ELEC_FROM_HEAT · Electricity generated from heat with nonlinear pyroelectric materials

Electric energy stands for 20% of the total energy consumed in the world, and this share is expected to reach 40% by 2050 as an outcome of the need to decrease our dependence on non-renewable energies. Beyond sunlight and wind, heat is another formidable and poorly exploited source of electrical energy. Indeed, currently 72 % of the energy produced ends up in waste heat - and it has been predicted that up to 13 000 TWh could be recovered each year, which stands for Europe’s yearly total energy needs!In this context, my team recently showed that 40 grams of nonlinear pyroelectric ceramics can generate more than 10 Joules of electric energy from waste heat in one single thermodynamic cycle of 100 degrees. This is one order of magnitude larger than the closest state-of-the-art. We also demonstrated that these materials exhibit an energy efficiency of 40 % with respect to Carnot’s efficiency – which is beyond what photovoltaics and thermoelectrics can provide. Therefore, the scientific question of this project is the following: “Is it possible to generate Watts efficiently with this technology - and not only Joules?”Hence, the objective of this project is to show that energy harvesters made of nonlinear pyroelectric materials can generate 100 W of electric power from heat with 50 % energy efficiency. To do so, I will (1) design and fabricate environmentally friendly nonlinear pyroelectric harvesting modules, (2) analyse the fundamental role played by specific phase transitions on the heat-to-electricity thermodynamic conversion in such materials, (3) elaborate a power generator based on these harvesting modules with enhanced heat exchange capabilities able to generate 100 W of electricity from heat, and (4) prepare another specific heat-to-electricity generator showing that conversion efficiency can reach 50 %. This project will provide a compact, efficient, and low-cost technology to transform waste heat into a massive new source of electric energy.