Small-scale pellet boiler with thermoelectric generator

Pellet boilers need auxiliary electrical power to provide CO2-balanced heat in a comfortable and environment-friendly way. The idea is to produce this and some extra electricity within the furnace in order to save resources and to gain operation reliability and independency. Thermoelectric generators (TEGs) allow direct conversion of heat to electrical power. They have the advantage of a long maintenance-free durability and noiseless operation without moving parts or any working fluid. The useful heat remains almost the same and still can be used for heating. The challenge is the system integration and optimisation of TEGs in pellet burners. The consumption of electricity by the complete heating system is analysed and optimised in order to fulfil the purpose of independency. Grid independent operation is difficult to realise and optimise. In order to be successful it needs a simplified system. We do experiments with different arrangements of burners, heat exchangers and TEGs. We identified the important parameters to maximise the electricity produced. The potential of this technology strongly correlates with the efficiency and costs of thermoelectric materials. Optimised integration will result in additional benefits and saved resources. A novel kind of decentralised small-scale and micro-scale biomass-based combined heat and power generation will be developed. The basic system allows grid-independent operation of automatically running biomass furnaces including fuel delivery from storage and circulating the cooling respectively heating water. The advanced system also provides electricity for other electrical devices like radio, TV or light and is an additional benefit.