Rapporten är en utvärdering av möjligheten att generera elektrisk energi från fjärrvärme med Seebeck-effekten och görs på uppdrag av Skellefteå Kraft. Kursen är examensarbete för högskoleingenjörsexamen i Elkraftteknik, 5EL210 vid institutionen tillämpad fysik och elektronik på Umeå Universitet under vårterminen 2014.En termoelektrisk generator fungerar enligt Seebeck-effekten och genererar en elektrisk spänning som är linjär mot temperaturskillnaden mellan sina två metallytor. För att få en temperaturskillnad så krävs ett kylmedium vilket skapar ett värmeflöde från den varma energikällan till kylmediumet. Utan kylmediumet så kommer temperaturerna gå mot samma värde. Ett kylmedium kan till exempel vara snö, markgrunden eller vattenradiatorer. Eftersom en termoelektrisk generator är väldigt ineffektiv så lämpar det sig inte att använda markgrunden eller snö som kylmedium för att endast generera upp till 4% el av den tillförda värmeenergin och resten går till förluster. Av denna anledning valdes radiatorerna i villan som kylmedium för detta examensarbete.En teoretisk experimentuppställning gjordes med 16 stycken termoelektriska generatorer. Resultatet visade att värmeöverföringen genom de termoelektriska generatorerna begränsades till ca. 250W värmeenergi. Med relativt låga temperaturer så är effektiviteten endast 2% vilket genererar ca. 5W elektrisk energi.Slutsatsen är att med denna experimentuppställning så genereras inte tillräckligt med energi för att driva en cirkulationspump. Effektiviteten av de termoelektriska generatorerna är för dålig och de leder värme dåligt på grund av dess höga termiska resistans.

Today, the investigation of fuel economy improvements in internal combustion engines (ICEs) has become the most significant research interest among the automobile manufacturers and researchers. The scarcity of natural resources, progressively increasing oil prices, carbon dioxide taxation and stringent emission regulations all make fuel economy research relevant and compelling. The enhancement of engine performance solely using incylinder techniques is proving increasingly difficult and as a consequence the concept of exhaust energy recovery has emerged as an area of considerable interest. Three main energy recovery systems have been identified that are at various stages of investigation. Vapour power bottoming cycles and turbo-compounding devices have already been applied in commercially available marine engines and automobiles. Although the fuel economy benefits are substantial, system design implications have limited their adaptation due to the additional components and the complexity of the resulting system. In this context, thermo-electric (TE) generation systems, though still in their infancy for vehicle applications have been identified as attractive, promising and solid state candidates of low complexity. The performance of these devices is limited to the relative infancy of materials investigations and module architectures. There is great potential to be explored. The initial modelling work reported in this study shows that with current materials and construction technology, thermo-electric devices could be produced to displace the alternator of the light duty vehicles, providing the fuel economy benefits of 3.9%-4.7% for passenger cars and 7.4% for passenger buses. More efficient thermo-electric materials could increase the fuel economy significantly resulting in a substantially improved business case. The dynamic behaviour of the thermo-electric generator (TEG) applied in both, main exhaust gas stream and exhaust gas recirculation (EGR) path of light duty and heavy duty engines were studied through a series of experimental and modelling programs. The analyses of the thermo-electric generation systems have highlighted the need for advanced heat exchanger design as well as the improved materials to enhance the performance of these systems. These research requirements led to the need for a systems evaluation technique typified by hardware-in-the-loop (HIL) testing method to evaluate heat exchange and materials options. HIL methods have been used during this study to estimate both the output power and the exhaust back pressure created by the device. The work has established the feasibility of a new approach to heat exchange devices for thermo-electric systems. Based on design projections and the predicted performance of new materials, the potential to match the performance of established heat recovery methods has been demonstrated.