  This work introduces solar, a collection of ten optimization problem
instances for benchmarking blackbox optimization solvers. The instances present
different design aspects of a concentrated solar power plant simulated by
blackbox numerical models. The type of variables (discrete or continuous),
dimensionality, and number and types of constraints (including hidden
constraints) differ across instances. Some are deterministic, others are
stochastic with possibilities to execute several replications to control
stochasticity. Most instances offer variable fidelity surrogates, two are
biobjective and one is unconstrained. The solar plant model takes into account
various subsystems: a heliostats field, a central cavity receiver (the
receiver), a molten salt thermal energy storage, a steam generator and an
idealized power block. Several numerical methods are implemented throughout the
solar code and most of the executions are time-consuming. Great care was
applied to guarantee reproducibility across platforms. The solar tool
encompasses most of the characteristics that can be found in industrial and
real-life blackbox optimization problems, all in an open-source and stand-alone
code.
