On December 9th, 2025, Siwar Saadaoui defended her PhD thesis, which develops a comprehensive and spatially explicit framework for assessing the sustainable deployment of dedicated energy crops. Her work integrates land availability, food security, agronomic performance, and economic cost modeling to clarify the realistic contribution of these crops to net-zero strategies. The abstract of her dissertation is detailed below:
Abstract
Achieving carbon neutrality requires a combination of demand reduction, electrification, geological sinks, and bioenergy options—including BECCS—while respecting strict safeguards on land, water, carbon, and biodiversity. This dissertation is framed within this context, proposing an operational framework to assess the mobilizable—and sustainable—contribution of dedicated lignocellulosic crops, explicitly linking food security, agronomic performance, and cost economics.
The overarching objective is to move from theoretical potential estimates to a spatial and economic diagnosis useful for public decision-making and private investment: where to deploy these crops, under what conditions, at what costs, and along which expansion trajectory compatible with climate goals. The thesis builds on three complementary components, all aligned to a consistent resolution (5 arc-minutes) to ensure comparability between land availability, productivity, and costs.
The first component establishes a strict sustainability filter, in which only low-conflict areas are considered eligible. It integrates food security ex ante through the economic value of agricultural land, alongside environmental safeguards (carbon, biodiversity, water, soil quality). This approach narrows the admissible perimeter and addresses methodological critiques raised against conventional “land balance” exercises.
The second component develops global yield maps for the main dedicated species (miscanthus, eucalyptus, poplar, willow, switchgrass) using machine learning, explicitly accounting for soil and topographic heterogeneity at the same spatial resolution. This harmonization avoids the optimism bias associated with climate-only models and anchors productivity in the geography of costs.
The third component combines these layers to construct cost-ranked capacity curves and, subsequently, econometrically estimated cost functions (average and marginal) at grid scale. These yield regional supply curves that capture economies of scale, inflection points, and spatial heterogeneity relevant for planning—such as geolocated siting, sequencing of volumes, and economic instruments calibrated “at the margin.”
Taken together, these three components deliver a conservative and reproducible framework designed to inform climate and industrial policy. It connects the “where,” “how,” and “at what cost” of dedicated energy crops, and positions their role within a net-zero portfolio that will remain conditioned by genuinely sustainable land availability, water constraints, CCUS infrastructures, and land governance.
You can find more information about her work here.
