<p>With the transition to a fully renewable energy grid arises the need for a green source of stability and baseload support, which classical renewable generation such as wind and solar cannot offer due to their uncertain and highly-variable generation. In this paper, we study whether green hydrogen can close this gap as a source of supplemental generation and storage. We design a two-stage mixed-integer stochastic optimization model that accounts for uncertainties in renewable generation. Our model considers the investment in renewable plants and hydrogen storage, as well as the operational decisions for running the hydrogen storage systems. For the data considered, we observe that a fully renewable network driven by green hydrogen has a greater potential to succeed when wind generation is high. In fact, the main investment priorities revealed by the model are in wind generation and in liquid hydrogen storage. This long-term storage is more valuable for taking full advantage of hydrogen than shorter-term intraday hydrogen gas storage. In addition, we note that the main driver for the potential and profitability of green hydrogen lies in the electricity demand and prices, as opposed to those for gas. Our model and the investment solutions proposed are robust with respect to changes in the investment costs. All in all, our results show that there is potential for green hydrogen as a source of baseload support in the transition to a fully renewable-powered energy grid.</p>