During the past several years we have developed a new material class based on regularly distributed Ge quantum dots (QDs) within the glass matrix. These materials are prepared by magnetron sputtering deposition followed by annealing and/or irradiation with heavy ions. We propose to advance our research to a new level by exploring complex Ge-based nanostructures in glasses and their applications in highly-efficient energy conversion and storage devices. Namely, the properties of materials based on pure, spherical Ge QDs can be significantly improved or designed specifically by addition of another material to Ge QDs in form of shell or capping layer, or by creating them to have some more complex shape. These new materials, based on complex Ge nanostructures, are very interesting from the fundamental point of view, while their highly-adjustable properties ensure their possible applications in modern opto-electronic devices. We expect successful production of several novel complex material types including Ge/metal core/shell QDs, continuous 3D nanowire networks and ion-beam induced specific nano-objects in different matrices. We will understand how their optical and electrical properties depend on their structure and how to tailor them to get the desired properties needed for the applications. As the final goal, we will use them to produce energy-efficient greenhouses, highly-efficient electrodes for water splitting and Li-ion batteries, and hydrogen storage reservoirs. In final, we expect that the proposed investigation will result in findings important for solving current energy-related problems, healthy food production and environment cleaning. We also expect a widening of scientific community interested for these novel material types. These materials and devices have great potential to be mass-produced and applied in modern nanotechnology since magnetron sputtering is the standard industrial technique for glass coating.