Pump Sequencing: The Data-Driven Approach to Pump Operations
How is your organization using its data to increase energy efficiency? While water agencies and districts are typically collecting significant amounts of data, including water supply and demand and energy consumption, often they aren’t fully using it to their advantage.
Using such data can help your organization make strategic data-driven decisions that can increase site reliability, conserve energy, and automate processes, which can significantly reduce your operational costs.
One of the more effective ways of using this data is to implement pump sequencing, which automates and prioritizes pumping operations based on energy efficiency. Pump sequencing projects can save up to 22% of the system’s baseline energy consumption and typically pays back within 3 years.
How Existing Pumping Systems can Benefit from Pump Sequencing
Based on Lincus’ experience, most water districts and agencies do not automate the operation of their pumping systems. Making use of available data for automated pump sequencing allows for pumping operations to be more energy efficient, reliable and less labor intensive.
Through pump sequencing, energy savings are achieved as least energy intensive pumps are prioritized to meet water demands. In addition, automated pump sequencing require less manual intervention from operators whenever there is a change in water demands.
How Pump Sequencing Can Be Implemented for Energy Efficiency
Pump sequencing benefits organizations as it allows them to autonomously develop a prioritization strategy to determine the operation of pumps based on relevant metrics. For energy efficiency, the metric often used is kilowatt-hour (kWh) per acre-feet (AF), or kWh/AF. Essentially, kWh/AF is an efficiency metric that encapsulates the energy requirement of a given pump to deliver one AF of water. In other words, the higher the energy intensity for a given pump, the more energy it will consume to deliver per unit of water.
The ideal setup for pump sequencing is when an existing system has multiple pumps with varying energy intensities serving the same zone. Sequencing these pumps ensures that water demands are met using the most efficient pumps. Here’s an example:
Ensuring that most of the water demand is met by less energy intensive pumps is the essence of pump sequencing. In the example shown above, water production for the most energy intensive pumps (Wells #4 – 6) are shifted to less energy intensive pumps (Wells #1 – 3) through pump sequencing.
Implementing pump sequencing requires the flow and power of each pump to be measured and relayed to a control system. For water systems, this data is typically relayed to the Supervisory Control and Data Acquisition (SCADA) system. Algorithms need to be programmed into the SCADA system to automatically determine which and when pumps turn on and off based on energy intensities (and other constraints) for a given pumping system. Some of these constraints may include maximum contaminant levels (MCL), capacity of the pump, water supply sources and local code requirements.
With more than 15 years of experience in energy modeling, energy efficiency consulting, and energy and sustainability consulting, Lincus Inc. has provided technical expertise in the evaluation and implementation of various pump sequencing projects for water and wastewater customers. We want to help you become more energy efficient and sustainable.
Contact us for further details on how you can evaluate pump sequencing opportunities.