Cloud providers are adapting datacenter (DC) capacity to reduce carbon emissions. With hyperscale datacenters exceeding 100 MW individually, and in some grids exceeding 15% of power load, DC adaptation is large enough to harm power grid dynamics, increasing carbon emissions, power prices, or reduce grid reliability. To avoid harm, we explore coordination of DC capacity change varying scope in space and time. In space, coordination scope spans a single datacenter, a group of datacenters, and datacenters with the grid. In time, scope ranges from online to day-ahead. We also consider what DC and grid information is used (e.g. real-time and day-ahead average carbon, power price, and compute backlog). For example, in our proposed PlanShare scheme, each datacenter uses day-ahead information to create a capacity plan and shares it, allowing global grid optimization (over all loads, over entire day). We evaluate DC carbon emissions reduction. Results show that local coordination scope fails to reduce carbon emissions significantly (3.2%--5.4% reduction). Expanding coordination scope to a set of datacenters improves slightly (4.9%--7.3%). PlanShare, with grid-wide coordination and full-day capacity planning, performs the best. PlanShare reduces DC emissions by 11.6%--12.6%, 1.56x--1.26x better than the best local, online approach's results. PlanShare also achieves lower cost. We expect these advantages to increase as renewable generation in power grids increases. Further, a known full-day DC capacity plan provides a stable target for DC resource management.

翻译：云服务提供商正在调整数据中心（DC）容量以减少碳排放。随着超大规模数据中心单个容量超过100兆瓦，且在部分电网中所占负荷比例超过15%，数据中心容量的调整规模已足以影响电网动态，可能加剧碳排放、推高电价或降低电网可靠性。为避免此类负面影响，我们探索了在空间和时间维度上协调不同范围的数据中心容量调整策略。在空间维度上，协调范围涵盖单个数据中心、数据中心集群以及数据中心与电网的协同；在时间维度上，范围从在线调整延伸至日前规划。同时，我们考虑了数据中心与电网所采用的信息类型（例如实时与日前平均碳排放数据、电价及计算任务积压量）。以我们提出的PlanShare方案为例，每个数据中心利用日前信息制定容量计划并共享，从而实现全局电网优化（涵盖所有负荷及全天时段）。我们对数据中心碳排放削减效果进行了评估。结果表明，局部协调范围难以显著降低碳排放（仅减少3.2%–5.4%）。将协调范围扩展至数据中心集群后，效果略有提升（减少4.9%–7.3%）。而采用电网级协调与全天容量规划的PlanShare方案表现最优，可实现11.6%–12.6%的碳排放削减，效果是最优局部在线方法的1.56–1.26倍。此外，PlanShare方案还能降低运营成本。我们预计，随着电网中可再生能源占比提升，这些优势将进一步扩大。同时，已知的全天数据中心容量规划为数据中心资源管理提供了稳定目标。