Energy recovery by waste incineration has a double function as waste treatment method and supplier of electricity and/or heat, thereby linking the systems of energy and waste management. Both systems are undergoing great changes, mainly due to new regulations. Important regulations within waste management in Sweden are a ban on landfill of combustible waste and organic waste, and a tax on landfill of waste. New waste incineration facilities are being built in order to increase capacity to meet these demands. The aim of this thesis is to investigate impacts on Swedish district heating systems of increased use of waste as a fuel in economic and environmental terms, the latter mainly by assessing emissions of carbon dioxide. Of importance is the influence of various policy instruments. To highlight the connection between the energy and waste management systems and how these influence each other is another goal, as well as the function of district heating systems as user of various waste heat supplies. An important assumption for this thesis is a deregulated European electricity market, where the marginal power production in the short term is coal condensing power and in the long term natural gas based power, that affects the conditions for combined heat and power in district heating systems. The method used is case studies of three Swedish municipalities that utilise waste in their district heating systems. In two papers, the scope is broadened from the energy utility perspective by comparing the energy efficiency of energy recovery and material recovery of various fractions, and the effect of including external costs for CO2 as well as SO2, NOx and particles. The ambition is that the results can be part of the decision making process for energy utilities and for policy makers in the energy sector and waste management. It is economically advantageous to use waste as a fuel in the energy sector and regulations in the waste management sector and high taxes on fossil fuels contribute to profitability. Waste incineration plants are base suppliers of heat because they derive revenue from receiving the waste. Economic conditions for waste incineration are altered with the introduction of a tax on incinerated municipal waste. A conflict may arise between combined heat and power production in district heating systems and waste incineration, since the latter can remove the heat sink for other combined heat and power plants with higher efficiencies. Combined heat and power is the main measure to decrease carbon dioxide emissions in district heating systems on the assumption that locally produced electricity replaces electricity in coal condensing plants. It can be difficult to design policy instruments for waste incineration due to some conflicting goals for waste management and energy systems. Comparing the energy efficiency of material recovery and energy recovery is a way to assess the resource efficiency of waste treatment methods. From that perspective, if there is a district heating system which can utilise the heat, biodegradable waste and cardboard should be energy recovered and plastics and paper material recovered. To put costs on environmental effects, so called external costs, is a way to take these effects into regard in traditional economic calculations, but the method has drawbacks, e.g. the limited range of environmental effects included and uncertainties in the monetary valuation of environmental effects.

The industrial sector uses about one third of the energy end-use in the world. Since energy use in many cases highly affects both the local and global environment negatively, it is of common interest to increase energy efficiency within industries. Furthermore, seen from the industrial perspective, it is also important to reduce dependency on energy resources with unstable prices in order to obtain economic predictability. In this thesis, the energy-saving potential within the chemical pulp and paper sector is analyzed. One market pulp mill and one integrated pulp and paper mill were studied as cases. Energy system changes at the mills were analyzed through cost minimization. The thesis focuses on principal energy issues such as finding the most promising alternatives for use of industrial excess heat, possible investments in electricity generation and choice of fuel. In order to find synergies, the same system was optimized first from the perspective of different operators respectively, and then from a joint regional perspective. Also, the prerequisites for a regional heat market in the region were analyzed. This thesis reveals that the use of excess heat from pulp and paper mills for district heating does not generally conflict with process integration measures. This is partly because of the great availability of industrial excess heat and partly because the different purposes require different temperatures and thereby do not compete. Rather, the results show that they strengthen each other since steam and hot water of higher temperatures are made available for district heating when hot water of lower temperature is used for process integration. However, there are cases when the conditions are complicated by preexisting technical solutions within a system. In these cases, a combination of measures could be necessary. Furthermore, it is concluded that energy cooperation in terms of a heat market between municipalities and industries in the studied region gives opportunity for positive synergies. Switching from expensive fuels such as oil to less expensive biofuel in the region proved to be particularly beneficial. Expanding the capacity for combined heat and power generation is also beneficial for the region as well as increased use of industrial excess heat for district heating. The most financially beneficial scenarios also have the greatest potential for CO2 emission reduction; the emissions would be reduced by about 700 thousand tonnes CO2/year for the region in those scenarios. / Den industriella energianvändningen utgör en tredjedel av världens totala energianvändning. Eftersom energianvändning i många fall har negativ miljöpåverkan både lokalt och globalt är det av allmänt intresse att öka industriernas energieffektivitet. Sett ur industriernas perspektiv är det dessutom viktigt att minska beroendet av bränslen med osäkra priser för att uppnå ekonomisk förutsägbarhet. I den här avhandlingen analyseras energibesparingspotentialen inom massa- och pappersindustrin. Ett fristående kemiskt massabruk och ett integrerat kemiskt massa- och pappersbruk har studerats. Förändringar i energisystemen på bruken analyserades genom kostnadsminimeringar. Avhandlingen fokuserar på principiella energifrågor, som att utvärdera olika sätt att använda industriellt spillvärme, investeringar i elgenerering och val av bränsle. För att hitta synergier optimerades samma system ur olika aktörers perspektiv och sedan ur ett regionalt perspektiv. Även förutsättningarna för en regional värmemarknad analyserades. Avhandlingen visar att användandet av överskottsvärme från massa- och pappersindustrin till fjärrvärme generellt sett inte står i konflikt med processintegreringsåtgärder inom bruken. Detta beror delvis på att stora mängder överskottsvärme finns tillgängliga och delvis på att det är olika temperaturnivåer som behövs till de olika syftena som därför inte konkurrerar. Resultaten visar snarare att de två åtgärderna stärker varandra eftersom processintegrering gör att större mängder varmvatten av högre temperatur blir tillgängliga för fjärrvärme. Det finns dock fall då förutsättningarna kompliceras av redan befintliga tekniska lösningar inom ett system. I dessa fall kan det vara nödvändigt med en kombination av åtgärder. Vidare dras slutsatsen att energisamarbete mellan kommuner och industrier i form av en värmemarknad ger möjlighet till positiva synergier i den studerade regionen. Särskilt lönsamt visade det sig vara att byta från dyra bränslen såsom olja till billigare bränslen som biobränslen. Att utöka kraftvärmekapaciteten inom värmemarknaden är också lönsamt liksom utökat användande av industriell spillvärme till fjärrvärme. De fall som var mest ekonomiskt lönsamma har även störst möjlighet till minskning av CO2-utsläpp; utsläppen från regionen skulle kunna minskas med cirka 700 000 ton CO2/år i dessa fall.

Global warming, in combination with increasing energy demand and higher energy prices, makes it necessary to change the energy use. To secure the energy supply and to develop sustainable societies, construction of energy-efficient systems is at the same time most vital. The aim of this thesis is therefore to identify how a local energy company, producing district heating (DH), district cooling (DC) and electricity in combined heat and power (CHP) plants, can contribute to resource-efficient energy systems and cost-effective reductions of global carbon dioxide (CO2) emissions, along with its customers. Analyses have been performed on how a local energy company can optimise their DH and DC production and what supply-side and demand-side measures can lead to energy-efficient systems in combination with economic and climate change benefits. The energy company in focus is located in Linköping, Sweden. Optimisation models, such as MODEST and reMIND, have been used for analysing the energy systems. Scenario and sensitivity analyses have also been performed for evaluation of the robustness of the energy systems studied. For all analyses a European energy system perspective was applied, where a fully deregulated European electricity market with no bottlenecks or other system failures was assumed. In this thesis it is concluded that of the DH-supply technologies studied, the biomass gasification applications and the natural gas combined cycle (NGCC) CHP are the technologies with the largest global CO2 reduction potential, while the biomass-fuelled plant that only produces heat is the investment with the smallest global CO2 reduction and savings potential. However, the global CO2 reduction potential for the biomass integrated gasification combined cycle (BIGCC) CHP and NGCC CHP, the two technologies with highest electricity efficiencies, is highly dependent on the assumptions made about marginal European electricity production. Regarding the effect on the DH system cost the gasification application integrated with production of renewable biofuels (SNG) for the transport sector is the investment option with the largest savings potential for lower electricity prices, while with increasing electricity prices the BIGCC and NGCC CHP plants are the most cost-effective investment options. The economic outcome for biomass gasification applications is, however, dependent on the level of policy instruments for biofuels and renewable electricity. Moreover, it was shown that the tradable green certificates for renewable electricity can, when applied to DH systems, contribute to investments that will not fully utilise the DH systems’ potential for global CO2 emissions reductions. Also illustrated is that conversion of industrial processes, utilising electricity and fossil fuels, to DH and DC can contribute to energy savings. Since DH is mainly used for space heating, the heat demand for DH systems is strongly outdoor temperature-dependent. By converting industrial processes, where the heat demand is often dependent on process hours instead of outdoor temperature, the heat loads in DH systems can become more evenly distributed over the year, with increased base-load heat demand and increased electricity generation in CHP plants as an outcome. This extra electricity production, in combination with the freed electricity when converting electricity-using processes to DH, can replace marginal electricity production in the European electricity market, resulting in reduced global CO2 emissions. Demonstrated in this thesis is that the local energy company, along with its customers, can contribute to reaching the European Union’s targets of reducing energy use and decreasing CO2 emissions. This can be achieved in a manner that is cost-effective to both the local energy company and the customers. / Den globala uppvärmningen i kombination med ett ökat energibehov och stigande energipriser gör det nödvändigt att förändra energianvändningen. Energieffektiva system är samtidigt en förutsättning för att kunna säkra energitillförseln och utveckla hållbara samhällen. Fjärrvärme har en viktig roll att fylla i den här omställningen. I fjärrvärmesystemen kan värmeresurser som annars kan vara svåra att nyttiggöras, som till exempel spillvärme och förbränning av avfall tas tillvara. Fjärrvärme kan även bidra till elproduktion i kraftvärmeverk där totalverkningsgraden är högre än vid separat el- respektive värmeproduktion. En omställning av energisystemet till en ökad användning av fjärrvärme och minskad användning av el genom effektiviseringar och konverteringar från olja och el till fjärrvärme kan bidra till att skapa energieffektiva system. Syftet med den här avhandlingen är att identifiera hur ett lokalt energibolag som producerar fjärrvärme, fjärrkyla och el i kraftvärmeverk kan bidra till att skapa energieffektiva system och kostnadseffektiva globala koldioxidreduktioner tillsammans med sina kunder. Det energibolag som framförallt har studerats i den här avhandlingen är Tekniska Verken i Linköping AB. För att optimera energibolagets fjärrvärme- och fjärrkylaproduktion har energisystemanalyser genomförts, där både åtgärder på tillförsel- och användarsidan har studerats. Genom att se energiförsörjningen ur ett systemperspektiv kan man undvika att ekonomiska och miljömässiga vinster vid en anläggning ersätts av förluster någon annanstans. Optimeringsmodeller, som MODEST och reMIND, har använts för energisystemanalyserna där även scenarier och känslighetsanalyser har inkluderats. För alla energisystemanalyser har ett europeiskt energisystemperspektiv använts där en totalt avreglerad europeisk elmarknad utan flaskhalsar eller andra systemfel antagits. Slutsatser från analyserna är att det lokala energibolaget kan bidra till kostnadseffektiva globala koldioxidreduktioner genom ett effektivt nyttjande av bränslen i kraftvärmeanläggningar och i bioraffinaderier. Speciellt kraftvärmeanläggningar med hög elverkningsgrad, som t.ex. biomasseförgasning- och naturgaskombianläggningar, har en betydande global koldioxidreduktionspotential. Även biomasseförgasningsanläggningar som är integrerade med produktion av förnybara drivmedel för transportsektorn har visat sig kostnadseffektiva med stor potential att reducera de globala koldioxidutsläppen. Styrmedel har dock en stor påverkan på det ekonomiska utfallet för förgasningsanläggningarna. Dessutom har studierna visat att energibesparingar kan åstadkommas genom att konvertera el och fossilbränsledrivna industriella processer till fjärrvärme och fjärrkyla. Eftersom fjärrvärme framförallt används för lokaluppvärmning är värmelasten i fjärrvärmesystem säsongsbetonad. Genom att konvertera industriella processer som inte är utetemperaturberoende till fjärrvärme kan fjärrvärmelasten bli mindre säsongsbetonad och mer jämt fördelad över året. En jämt fördelad värmelast är fördelaktig för driften av fjärrvärmeanläggningar och kan bidra till mer elproduktion i kraftvärmeanläggningar. Den extra elproduktionen, tillsammans med den el som blivit tillgänglig efter konvertering av eldrivna processer till fjärrvärme, kan ersätta europeisk marginalelsproduktion vilket kan reducera de globala koldioxidutsläppen. Det som har framkommit av dessa studier är att det lokala energibolaget, tillsammans med sina kunder, kan bidra till att uppfylla de mål den Europeiska Unionen har angående reduktionen av energianvändningen och koldioxidutsläppen. Dessutom kan detta ske på ett kostnadseffektivt sätt för både energibolaget och dess kunder.

This thesis deals with some challenges related to the mitigation of climate change and the overall aim is to present and assess different possibilities for the mitigation of climate change by: • Suggesting some measures with a potential to abate net greenhouse gas (GHG) emissions, • Discussing ideas for how decision-makers could tackle some of the encountered obstacles linked to these measures, and • Pointing at some problems with the current Kyoto framework and suggesting modifications of it. The quantification of the net CO2 effect from a specific project, frequently referred to as emissions accounting, is an important tool to evaluate projects and strategies for mitigating climate change. This thesis discusses different emissions accounting methods. It is concluded that no single method ought to be used for generalisation purposes, as many factors may affect the real outcome for different projects. The estimated outcome is extremely dependent on the method chosen and, thus, the suggested approach is to apply a broader perspective than the use of a particular method for strategic decisions. The risk of losing the integrity of the Kyoto Protocol when over-simplified emissions accounting methods are applied for the quantification of emission credits that can be obtained by a country with binding emissions targets for projects executed in a country without binding emission targets is also discussed. Driving forces and obstacles with regard to energy-related co-operations between industries and district heating companies have been studied since they may potentially reduce net GHG emissions. The main conclusion is that favourable techno-economic circumstances are not sufficient for the implementation of a co-operation; other factors like people with the true ambition to co-operate are also necessary. How oxy-fuel combustion for CO2 capture and storage (CCS) purposes may be much more efficiently utilised together with some industrial processes than with power production processes is also discussed. As cost efficiency is relevant for the Kyoto framework, this thesis suggests that CCS performed on CO2 from biomass should be allowed to play on a level playing field with CCS from fossil sources, as the outcome for the atmosphere is independent of the origin of the CO2. / QC 20101015

The objective of the study is to analyse the conditions for connection of residential buildings in heat sparse areas to district heating systems in order to increase electricity production in municipal combined heat and power plants. The European electricity market has been assumed to be fully deregulated. The relation between connection of heat sparse areas, increased electricity and heat production as well as electricity prices, fuel prices and emissions rights is investigated. The results of the study show that there is potential to expand the district heating market to areas with lower heat concentrations in the cities of Gavle, Sandviken and Borlange in Sweden, with both economic and environmental benefits. The expansion provides a substantial heat demand of approximately 181 GWh/year, which results in an electricity power production of approximately 43 GWh/year. Since the detached and stand-alone houses in the studied heat sparse areas have been heated either by oil boiler or by direct electricity, connection to district heating also provides a substantial reduction in emissions of CO2. The largest reductions in CO2 emissions are found to be 211 ktonnes/year assuming coal-fired condensing power as marginal electricity production. Connection of heat sparse areas to district heating decrease the system costs and provide a profitability by approximately 22 million EURO/year for the studied municipalities if the price of electricity is at a European level, i.e. 110 EURO/MWh. Sensitivity analysis shows, among other things, that a strong relation exists between the price of electricity and the profitability of connecting heat sparse areas to district heating systems. / Original Publication:Shahnaz Amiri and Bahram Moshfegh, Possibilities and consequences of deregulation of the European electricity market for connection of heat sparse areas to district heating systems, 2010, Applied Energy, (87), 7, 2401-2410.http://dx.doi.org/10.1016/j.apenergy.2010.02.002Copyright: Elsevier Science B.V., Amsterdam.http://www.elsevier.com/

Vi står inför en förändring, att minska vårt beroende av fossil energi till förmån för en ökad användning av förnybar energi. Incitament i form av ökade punktskatter på fossilt bränsle påskyndar omställningen för företag till förnybar energi och- eller energieffektivisering av sin produktion. Konsekvensen blir en successivt fördyrad kostnad för produktion av fjärrvärme med eldningsolja till tillverkningsindustrin. Punktskatt på eldningsolja stiger med 41 procent, från 2010 till 2015 för företagen. Att konvertera befintliga oljepannor med träpulverbrännare är en lösning för att hålla produktionskostnaden nere och behålla sin konkurrenskraft. I detta examensarbete utreds möjligheten att konvertera oljepannor i storleksklassen 5-10 MW. Studien tar ett helhetsgrepp om RMT´s fjärrvärmeproduktion för att söka svaret på, om det är möjligt att göra en konvertering ur ett tekniskt, hållbarhets och ekonomiskt perspektiv. Det kända behovet av spetslast från oljepannorna vid -3°C visade sig inte stämma utan brytpunkten hamnade vid -6°C. Resultatet pekar på att en 10 MW oljepanna kan konverteras till 5 MW träpulver men ändå behålla sin ursprungliga effekt genom en kombibrännare. Tidigare problem som fanns med träpulveranläggningar är åtgärdade och referensanläggningar i den aktuella storleksklassen finns i drift. Ett förfrågningsunderlag skickades ut för att få in budgetpris på konvertering av 5 och 10 MW oljepannor för utvärdering. Trots att alla leverantörer gavs samma förutsättningar så varierade budgetpriserna väldigt mycket. En stor överraskning var den korta payoff tid på konverteringar med liten värmeeffekt. Att en konvertering av en 10 MW OP har en återbetalningstid på 20 månader var rätt osannolikt innan studien utfördes. Denna studie kan även ses som en inspirationskälla till andra företag som har mindre spetslastpannor och vill fasa ut sitt fossila beroende med förnybar energi, samtidigt behålla sin konkurrenskraft. I fjärrvärmebranschen är dessa 5 och 10 MW oljepannor vanliga som spetslastpannor. Det finns ca 1000 oljepannor i storleken 5-10 MW i Sverige så det bör finnas en stor potential i att konvertera oljepannor till träpulver. / We are facing a change, to reduce our dependency on fossil fuels in favor of increased use of renewable energy. Incentives in the form of increased excise taxes on fossil fuels for companies accelerate the conversion to renewable energy or energy efficiency of its production. The consequence is a progressively more expensive cost for district heating with fuel oil to manufacturing industry. Excise tax on fuel oil rises by 41 percent, from 2010 to 2015 for those companies. To convert existing oil boilers with woodpowderburner is a solution to keep production costs down and remain competitive. In this thesis studied the possibility of converting oil boilers in the size range of 5 to 10 MW. The study takes a holistic approach to RMT's district heating to search the answer, if it is possible to do a conversion from a technical, sustainability and economic perspective. The felt need for peak load from oil boilers at -3° C appeared not to sue; it ended up at -6° C. The results indicate that a 10 MW oil boiler can be converted to 5 MW wood powder and while retaining its original power through a combination burner. Previously problems with woodpowderplant are taken care of and reference facilities in the current magnitude are in operation. An inquiry was sent out to get budget prices at a conversion of 5 and 10 MW oil boilers for evaluation. Even though all the suppliers was given the same opportunities so varied budget prices very much. A big surprise was the short payoff time on conversions of small oil boilers. The conversion of a 10 MW OP has a payback period of 20 months and that was rather unlikely before the study was performed. This study can also be seen as a source of inspiration to other companies that have small peak load boilers and want to phase out their fossil fuel dependence with renewable energy, and retain their competitiveness. In the district heating sector, these 5 and 10 MW oil boilers are ordinary peak load boilers. There are about 1000 oil boilers in the size from 5 to 10 MW in Sweden so it should be a large potential in converting oil boilers to wood powder

The aim of this master thesis project is to make an energy survey for a group of apartments and suggestions to change the heating system from electricity to a more efficient one. There are in total 73 flats in 21 buildings. All flats are separated in several houses from two to five flats in one building. There are two different kinds of flats. One with three rooms in one floor, in the following referred to as ‘flat A’ and the other one with four rooms in two floors, in the following referred to as ‘flat B’. [1] In the area there are also two buildings for the commonalty. In these buildings there are a shelter and several common rooms like a storage and a laundry. In our work these two buildings are not included because they are used by everyone inside the community and we could not obtain exact values for the used electricity and the water consumption. So our work is specialised only on the residential houses. The first part of this thesis contains the energy balance for the different kinds of flats to see how much energy they consume for heating and hot tap water. To get theses values we have to analyse the total energy flow into one flat and compare it with the energy which is used because of transmission losses, ventilation losses, hot tap water, electricity for the household and natural ventilation and infiltration. The total energy consumption for flat A is about 19000 kWh per year and in flat B about 23200 kWh per year. But the electricity which is used and has to be bought is about 15600 kWh per year in flat A flat and 17600 kWh in flat B. The rest of the energy is from so called free heat caused by solar radiation and internal heat generation. [1] These numbers for the electricity need in one year create annual costs of about 20000 SEK in flat A and 22500 SEK in flat B. To reduce these costs it is necessary to know where this energy goes and for what it is used. The important parts of the energy balance for this thesis are the transmission losses, the losses caused by natural ventilation and infiltration and the used energy for hot tap water. The losses caused by mechanical ventilation have also a significant value, but they would only affect the new heating system if the ventilation system would be connected to the new system. And the electricity used in the household for electrical devices can only be changed by the consumer himself. The part which is affecting the energy costs for the transmission and natural ventilation losses and the hot tap water sums up to 9240 kWh per year in flat A and flat B. This causes costs of about 10000 SEK per year. To reduce these costs it is necessary to change the actual heating system. In the following we analyse the saving potentials with a change to an air-water heat pump or with a connection to the local district heating network. The costs which can be saved with the installation of a heat pump sum up to about 7000 SEK per year. The installation costs are about 100000 SEK to 125000 SEK depending on the different proposed models. If you consider that the existing electrical boiler has to be changed anyway in the next years the investment costs for the combination with a heat pump decreases. The payback time is then between 9½ and 13½ years. With assumed increasing electricity prices of 5 % each year the payback time decreases to 8½ to 11 years. With a connection of each flat to the local district heating network the energy costs for heating and hot tap water decreases to 3200 SEK per year. Although the price per kWh for district heating is much lower than for electricity the costs are not decreasing a lot because of a high annual fixed fee of 7100 SEK. The saved money per year sums up to 300 SEK and 1000 SEK depending on the electricity contract. The payback time for this alternative is between 50 and up to 160 years. An alternative to the exchange of the heating and hot water system is to change the actual heat exchanger of the ventilation system. With this measure the energy consumption can be reduced with less investment costs. The investment costs for a new heat exchanger are about 35000 SEK, including a new exhaust hood from the kitchen outwards to reduce the contamination of the filters in the heat exchanger. [1] The payback time ranges from 13 years in flat A to 21 years in flat B.

Energi Intelligent is a program in Dalarna County with the purpose of finding ways of enhancing the efficiency of energy use and thereby be able to reach a more sustainable use of energy resources[1]. The basis of this program is the energy goal that has been prepared for Dalarna County published in Dalarnas miljömål[2].  The energy goal is divided into a number of intermediate goals, the sixth, Delmål 6, is to reduce energy consumption in buildings with 50 percent until 2050, and with 30 percent until 2025[3].   There are often a large number of different sectors involved that have got differing opinions and intentions. This makes the task far more complex than simply reducing energy consumption, because energy efficiency is one goal and that would mean that power companies would not be able to continue increasing their profit.   The aim of this project was to analyze the effects on energy production when reducing the use of heat demand in buildings until 2050. The district heating systems constitutes the main part of heating of buildings in the county and that is why it has been analyzed in this project.  The simulation tool that was suggested in the declaration of the thesis work was LEAP, the Long range energy alternative planning system tool for simulating different scenarios over years from the base year of the model.  The idea was to build energy models of Falun district heating system and Borlänge district heating system in LEAP. Scenarios were defined for the energy goals and then simulated in a model of district heating system. Simulation of the district heating systems were made from the scenarios; reducing the district heating production with 30 percent until 2025 and 50 percent until 2050. The results from the analysis showed that for Falun district heating system the reduction of district heat demand will lead to decreased heat and electricity production and there will be no need for further investment. In Borlänge district heating system capacity is lower than the total capacity of all the available waste resources and there have been discussions about investing in a third municipal waste incineration boiler that would increase the total capacity so Borlänge district heating system could have waste incineration that covers the resources of the fuel cost favorable municipal and industrial waste.

Within the next years, the amount of consumption data will increase rapidly as old meters will be exchanged in favor of meters with hourly remote reading. A new refined supervision system must be developed. The main objective of this thesis is to investigate mathematical methods that can be used to find incorrect hourly measurements in district heat and electricity consumption, for each consumer. A simulation model and a statistical model have been derived. The model parameters in the simulation model are estimated by using historical data of consumption and outdoor temperature. By using the outdoor temperature as input, the consumption can be simulated and compared to the actual consumption. Faults are detected by using a residual with a sliding window. The second model uses the fact that consumers with similar consumption patterns can be grouped into a collective. By studying the correlation between the consumers, incorrect measurements can be found. The performed simulations show that the simulation model is best suited for consumers whose consumption is mostly affected by the outdoor temperature. These consumers are district heat consumers and electricity consumers that use electricity for space heating. The fault detection performance of the statistical model is highly dependent on finding a collective that is well correlated. If these collectives can be found, the model can be used on district heat consumers as well as electricity consumers.

Arvika Fjärrvärme AB, a district heating company from Arvika, today cover 74 % of their total energy production with biofuel wich runs a 16 MW bioler giving process water at saturated liquid state. In recent years Vaporel AB has introduced a new tecnique that gives an external generation of steam after boilers. The concept is built on an adiabatic pressure drop of the saturated liquid in a so called Flashbox which makes a small part of the liquid to evaporate. The generated steam is lead into a turbine where electricity is in a conventional manner. The purpose with this rapport was to do a basic study for the specific system at Arvika where it’s possible to see the potential production of electricity that follows an installation of a flasbox. The final goal was to introduce an economic analysis of a flashox installation at given conditions. To reach our goals we have created a model in Excel where we used the given conditions at Arvika Fjärrvärme to do our calculations. The model has been tested at three different states, of process water returning to potboiler, to be able to decide the optimal operation for the system at present. The studies have resulted in a pressure of the processwater at 14,5 bar (at) and a pressuredrop to 9,5 bar (at) in the flashbox. The condenser pressure is set to 0,5 bar (at) what is equal to 81 ˚C. Energy to the district heating net is produced in the condenser and heat exchanger. The result of our calculations clearly shows that to reach the highest turbine-efficiency as possible and gain the largest profit the highest process-waterflow possible should be used. That means 70 kg/s after present conditions. At the highest boiler efficiency the turbine will produce 694 kW. At this state the water that returns to the boiler will be at temperature 148 ˚C (14, 5 bar). Totally during a year the production of electric energy could reach 2, 47 GWh/year. The energy used by the pumps will increase with 0,21 GWh over the year at that state. Included all economic factors this will generate a profit of 0, 97 million (SEK)/year. To make an installation of a flashbox system more profitable an increased generation of electricity have to be made. This could be done by an installation of new pumps to be able to run the process-water at a larger flow to increase the amount of steam made in the flashbox. / Arvika fjärrvärme producerar idag 74% av sitt värmeunderlag via en hetvattenpanna som drivs med biobränsle och har en maxeffekt på 16 MW. På senare år har företaget Vaporel AB introducerat en ny teknik på marknaden som ger en extern ångproduktion efter hetvattenpannor. Konceptet är byggt på en trycksänkning som medför att delar av det mättade vattnet förångas efter att ha letts in i en så kallad flashbox. Efter flashboxen äntrar ångan en turbin där el produceras på konventionellt vis. Syftet med denna rapport har varit att ta fram en grundläggande studie för Arvikas specifika system där det är möjligt att se den potentiella elproduktionen vid en flashboxinstallation. Det slutgiltiga målet med rapporten har varit att kunna presentera en lönsamhetsbedömning för en flashboxinstallation vid givna driftfall. För att kunna uppfylla uppsatta mål har en Excelmodell konstruerats där beräkningar utförts efter givna förutsättningar, detta utefter tre olika driftfall för att kunna fastställa den mest optimala driften för systemet i dagsläget. Studierna har lett fram till att vi har kunnat fastställa ett maximalt tryck efter pannan på 14,5 bar (at) samt en trycksänkning över flashboxen till 9,5 bar. Kondensortryck efter turbinen har satts till 0,5 bar(a) vilket ger en kondensations temperatur motsvarande 81 ˚C. Energi till att värma fjärrvärmevattnet tas via kondensorn samt en värmeväxlare. Resultatet av våra beräkningar visar tydligt att vi för att nå en så hög turbineffekt som möjligt och därmed en större lönsamhet skall ha ett så högt processvattenflöde som tillåts, enligt dagens förutsättningar 70 l/s. Vid högsta panneffekten kommer turbinen att ge 694 kW, enligt Excelmodellen, vid en returtemperatur till pannan satt till 148 ˚C. Sammanlagt under året, med Arvikas varaktighetsdiagram som grund, kommer vi att kunna producera 2,47 GWh el/år varav pumparna kommer att kräva 0,21 GWh el extra per år. Med alla ekonomiska faktorer inräknade så kommer detta att ge en vinstkalkyl på 0,97 miljoner /år. För att kunna göra dessa installationer lönsamma krävs att vi ökar elproduktionen och därmed den årliga vinsten, detta skulle kunna göras i och med installation av nya pumpar för att uppnå ett större flöde i pannkretsen. Vidare bör en studie göras för att bedöma lönsamheten gällande en ombyggnad av rökgaskondenseringen för att kunna klara en större effekt och därmed kunna använda högre returtemperaturer till biopannan. Detta skulle generera ett högre genomsnittligt flöde över året.