Energy Efficiency: A Best Practice Necessity for the Water Industry

Rising energy costs have made energy efficient technologies and the introduction of best practices increasingly valuable to all organizations. The water and wastewater industry has however been reticent to accept some of these energy efficient practices. For water and wastewater operators, strained budgets coupled with an aging infrastructure make the pursuit of energy efficiency a necessity today. Furthermore, by introducing energy efficient technologies the industry can feasibly reduce their operating costs. Here’s how:

Water and wastewater industries rely heavily on grid-supplied electrical energy to power equipment for the conveyance and treatment of water. Large pumps and motorized processes handling millions of gallons of water per day are among the largest energy expenses for many municipalities. The energy demands of water and wastewater treatment facilities for example comprise over 30% of many municipalities’ operating budgets.

As many in our industry recognize, trimming the use of blowers by managing dissolved oxygen (DO) levels, represents the low hanging fruit for saving energy dollars. While this wisdom is widely accepted, many facilities can’t take advantage of this saving, because they are unable to modify the blower demand given the lack of variable frequency drives on the blowers. In these cases, facility management should take a more holistic view of the overall energy profile in the plant to evaluate cost savings opportunities – for example, by limiting the number of motors starting simultaneously or shifting loads to off-peak hours. In executing a holistic analysis, management may discover unique opportunities to improve efficiency, manage loads and lower costs by fine-tuning the timing of operations relative to each other and to the time of day.

In addition to managing consumption (kWh), management should also carefully evaluate the impact of demand (kW) charges associated with many electric tariffs. These charges can account for as much as 50% of the total bill if not kept in check. Understanding how individual plant equipment contributes to these charges is as important as managing the overall plant consumption. When evaluating new technologies for plant upgrades, it’s equally important to determine what impact the equipment under consideration may have on the demand charges each month.