Energy-intense enterprises that flexibilize their electricity consumption can market this either at electricity spot markets or by offering ancillary services on demand, such as balancing power. We formulate optimization of the balancing power bidding strategy as a mixed-integer nonlinear program considering both price forecasts for the ancillary service market and hourly varying spot market prices. We solve this two-stage approach by decomposition into a nonlinear bidding problem and a mixed-integer linear scheduling problem. We consider aluminum electrolysis participating in the German primary balancing market. We show savings in weekly production costs of 5–20% compared to stationary operation. The savings due to the optimal bidding strategy are up to twice the savings from pure exploitation of electricity spot market price spreads. We thus demonstrate that energy-intense processes can systematically take advantage of highly profitable demand-side management measures beyond a spot market price adjusted production.

灵活利用电力的能源密集型企业可以在电力现货市场或通过按需提供辅助服务（例如平衡电力）来进行销售。考虑到对辅助服务市场的价格预测和按小时变化的现货市场价格，我们将平衡力竞价策略的优化制定为混合整数非线性程序。我们通过分解为非线性投标问题和混合整数线性调度问题来解决这种两阶段方法。我们认为铝电解参与了德国主要的平衡市场。与固定运行相比，我们发现每周的生产成本节省了5–20％。由于采用了最佳的竞标策略，因此节省的费用是纯利用现货电价差价节省的费用的两倍。