A search for a suitable hydrogen storage material has been extensively performed in the past decade. The ability to reversibly store (i.e., absorb and desorb) hydrogen with faster kinetics (at mild condition) still forms a challenge for the establishment of the much sought-after hydrogen economy. Solid-stage storage, in the form of light-metal hydrides, offers the best compression rates and safety during hydrogen compression and storage available so far, with bulk Mg or Mg films appearing as the most suitable candidate to date. However, there are certain hindrances that need to be overcome for their widespread utilization, the slow diffusion rate being, arguably, the most important one. The nanoportal structure presented in this chapter, consisting of nanoparticles deposited on Mg films by some CBD technique, is an excellent tool for the in-depth investigation of the hydrogenation mechanism, both qualitative and quantitative. It avails the spatial and temporal decoupling of the hydrogenation through individual nanoparticles; as such, it enables the underlying principles of the hydrogen penetration (or not) inside metallic Mg, Mg oxide, or Mg hydrides and the calculation of the apparent diffusion coefficient of hydrogen in the Mg films. Potentially, the nanoportals (possibly embedded into rolled sheets of thin film) may offer solutions for desorption, which is another hindrance factor. Specifically, at a large scale, the thermodynamics of charging/discharging of metal hydrides need to be carefully engineered for efficient use of involved energy. For instance, use of onboard heat exchanger can save a lot of waste heat during charging of metals. Moreover, more compositions may be investigated, owing to the flexibility and good control of the CBD method.