  Energy management, in sense of computing optimized operation schedules for
devices, will likely play a vital role in future carbon neutral energy systems,
as it allows unlocking energy efficiency and flexibility potentials. However,
energy management systems need to be applied at large scales to realize the
desired effect, which clearly requires minimization of costs for setup and
operation of the individual applications. In order to push the latter forward,
we promote an approach to split the complex optimization algorithms employed by
energy management systems into standardized components, which can be provided
as a service with marginal costs at scale. This work is centered around the
systematic design of a framework supporting the efficient implementation and
operation of such forecasting and optimization services. Furthermore, it
describes the implementation of the design concept which we release under the
name \emph{Energy Service Generics} as a free and open source repository.
Finally, this paper marks the starting point of the \emph{Open Energy Services}
community, our effort to continuously push the development and operation of
services for energy management applications at scale, for which we invite
researchers and practitioners to participate.
