1. A computer-readable non-transitory storage medium configured with data and with instructions that when executed by at least one processor causes the processor(s) to perform a process for managing power consumption and computational availability, the process comprising the steps of: monitoring electrical power consumption of a computational cluster which is operating at a current cluster capacity level; predicting demand for computational availability of the computational cluster based at least on a job queue length; determining that a threshold condition for switching the computational cluster to a different cluster capacity level is satisfied, the threshold condition based at least on the current cluster capacity level and the predicted demand; and ascertaining whether switching the computational cluster to the different cluster capacity level will violate a stability constraint of the computational cluster, the stability constraint based at least on a history of cluster capacity level switches within a period of time which is not earlier than a specified history cutoff.