🤖 AI Summary
This study addresses the surge in AI-driven data center electricity demand and its unintended consequences for grid decarbonization. While renewable energy certificates (RECs) and power purchase agreements (PPAs) are commonly used to claim carbon neutrality, they often fail to ensure real-time matching between consumption and renewable generation, potentially exacerbating grid emissions, wholesale price spikes, and reliability issues. The authors develop a game-theoretic model that, for the first time, identifies and quantifies the negative externalities arising from temporal mismatches between AI-induced load and renewable supply. Leveraging the phased rollout of large language models as a natural experiment, they employ a difference-in-differences approach to validate their theoretical predictions. Results show that AI workloads significantly increase fossil fuel use, raise wholesale prices by up to 25%, and elevate outage frequency by 0.5–1 times annually. Co-locating behind-the-meter renewables with storage eliminates revenue risk and improves power quality, while edge inference and spatial load reallocation effectively mitigate grid impacts—unlike REC-only strategies, which prove ineffective.
📝 Abstract
Data centers now account for 4.4% of United States electricity demand, yet the grid-level effectiveness of the renewable energy certificates (RECs) and power purchase agreements (PPAs) hyperscalers use to claim carbon neutrality remains unclear. We develop a game-theoretic model in which a data center operator chooses among RECs, PPAs, and behind-the-meter colocation while generators make entry decisions under endogenous financing costs. The model identifies a timing wedge -- the mismatch between consumption and credited renewable generation -- as a central mechanism through which AI demand degrades reliability, raises prices, and increases emissions even when RECs cover 100% of annual consumption. Colocation with storage addresses this wedge directly and induces the greatest renewable entry by eliminating generator revenue risk. We test these predictions by exploiting the staggered release of large language models as a natural experiment, using difference-in-differences on a novel dataset linking AI activity to local grid outcomes. AI demand significantly increases fossil generation, wholesale prices (up to 25% in treated PJM zones), and outage frequency (0.5--1 additional outages per year) near data centers, with impacts scaling in model size. Data centers with on-site generation exhibit a sign reversal in power-quality effects, consistent with the model's prediction that behind-the-meter capacity absorbs demand spikes. Counterfactual analyses show that edge inference, spatial reallocation, and colocated storage each substantially mitigate grid impacts, while REC-only strategies do not. Together, our results demonstrate that the externalities of AI to the grid are tightly coupled to procurement design and the spatial organization of data center infrastructure.