O objetivo do trabalho foi investigar o efeito da suplementação isolada de cafeína e bicarbonato de sódio sobre a contribuição dos sistemas energéticos, desempenho e reativação parassimpática após simulação de luta de taekwondo. Para tanto, a presente tese foi dividida em estudo 1, com a suplementação de cafeína e estudo 2, com a suplementação de bicarbonato de sódio. Portanto, no estudo 1, o objetivo foi investigar o efeito da suplementação de cafeína sobre a contribuição dos sistemas energéticos, desempenho e reativação parassimpática em simulação de luta de taekwondo. 10 atletas de taekwondo foram submetidos a duas sessões experimentais separadas por no mínimo de 48 horas entre elas. Nas duas visitas os atletas consumiram uma cápsula contendo cafeína (5 mg.kg-1 de massa corporal) ou placebo (celulose) uma hora antes da simulação da luta de taekwondo, composta por 3 rounds de 2 minutos com 1 minuto de intervalo entre os rounds. A ordem das sessões experimentais foi randomizada, duplo-cego e cruzada. Todas as simulações de luta foram filmadas para quantificar as ações técnico-táticas durante os rounds. Foram mensuradas a concentração de lactato, a percepção subjetiva de esforço (PSE) antes e após cada round,e a frequência cardíaca (FC) e a contribuição dos sistemas energéticos foi estimada durante a simulação de luta. Além disso, foram mensurados alguns índices da reativação parassimpática após o terceiro round. A concentração de lactato, a PSE, a FC e a contribuição dos sistemas energéticos foram comparados usando análise de variância de dois fatores (condição e tempo). Adicionalmente, os índices da reativação parassimpática foram comparados utilizando o teste t de Student entre as condições cafeína e placebo. Os principais resultados indicam que: a suplementação de cafeína aumentou a contribuição do sistema glicolítico em relação ao placebo. Porém, a cafeína não melhorou o desempenho ou alterou a PSE, a FC ou a contribuição dos sistemas oxidativo e ATP-CP quando comparados ao placebo. Adicionalmente, nenhum índice da reativação parassimpática foi afetado pela suplementação de cafeína. No estudo 2, o objetivo do estudo foi investigar o efeito da suplementação de bicarbonato de sódio sobre a contribuição dos sistemas energéticos durante a simulação de luta de taekwondo. Para tanto, foram avaliados 9 atletas de taekwondo, os quais foram submetidos a duas condições experimentais, separadas por um mínimo de 48 horas entre elas. Nas duas visitas os atletas ingeriram uma cápsula contendo 0,03 g.kg-1 da massa corporal de NaHCO3- ou placebo (carbonato de cálcio), 90 minutos antes da simulação de luta de taekwondo, composta por 3 rounds de 2 minutos com 1 minutos de intervalo entre os rounds. A ordem das sessões experimentais foi randomizada, duplo-cego e cruzada. Todas as simulações de luta foram filmadas para quantificar as ações técnico-táticas durante os rounds. Foram mensuradas a concentração de lactato, a percepção subjetiva de esforço antes e após cada round, a frequência cardíaca e a contribuição dos sistemas energéticos foram estimadas durante a simulação de luta. Além disso, foram mensurados alguns índices da reativação parassimpática após o terceiro round. A concentração de lactato, a PSE, a FC e a contribuição dos sistemas energéticos foram comparadas usando análise de variância de dois fatores (condição e tempo). Além disso, os índices da reativação parassimpática foram comparados utilizando o teste t de Student entre as condições NaHCO3 e placebo. Os principais resultados demonstraram que a suplementação de NaHCO3 aumentou a contribuição do sistema glicolítico e o tempo total de ataque em relação ao placebo. Porém, o NaHCO3 não alterou a FC, a PSE ou a contribuição dos sistemas oxidativo e ATP-CP durante a simulação de luta quando comparados ao placebo. Além disso, nenhum índice da reativação parassimpática foi afetado pela suplementação de NaHCO3 ou placebo / The aim of this study was to investigate the isolated effect of caffeine and sodium bicarbonate ingestion on performance, estimated energy system contribution and on post-exercise parasympathetic reactivation during a simulated taekwondo combat. Therefore, this thesis was divided in two studies: study 1 investigated the effect of caffeine, while study 2 investigated the effect of sodium bicarbonate. Thus, in study 1, the aim was to investigate the effect of caffeine supplementation on performance, estimated energy system contribution and on post-exercise parasympathetic reactivation during a taekwondo combat. Ten taekwondo athletes completed two experimental sessions separated by at least 48 hours. Athletes consumed a capsule containing either 5 mg?kg-1 body mass of caffeine or placebo (cellulose) one hour before the combat simulation (3 rounds of 2 min separated by 1-min passive recovery), in a double blinded, randomized, repeated-measures crossover design. All simulated combat was video recorded to quantify the time spend fighting in each round. Lactate concentration and rate of perceived exertion were measured before and after each round, while heart rate and the estimated contribution of oxidative, ATP-PCr and glycolytic systems were calculated during the combat simulation. Furthermore, parasympathetic reactivation after the combat simulation was evaluated. Lactate concentration, rate of perceived of exertion, heart rate, estimated system contributions and indices of time-motion were compared by two-way ANOVA (condition x time). All indices of parasympathetic reactivation were compared using a Student\'s t-test in both caffeine and placebo conditions. The main results showed that caffeine ingestion increased the estimated glycolytic system when compared to placebo condition. However, caffeine ingestion did not alter the rate of perceived exertion, heart rate, estimated oxidative and ATP-PCr contribution or improve the performance in relation to placebo condition. Furthermore, caffeine ingestion did not influence post-exercise parasympathetic reactivation following a taekwondo simulation when compared to placebo condition. In study 2, the main aim of the study was to investigate the effect of sodium bicarbonate ingestion on performance, estimated energy system contribution and on post-exercise parasympathetic reactivation during simulated taekwondo combat. Nine taekwondo athletes completed two experimental sessions separated by at least 48 hours. Athletes consumed 300 mg?kg-1 body mass of sodium bicarbonate or calcium bicarbonate (placebo) 90 minutes before the combat simulation (3 rounds of 2 min separated by 1-min passive recovery), in a double blinded, randomized, repeated-measures crossover design. All simulated combat was video recorded to quantify the time spent fighting in each round. Lactate concentration and rate of perceived exertion were measured before and after each round, while heart rate, estimated contribution of oxidative, ATP-PCr and glycolytic systems were calculated during the combat simulation. Furthermore, parasympathetic reactivation after the combat simulation was calculated. Lactate concentration, rate of perceived exertion, heart rate, estimated system contributions and indices of time-motion were compared by two-way ANOVA (condition x time). All indices of parasympathetic reactivation were compared using a Student\'s t-test. The main results showed that sodium bicarbonate ingestion increased the lactate concentration, estimated glycolytic contribution and total attack time when compared with placebo condition. However, sodium bicarbonate ingestion did not influence heart rate, rate of perceived exertion, estimated oxidative and ATP-PCr contribution during combat simulation compared to placebo. Furthermore, no indices of parasympathetic reactivation were different between sodium bicarbonate and placebo conditions

<p></p><h1>Abstract</h1><p>Waste disposal is a global problem contributing to the ongoing climate change by large emissions of greenhouse gases. By using waste material as a resource instead of landfilling, the greenhouse gas emissions from landfills are reduced. Waste material can be used for waste incineration with energy recovery, thus decreasing the greenhouse gas emission from energy utilization by changing from fossil fuels to a partly renewable fuel.</p><p>Arges County in Romania has severe problems with its waste material, mainly sewage sludge and waste from households and industries. As a consequence of the Romanian EU accession in 2007, Arges County is obliged to close its landfills for waste in a near future. A reconstruction of the wastewater treatment plant and an improved management of the sewage sludge residue are necessary in order to comply with EU standards. The requirements from the EU regarding waste disposal together with the existence of a district heating network in the residence city Pitesti, makes it interesting to investigate energy recovery from waste material in Arges County.</p><p>Therefore, the goal of the study is to evaluate the possibility to extract energy from co-incineration of the waste material, sewage sludge and waste generated in Arges County. In order to reach this goal, the composition and quantities of the waste material is investigated. A suitable technology for the waste-to-energy (WTE) plant is proposed, based on the data of the waste material as well as on   established WTE technologies and their costs. It is assumed that the WTE plant will be implemented in 2020 and that all the generated waste will be incinerated. Furthermore, an environmental analysis is carried out, which presents the reductions of greenhouse gas emissions with the proposed WTE plant in comparison with the present system; including the management of waste and sludge and the district heating production, which is based on fossil fuels.</p><p>The result shows that the waste material in Arges County has a calorific value of 7.5 MJ per kg, which is suitable for co-incineration of waste and sludge. The suggested WTE plant has the total power of 130 MW, annually recovering 620 and 330 GWh of heat and electric power respectively. The investment cost of the WTE plant is estimated to 226 million euro with a payback time of 8 years. The environmental analysis shows that the proposed system in comparison with the present system will decrease greenhouse gas emissions by 88 percent.</p><p>A WTE plant appears to be a sound investment in Arges County and would sharply reduce the emissions of greenhouse gases in the county. However, some obstacles exist. Waste management is a new field in Romania and currently there are no WTE plants. Furthermore, the data used in this study concerning the quantity and composition of the waste, is uncertain and further studies are necessary before a WTE plant can be established.</p><p> </p>

Bioenergy will play an important role in reaching the EU targets for renewable energy. Sweden, with abundant forest resources and a well-established forest industry, has a key position regarding modern biomass use. Biomass gasification (BMG) offers several advantages compared to biomass combustion-based processes, the most prominent being the possibility for downstream conversion to motor fuels (biofuels), and the potential for higher electrical efficiency if used for electricity generation in a biomass integrated gasification combined cycle (BIGCC). BMG-based processes in general have a considerable surplus of heat, which facilitates integration with district heating or industrial processes. In this thesis integration of large-scale BMG, for biofuel or electricity production, with other parts of the energy system is analysed. Focus is on forest-based biomass, with the analysis including techno-economic aspects as well as considerations regarding effects on global fossil CO2 emissions. The analysis has been done using two approaches – bottom-up with detailed case studies of BMG integrated with local systems, and top-down with BMG studied on a European scale. The results show that BMG-based biofuel or electricity production can constitute economically interesting alternatives for integration with district heating or pulp and paper production. However, due to uncertainties concerning future energy market conditions and due to the large capital commitment of investment in BMG technology, forceful economic support policies will be needed if BMG is a desired route for the future energy system, unless oil and electricity prices are high enough to provide sufficient incentives for BMG-based biofuel or electricity production. While BMG-based biofuel production could make integration with either district heating or pulp and paper production economically attractive, BIGCC shows considerably more promise if integrated with pulp and paper production than with district heating. Bioenergy use is often considered CO2-neutral, because uptake in growing plants is assumed to fully balance the CO2 released when the biomass is combusted. As one of the alternatives in this thesis, biomass is viewed as limited. This means that increased use of bioenergy in one part of the energy system limits the amount of biomass available for other applications, thus increasing the CO2 emissions for those applications. The results show that when such marginal effects of increased biomass use are acknowledged, the CO2 mitigation potential for BMG-based biofuel production becomes highly uncertain. In fact, most of the BMG-based biofuel cases studied in this thesis would lead to an increase rather than the desired decrease of global CO2 emissions, when considering biomass as limited. / Bioenergi spelar en viktig roll för att nå EU:s mål för förnybar energi. Sverige har med sina goda skogstillgångar och sin väletablerade skogsindustri en nyckelposition vad gäller modern bioenergianvändning. Förgasning av biomassa har flera fördelar jämfört med förbränningsbaserade processer - i synnerhet möjligheten att konvertera lågvärdiga råvaror till exempelvis fordonsdrivmedel. Används gasen istället för elproduktion kan en högre verkningsgrad nås om gasen används i en kombicykel, jämfört med i en konventionell ångturbincykel. De förgasningsbaserade processerna har i allmänhet ett betydande överskott av värme, vilket möjliggör integrering med fjärrvärmesystem eller industriella processer. I denna avhandling analyseras integrering av storskalig biomassaförgasning för drivmedelseller elproduktion, med andra delar av energisystemet. Skogsbaserad biomassa är i fokus och analysen behandlar såväl teknoekonomiska aspekter, som effekter på globala fossila CO2-utsläpp. Forskningen har gjorts på två olika systemnivåer - dels i form av detaljerade fallstudier av biomassaförgasning integrerat med lokala svenska system, dels i form av systemstudier på europeisk nivå. Resultaten visar att förgasningsbaserad biodrivmedels- eller elproduktion kan komma att utgöra ekonomiskt intressanta alternativ för integrering med fjärrvärme eller massa- och papperstillverkning. På grund av osäkerheter i fråga om framtida energimarknadsförhållanden och på grund av de höga kapitalkostnaderna som investering i förgasningsanläggningar innebär, kommer kraftfulla ekonomiska styrmedel krävas om biomassaförgasning är en önskad utvecklingsväg för framtidens energisystem, såvida inte olje- och elpriserna är höga nog att i sig skapa tillräckliga incitament. Medan förgasningsbaserad drivmedelsproduktion kan vara ekonomiskt attraktivt att integrera med såväl fjärrvärme som med massa- och papperstillverkning, framstår förgasningsbaserad elproduktion som betydligt mer lovande vid integrering med massa- och papperstillverkning. Användning av bioenergi anses ofta vara CO2-neutralt, eftersom upptaget av CO2 i växande biomassa antas balansera den CO2 som frigörs när biomassan förbränns. Som ett av alternativen i denna avhandling ses biomassa som begränsad, vilket innebär att ökad användning av bioenergi i en del av energisystemet begränsar den tillgängliga mängden biomassa för andra användare, vilket leder till ökade CO2-utsläpp för dessa. Resultaten visar att när hänsyn tas till denna typ av marginella effekter av ökad biomassaanvändning, blir potentialen för minskade globala CO2-utsläpp med hjälp av förgasningsbaserade tillämpningar mycket osäker. I själva verket skulle de flesta av de förgasningsbaserade drivmedel som studerats i denna avhandling leda till en utsläppsökning, snarare än den önskade minskningen.

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.

Abstract Waste disposal is a global problem contributing to the ongoing climate change by large emissions of greenhouse gases. By using waste material as a resource instead of landfilling, the greenhouse gas emissions from landfills are reduced. Waste material can be used for waste incineration with energy recovery, thus decreasing the greenhouse gas emission from energy utilization by changing from fossil fuels to a partly renewable fuel. Arges County in Romania has severe problems with its waste material, mainly sewage sludge and waste from households and industries. As a consequence of the Romanian EU accession in 2007, Arges County is obliged to close its landfills for waste in a near future. A reconstruction of the wastewater treatment plant and an improved management of the sewage sludge residue are necessary in order to comply with EU standards. The requirements from the EU regarding waste disposal together with the existence of a district heating network in the residence city Pitesti, makes it interesting to investigate energy recovery from waste material in Arges County. Therefore, the goal of the study is to evaluate the possibility to extract energy from co-incineration of the waste material, sewage sludge and waste generated in Arges County. In order to reach this goal, the composition and quantities of the waste material is investigated. A suitable technology for the waste-to-energy (WTE) plant is proposed, based on the data of the waste material as well as on   established WTE technologies and their costs. It is assumed that the WTE plant will be implemented in 2020 and that all the generated waste will be incinerated. Furthermore, an environmental analysis is carried out, which presents the reductions of greenhouse gas emissions with the proposed WTE plant in comparison with the present system; including the management of waste and sludge and the district heating production, which is based on fossil fuels. The result shows that the waste material in Arges County has a calorific value of 7.5 MJ per kg, which is suitable for co-incineration of waste and sludge. The suggested WTE plant has the total power of 130 MW, annually recovering 620 and 330 GWh of heat and electric power respectively. The investment cost of the WTE plant is estimated to 226 million euro with a payback time of 8 years. The environmental analysis shows that the proposed system in comparison with the present system will decrease greenhouse gas emissions by 88 percent. A WTE plant appears to be a sound investment in Arges County and would sharply reduce the emissions of greenhouse gases in the county. However, some obstacles exist. Waste management is a new field in Romania and currently there are no WTE plants. Furthermore, the data used in this study concerning the quantity and composition of the waste, is uncertain and further studies are necessary before a WTE plant can be established.

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.

Factors of very rapidly rising oil prices, the running out time limits on continued use of fossil fuels, as well as elements of the Kyoto Protocol, have greatly arouses the increasing emphasis on natural and renewable energy sources. 40 minutes of total solar radiation on earth could provide enough power to meet the energy needs of all human beings for approximately one year. The potential of solar energy is virtually limitedless. Moreover, by means of solar powered batteries, solar energy can be directly converted to electric power. Since it neither pollutes the environment or ecology, solar is an extremely clean source of energy. The life-span of solar cell is very long, possibly 20 years or more. The capability of solar batteries to provide energy is approximately proportional to the intensity of the sunlight. This thesis proposes the use of Artificial intelligence for "Sun Track Solar Energy System". This system employs Fuzzy Logic Control Theory, combined with Grey Relational Analysis, for tracking the angle of the sun, and further control the motor to adjust the angle for tracking, so direct sunlight could be acquired to increase power output. As a result of the experiment, comparing the electricity generated from the fix angle solar battery with the AI-based Sun Track Solar Energy System, the latter one has an efficiency increase up to 23% for the same amount of sunlight.

Two of the most significant challenges facing the world in the 21st century are improving energy security and mitigating the effects of climate change. To counter these challenges, renewable energy sources, such as wind, are considered a possible solution and have gained importance worldwide. With many jurisdictions setting high wind-energy targets for the coming decades, risks have grown as the demand for new wind turbines has outstripped the growth of its suppliers. Integrating significant amounts of wind-electricity into existing networks raises reliability concerns due to variable nature of wind. A method for estimating the reliability of wind-energy systems is presented which is a combination of a forecasting method (probabilistic approach) and RL (Resistance-Load) technique (risk-based approach), demonstrated through a case study, and verified using real-time wind farm data.

Lithuania has limited domestic energy resources, and is therefore, heavily dependent on imports of oil products and natural gas. Lithuania imported around 90% of its oil and 100% of natural gas in 2009. Particularly, after the accession to the European Union (EU), and decommissioning of main electricity generation source Ignalina Nuclear Power Plant (NPP), energy security became one of the main concerns. Therefore, it is vital to evaluate different pathways the country could take in order to achieve desirable energy security, and ensure sustainable development of the energy system in Lithuania. The study was conducted using LEAP, the Long range Energy Alternatives Planning System, to develop energy policy analysis. Different scenarios presented in the report show how Lithuanian energy system would react in given different circumstances. Moreover, it demonstrates how implementation of existing energy projects separately or combined together would affect the level of energy security and sustainability in Lithuania. The research shows that current government policies could lead Lithuania to more secure and sustainable energy future. However, in a long run higher investments in renewable energy might be more environmentally and economically competitive alternative.

After the nuclear fallout in Japan, Germany decided to back out from nuclear energy while at the same time changing the energy supply from fossil to renewable sources. This elaborate plan, known as Energiewende, will require significant economic and structural efforts that will have profound impacts on the environment and society itself. It is therefore crucial to identify possible technological pathways that can lead to a renewable energy supply, while reducing negative impacts on a holistic scope. In order to analyse alternative energy technology scenarios in Germany, this thesis focuses on the development of an indicator-based numerical Sustainable Energy Systems (SEnSys) model approach. Other than previous approaches, the SEnSys model considers full aggregated impacts of technological pathways leading to future configurations. With the help of an exemplary case study on two alternative energy technology scenarios (Trieb1 and Trieb2), the feasibility of the SEnSys model in evaluating sustainability is subsequently assessed. The results can affirm the findings of previous studies concerning lower economic and environ- mental impacts for scenario Trieb2, with small shares of renewable energy imports, compared to scenario Trieb1 based on only local but fluctuating renewables. Additionally, the results are in accordance with other relevant studies, while offering new valuable insights to the topic. Given a comprehensive revision of the identified uncertainties and limitations, it can be stated that the SEnSys model bares the potential for further analysing and improving sustainability of energy technology scenarios in Germany and other countries.