BACKGROUND
Aqua Water Supply Corporation, the second largest water supply corporation in Texas, delivers retail water to customers in the greater Austin-area. Aqua’s service area covers 953 square miles and water is supplied from 29 production wells. Aqua is always looking to improve operational efficiencies by implementing innovative technologies and applying sound asset management practices. As an early adopter of technology, Aqua has established itself as a pioneer of efficiency in the water space.
THE CHALLENGE
Aqua has large well pumps that are significant consumers of energy. Several of these wells have variable frequency drives that allow pumps to operate over a range of speeds in response to varying demands and aquifer levels. Aqua was looking for technology that would continually adjust well pump speeds to minimise energy consumption while still meeting volume demands. In addition, Aqua wanted to identify a cost-effective way to increase production at the S8 Well site that would not require Aqua to drill a new secondary well.
THE SOLUTION
Aqua’s S8 well produces up to 1,800 gallons per minute (gpm) from the Carrizo-Wilcox aquifer. The well is powered by a 250 HP submersible motor with a variable frequency drive. Aqua selected Specific Energy to install Dynamic Pump Optimiser (DPO) at this well site to optimise pumping and improve production. After easy installation of the DPO edge device, energy consumption immediately dropped by 28%, while the well maintained production to meet demand. Specific Energy’s DPO delivered energy savings using a physics-based model looking at live sub-second sensor data, adjusting pump speed to achieve peak energy efficiency under varying system conditions. Data received from the DPO concluded that instead of running the pump 6 hours a day at full flow, the pump could run at half flow 13.1 hours and accomplish the same volume at an annual savings of 81 MWh (megawatt-hours) or $10,200/year.
RESULTS
Due to the use of DPO, Aqua now benefits from the following strategies which are not commonly seen in well field pumps.
- Aqua can confidently operate at the lowest speed/energy usage to keep pump within the prefered operating range (POR) and meet demand.
- Aqua can now track the historical performance of their aquifer and its impact on pump operation.
- Aqua has a dashboard that lets them know where the pump is operating on its curve and allows intelligent data gathering and infrastructure planning.
- Aqua can now operate and view their pump in such a way as to have confidence in the health of their infrastructure.
This project was completed at a very economical cost of $150,000, compared to a new well cost of over $2,000,000.
Since the DPO system was installed in 2012, the pump has run over 44,000 hours and pumped over 2.5 billion gallons of water without being pulled out of service once for maintenance.
