Saving Energy

Minimizing Specific Energy Consumption (SEC)

Specific Energy pioneered the concept of operating water pump systems to minimize Specific Energy Consumption (SEC). SEC is defined as the kilowatt-hours (kWh) consumed per million gallons (MG) pumped, making it a comprehensive, high-level measure of pump station efficiency that accounts for the many complex variables within the system. Specific Energy's Optimization Suite continually recalculates the optimal pumps and speeds that deliver the required flow at minimal energy consumption. Customers typically see a 10% to 25% reduction in energy costs with Dynamic Pump Optimizer (DPO).

The DPO measures a pump station’s SEC in real time so operators can make informed decisions to optimize the overall water system. By monitoring SEC over time, operators can track reduced equipment efficiency due to pump impeller wear and more accurately schedule service calls.

Specific Energy's Solver

Every few minutes, the DPO calculates a new solution for the map of SEC versus flow values. The DPO uses models of individual pumps, learned through periodic, automatic tests, to simulate all pump combinations and calculate the optimal SEC for each combination. The DPO then selects the pump combination that delivers the required flow at the lowest possible SEC.

The DPO must calculate a new solution for the SEC versus flow map every few minutes because the solution can change frequently as system conditions change. Changes in tank levels, demand, and valve configurations will all affect the SEC Map solution, and thus the optimal configuration of pump speeds and combinations for a given flow.

Because of the dynamic nature of pump station operation, it is not possible to consistently operate at minimum SEC without continually re-solving new SEC Map solutions in the face of changing system conditions. By continually re-solving the SEC Map solution, Specific Energy ensures that your pump stations are operating at their minimum SEC.

The figure above shows an SEC Map solution computed by the Optimization Suite. The operator can interact with Specific Energy's user interface to view pump speeds and predictions for flow, SEC, and pressure at specific points on the SEC Map.

In Dynamic Pump Optimizer (DPO) Mode, the DPO selects the optimal pump configuration using the latest SEC Map solution, and informs your PLC of the desired pump combination.