Water Source (or Supply Side) Efficiencies: Energy Saving Investigation Process
What do the icons below mean?
- To begin with, ask yourself, “Is the source water actually making it to a tank? Does it really need to?” (See Leaping.) This can be modeled and monitored in a SCADA system setting.
- Run sources (or prioritize them) based on energy costs per unit of water (also known as Specific Energy), and choose the most efficient sources first—given water rights and other water quality implications and considerations. This figure would be in a unit such as kwh/Acre-foot, or kwh/MG, or kwh/1000 gallons, etc.
- Monitor well Specific Capacity (standard flow per standard drawdown unit, such as gpm/foot) on a real-time basis using SCADA to test for changing well efficiencies overtime or by season.
- Through a change application process with the State Engineer, determine whether water rights could be transferred from an expensive source to a less expensive one. Or could multiple sources or points of diversion share the same water rights, allowing you to have greater flexibility in how you operate sources.
- Monitor in real time with SCADA, and log sources and pumping systems for not only Specific Energy, as discussed above, but also Specific Power. This process allows you to see the effect of the demand component of your power bills and take steps to minimize its impact (i.e., should I use off-peak or load factor extension strategies). This calculation is typically expressed as kw/gpm or gpm/kw. This figure, along with Specific Energy, as described above, is also often used to check for the trending of pump efficiencies overtime, and possible needs for well and pump maintenance.
- Remain current on all water source protection plans and work to mitigate any possible threats to said sources. Ensure that each source has an approved and recorded protection zone. Work with city or county officials to assist in the adoption of a source protection element to a zoning code or regulation. Losing a source, either temporarily or permanently, can cost the public and the environment significantly.
- Monitor total source production monthly and daily if possible. Tie source capacity to the number of standardized ERCs to establish a running trend of capacity utilized and available, as well as overall efficiency.
- Well Issues:
- Well screen maintenance issues creating a greater draw-down than the well was originally equipped for.
- Excessive VFD Harmonics or inadequate filtering, along with issues associated with excessive cable lengths between the VFD and motor.
- Improper well power cabling used for a VFD controlled motor.
- Well pump and/or motor sizing errors or condition changes over time.
- Line drive well-pumping systems are typically more efficient than submersible pump systems, if the well can be equipped for such and has the proper characteristics.
- Undersized well casing, preventing more efficient pump and motor selections.
- Corroded or leaking pump column piping.
- Spring Issues:
- Loss of flows due to roots or damaged collection systems.
- Lack of vegetation control in the spring collection areas.