The new Power Surface Approximation (PSA) method was added to the Optimization Power category. The method allows for the modeling of dynamic Operating Head to be incorporated into Optimization Power modeling. The method introduces a new variable, PSA Head Factor, which represents the weighted contributions of Storage, Spill and Tailwater Base Value (if applicable) to Operating Head. The method generates a set of planes to constrain power as a function of Turbine Release and the new PSA Head Factor. The method provides a significant improvement in the Power approximation error for projects that exhibit a wide range of Operating Head over the course of the run. Full documentation of the new method can be found Power Surface Approximation in Optimization

A new category, Optimization Reserves, was added to Power Reservoirs. The category is dependent on the Optimization controller being selected and either Plant Power Coefficient or Plant Efficiency Curve being selected in the Power category. The new Constraint Based Single Timestep method in the category allows users to account for power reserve requirements in the optimization policy. The method introduces a set of duplicate variables that represent the value of standard variables assuming full deployment of either upward or downward reserves. In the RPL Optimization Goal Set, the users can then write parallel constraints using the duplicate reserve variables for any constraint that cannot be violated while deploying reserves. The purpose of the new variables and their parallel constraints is so that the only reserves that are credited to a hydropower project are those that can actually be reasonably deployed. In other words, it will not “count” reserves that could not be deployed without violating specified constraints. The new method also introduces new variables for upward and downward reserves, which allow the user to write policy on the reserves themselves, for example, minimum reserve requirements at individual reservoirs or total system reserve requirements. Full documentation of the new method can be found Optimization Reserves in Optimization.