This seminar will address current motivations and ambitions in Denmark in terms of power-to-X, and then will focus on convex modeling of the physics of electrolyzers and compressors as accurate as possible. Next, it will be discussed how a hybrid power plant including co-located wind, battery, electrolyzer, hydrogen buffer tank, and compressor can be operated in a stochastic environment to earn the highest potential profit by optimally trading in different markets, including power and ancillary services.