Exporting sunshine: Planning South Americas energy transition with hydrogen exports

In the developed world, the transition towards carbon-neutral sources has been planned intensively. However, the amount of research trying to understand South America as an interconnected energy system is limited, despite its great renewable energy potential and its population increasing to levels comparable to Europe or North America. This work aims to model South Americas electricity transition until the year 2050, including scenarios for hydrogen export. First, we set up a comprehensive energy database for South America with a focus on a high technological, spatial, and temporal resolution. Second, we write a mathematical minimization model to simulate optimal expansion pathways. The model considers hourly energy production from solar, wind, and hydro sources and uses diverse energy storage technologies to match the projected power demand. And third, the spatial resolution of the system was systematically varied in scenarios to analyze the implications of planning with different numbers of nodes (1, 16, 30, 43 nodes). The results show that South America has not only, as to be expected, enough potential for a fully renewable power supply but that renewable technologies also allow a cheaper supply than our current fossil-based system. Solar energy is projected to become the main power source followed by wind and hydropower. Storage technologies such as Li-ion batteries and pumped energy storage buffer the variability of RE sources. Exports of green hydrogen are cost competitive. In terms of studying the spatial resolution, the high spatial resolution of 43 nodes discloses a 6% of higher total costs that would else remain hidden in a simplistic 1-node approach. This higher resolution is also important to more precisely understand the tradeoffs between storage and transmission facilities. Modeling with 30 nodes seems to be a fair tradeoff between precision (2% cost difference) and computing costs.