buses driving a public transport route in Gothenburg-Sweden as well as with realistic simulations for 24 hours traffic in the city of Luxembourg connected to a high fidelity vehicle model. Routing solutions are compared with a deterministic formulation of the problem similar to the ones found in the literature. The results indicate high accuracy for the energy prediction as well as energy savings and more reliability for the routes. [ABSTRACT FROM AUTHOR]

Sweden is considered an environmental sustainability pioneer, targeting a 50% reduction in energy use in buildings by 2050. This ambitious goal requires the active engagement of municipal actors and the building sector. Dialogue processes have been identified as a way to mobilize such engagement, but in earlier research, there has been a lack of studies where dialogue practices are analyzed in real-time and on location and where the role of leadership has been scrutinized. Taking two cases in Malmö as a starting point, the aim of this paper is to analyze the interconnections between dialogue models and the local context and to examine how the role of process leadership affects exchanges between included actors. The results show that it is difficult to create guidelines useful in the local context and that learning was embedded in the doing and was transferred through the process leaders. [ABSTRACT FROM AUTHOR]

• This study evaluates cost-optimal energy renovation strategies for various historic building types in a Northern European climate using LCC optimization software OPERA-MILP. • Twelve building types, which are typical of the historic building stock in Visby, Sweden, are selected as the study object. • Decreases of 12–38% in LCC can be obtained by selecting various cost-effective energy efficiency measures and a cost-optimal heating system. • The environmental performance of the energy renovations is closely connected to the assumptions made about the energy system boundary. The life cycle cost (LCC) optimization is a vital method when performing building energy renovation. The present paper provides an evaluation of cost-optimal energy renovation strategies for historic buildings using LCC optimization software OPERA-MILP. The evaluation is performed based on preset targets depending on LCC (LCC optimum) and energy use (decrease by 50%), where the environmental performance is also addressed. Twelve building types, which are typical of the historic building stock in Visby, Sweden, are used as the study object. The results show possible decreases of 12–38% in LCC when targeting LCC optimum. When targeting a 50% decrease in energy use, the LCC is decreased in 21 of 26 cases compared to before energy renovation. Cost-efficient EEMs on the building envelope are characterized by low renovation costs and additional insulation of building components with poor thermal properties. Furthermore, the environmental performance from the energy renovations is highly dependent on the chosen energy system boundary. [ABSTRACT FROM AUTHOR]

• Effects of cold and hot ambient conditions on the same CPV/T are studied. • A multiphysics (thermal-fluid coupling) 3D FE model of CPV/T is developed. • Effects of fluid flow rate on CPV/T performance are described. • Different cross-section coolant fluid channels are studied. • Annual CPV/T performance for Lisbon (Portugal) and Gävle (Sweden) is a case study. In the presented paper, we developed a partnership with the Swedish company Solarus AB to study the performance of a CPV/T under very distinct climate zones: Sweden and Portugal. We focus on thermal effects and their influence on the CPV/T's energy efficiency. Therefore, we develop an electromagnetic-thermal finite element model (FEM) of the CPV/T in 2D and 3D, capable of computing the heat transfer occurring due to the flow of cooling fluid. Furthermore, we use the developed model to evaluate temperature conditions over the different layers of the photovoltaic panel and fluid temperature along the CPV/T. The evaluation shows that it is the CPV/T cooling structure that has a major influence on CPV/T's performance when it functions in climate zones with very different temperature scales along the year. The shape of cooling channels, for example, must continue to ensure a better heat transfer, leading thus to a more uniform distribution of the temperature along with the receiver. Also, fluid flow rates must be carefully selected to avoid solar cells reach their maximum operating temperatures (85 °C). [ABSTRACT FROM AUTHOR]

This paper presents assessment of natural and anthropogenic sources of blue energy within Swedish territory to identify suitable spots for implementing new projects. The natural energy potential of salinity gradients was found to be higher in southwest Sweden, and a national energy resource potential of 2610.6 MW from seawater/river water mixing will be reduced to a technical potential ranging from 1044.3 MW to 1825.4 MW considering technical and environmental constraints. It has been found that the theoretical extractable energy potential in Sweden is equivalent to 13% of the total electricity consumption and 6.2% of the total final energy consumption by energy commodities. Anthropogenic water sources were also highlighted as promising low and high-concentration solutions for SGE extraction. Gotland was identified as an attractive location for generating salinity gradient power. The total salinity gradient power obtainable by mixing municipal wastewater with seawater in Sweden was estimated to be 11.8 MW. The most promising site for this process was determined to be Gryaab AB Ryaverket in Gothenburg, which accounted for 45.8% of the total national potential from anthropogenic sources. [Display omitted] • The blue energy in Sweden was mapped. • The theoretically obtainable blue energy at river mouths in Sweden was calculated. • Hot spots for blue energy harvesting were detected. • The implementation of blue energy extraction at hot spots was evaluated. [ABSTRACT FROM AUTHOR]

Improved energy efficiency is one of the most effective strategies for achieving energy sustainability and independence locally, regionally and globally. Industry accounts for 40% of global energy usage each year, which suggests its potentially significant impact on overall energy use. The rapid development of standards for more efficient equipment and components are pushing manufacturers towards further improvements on a component level. However, it has been shown that the largest efficiency potential is actually found in higher system levels in which components serve, such as production processes, ventilation or hydraulic systems. Even though the importance of increasing energy efficiency at a systemic level has been widely acknowledged in recent years, practical approaches are seldom discussed in the literature. This gap between aspiration and achievement calls for the development of new approaches to foster system efficiency in industrial systems. This paper presents a systems analysis and corresponding model to increase the energy efficiency of industrial processes that involve intensive usage of electric motor systems. The model originates from traditional value stream mapping. Three case studies representing three different industrial processes were conducted to develop and validate the model. In total, 31 energy efficiency measures were identified, 29 of which address actions beyond component levels. Alongside identifications of energy efficiency measures, the model promotes the creation of conditions for cross-functional worker participation. By applying this model, the knowledge and skills gained by industrial personnel working with improved energy efficiency, maintenance and production processes can be used immediately to generate improvement suggestions. The paper concludes that this model, based on a simplified energy-focused value stream mapping, could broaden the scope of energy efficiency actions, engage a larger group of workers within the organisation and increase systems efficiency. This can be further used as a practical tool for finding continuous improvement possibilities that will result in strengthened competitiveness and more cost-effective and sustainable manufacturing. [ABSTRACT FROM AUTHOR]

The industrial sector accounts for 35%–40% of total energy use in Sweden, where 30% of industrial energy use comes from non-energy-intensive small and medium-sized enterprises (SMEs). This sector has not historically received much attention when it comes to improving energy efficiency due to limited resources, lower priority given to energy issues, rather small energy-saving potential for a single company, and great heterogeneity of the SMEs. However, the accumulative energy-saving potential for SMEs can be quite high and achieved at very low costs, partly because most improvements are found in support processes and are relatively easy to implement. Various public policies, such as industrial energy audit programmes, serve as a means for overcoming barriers to energy efficiency in the sector of SMEs. One example is the Swedish Energy Audit Programme (SEAP), a stand-alone audit programme functioning between 2010 and 2014. The aim of this paper is to examine the programme by means of process and impact evaluation. The results show that the programme resulted in annual net energy efficiency savings equivalent to 340 GWh/year or 6% of the 713 participating companies' energy end use. The implementation rate in the audit programme was 53%. On average, the public cost of one implemented measure was € 700. Derived from the amount of energy saved, the audit programme's annual cost-effectiveness is €7/MWh saved energy. This paper adds a significant scientific contribution due to the method used for evaluation. Multiple company visits and availability of quantitative data from 713 companies gave the possibility to address the additionality effects and estimate net energy savings more precisely. [ABSTRACT FROM AUTHOR]

An increased interest for separate collection of household food waste in Sweden has led to development of a number of different collection-systems – each with their particular benefits and drawbacks. In the present study, two systems for collection of food waste in households were compared; (a) use of food waste disposers (FWD) in kitchen sinks and (b) collection of food waste in paper bags for further treatment. The comparison was made in relation to greenhouse gas emissions as well as primary energy utilization. In both cases, collected food waste was treated through anaerobic digestion and digestate was used as fertilizer on farmland. Systems emissions of greenhouse gases from collection and treatment of 1 ton of food waste (dry matter), are according to the performed assessment lower from the FWD-system compared to the reference system (−990 and −770 kg CO 2 -eq./ton food waste dry matter respectively). The main reasons are a higher substitution of mineral nitrogen fertilizer followed by a higher substitution of diesel. Performed uncertainty analyses state that results are robust, but that decreasing losses of organic matter in pre-treatment of food waste collected in paper bags, as well as increased losses of organic matter and nutrients from the FWD-system could change the hierarchy in relation to greenhouse gas emissions. Owing to a higher use of electricity in the FWD-system, the paper bag collection system was preferable in relation to primary energy utilization. Due to the many questions still remaining regarding the impacts of an increased amount of nutrients and organic matter to the sewage system through an increased use of FWD, the later treatment of effluent from the FWD-system, as well as treatment of wastewater from kitchen sinks in the reference system, was not included in the assessment. In future work, these aspects would be of relevance to monitor. [ABSTRACT FROM AUTHOR]

Highlights • An energy model is shown including topography, speed, acceleration and powertrain efficiency. • A method to calculate energy cost coefficients for the road network is proposed. • The cost coefficients are incorporated into the vehicle routing problem. • A two-stage approach is presented, integrating path finding with route planning. • Results show that energy and time estimation are more precise than existing methods. Abstract When planning routes for fleets of electric commercial vehicles, it is necessary to precisely predict the energy required to drive and plan for charging whenever needed, in order to manage their driving range limitations. Although there are several energy estimation models available in the literature, so far integration with Vehicle Routing Problems has been limited and without demonstrated accuracy. This paper introduces the Two-stage Electric Vehicle Routing Problem (2sEVRP) that incorporates improved energy consumption estimation by considering detailed topography and speed profiles. First, a method to calculate energy cost coefficients for the road network is outlined. Since the driving cycle is unknown, the model generates an approximation based on a linear function of mass, as the latter is only determined while routing. These coefficients embed information about topography, speed, powertrain efficiency and the effect of acceleration and braking at traffic lights and intersections. Secondly, an integrated two-stage approach is described, which finds the best paths between pairs of destinations and then finds the best routes including battery and time-window constraints. Energy consumption is used as objective function including payload and auxiliary systems. The road cost coefficients are aggregated to generate the path cost coefficients that are used in the routing problem. In this way it is possible to get a proper approximation of the complete driving cycle for the routes and accurate energy consumption estimation. Lastly, numerical experiments are shown based on the road network from Gothenburg-Sweden. Energy estimation is compared with real consumption data from an all-electric bus from a public transport route and with high-fidelity vehicle simulations. Routing experiments focus on trucks for urban distribution of goods. The results indicate that time and energy estimations are significantly more precise than existing methods. Consequently the planned routes are expected to be feasible in terms of energy demand and that charging stops are properly included when necessary. [ABSTRACT FROM AUTHOR]

Highlights • Four different energy performance indicators of public bus transport are discussed. • Regional differences in fuel use are strongly correlated with the propulsion systems. • A life cycle view is necessary to estimate the environmental impact of fuel use. • Fuel efficient buses may still have a high WTW energy use and environmental impact. • Biogas is more efficient than other alternative fuels in reducing GHG emissions. Abstract The share of renewable fuels in Swedish public transport is steadily increasing, in line with European energy and climate goals as well as a national goal of a fossil-free vehicle fleet by 2030. However, the progression towards this goal is quite different among the Swedish regions, and efforts have been made on a national level to compare the public bus transport systems and provide a foundation for policymaking. This paper investigates different ways of assessing and presenting the energy performance of public bus transport systems. The analysis includes use of renewable and fossil fuels as well as energy efficiency and its underlying factors. Various energy performance indicators are presented and discussed with regards to practical implications and applicability for policy support. A life cycle perspective on fuels ("well-to-wheel") is found to have clear advantages when it comes to global reductions of fossil energy use and emissions. This requires detailed information about the fuel use, which is not always the case with the existing reporting system. Setting the energy use in relation to number of passengers transported rather than just the distance covered would better reflect the function of the transport system, but is also more uncertain with the current data available. [ABSTRACT FROM AUTHOR]

This paper investigates problem areas related to energy efficiency implementation in Swedish multifamily buildings. The paper first presents a generic list of (theoretical) problem areas identified through a literature survey. Using a qualitative approach, the paper also investigates if the problem areas identified in the literature also have an impact on the Swedish building sector. Results from the interview study reveal a strong coherence between problem areas in the literature and those expressed by the interviewees. However, this paper identifies seven novel challenges that cannot be derived from the list of barriers in the literature. Moreover, results reveal that as many as 12 problem areas have their origin in national factors such as agreement structures, incentive schemes, and cost calculation methods. [ABSTRACT FROM AUTHOR]

Energy efficiency is one of the major means of reducing CO 2 emissions resulting from industrial use of energy. Both from a societal as well as business perspective it is of great importance to reduce industrial energy end use (EEU). The implementation of energy-efficient technologies as well as increased focus on energy management practices has been stated by previous research to be the two most important methods of improved industrial energy efficiency. To date, however, there are few (if any) studies that have analyzed the proportion of industrial energy savings that derive from implementation of new technology versus from continuous energy management practices. By analyzing substantial data from the Swedish PFE program this paper aims to quantify what previously has been referred to as the extended energy efficiency gap. Results show that about 61% of the analyzed 1254 energy efficiency measures are derived from the implementation of new technology, and the rest stems from management and operational measures. The results presented in this paper are of outmost importance for industrial energy managers and energy auditors as well as industrial associations and policy-makers in order to cost-effectively address these no-regret measures. [ABSTRACT FROM AUTHOR]

Combined heat and power (CHP) plants are a great improvement over waste-to-energy incineration plants supplying only heat, and power plants supplying only electricity. The primary purpose of a functioning CHP plant however, may be to provide district heating services, and thereby its main output will be heat energy. This paper is a case study commissioned by Karlskoga Energi och Miljö AB (KEMAB in short; Karlskoga Energy and Environment) in the Värmland State of south-central Sweden, and focuses on the functioning of the CHP plant owned and operated by the company. The life-cycles of the fuels used by the CHP – household/industrial waste, bio-oil, light fuel oil, wood waste, wood chips, a slaughterhouse-waste-derived product and peat to generate 202,222 MWh of heat, 119,234 MWh of steam and 28,220 MWh of electricity have been studied, and the carbon footprint calculated for year-2016. Using two sets of emissions factors for the combustion stage of the life-cycle, as part of a data uncertainty analysis, the total emissions were 44,000 tonnes carbon dioxide equivalents (CO 2 -eq) and 58,000 tonnes CO 2 -eq respectively. A quasi-realistic scenario analysis in which plastics are not available for incineration and have to be substituted with alternatives has also been carried out, and while wood waste has been suggested as the best alternative with regard to greenhouse gas (GHG) emissions, availability permitting, a combination of alternatives has been mooted as the practical option. [ABSTRACT FROM AUTHOR]

Public acceptability appears an essential condition for the success of low-carbon transition policies. In this paper, we investigate the role of self-interest on citizens' preferences for the distribution of costs and environmental benefits of energy efficiency policies. Using a discrete choice experiment on nationally representative household samples of Sweden, Italy, and the United Kingdom, we first investigate preferences for national burden-sharing rules and for the distribution of environmental benefits accruing primarily in rural and/or urban areas. We examine the role of self-interest and self-serving bias in a correlational manner by looking at the effects of income and location of residency on preferences for these policy attributes. Moreover, we investigate the effect of self-serving bias on preferences for burden-sharing rules in a causal manner by experimentally priming randomly assigned groups of participants to feel either rich or poor. Our results suggest that the accountability rule is the most popular and the equal-amount rule the least popular burden-sharing rule. Further, policies with environmental benefits accruing primarily in rural areas are least preferred. We find some evidence for self-interest, especially through our correlational approach. Finally, across country samples, our results reveal heterogeneity in preferences for policy attributes and in the prevalence of self-interest. [ABSTRACT FROM AUTHOR]

The Swedish research project 'Potential and Policies for Energy Efficiency in Swedish Historic Buildings' aims to investigate the interdependency between political energy targets and effects on the built heritage. The first part of this paper presents an iterative and interactive method to assess the potential for and consequences of improving the energy performance in a stock of historic buildings. Key elements in the method are: categorisation of the building stock, identifying targets, assessment of measures, and life-cycle cost optimisation. In the second part of the paper, the method is applied to a typical Swedish building. The selected case study shows how the method allows for an interaction between the quantitative assessment of the techno-economic optimisation and the qualitative assessment of vulnerability and other risks. Through a multidisciplinary dialogue and iteration it is possible to arrive at a solution that best balances energy conservation and building conservation in a given decision context. [ABSTRACT FROM AUTHOR]

Abstract: The EU has established so-called 20–20–20 targets, which in relation to energy mean that each Member State shall improve energy intensity levels by 3.3% annually, leading to a reduced primary energy use of 20% by the year 2020, calculated from a projected level based on the primary energy use in 2005. Sweden has established a less ambitious target of 1.7% annual energy intensity improvement through 2020. The aim of this paper is to evaluate, ex-ante, the EU 2020 primary energy target for the Swedish industrial sector. An applied backcasting methodology is used. The assessment made in this paper is that actions that lead to between 31.6 and 33.2 TWh/year reductions in energy end-use are needed if the EU target is to be achieved. Results from this paper shows that the current energy policy instruments are not sufficient to the EU or Swedish targets. Estimations in this paper are that a primary energy target of about 22.3 TWh/year is reasonable. The paper concludes by presenting a roadmap on how the Swedish 2020 target can be achieved through: i) energy management; ii) energy-efficient technology; and iii) energy supply measures, with an approximate cost of 280–300 MEUR or 75–80 kWh per public EUR. Three major additional policy measures are needed compared with the current policy: including all energy carriers, not just electricity, in the Swedish long-term agreements program PFE; setting up networks; and making it possible for third parties, i.e., industry, to deliver excess heat into the monopolized Swedish district heating grids. [Copyright &y& Elsevier]

The increasing population living in cities is leading to higher resource utilization, which strains the cities’ ability to focus on sustainability. Adoption of different technologies can transform cities into “smart cities” that utilize energy in a more efficiently. This paper presents results from a technology assessment tool developed together with six mid-sized European cities. The main areas of focus have been evaluated based on the cities’ priorities: transportation (both public and private) and consumers’ perspectives on the use of smart electricity meters. The use of electric vehicles in Sweden, and a techno-economic evaluation of biogas-derived biomethane and electricity use in public transportation have been analyzed. The main conclusions show an overall higher efficiency for biogas-derived electricity use in electric buses; a need for higher consumer engagement through more detailed information provision for both increasing EV market penetration and electricity savings; and a need to establish detailed technology assessments for successful technology adoption in cities. [ABSTRACT FROM AUTHOR]

The EU Energy Efficiency Directive (EED) aims at improving energy efficiency by implementing actions in all sectors of the economy in the EU. Article 7 of the EED sets the target of 1.5 % cumulative annual energy end-use savings. An energy efficiency obligation scheme (EEO) is one of the policy mechanisms proposed to reach this target. This paper assesses the impact of implementing a Swedish EEO and the implications that such a scheme may have for Swedish energy-intensive industries. The assessment was based on cost-benefit analysis (CBA) methodology. The benefit-to-cost ratio (BCR) ranges from 1.56 to 2.17 and the break-even cost ranges from 83.3 to 86.9 €/MWh with sensitivity analyses performed for the emission allowance prices and eventual costs of the EEO. The annual energy savings potential is estimated to be 1.25 TWh/year. A Swedish EEO could motivate investments in energy efficiency measures and thus help Sweden reach the energy efficiency targets set in the EED. [ABSTRACT FROM AUTHOR]

Improved energy efficiency has become a strategic issue and represents a priority for European competitiveness. Countries adopt various energy policies on local and national levels where energy audit programs are the most common energy end-use efficiency policy for industrial small- and medium-sized enterprises (SMEs). However, studies indicate that cost-efficient energy conservation measures are not always implemented, which can be explained by the existence of barriers to energy efficiency. This paper investigates how Swedish municipalities can support local micro- and small-sized enterprises with improved energy efficiency and the existence of different barriers to the implementation of energy efficiency. Relating this empirical case study to the theoretical barriers outlined in the text, this study found that the major explanatory factors related to non-implementation of cost-effective energy efficiency measures among micro- and small-sized industrial enterprises were bounded rationality (lack of time and/or other priorities), split incentives (having other priorities for capital investments), and imperfect information (slim organization and lack of technical skill). This study also found that information in the form of a report was the main thing that companies gained from working on the project "Energy-Driven Business". Notably, the study involved companies that had participated in a local energy program and, still, companies face major barriers inhibiting implementation, indicating a need to further study other alternative policy models and how knowledge transfer can be improved. [ABSTRACT FROM AUTHOR]

Abstract: To face global competition, and also reduce environmental and climate impact, industry-wide changes are needed, especially regarding energy use, which is closely related to global warming. Energy efficiency is therefore an essential task for the future as it has a significant impact on both business profits and the environment. For the analysis of possible changes in industrial production processes, and to choose what changes should be made, various modelling tools can be used as a decision support. This paper uses two types of energy analysis tool: Discrete Event Simulation (DES) and Energy Systems Optimisation (ESO). The aim of this study is to describe how a DES and an ESO tool can be combined. A comprehensive five-step approach is proposed for reducing system costs and making a more robust production system. A case study representing a new investment in part of a Swedish iron foundry is also included to illustrate the method''s use. The method described in this paper is based on the use of the DES program QUEST and the ESO tool reMIND. The method combination itself is generic, i.e. other similar programs can be used as well with some adjustments and adaptations. The results from the case study show that when different boundary conditions are used the result obtained from the simulation tools is not optimum, in other words, the result shows only a feasible solution and not the best way to run the factory. It is therefore important to use the optimisation tool in such cases in order to obtain the optimum operating strategy. By using the optimisation tool a substantial amount of resources can be saved. The results also show that the combination of optimisation and simulation tools is useful to provide very detailed information about how the system works and to predict system behaviour as well as to minimise the system cost. [Copyright &y& Elsevier]

Abstract: Industrial energy programs such as energy audit programs and long-term agreements (LTAs) are one of the most common means of promoting energy efficiency in industry. As a result of the European Energy End-Use Efficiency and Energy Services Directive from 2006, the Swedish Government Bill proposed a national energy program towards industrial small- and medium-sized enterprises (SMEs) using more than 500MWh energy annually. The aim of this paper is to present the structure and design of the program, adopted in 2010, the logics in brief behind the structure, as well as an ex-ante evaluation of the program’s cost-effectiveness. The paper is aimed towards the part of the program involving industry, i.e. not the part involving companies within service and sales etc. The proposed design primarily includes a subsidized energy audit with some minor LTA-elements, such as the need to report results from the energy audit, to present a plan over which measures to conduct, and after three years present which measures that were implemented. The ex-ante evaluation of the program shows a cost-effectiveness of 0.25–0.50Eurocents/kWh, yielding savings of about 700–1 400GWh annually. [Copyright &y& Elsevier]

Abstract: The paper focuses on Swedish homeowners’ need for and perceptions about adopting building envelop energy efficiency measures. The paper is based on a questionnaire survey of 3059 homeowners (response rate of 36%) selected by stratified random sampling during the summer of 2008. The results showed that 70–90% of the respondents had no intention of adopting such a measure over the next 10years. The main reasons for non-adoption were that homeowners were satisfied with the physical condition, thermal performance, and aesthetics of their existing building envelope components. A greater proportion of respondents perceived that improved attic insulation has more advantages than energy efficient windows and improved wall insulation, but windows were more likely to be installed than improved attic insulation. Respondents gave high priority to economic factors in deciding on an energy efficiency measure. Interpersonal sources, construction companies, installers, and energy advisers were important sources of information for homeowners as they planned to adopt building envelope energy efficiency measures. Policy measures to facilitate the rate of adoption of energy efficient building envelope measures are discussed. [Copyright &y& Elsevier]

Local governments increasingly initiate measures addressing global sustainability challenges, so-called local governance experiments. But the knowledge about their actual outcome is limited. Responding to this gap, this paper provides an assessment of a local governance experiment in the form of a programme for sustainable buildings in Malmö, Sweden, focusing on its energy components. The study assesses the initiative by studying all new multi-residential units constructed in Malmö and analysing their performance along with programme applicability. Findings indicate the effectiveness of the programme, and further improved performance when the programme was combined with a dialogue process together with developers in a showcase area of Malmö. The majority of developers estimated the costs for following the programme as limited. The findings contradict the view that local initiatives addressing global sustainability challenges are merely rhetorical. However, the partly insufficient implementation risks undermining the trust-building function of local governance experimets. [ABSTRACT FROM AUTHOR]

• This paper presents a unique change-point model based on selected time periods. • Time-dependent variations in climate and user behavior are central in the selection of time periods. • The model allows for differentiation between thermal power characteristics. • The selected time period for prediction of Q total corresponds to the highest R2 value, 0.70. The building and service sector accounts for nearly 40% of total energy use in Sweden. The existing, historic building stock accounts for large part of this energy use and comprises an important part of the national pursuit to increase energy efficiency. One main problem for decreasing energy use in the existing building stock is the lack of data describing thermal performance characteristics. This paper presents a novel development of the change-point model for predicting the thermal performance of buildings using selected time periods based on time-dependent variations in climate and user behavior. The predicted thermal power characteristics include total specific heat losses (Q total), energy use for hot water circulation (HWC) and hot tap water (HTW), and balance temperature. A residential district with 73 historic buildings in Linköping, Sweden, has been used as the study object. The developed model is shown to be effective and robust for describing building thermal performance. The average R2 was 0.70 for predictions of specific heat losses. The sensitivity analyses conclude that the selected time steps and months correspond to the highest R2 value. The average variation width for prediction of the balance temperature is 0.9 °C for buildings in the interquartile range based on a three-year comparison of hourly heating power supply data. Moreover, from a property owner perspective, the model is shown to be useful for identifying deviating thermal power characteristics and can easily be used to get an overview of a district. [ABSTRACT FROM AUTHOR]

Abstract: In 2011, the total consumption of pellets in Sweden amounted to 1.9 million tons, which represents an energy value of 9 TWh. The pellets are used in large-scale as well as in small-scale applications, and increased demands on pellet quality are likely to force pellet producers to improve on the pellet properties. One way of increasing pellet quality is by using additives. The purpose of this article, therefore, is to examine kraft lignin as an additive. Pellets were produced in a small industrial pellet press located at Karlstad University, Karlstad, Sweden, and 1–4% of kraft lignin was added to the pellets. The results indicate that the addition of an increased amount of kraft lignin to the pellets increases their mechanical durability and their lengths. The results also indicate that dry kraft lignin yields pellets with higher durability as compared to wet kraft lignin. The energy demand was unaffected by the increased use of kraft lignin. The general results presented in this paper are useful for producers of lignin, pellet producers and end-users of pellets, who are interested in developing their products and/or improving the production processes. [Copyright &y& Elsevier]

Abstract: The paper looks at changes in Sweden’s new car fleet between 2002 and 2010. Between 2002 and 2007 consumer amenities such as acceleration capacity and passenger space continued to increase while fuel consumption steadily decreased. During these years the main technological and market change was a shift toward diesel and flex-fuel ethanol vehicles. After 2007 the average weight and power of the vehicles were more or less constant, while fuel consumption decreased by 13% between 2007 and 2010. The developments after 2007 suggest that 77% of the technological development between 2002 and 2010 resulted in reductions in fuel consumption compares to previous years when 35% of any technology change resulted in a net reductions. The shift can partly be attributed to the increased share of diesels and an engine downsizing. [Copyright &y& Elsevier]

Abstract: Energy use in the built environment represents a large part of total energy use in Sweden and is one important sector where energy conservation needs to be significantly improved in order to meet the national implementation of the European goals. One key question that needs to be investigated in relation to these goals is the performance and implementation of passive or low-energy houses. This paper presents results and an evaluation of a newly built house in an area with passive houses in Linköping, Sweden. Nine passive houses were built with the aim to be energy efficient, with an annual space heating demand of 21kWh/m2, and at the same time to have the same visual appearance as any other building in the surrounding area. This study evaluates the energy performance of a residential area with low-energy buildings based on Building Energy Simulation (BES) (IDA ICE 4), and measurements from the real object. Both annual and hourly validation is performed using room by room modeling and internal heat gains. A novel approach to internal heat gain modeling is presented using time-use data (TUD). The results show possible improvements in the design, the building envelope and in the heating control. [Copyright &y& Elsevier]

Abstract: The processes of iron and steel making are energy intensive and consume large quantities of electricity and fossil fuels. In order to meet future climate targets and energy prices, the iron and steel industry has to improve its energy and resource efficiency. For the iron and steel industry to utilize its energy resources more efficiently and at the same time reduce its CO2 emissions a number of options are available. In this paper, opportunities for both integrated and scrap-based steel plants are presented and some of the options are electricity production, fuel conversion, methane reforming of coke oven gas and partnership in industrial symbiosis. The options are evaluated from a system perspective and more specific measures are reported for two Swedish case companies: SSAB Strip Products and Sandvik AB. The survey shows that both case companies have great potentials to reduce their CO2 emissions. [ABSTRACT FROM AUTHOR]

Abstract: Where and when farmers will adopt new energy crops is a key issue for the proper development of a country''s energy strategy on renewables based in bioenergy. This paper analyses the spread of willow cultivation for bioenergy in Sweden, during the period 1986–2005, linked to the changes in the policies of promotion of wood-energy crops and to the local economic framework. To perform the study, a geostatistic method based on kernel analysis is applied, in order to identify the spatial grouping patterns of growers and plantations, and the areas where cultivation was successful. The analysis of the resulting figures shows that the development of an infrastructure and a market for willow chips are essential pre-conditions for the development of short rotation coppice for bioenergy. The results of this study confirm that probably the most important factor in the location of willow plantations is the existence of consumers that can guarantee a long-term demand for willow chips. The tools and methods presented, and its analysis, can provide a better understanding of the interactions between the biomass producers, the energy consumers and the different local and national actors. [Copyright &y& Elsevier]

Abstract: The energy performance of buildings has become increasingly important in the general strive to reduce the overall energy use, which is manifested in the Energy Performance of Buildings Directive launched by the European Union. An important first step is of course to identify and address buildings that have an energy saving potential. In order to achieve this, robust methods for evaluation as well as reliable energy key figures are needed. For a large majority of multifamily buildings in Sweden the available data of the energy use originates from the property holder. Unfortunately, the data is often limited to the energy that the property holder is responsible for. Thus, information from the tenants about their household electricity use, indoor temperatures, number of residents, etc., is missing. In this paper an evaluation was conducted on monthly consumption data registered by the property holders for over 100 multifamily buildings/real estates in Sweden. The used approach, based on the energy signature method, was developed for evaluating the energy performance of multifamily buildings in terms of the overall heat loss coefficient, K tot. To compensate for the missing data, different assumed consumption profiles have been used. The results shows that although the obtained value of K tot for an individual building is rather sensitive to the assumed consumption profiles of household electricity, the sensitivity is reduced if the evaluation is made in relative and not absolute terms. Thus, the use of consumption profiles could be a successful way to circumvent the present lack of a detailed knowledge of a buildings total energy use. In addition, an evaluation in relative terms instead of absolute values is also more correct, since available data in almost all cases does not support the determination of the true value of K tot. The use of an average consumption profile instead of a detailed knowledge is of course not desirable, but for fairly large buildings such an approach could be successful. [Copyright &y& Elsevier]

Energy taxation in Sweden is complicated and strongly guides and governs district energy production. Consequently, there is a need for methods for accurate calculation and analysis of effects that different energy tax schemes may have on district energy utilities. Here, a practicable method to analyse influence of such governmental policy measures is demonstrated. The Swedish Government has for some years now been working on a reform of energy taxation, and during this process, several interest groups have expressed their own proposals for improving and developing the system of energy taxation. Together with the present system of taxation, four new alternatives, including the proposed directive of the European Commission, are outlined in the paper. In a case study, an analysis is made of how the different tax alternatives may influence the choice of profitable investments and use of energy carriers in a medium-sized district-heating utility. The calculations are made with a linear-programming model framework. By calculating suitable types and sizes of new investments, if any, and the operation of existing and potential plants, total energy costs are minimized. Results of the analysis include the most profitable investments, which fuel should be used, roughly when during a year plants should be in operation, and at what output. In most scenarios, the most profitable measure is to invest in a waste incineration plant. However, a crucial assumption is, with reference to the new Swedish waste disposal act, a significant income from incinerating refuse. Without this income, different tax schemes result in different technical solutions being most profitable. An investment in cogeneration seems possible in only one scenario. It is also found that particular features of some alternatives seem to oppose both main governmental policy goals, and intentions of the district heating company. Copyright © 2002 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Inclusion of energy efficiency measures (EEMs) in the renovation of the single-family housing stock can unlock the potential for much-needed energy efficiency to tackle climate change. Energy renovation (ER) in single-family houses is often promoted as an aggregate process, and EEMs are treated homogenously without sufficient attention to their differences. This study applies a comparative analysis on common EEMs using chi-square test to investigate the influence of factors already found affecting the implementation of ER. This paper addresses the "personal" and "house-related" factors influencing the adoption of EEMs regardless of motives or barriers leading the adopters' decisions. This strategy is useful to highlight the contexts leading to an increase in the adoption rate of different EEMs. The analysis is based on a questionnaire survey mailed in spring 2017 to 1550 single-family homeowners in the northern region of Sweden. Approximately 60% of respondents showed interest in adopting at least one EEM if they implement a major renovation. About 46% of respondents stated to have at least one indoor environmental problem (IEP) in their houses, and IEPs are found to have significant relations with homeowners' interest to adopt several different EEMs. The policy implications related to different EEMs are discussed. [ABSTRACT FROM AUTHOR]

Inclusion of energy efficiency measures (EEMs) in the renovation of the single-family housing stock can unlock the potential for much-needed energy efficiency to tackle climate change. Energy renovation (ER) in single-family houses is often promoted as an aggregate process, and EEMs are treated homogenously without sufficient attention to their differences. This study applies a comparative analysis on common EEMs using chi-square test to investigate the influence of factors already found affecting the implementation of ER. This paper addresses the "personal" and "house-related" factors influencing the adoption of EEMs regardless of motives or barriers leading the adopters' decisions. This strategy is useful to highlight the contexts leading to an increase in the adoption rate of different EEMs. The analysis is based on a questionnaire survey mailed in spring 2017 to 1550 single-family homeowners in the northern region of Sweden. Approximately 60% of respondents showed interest in adopting at least one EEM if they implement a major renovation. About 46% of respondents stated to have at least one indoor environmental problem (IEP) in their houses, and IEPs are found to have significant relations with homeowners' interest to adopt several different EEMs. The policy implications related to different EEMs are discussed. [ABSTRACT FROM AUTHOR]

• Investigation of two residential buildings in a sub-Arctic region. • One building subject of energy-retrofit, one maintained the original envelope. • No significant improvement to the heat supply after energy efficiency measure. • The thermal indoor climate showed signs of overheating. • The heating system should be reviewed when an energy-retrofit is done. There is a need to improve the understanding and the knowledge of energy efficiency measures for residential buildings in sub-Arctic climate regions. This paper presents an investigation of two identical multi-family residential buildings in the sub-Arctic climate of northern Sweden, before and after renovation. During the renovation, additional insulation of the external walls and new windows were installed in one building, while the other building retained its original envelope. The energy usage data for the past four heating seasons were collected, including data from before and after the renovation. Detailed thermal indoor climate data were gathered for specific months. The data from the two separate buildings showed that the renovation did not result in a significant improvement in energy usage. Prior to the renovation, the energy usage data showed a difference of 2–3% in the heat supply between the two buildings, and this difference persisted after the renovation. On the other hand, the indoor air temperature was raised. The renovated building had an indoor air temperature which was 2 °C higher than the not yet renovated building. IDA ICE models were constructed and validated with the measured data to investigate how a lower indoor air temperature would affect the energy usage and indoor thermal climate. The models showed that with a reduction in the indoor air temperature by 2 °C after the renovation, the thermal climate would maintain an acceptable level according to PMV/PPD standards, and would result in a 13–14% reduction of the heat supply during the cold months. With an annual reduction of 15%, the heat supply could be reduced by 270 MWh per year for the whole area where the buildings are located. This clearly demonstrates the importance of adjusting the heating system after an energy efficiency measure has been performed. [ABSTRACT FROM AUTHOR]

Municipal energy systems in the northern regions of Finland, Norway, and Sweden face multiple challenges: large-scale industries, cold climate, and a high share of electric heating characterize energy consumption and cause significant peak electricity demand. Local authorities are committed in contributing to national goals on CO2 emission reductions by improving energy efficiency and investing in local renewable electricity generation, while considering their own objectives for economic development, increased energy self-sufficiency, and affordable energy costs. This paper formulates a multi-objective optimization problem about these goals that is solved by interfacing the energy systems simulation tool EnergyPLAN with a multi-objective evolutionary algorithm implemented in Matlab. A sensitivity analysis on some key economic parameters is also performed. In this way, optimal alternatives are identified for the integrated electricity and heating sectors and valuable insights are offered to decision-makers in local authorities. Piteå (Norrbotten, Sweden) is used as a case study that is representative of Nordic municipalities, and results show that CO2 emissions can be reduced by 60% without a considerable increase in total costs and that peak electricity import can be reduced by a maximum of 38%. [ABSTRACT FROM AUTHOR]

Building energy simulation (BES) models rely on a variety of different input data, and the more accurate the input data are, the more accurate the model will be in predicting energy use. The objective of this paper is to show a method for obtaining higher accuracy in building energy simulations of existing buildings by combining time diaries with data from logged measurements, and also to show that more variety is needed in template values of user input data in different kinds of buildings. The case studied in this article is a retirement home in Linköping, Sweden. Results from time diaries and interviews were combined with logged measurements of electricity, temperature, and CO2 levels to create detailed occupant behavior schedules for use in BES models. Two BES models were compared, one with highly detailed schedules of occupancy, electricity use, and airing, and one using standardized input data of occupant behavior. The largest differences between the models could be seen in energy losses due to airing and in household electricity use, where the one with standardized user input data had a higher amount of electricity use and less losses due to airing of 39% and 99%, respectively. Time diaries and interviews, together with logged measurements, can be great tools to detect behavior that affects energy use in buildings. They can also be used to create detailed schedules and behavioral models, and to help develop standardized user input data for more types of buildings. This will help improve the accuracy of BES models so the energy efficiency gap can be reduced. [ABSTRACT FROM AUTHOR]