Water Distribution Optimization: Taking SCADA One Step Forward: A Case Study

1. Water Distribution Optimization: Taking SCADA One Step Forward: A Case Study Chuck Weber - WaterOne Simon Bunn – Derceto Inc

2. 1950’s – 1970’s Control room

3. PLC and RTU provide local control

4. 1970’s : Mixed auto/manual systems

5. 1980’s : SCADA systems appear

6. 1990’s :Historical Databases arrive

7. 1990-2000 Smart Instruments arrive

8. WaterOne is a quasi-municipal agency that provides water to more than 400,000 individuals • WaterOne serves residential and commercial accounts in 16 cities in the Johnson County area. WaterOne serves approximately 135,000 customers. • WaterOne has nearly 3,000 miles of transmission and distribution mains, equal to the distance from Kansas City to Seattle. • WaterOne's service area covers more than 270 square miles. • WaterOne’s current treatment capacity is 180 millions gallons per day. 

10. Modern UCOS Scada System • Single control room for treatment and distribution • Installed in 1991, upgraded 2006

11. What next after Scada?

12. Decision Support Systems

13. Energy cost minimization is a good target, as it is one of the highest costs in producing the “next gallon of water.” "The more than 60,000 water systems and 15,000 wastewater systems in the United States are among the country’s largest energy consumers, using about 75 billion kWh/yr nationally – 3 percent of annual U.S. electricity consumption."Electric Power Research Institute, Energy Audit Manual for Water/Wastewater Facilities, (Palo Alto: 1999), Executive Summary. What to optimize?

14. Electricity Use by WaterOne

15. Energy and Demand Charges • Pricing is based on two components, energy use in kWh and demand in kW Car Analogy for kWh and kW • kW is like the speed that is measured by a speedometer • kWh is the distance measured by the odometer

16. Electricity Supply tariffs • Kansas City Power & Light (KCPL) • Flat kWh tariff applies 24 hours day, 365 days year • Flat demand charge, 24 hours a day, 365 days year • Kansas City Board of Public Utilities (KCBPU) • Flat kWh tariff applies 24 hours day, 365 days year • Demand charge only applies 10 hours/weekday with monthly peak and 70% of highest summer peak setting winter charge (effectively a 12 month ratchet clause) • Almost no incentive at all for shifting electrical load • No options for time-of-use or real-time pricing • Last KCPL tariff structure changes were made10 years ago • Market is unlikely to change or deregulate in the mid term

17. Solving the energy equations Numerically impossible to solve, but the following techniques have been attempted • Localized optimization at each pump station using profiling or time triggers • Expert Systems using cascading rules • Advanced techniques using Genetic Algorithms • Multi-Objective Polynomial Systems (MOPS) • Dynamic Programming with Stochastic analysis All still make considerable assumptions and do not achieve optimality A 2001 AWWA report said “the market is waiting for an off-the-shelf solution”

18. A New Customized-Off-The-Shelf tool • Over the last 4 years, Derceto Aquadapt has implemented energy cost optimization systems with leading US water utilities • Five key cost reduction techniques were employed • Electrical load shifting in time, to maximize utilisation of low cost kWh tariff blocks (time-of-use tariffs) • Peak electricity kW demand reduction • Energy efficiency improvements from pumps and pumping plants. • Utilization of lowest production and chemical cost sources of water. • Utilization of shortest path between source and destination • WaterOne benefited primarily from peak demand reduction and lowest cost source selection

19. Key Energy Management Modules Operator Panel PC on LAN SCADA Interface OPC Primary Database Current day / real-time Aquadapt Primary Database (Live Server) Data Cleaner Optimizer Operations Simulator Application Manager Aquadapt Back-up Database (Historical Server) Backup Database PC on LAN Dashboard PC on LAN WaterOne UCOS SCADA System

22. Project Timeline • Feasibility Study - June 2004 to August 2004 • Detailed Design - September 2004 to April 2005 • Configuration and Testing - July 2005 to Mar 2006 • Delivery, Implementation and Site Testing - April/May 2006 • Had to be ready in time for peak summer demand otherwise majority of savings would be lost for 2006/07 • WaterOne created and maintained an audit tool to measure savings on a monthly basis. This is a sophisticated analysis tool • Uses formulation of kW versus MGD from four previous years • Created non-linear functions to calculate kW at each major point • Allowed for changes in tariff in future years to be incorporated • Maintenance, Enhancement and Support contract started in June 2006 with latest Aquadapt version 5.5 rolled out in 2008

23. Peak Demand Reductions 5 MW Reduction

24. Even after a major Pipe-break

25. Results to date – Electricity $ savings • First month of operation May 2006, saved $90,000 • First year of operation May 06 to April 07 saved $565,000 • First six months of 2007/08 saved $553,000 • Total of $1,118,000 saved in 18 months of operation • Reduced greenhouse gas emissions by 4800 tons/year Other impacts • Has required changes in operation, but no additional hardware or instrumentation was required • Operators were involved all the way through the process and had valid concerns which needed to be addressed • Ongoing program of training and product enhancement is helping culture change and acceptance • Aquadapt is now being used to identify areas where further savings can be made

29. Conclusions • The considerable investment in a Scada system is often hard to justify financially, but it is an essential tool • Utilization of the data and interfaces presented by a Scada system in areas such as planning and operations optimization can provide additional financial benefits • Even in an energy market that looked unfriendly to energy optimization, significant benefits were achieved • Buying advanced software “off-the-shelf” reduces risk • Use robust systems to measure the benefits to avoid doubt • Operators need to be involved from start to finish, they know the treatment and distribution systems best • This is just one step in the path to operations optimization, keep an eye on costs and benefits in all areas to best serve your customers

30. Questions?