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Through energy efficiency measures, it is possible to reduce heat surplus in the pulp and paper industry. Yet pulp and paper mills situated in countries with a heat demand for residential and commercial buildings for the major part of the year are potential heat suppliers. However, striving to utilize the heat within the mills for efficient energy use could conflict with the delivery of excess heat to a district heating system. As part of a project to optimize a regional energy system, a sulfate pulp mill situated in central Sweden is analyzed, focusing on providing heat and electricity to the mill and its surrounding energy systems. An energy system optimization method based on mixed integer linear programming is used for studying energy system measures on an aggregated level. An extended system, where the mill is integrated in a regional heat market (HM), is evaluated in parallel with the present system. The use of either hot sewage or a heat pump for heat deliveries is analyzed along with process integration measures. The benefits of adding a condensing unit to the back-pressure steam turbine are also investigated. The results show that the use of hot sewage or a heat pump for heat deliveries is beneficial only in combination with extended heat deliveries to an HM. Process integration measures are beneficial and even increase the benefit of selling more heat for district heating. Adding a condensing turbine unit is most beneficial in combination with extended heat deliveries and process integration. [ABSTRACT FROM AUTHOR]

This paper presents a study on alternative pathways to a fossil-fuel free regional energy system in the Mälardalen region of Sweden with a population of 3 million inhabitants. We describe and address how the region can be made independent of fossil fuels by integration of resource management, technology advances, and behaviour change in energy use. First we investigate the consumption pattern of the inhabitants. Then we study what resources are available, and how these can be used to fulfil the different demands. If we just use the resources in a pattern of business as usual today without changing the behaviour, the balance between demands and resources is difficult to reach. By combining a slightly different behaviour and a change of crops we can fulfil the needs and it might even be possible to have a surplus of resources. Some advanced technological solutions have also been proposed. For example, dedicated biomass energy plants such as Salix, straw, hemp and some cereals can be used for ethanol production and the residues can be gasified to produce dimethylether (DME), which is good as a replacement for diesel fuel. Still the fuel demand for transport is high, and the vehicle weight could be further reduced. For example, by going back to the car size we had only 10 years ago the weight would be 25–30% less, and fuel consumption would be at least 15% lower. With diesel engines instead of Otto engines the fuel consumption could be reduced by 35%, and with hybrid technology additional 20% fuel reduction could be gained. Improved public transportation will also give a positive effect especially for those commuting between the larger cities and between the cities and the suburbs. The results of our calculations show that it would be possible to accomplish a fossil-free energy system in the Mälardalen region. The results of this study are important since it shows that an energy balance without fossil fuels could be possible for an area with a population in the order of 3 million people, which would also be valuable in studies of other areas in the world. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The electricity market in Sweden has changed during recent years. Electricity for industrial use can now be purchased from a number of competing electricity suppliers. Hence, the price for each kilowatt-hour is significantly lower than it was just two years ago and interest in electricity conservation measures has declined. However, part of the electricity tariff, i.e. the demand cost expressed in Swedish Kronor (SEK) for each kilowatt, is almost the same as before. Attention has thereby been drawn to load management measures in order to reduce this specific cost. Saving one kWh might lead to a monetary saving of between SEK 0.22 and SEK 914; this paper demonstrates how to eliminate only those kWh that actually save a significant amount of money. A load management system has been installed in a small carpentry factory that can turn off equipment based on a pre-set priority and number of minutes each hour. The question now is what level of the electricity load is optimal in a strictly mathematical sense, i.e. how many kW should be set in the load management computer in order to maximise profitability? In this paper, we develop a mathematical model that can be used as a tool both to find the most profitable subscription level and to control the choices to be made. Numerical results from a case study are presented. Copyright © 2004 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Summary: The COVID‐19 pandemic has made a significant disruption in the renewable industry, and the effects will last longer. In this context, understanding how and which specific renewable power got affected due to this crisis is of crucial importance. This study examines the nexus between COVID‐19 and Sweden's renewable electricity production from three sources of energy such as nuclear, solar, and wind, where the data ranges from January 1, 2019, to February 17, 2021. Since this study compares the period before and during the pandemic event, the study uses Air Quality Index as a measure of COVID‐19 induced event and thus study the linkage between air quality and electricity production from three types of renewable energy. To analyse the above issue, several advanced techniques such as Wavelet Power Spectrum, Wavelet Coherence, Partial and Multiple Wavelet Coherence have been applied. The findings from the Wavelet Coherence approach demonstrate that COVID‐19 has disrupted the linkage between wind energy generation and air quality, while the disruption in the case of solar and nuclear electricity generation has been minimal. Moreover, solar energy generation and air pollution both negatively affect each other, implying the need to generate solar power as well as reduce the level of air pollution in Sweden. In light of the above findings, the study discusses possible policy actions the country can take to fulfil its renewable development goals. [ABSTRACT FROM AUTHOR]

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]

Solar radiation is an abundant free resource which may be used in the form of solar heated water. This is achieved in solar collectors which, unfortunately, are expensive devices and, further, the warm water must be stored in accumulators—items which also cost money. This paper shows how we have optimized the situation for a block-of-flats in Sweden. In order to find this point we have used the minimum life-cycle cost (LCC) concept as a criterion. The best solution is therefore found when that cost finds its lowest value. It is also examined under which conditions solar collectors are part of the optimal solution and further it is calculated what happens if this optimal point is abandoned, i.e. how much will the LCC increase if other than optimal solutions are chosen. LCC optimization for multi-family buildings almost always results in a heating system with low operating costs such as district heating or dual-fuel systems where a heat pump takes care of the base load and an oil boiler the peak. The installation cost must, however, be kept to a reasonable level. Expensive solar panel systems are therefore normally avoided if the lowest LCC shall be reached, at least for Swedish conditions. This is so even if the solar system has a very low operating cost. For buildings where the only alternative energy source is electricity, solar collectors seem to be on the rim of profitability, i.e. for an energy price of about 0.6 SEK kWh−1. Copyright © 2001 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Summary Among household electricity end users, there is growing interest in local renewable electricity generation and energy independence. Community‐based and neighborhood energy projects, where consumers and prosumers of electricity trade their energy locally in a peer‐to‐peer system, have started to emerge in different parts of the world. This study investigates and compares the costs incurred by individual households and households organized in electricity trading communities in seeking to attain greater independence from the centralized electricity system. This independence is investigated with respect to: (i) the potential to reduce the electricity transfer capacity to and from the centralized system and (ii) the potential to increase self‐sufficiency. An optimization model is designed to analyze the investment and operation of residential photovoltaic battery systems. The model is then applied to different cases in a region of southern Sweden for year 2030. Utilizing measured electricity demand data for Swedish households, we show that with a reduced electricity transfer capacity to the centralized system, already a community of five residential prosumers can supply the household demand at lower cost than can prosumers acting individually. Grouping of residential prosumers in an electricity trading community confers greater benefits under conditions with a reduced electricity transfer capacity than when the goal is to become electricity self‐sufficient. It is important to consider the local utilization of photovoltaic‐generated electricity and its effect on the net trading pattern (to and from the centralized system) when discussing the impact on the electricity system of a high percentage of prosumers. [ABSTRACT FROM AUTHOR]

SUMMARY Road transport is responsible for a large and growing share of CO2 emissions in most countries. A number of new fuel-efficient vehicle technologies and renewable transport fuels are possible alternatives to conventional options but their deployment relies strongly on different policy measures. Even though a future higher use of transport biofuels and electric vehicles is likely to increase the interaction between the transportation sector and the stationary energy system (heat, power, etc.), these systems are often analysed separately. In this study, a transport module is developed and integrated into the MARKAL_Nordic energy system model. The transport module describes a range of vehicle technologies and fuel options as well as different paths for conversion of primary energy resources into transport fuels. The integrated model is utilized to analyse the impact of transport fuel tax designs on future cost-effective fuel and technology choices in the Swedish transportation sector, as well as the consequences of these choices on system costs and CO2 emissions. The model, which is driven by cost-minimization, is run to 2050 with various assumptions regarding transport fuel tax levels and tax schemes. The results stress the importance of fuel taxes to accelerate the introduction of fuel-efficient vehicle technologies such as hybrids and plug-in hybrids. Tax exemptions can make biofuels an economically favourable choice for vehicle users. However, due to limitations in biomass supply, a too strong policy-focus on transport biofuels can lead to high system costs in relation to the CO2 abatement achieved. The modelling performed indicates that the effects caused by linkages between the transportation sector and the stationary energy system can be significant and integrated approaches are thus highly relevant. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Control of CO2 emissions is a major environmental issue in most countries. The Swedish car market shows remarkably low new Diesel passenger car registrations compared to the average European Union car market. Therefore, a simple way to decrease CO2 emissions from the transport sector in Sweden would be the replacement of gasoline by Diesel passenger cars, which emit less CO2. The combined effects of probable changes in Diesel and gasoline future fuel consumption, new passenger car sales and market segmentation have been evaluated for different Diesel passenger cars penetrations. The results show a benefit in CO2 emissions of about 2.8% with 30% Diesel penetration; if Diesel penetration reaches 50%, the benefit attains 7.5%. Future rises of CO2 emissions caused by higher new passenger car registrations or unfavourable market segmentation could be at least partially counterbalanced by the introduction of more Diesel passenger cars. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]