The climate crisis requires a transition to a climate neutral energy system, particularly in sectors that are hard to decarbonize. For these sectors, biomass-based energy carriers often represent a comparatively cost-effective decarbonization option. Given limited suitable land availability and high energy demand, identifying land-efficient solutions for renewable energy production is crucial. The present study is concerned with the collection and harmonisation of data on the multi-land-use concepts of agricultural photovoltaics (Agri-PV) and agroforestry. Both concepts are considered here as systems capable of contributing to renewable energy supply, through electricity generation and biomass production for energy use. The objective is to integrate these concepts into a model of the German energy system and use the energy system optimization model BENOPTex to evaluate their economic viability. In various sensitivity analysis, we determine the most cost-effective land allocation for energy production on the 2.16 million hectares currently used for energy crops. Results indicate that, under current yield and cost assumptions, neither Agri-PV nor agroforestry systems outperform monoculture systems (e.g. Miscanthus) or ground-mounted PV. However, the analysis identifies yield and cost thresholds at which specific combinations become competitive. For example, a Miscanthus-sugar beet agroforestry system becomes viable with a 6% yield increase in Miscanthus compared to the monoculture yield. Despite their current economic disadvantages, Agri-PV and agroforestry offer non-monetized benefits including biodiversity enhancement and climate resilience. The study concludes that bridging the economic gap may require valuing these co-benefits or achieving significant cost and yield improvements through research and innovation.