Water Utility Energy Management Enters New Era

Throughout the 1990s, water utilities have been under increasing pressure to improve operational efficiency, customer service, and bottom line performance. One area that has been identified for this type of impact is energy management.

An energy management system for water utilities requires a total solution approach: it must automate the scheduling and operation of an entire water system and enable water utilities to effectively manage energy costs. Integrated with a water systems SCADA system, it should predict the daily demand profile, develop the most cost effective daily operating plan, and operate the water system according to plan within the operating rules and constraints set by the system configuration and the utility.

Three different factors are converging to make energy management not only viable, but critical. The first is growth in new technology, with open systems, industry standards and advances in computing power and database management creating a new paradigm in energy management. The second is the newly deregulated energy marketplace. Energy providers now have incentives to work with their customers to create cost saving opportunities. This is particularly the case with large energy customers, such as water utilities.

And finally, water utility managers are seeing changes in their regulatory environment and organizational structures that are creating opportunities for programs that have a significant bottom line impact. Since energy costs can approach 65 percent of a water utilitys annual operating budget, energy management can have a major impact in a relatively short period of time.

For a water utility to have a successful energy management program it must have a clear set of requirements in place before the program is implemented. All parties involved (i.e., users, vendors, and consultants) must be in agreement on these requirements, which include:

Operational Reliability & Quality: Water supply reliability and water quality need to be priority factors for all efficiency considerations.
Interoperability: Software modules need to effectively integrate with any SCADA system.
Universality: The applied algorithms need to be universal; that is, they need to be applicable to a broad range of water system configurations.
Running Mode: The system needs to be able to run in both an offline mode, for planning and "what if" scenario analysis, and in an online mode that can operate the water system automatically by closing the control loop.
Flexibility in Implementation: The utility needs to be able to redefine the water system configuration within the software system without having to involve the vendor (i.e., having to recode the software).
Flexibility in Operation: The system operator needs to be able to adjust the optimization solutions and/or override the forecasts & schedules that are generated.
User Interface: The system operator needs to be able to access, analyze and report data.

The American Water Works Associations Research Foundation and the Electric Power Research Institute are working together to underwrite a program to develop standards for energy management systems. The Energy and Water Quality Management System (EWQMS) project was initiated to establish a set of software and communications standards that can be used by water utilities to facilitate the implementation of systems to better manage their energy costs while not compromising water quality standards. The goal is to develop standard software modules that solve energy management and water quality problems.

Water utility energy management as an "industry" is in its development stage. One of the first systems available is EMPWR? from Westin (Sacramento, CA). It is comprised of:

Software designed for energy management, including demand forecaster, which develops 24-hour demand curves for each delivery point to be used for scheduling pumps and valves, and optimizer/scheduler, which includes a pump scheduler optimizer, a state estimator, and a cost calculator for both energy and water.
A services methodology allowing for data and project task results to be captured and shared through the software tools.

One key feature of the EMPWR? is that the energy management software tools will allow a water utility to adjust to changes in the energy supply market. In an energy market that has different players and rules on a seemingly daily basis, this is critical.

Conclusion

The water industry is poised for a major shift in how energy management is viewed and implemented. For the first time in the industrys history, the right technology is available at the right time for the right reasons. Energy management systems will be critical in most large water utilities within the next three to five years. And the industry and its customers will be the recipients of the benefits of this new technology.