Maximum deviation: 0.1% from proven global optimum.
Why the Refinement Matters
Before the marginal-cost refinement loop, the gap at 50% demand was 2.12%. The BEP-Gravitation slope estimate pushed 14.6 m3/h to C5 (costing 5.0 kW) when the optimum was 6.5 m3/h (0.59 kW). The refinement loop corrects this by shifting flow from highest actual dP/dQ to lowest until no improvement is possible.
Stability
Sweep 5-95% in 2% steps: 1 switch (rising), 1 switch (falling), same transition point. No hysteresis. See Pump Switching Stability.
Computational Cost
0.027-0.153ms median per optimization call (3 pumps, 6 combinations). Uses 0.015% of the 1000ms tick budget.