NRG Energy Center Minneapolis

Transcription

1 NRG Energy Center Minneapolis Beyond the Strip Chart: Drivers, Goals and Lessons Learned in Customer Metering Modernization Presented by: Tim Johnston, P.E., NRG Energy Center Minneapolis at the IDEA 99 th Annual Conference and Trade Show July 2, 2008 in Orlando Florida

2 Presentation Outline Overview of NRG Energy Center Minneapolis District Heating and Cooling System Drivers and Goals for Initial Customer Telemetry Installation Initial Customer Telemetry System Architecture Experiences and Lessons Learned From Initial Installation Drivers and Goals for 2005 System Upgrade and Enhancement Overview of Current System Architecture Experiences and Lessons Learned From Enhancement Project Future Goals and Initiatives Questions

3 OVERVIEW OF NRG ENERGY CENTER MINNEAPOLIS Organization Privately owned District Heating and Cooling Company Non Regulated One of eight NRG Thermal Companies Fully owned subsidiary of NRG Energy Inc.

4 OVERVIEW OF NRG ENERGY CENTER MINNEAPOLIS Operations Began both heating and cooling operations in 1972 Currently serve 52 chilled water customers and 101 steam customers Utilize primarily 250 psig or 150 psig steam for heating. One customer served via hot water. Maximum steam production capacity - 950,000 lb/hr Peak steam demand 700,000 lb/hr Maximum chilled production capacity 33,000 Tons Peak cooling demand 31,000 Tons

5 OVERVIEW OF NRG ENERGY CENTER MINNEAPOLIS Distribution System Map Aqua Chilled Water Customer Red Steam Customer Red & Aqua Steam & Chilled Water Customer Orange Steam & Condensate distribution Blue Chilled Water Distribution Yellow Production Facilities

6 OVERVIEW OF NRG ENERGY CENTER MINNEAPOLIS Financial 20 year contracts for steam and chilled water Demand charge for both steam and chilled water based on one hour rolling average Billed 12 months of the year Sliding rate scale, higher demand = lower rate Demand adjusted annually based on previous heating and cooling seasons peak demand. Demand can float between 90% of contract demand and actual recorded demand in excess of contract demand Consumption charge for both steam and chilled water Pass through of actual operating expenses, i.e. fuel, maintenance, labor, taxes, insurance, etc. Sliding rate scale, higher consumption = lower rate True up at the end of the year

7 INITIAL CUSTOMER TELEMETRY PROJECT Project Drivers System at the time served 28 chilled water customers and 82 steam customers With the building boom of 1990 s significant expansion was expected to occur in the next five years Historical data was limited to totalizers combined with strip or circle chart recorders displaying instantaneous flows, pressures and temperatures. Meters were only able to be checked on a bi-weekly basis High incidence of torn charts, empty ink pens or failed recorders resulted in lost demand revenue due One hour rolling average demand had to be extrapolated by manual inspection of multiple charts for the last heating and cooling season

8 INITIAL CUSTOMER TELEMETRY PROJECT Project Drivers Cont d Paper charts had proven to be an difficult tool to use when attempting to advise customers Large mix of energy computer manufacturers utilized made maintenance and calibration activities more difficult Two major distribution expansions were planned, the largest of which, serving a new remote satellite plant required a dedicated communications link back to the main plant.

9 INITIAL CUSTOMER TELEMETRY PROJECT Project Goals Connect largest steam & chilled water customers along route of two proposed expansions to a real time metering telemetry system Customers with the greatest potential for financial loss Begin to standardize on a smaller set of energy computer manufacturers. Improve accuracy of calibrations and configuration Utilize off the shelf, proven equipment and software to the maximum extent possible. Limit the need for extensive staff training Provide means of centrally archiving retrieved customer data. Simplify data back-up process and software maintenance

10 INITIAL CUSTOMER TELEMETRY PROJECT Project Goals Cont d Provide graphical interface and trending package (HMI) to permit access to the historical data for review and analysis Permit more timely review and monitoring of meter performance Provide more useful tools to assist in verifying the accuracy of Customer meters Provide more useful tools to assist with working with Customers to improve energy consumption Provide better back-up documentation to verify invoiced demand charges

11 INITIAL CUSTOMER TELEMETRY PROJECT Initial System Architecture Two fiber optic main lines were installed along the routes of the two distribution expansion projects. Fiber optic modems were placed at multiple nodes along the path of the two fiber circuits Fiber modems were connected to RS-485 multiplexers Twisted pair RS-485 circuits were extended from multiplexers to individual customer buildings

12 INITIAL CUSTOMER TELEMETRY PROJECT Initial System Architecture Cont d Fisher ROC 300 series remote operations controllers (RTU s) were selected for use as energy computers in Customer buildings. Off the shelf product Proven track record Flexible configuration capabilities, i.e. one hour rolling average capability Modular designs with capacity for future I/O expansion RS-485 communication capability Excellent local sales, service and programming assistance support

13 INITIAL CUSTOMER TELEMETRY PROJECT Initial System Architecture Cont d Intellution FIX32 was selected for HMI Off the shelf product Proven track record Numerous local service and programming sources Very flexible configuration options. But Did require development of custom communications driver by HMI manufacturer for communication with RTU s Implementation Phase I added 16 customers to the system in 1997 Phase II added 9 customers to the system in 1999

14 INITIAL CUSTOMER TELEMETRY PROJECT

15 INITIAL CUSTOMER TELEMETRY PROJECT Progressive Enhancements Upgraded to IFix and IHistorian as Intellution product developed. Attempted to add five new customers to system utilizing 2.4 GHz radio communications. Added 5 additional customers to the hardwired RS-485 system

16 INITIAL CUSTOMER TELEMETRY PROJECT Operational Experience and Lessons Learned Original fiber modems and RS-485 multiplexers were very susceptible to failure due to power surges from lightning strikes. Reliability of custom communications driver between HMI and RTU s was quickly overcome as more devices were added. As time went by finding qualified engineers to make changes to the custom communications driver became difficult Initial and later versions of HMI databases crashed often and or became corrupted following communications interruptions or when attempting to add new customers

17 INITIAL CUSTOMER TELEMETRY PROJECT Lessons Learned Cont d Local support for the HMI product was not up to expectations Consistent communications interruptions combined with lack of significant internal data storage on RTU s resulted in excessive lost historical data 2.4 GHz radio communications reliability was very poor Thick client architecture of HMI product made keeping software up to date more difficult. It was difficult for individual users to customize trends and reports, limiting the effective use of archived data

18 2005 UPGRADE & ENHANCEMENT PROJECT Project Goals Eliminate custom communications driver Eliminate need for data to flow through HMI database to historian database Create additional data archiving redundancy Move to web based thin client software applications Streamline software maintenance and upgrade efforts Provide end users more flexibility in determining how they view, analyzing and report archived data Move to RTU s with more onboard historical data storage Move to more reliable radio communications system Move telemetry system to a dedicated network

19 2005 UPGRADE & ENHANCEMENT PROJECT Implementation Developed standard policy for which new and existing customers would be added to the telemetry system. Policy was roughly based on the cost of implementation providing a two year or less payback based on lost demand revenue All customers taking both steam and chilled water would be connected to real time telemetry via hardwire or 900 MHz radio. Developed functional specification for enhanced system Solicited proposals to complete study and provide a report with recommendations for multiple implementation options

20 2005 UPGRADE & ENHANCEMENT PROJECT Implementation Cont d Selected Matrikon Inc. to complete the study Upon receipt of study report conducted review meetings with stakeholders to reach a consensus on a selected implementation option Partnered with Matrikon Inc. to implement the system enhancements

21 2005 UPGRADE & ENHANCEMENT PROJECT Selected Architecture Retained existing fiber optic and RS-485 communications backbone but upgraded fiber modems and installed protection devices in front of RS-485 multiplexers to eliminate failures due to lightning strikes Selected Fisher ROC800 series equipment for all new and some existing customer RTU s to be connected to real time telemetry system. Greater on board history storage and Ethernet capable Selected Yokogawa DAQStation paperless chart recorder for customers RTU s not connected to the real time telemetry system Smart data card storage which could be retrieved on biweekly routes

22 2005 UPGRADE & ENHANCEMENT PROJECT Selected Architecture Cont d Replaced custom communications driver with AutoSol Enterprise OPC Server Open, widely implemented communications standard Installed dedicated T-1 line between plant and corporate office Installed dedicated servers for each core application Customer data collection, Plant data collection, Central data archive and HMI server Installed multiple routers and switches to ensure system security Abandoned 2.4 GHz radio communications systems and moved to 900 MHz radio communications system Required all radio installations to have line of sight data transmission

23 2005 UPGRADE & ENHANCEMENT PROJECT Selected Architecture Cont d Commissioned Matrikon to develop application to automatically import customer metering data from smart cards retrieved from paperless chart recorders Replaced existing Historian with multiple installations of Matrikon OPC Desktop Historian (ODH) Open OPC standard Very cost effective for small tag count Two installations in main plant, one for customer data and one for plant operating data and one installation in corporate office in IDS tower

24 2005 UPGRADE & ENHANCEMENT PROJECT Selected Architecture Cont d Replaced existing HMI with Matrikon Operational Insight, web based thin client application Only one location to maintain and upgrade Utilizes open OPC standard Built in tools for creating trends, graphs and reports Supports current widely used custom configuration tools, HTML, Java, etc. Provides users flexibility to modify how they view analyze and report data Easily create custom trends or modify and save existing trends Export trend data directly to Microsoft Excel Has tools to import historical data directly into Microsoft Excel from ODH based on user selectable date ranges, sample periods and data functions, (maximum, minimum, average)

25 2005 UPGRADE & ENHANCEMENT PROJECT GENERAL SYSTEM ARCHITECTURE

26 2005 UPGRADE & ENHANCEMENT PROJECT DETAILED NETWORK ARCHITECTURE

27 2005 UPGRADE & ENHANCEMENT PROJECT HMI MAIN PAGE Click on Building to bring up overview sheet Tree menu can be used as alternate to interactive graphics

28 2005 UPGRADE & ENHANCEMENT PROJECT HMI CUSTOMER OVERVIEW SHEET Click on bar to bring up trend Current values

29 2005 UPGRADE & ENHANCEMENT PROJECT HMI CUSTOMER TREND Export current trend to Excel Add/modify/delete trend tags Scroll forward/backward % of current time window Set specific time window Change time window

30 2005 UPGRADE & ENHANCEMENT PROJECT Progressive enhancements Added 12 more customers to the real time telemetry system for a current total of 51 Added 6 customers to smart card based system for a total of 11 Commissioned Matrikon to create a Customer Demand Management Application Application automatically updates and stores peak instantaneous demand and six highest one hour average demands. Recorded demands are linked to corresponding historical trends Data is archived based on heating or cooling season utilizing SQL database facilitating advanced queries for reporting and analysis

31 DEMAND MANAGEMENT APPLICATION SUMMARY TAB WINDOW Select the season and year Expand Customer Information

32 DEMAND MANAGEMENT APPLICATION EXPANDED CUSTOMER DETAIL SCREEN Add specific notes for each demand Checking box disregards demand Six Highest Peaks Clicking on value brings up 24 hour window trend

33 DEMAND MANAGEMENT APPLICATION CUSTOMER INFORMATION SCREEN Automatic Application records demands Manual Demand input manually from strip charts OPC Demand Tags

34 2005 UPGRADE & ENHANCEMENT PROJECT Operational Experience and Lessons Learned Implementation went fairly smooth. A few minor issues getting RTU s to synch up to OPC Server. Communications issues have all but eliminated Software packages have been very reliable with minimal outages System is very easy to maintain, expand and modify Vendor service and support has been excellent Increased flexibility in trending and reporting has greatly increased the usability of the archived data.

35 FUTURE GOALS Improve ability to monitor and troubleshoot meter and telemetry system accuracy Currently soliciting proposals to implement a equipment condition monitoring strategy Install remote historian nodes at select locations in the system Upgrade RS-485 communications trunks to Ethernet via fiber or CAT6 cable Add approximately 10 additional existing customers to real time telemetry system Add approximately 15 additional existing customers to smart card based system Enhance operator interface screens to provide more pertinent targeted information Dashboard approach utilizing KPI s

36 FUTURE GOALS Develop application to predict customer building operation based on historical usage and weather Develop application to permit benchmarking actual customer building performance against both predicted building performance and historical performance of that customer and similar class buildings. Better Integrate Customer data with Plant Operational data Develop program to utilize predicted customer demands to help advise operating staff of what equipment to run and when Integrate customer demand data with steam and chilled water hydraulic models Initially - validate existing models Future - Make models dynamic to pumping and production equipment selection

37 WRAP UP Thank you for your attention QUESTIONS? Special thanks to our integration partner Matrikon Inc. for their assistance in preparing this presentation Contact Information: Tim Johnston Phone: (612)