arXiv:2604.06924v2 Announce Type: replace Abstract: Data centers unsettle the paradigm of location-bound electricity demand: computing workloads can migrate across sites and hours, whereas facilities and grid connections remain fixed. This mobility reduces electricity costs but reshapes the spatiotemporal structure of nodal prices. A model-driven framework couples US wholesale market signals with optimal fleet scheduling, showing how their interaction alters prices and other participants' responses. Greater flexibility enlarges savings yet can erode network benefits: in a Texas study, temporal shifting and cross-site allocation each relieve congestion, but their combination leaves total congestion nearly unchanged. At continental scale, computing demand gravitating toward cheaper electricity narrows price differences and compresses the low-price hours storage arbitrage relies on, threatening storage investment recovery. Cost-minimizing scheduling may therefore undermine grid-supporting resources. Comparing job-level and aggregate fleet representations reveals a trade-off between operational visibility and information disclosure, informing requirements and incentives that could turn workload mobility into a lever for system-wide efficiency.