Storage system integration in the industrial and building sector is bound to play an important role in the future energy system to enable the integration of a large share of renewable energies and the recovery of waste heat from industrial processes. The development of sustainable thermal storage technologies at relevant temperature levels, that are associated with low costs in production and maintenance, and can deliver the high heat transfer characteristics required by many applications is therefore an important research topic. Latent Heat Storage technologies (LHS), using Phase Change Materials (PCM) allow for compact and reliable storage of thermal energy as they can offer a higher volumetric energy density at a more constant temperature level in comparison to conventional sensible storage. However, most conventional PCM systems suffer from low heat transfer rates and require the implemetation of complicated and costly heat exchangers to achieve a higher thermal power output. In this work we investigate novel storage technologies that can deliver a high and flexible thermal power output. The investigated concepts are based on (i) direct contact heat exchange, (ii) phase change material slurries and (iii) advanced finned tube heat exchangers.. The main objective of the project is to develop storage units that reach energy densities over 60 kWh/m3 and power-to-capacity ratios in the order of 1-4 kW/kWh. Further goals include developing integration tools for such storages within industrial/building applications including power-to-heat concepts.