When every inch counts, does every pump-hour?

Gross benefit = potential units × economic unit value × realized share.

Full year-one cost = full upfront deployment + annual operating cost. Net = benefit − full cost. Year-one ROI = net ÷ full cost × 100. Each cost is subtracted once.

Simple upfront payback = upfront cost ÷ (annual benefit − annual operating cost) × 12 months, only if annual net benefit is positive. It assumes steady annual realization, not a discounted cash-flow forecast. Year-one break-even units = full year-one cost ÷ realized unit value.

Compare seasonally or annually recorded energy use with prior operating conditions, as NRCS specifies for energy-reduction analysis. Use pump-test power input, flow, lift, and discharge pressure; document irrigation-event volumes and timing. Normalize comparisons for operating conditions and meter coverage. The realization share is an explicit sensitivity assumption about the portion of scoped energy cost avoided—not the probability that a project succeeds.

These sources explain the economic mechanism and measurement—not Alma Hunter performance:

• USDA NRCS, Conservation Practice Standard 449: Irrigation Water Management (January 2024 proposed full text) — Defines irrigation water management as measuring and controlling water volume, timing, and application rate; describes scheduling using crop evapotranspiration, soil-moisture monitoring, local climate, and crop characteristics. Calls for event-volume and timing records, flow measurement, and—when reduced energy use is the purpose—comparison of average annual or seasonal energy use with prior operating conditions. The document says to check NRCS for the current standard.
• Bonneville Power Administration, Irrigation Pump Testing — States pump tests measure lift, discharge pressure, power input, and water flow; describes testing to assess pump performance and energy-saving opportunities such as pump or motor changes, VFDs, friction-loss reduction, or system redesign. Outcomes are opportunities identified by testing, not guaranteed savings.
• U.S. Geological Survey, Irrigation Water Use — Distinguishes irrigation withdrawals from consumptive use and notes that withdrawals include losses before field application, runoff, plant consumption, and aquifer recharge. Supports treating water accounting as a measured, site-specific quantity rather than assuming that a control intervention saves an equivalent amount of consumptive water.