Mark Puckett is vice president of product development for XiO, Inc. Puckett can be reached at [email protected] or 415.299.9095. Jared Bouchard is general manager for Pleasant Valley County Water District. Bouchard can be reached at [email protected] or 805.207.1588.
undefinedLocated in Camarillo, California, Pleasant Valley County Water District (PVCWD) supplies irrigation water to agricultural end-users in Ventura County.
In keeping with the state of California’s broad goals of slowing the growth of energy demand statewide, PVCWD was offered a financial incentive in the form of a rebate to improve the energy efficiency of their pumps. Essentially, the district needed to pump the same amount of water using less energy.
Revised Water Sampling Rules
While district staff sought to optimize operation of 11 groundwater pumps via automation, they considered the up-front costs associated with custom engineering and programming for a traditional SCADA system, as well as the on-going expenses for maintenance, programming and updates on a SCADA server.
When considered together, the hardware and software costs made the overall project cost prohibitive. Concerned about rising operational costs, the district pivoted to an emerging solution that leveraged the power of cloud computing to reduce automation and control system costs while increasing efficiency and security. The result was the successful award of a $50,000 rebate and a reduction in annual energy costs of more than $110,000 per year.
Equally important was the shift away from a traditional SCADA hardware and software system to a cloud-based model, which offers dramatically lower operating costs. Overall, the project achieved a return-on-investment of less than one year, but the reduction in operating costs (energy, staff, consulting, programming, upgrades), is ongoing.
Seeking Energy Efficient Improvements
PVCWD delivers approximately 15,000 acre-feet of water each year to a service area of approximately 10,000 irrigated acres. Delivering consistent irrigation water in a temperate climate with no measurable precipitation for more than nine months of the year requires the district to meet customer demand through a diverse water supply portfolio that includes surface water and groundwater, which fill a large open reservoir before being pumped to customers.
The district prioritizes the use of surface water from the Santa Clara River and nearby Conejo Creek first, depending on stream flow and availability. Eleven deep groundwater wells are used to augment surface water supplies, especially during periods of drought and extended dry seasons. The District operates the 200 HP well pumps intermittently throughout the year, yet the electricity to operate them, in addition to three booster pumps, is a major financial expense to the district.
Southern California Edison (SCE), the regional power company in Southern California, offers numerous rebate and incentive programs to municipal customers such as water districts to improve energy efficiency and reduce overall energy demand. PVCWD enrolled in the Southern California Regional Energy Network (SoCalREN) Public Agency Program offered by the county of Los Angeles and implemented by The Energy Coalition, and the Water Infrastructure and System Efficiency (WISE) Program offered by Lincus Inc., an energy-demand side management consulting firm, in early 2018.
Pump Sequencing Algorithms & Optimized Performance
The district was interested in an effort to identify, implement and facilitate incentive payments for energy efficiency projects. Staff from Lincus provided an initial evaluation to determine potential efficiency gains available to PVCWD through the development of a pump sequencing algorithm to optimize pump performance using energy intensity rates for the 11 well pumps in the service area.
While the pumps were meeting the variable water demands of PVCWD’s customers, their energy intensity rates varied due to changes in normal pump efficiency and fluctuating groundwater levels. The project that was ultimately approved for the rebate program called for an automated system that would continuously evaluate energy intensity rates for all 11 pumps and order the operation of the most efficient (least energy-intensive) pump for the conditions at any given time.
In preparation for the project, PVCWD General Manager Jared Bouchard examined costs associated with a traditional SCADA system. To understand the true lifecycle costs of a proposed control system, he included both the initial capital costs for the system configuration and hardware with the ongoing operating expenses for software maintenance and support.
When considered as a whole, the hardware, programming, and ongoing software updates and support fees made the system cost-prohibitive for the district. The district operates with a small staff and there were concerns about the amount of staff and consultant time that could be required to troubleshoot and maintain an in-house system.
Software as a Services (SaaS) for the Water Sector
As the district began to seek out other solutions, they evaluated a Software as a Service (SaaS) model that offers cloud-based SCADA solutions as a service.
Just as Salesforce.com offers users a platform for customer relationship management that does not require a server and software, emerging cloud-based SCADA platforms offer automation and control systems to users from a web-enabled device.
After a thorough investigation, the district determined that XiO, a cloud-based SCADA provider with experience in engineering automation and control solutions for the water sector, could deliver the sophisticated pump sequencing programming required to meet the goals of the project. Use of the cloud platform eliminated the costs and staff resources required to maintain a dedicated physical SCADA server. The cloud platform also provided superior security with its built-in authentication and authorization for all users.
Cloud-Based Controls Realize Energy Savings
Following scoping meetings between PVCWD, Lincus and XiO, the first phase of the project moved forward. The initial challenge was to accurately measure energy intensity (kWh/AF) real-time.
Electricians installed field controllers and current transducers at each of the 11 well sites in March 2020. The field controllers were wired to read digital pulses from the existing water meters as well as inputs from the current transducers. The field controllers were then connected to each other using a combination of point-to-point radios and cellular modems. Once the field hardware and sensors were calibrated, data from each controller was transmitted via cellular modem to the cloud portal, where energy intensity rates were calculated daily and pump operations were programmed to change dynamically based on the energy intensity rankings.
The cloud platform provided PVCWD staff with secure access to monitor and control their system from any web-enabled device, as well as 24/7 access to technical support.
Since the project was part of a rebate program, representatives from Lincus worked with PVCWD to obtain two months of post-installation measurement and verification data to compare with baseline values collected earlier.
Post-installation data from June 18, 2020 to August 17, 2020, showed a reduction (savings) in kWhs of greater than 17% (5,340,144.2 kWh vs. 4,433,441.1 kWh). The savings in kWh (906,703.1 kWh) translated to a projected annual cost savings to PVCWD of more than $110,000 per year.
The total cost to implement the project was roughly $117,000. Based on the strong performance and energy demand reduction, PVCWD received the maximum financial incentive from the energy utility (50% of project cost). After factoring in the value of the incentive, the project demonstrated a simple payback period of roughly six months.
The annual fees for the cloud-based SCADA portal, including technical support, are less than $8,000 per year for the entire system. The project successfully demonstrated how leveraging the power of cloud computing can help utilities and municipalities gain greater levels of control and efficiency at affordable rates. Together, the ongoing energy cost savings and the savings from the cloud-based SCADA portal will enable PVCWD to fund other future infrastructure projects.
“PVCWD has realized a multitude of benefits that extend beyond the energy cost savings. Increased data collection, real-time monitoring of production and operational performance, and increased staff efficiency through the ability to prioritize well maintenance tasks has resulted in further savings by reducing overtime,” Bouchard said.
