We are currently undergoing a transformation in the way energy is supplied. Traditionally, heating of buildings was predominantly based on fossil fuels. In the past, coal- and oil-fired heating systems were widely used for heat generation, while in more recent years these have largely been replaced by natural gas heating. Current developments and increasing evidence of climate change are forcing us to move away from this approach. The need to reduce CO2 emissions is driving a complete transition away from fossil fuels. In addition, the supply of fossil fuels is increasingly being used as a political instrument by countries with significant reserves against those without such resources. We therefore need to achieve greater independence in our energy supply, and this can only be accomplished by making use of renewable energy sources that are freely available everywhere. Renewable energy is already being used successfully to generate sufficient electricity. However, the overall energy yield can be further increased by also harnessing thermal energy from solar radiation. If available at a sufficiently high temperature, this thermal energy can either be used directly within a building or serve as a heat source for a heat pump. To effectively utilize heat from renewable energy sources, we require systems that can collect, store, and distribute this energy throughout a building. At present, there are only a few solutions on the market that can perform all of these functions simultaneously, and many of them remain limited in their ability to fulfil the intended tasks. For example, solar thermal systems can harvest heat from solar radiation, but they cannot store this energy themselves.