Hydraulic Head

Category: science

The vertical distance between the surface elevation of the source water reservoir and the turbine discharge point, determining the potential energy available.

Hydraulic head is the foundational metric of a hydropower asset's potential power output, directly driving the fluid pressure equations. It is categorized as "gross head" (the total static vertical drop) and "net head" (the actual pressure head hitting the runner after accounting for hydraulic friction losses within the penstock pipeline). High-head systems require less volume flow rate to generate identical megawatt capacities compared to low-head run-of-the-river assets.

Common Examples

• The hydro plant's power calculations factor in a three-hundred-foot hydraulic head to determine our peak megawatt generation capacity during spring runoff.
• A drop in the reservoir surface elevation directly reduces the effective hydraulic head, squeezing the plant's absolute mechanical efficiency.