Clean Air Markets Program Data

1. Clean Air MarketsProgram Data UC Energy Institute University of California at Berkeley November 10, 2003 Martin Husk

2. Overview • How emissions and heat input are monitored • Monitoring system certification requirements and testing • On-going quality assurance testing • Contents of the Electronic Data Report

3. Overview • Quality assurance standards • Data availability • Uses of the data • Questions and answers

4. How Emissions are Monitored • Identify which pollutants require monitoring • Identify which other parameters may require monitoring

5. How Emissions are Monitored • Select the most appropriate monitoring type: • Continuous Emissions Monitoring System (CEMS) • Appendix D and E • Low Mass Emissions Methodology (LME) • Predictive Emissions Monitoring System (PEMS)

6. Continuous Emissions Monitoring System (CEMS) • Part 72 defines it as equipment used to “sample, analyze, measure and provide…a permanent record of emissions.” • CEMS consists of monitors installed in stacks and/or ducts, and a Data Acquisition and Handling System (DAHS). • Measure emissions and heat input every 15 minutes.

7. Types of CEMS • Conventional Extractive (Wet or Dry Basis Measurement) • Hot Wet - Wet Basis • Cool Dry with condenser near the CEMS Shelter - Dry Basis • Cool Dry with condenser at the probe - Dry Basis • Dilution Extractive (Wet Basis Measurement) • In Stack Dilution • Out of Stack Dilution • In-situ (Wet Basis measurement in the stack) • Point • Path

8. Conventional Extractive CEMS

9. Conventional Extractive Systems • Representative sample of the flue gas is continuously withdrawn from the stack, transported to a CEMS shelter and analyzed • Components of an extractive system • Probe • Sample lines • Filters • Moisture removal system • Pump • Analyzer • Extractive systems usually make measurements on a dry basis

10. Dilution Extractive CEMS(wet basis) • Flue gas is diluted with clean dry air to lower the dew-point of the sample • Eliminates the need for • Heated sample lines • Moisture removal system • In Stack Dilution • Critical Orifice is in the probe • Sample Temperature is Stack Temperature • Quicker response than out of stack dilution • No temperature controls to maintain

11. Point Electro-optical, or Electrochemical sensor Measurement over short distant (~cm) Path Light or sound is transmitted across the stack The interaction with the stack gas is related back to a gas characteristic In-Situ CEMS

12. In-Situ CEMS • Typical Applications: • Opacity Measurement • Path - Light • Stack Flow • Point - Differential Pressure (s-type Pitot) • Path - Ultra-sonic (sound waves)

13. Alternatives to CEMS • CEMS are required except for cases that qualify to use the following options: • Appendix D - SO2 and Heat Input Monitoring Options • Appendix E - NOxEmission Rate Estimation Procedures • Low Mass Emissions - Estimation of SO2, NOx, and CO2 emissions and total heat input using: • Default or site-specific emission factors, and • Max. unit heat input or actual heat input from fuel usage data • Predictive Emissions Monitoring - Estimation of NOx emissions using • CEMS validation of estimation procedures

14. Appendix D • Applicability • May be used in lieu of SO2 and/or flow and diluent monitors to determine hourly SO2 mass emissions and/or heat input rate • Gas and Oil fired units only • Principle: • Fuel Flow Rate * Sulfur content = SO2 emissions • Fuel Flow Rate * Gross Calorific Value (GCV) = Heat Input • Requires Monitoring of: • Hourly Fuel Usage (fuel flowmeters) • GCV and Sulfur content of the fuel (default SO2 emission rates allowed for gaseous fuels)

15. Appendix E • May be used in lieu of a NOx-diluent CEMS for determining hourly NOx emission rate (lb/mmBtu) • Applicable only to Gas and Oil-Fired Peaking Units • If you qualify for Appendix E, you must use Appendix D to determine heat input rate

16. Appendix E • Units that hold peaking status must continue to meet the peaking unit definition from year-to-year • If a unit fails to meet the criteria it must install & certify a NOx CEM by December 31 of the year after the year for which the criteria are not met • A unit may then only re-qualify by providing three consecutive years (or ozone seasons) of qualifying capacity factor data

17. How Appendix E Works • The average NOx emission rate (lb/mmBtu) is determined from fuel specific NOx emission rate testing at four, equally spaced load levels • The hourly heat input rate is determined using the fuel flow monitoring procedures of Appendix D • The NOx Emission Rate is plotted vs. Heat Input Rate to create a baseline correlation curve • The baseline correlation curve is programmed into the DAHS and is used to determine the hourly NOx emission rate corresponding to the heat input rate for each hour of operation

18. Segment 4 Segment 3 Operating Level 4 Operating Level 1 Segment 2 Operating Level 3 Segment 1 Operating Level 2

19. Low Mass EmissionsMethodology (LME) • Procedure that may be used in lieu of CEMS and the Appendix D and E methodologies to report SO2, NOx, and CO2, emissions and Heat Input • Gas-fired and oil-fired units only • DAHS is not required -- EDR reports can be generated using EPA’s MDC (or any other) software • Emissions limitations • Annual NOx limit: NOx < 100 tons/year • Ozone season NOx limit: NOx < 50 tons/control period • SO2 limit < 25 tons/year (ARP units only)

20. Predictive EmissionsMonitoring Systems (PEMS) • May be used in lieu of a NOx monitoring system • Consists of PEMS software and a DAHS • Software “predicts” what the NOx emissions will be for each hour, based on comparison testing with CEMS

21. Monitoring System CertificationRequirements and Testing • CEMS Testing: • Gas Monitors • 7-day calibration error check • Linearity check • Cycle time test • RATA/Bias test • Flow Monitors • 7-day calibration error check • 3 load RATA and Bias tests

22. 7-day Calibration Error Test • Measure calibration error of each pollutant monitor while unit is combusting fuel once each day for 7 consecutive operating days

23. Linearity Check • 3 point check of linearity of each pollutant monitor while unit is combusting fuel at conditions of typical stack temperature and pressure • Low (20 - 30% of span) • Mid (50 - 60% of span) • High (80 - 100% of span)

24. Cycle Time Test • Determine time it takes for 95% of step change to occur going from: • a stable zero gas value to stack emission value, and • a stable high calibration gas value to stack emission value • The cycle time is the slower of the two responses

25. Relative Accuracy TestAudit (RATA) • Compares CEMS measurements to appropriate EPA reference method • Conduct a minimum of 9 valid runs • May discard up to 3 runs but must report all runs performed • Recommended that RATA not be commenced until completion of other required certification tests

26. Bias Test • Statistical test that evaluates RATA data to determine if a low bias exists in the CEMS measurements, and to determine need for calculating a Bias Adjustment Factor (BAF)

27. Monitoring System CertificationRequirements and Testing • Appendix D • Fuel Flowmeter Accuracy Test is generally required annually • Fuel Flow-to-Load Ratio or Gross Heat Rate-to-Load evaluation may be used as a quarterly check of the fuel flowmeter accuracy • Can be used to extend the interval between fuel Flowmeter Accuracy tests to up to 5 years

28. Monitoring System CertificationRequirements and Testing • Appendix E: • The NOx emission rate testing must be repeated once every 5 years • Appendix D fuel flowmeter QA required

29. On-going Quality AssuranceTesting for CEMS • Daily Calibration Error Test • Daily Interference Check (flow monitors only) • Quarterly Linearity Check • Quarterly Flow-to-Load Ratio (flow only) • Quarterly Leak Checks (differential pressure flow systems) • Relative Accuracy Test Audit (RATA) • Bias Test (SO2, NOx, and flow monitors only)

30. Calibration Error Checks • Measure the calibration error of each pollutant monitor while the unit is combusting fuel by injecting a known calibration gas into the system at the point of sample collection • Zero Gas (0 - 20% of span) • High Gas (80 - 100% of span) or Mid Gas (50-60%) • For initial certification, a CEMS must meet a tight calibration standard for 7 consecutive operating days • For ongoing QA, daily calibration error checks are required

31. Interference Check • Daily QA check required for stack flow monitors • Diagnostic check that confirms that monitor is ready for use

32. Flow-to-Load Ratio Test • Quarterly evaluation of a stack flow monitor’s accuracy • A baseline comparison of the hourly ratio of flow rate to unit load (Q/L) and a reference Q/L determined during the last flow RATA test

33. Leak Check • Quarterly QA check for differential pressure type flow monitors • Confirms the absence of leaks in the connections and lines

34. SO2 Monitoring

35. NOx Monitoring

36. Contents of theElectronic Data Report (EDR) • EDR required each quarter or during Ozone Season • Collection of EDR data is fundamental to verifying program • EDR Files contain the following items: • Facility information • As-monitored emissions data (measured in ppm)

37. Contents of the ElectronicData Report (EDR) • EDR Files contain the following items: • Operational data (operating time, heat input) • Calculated mass emissions and heat input data • Monitoring Plan • Quality assurance/test data • Certification records

38. Quality Assurance Standards • Extensive QA process for EDR data • “Instant Feedback” based on ETS data checking • Audit process feedback provided after all data are submitted

39. Quality Assurance Standards • ETS data checking in two stages • File Summary: checks general format and integrity of file. • File Content: checks the data within the file • recalculate all hourly data • hourly sums vs. aggregates • monitoring plan checks • Over 150 checks performed on EDR data

40. Quality Assurance Standards • Audit Process is run to evaluate the monitoring plan, and QA and test data • Process is run after the end of each reporting period • Feedback Emailed to sources • Resubmissions of EDR data often required

41. Data Availability • EDR data are submitted during the month after each calendar quarter • “As reported” EDR files posted on the CAMD web site 20 days after the end of each reporting period • Summary Emissions Reports posted on CAMD web site 20 days after the end of each reporting period

42. Data Availability • Annual and Ozone Season data posted on Data and Maps web site page after program compliance is determined • Hourly, monthly and quarterly posted on Data and Maps web site page after program compliance is determined • Resubmitted EDR files are updated to the Data and Maps page each quarter

43. Uses of the Data • EPA uses of the data • Annual Acid Rain Program and NOx Budget Program Compliance • Public access through web site • Provide to other government agencies • Compare to other agencies’ data

44. Uses of the Data • Your uses of the data • What EPA data do you use? • How do you access the data? • What analyses are performed based on EPA data? • Are there other pieces of data you need for your analyses?

45. Questions and Answers