Astronomical research infrastructure of the future should be powered by low-greenhouse gas emission solutions, which additionally provides a reliable security of supply and best have little upstream-environmental impacts. Sounds like a lot of research to conduct? After three years of hard work, we are proud to present our findings and learnings from designing energy systems relying on solar photovoltaic generation for the new telescope AtLAST. This talk gives an overview over the design of a renewable energy-based off-grid energy system for AtLAST. We discuss which relevant generation options we consider, how these can operate together with energy storage solutions, and what costs, climate change impact, water use, resource use and land use they entail. To pave the way for fellow astronomers and energy system designers, we finally dive into our learnings from this project, and showcase how other research infrastructure can plan their power supply with higher shares of renewables.