1	"Dan Bilello" Dan Bilello International and Environmental Studies Group National Renewable Energy Laboratory
2	Objectives Overview of GHG calculation process and methodologies Provide practical tips with a few examples Provide useful references and resources
3	“Take-Aways” from the NREL Experience Measuring is first step in managing Focus on your primary (most significant) emission sources GHG management lends itself to staff awareness (cost savings, energy savings, and environmental benefits) EE before RE
4	What Are We Trying to Measure? Most common emission sources at the facility level CO2 (purchased and on-site power generation, transport) CH4 (landfill and waste) N2O (transport, fertilizer) SF6 (tracer gas, industry specific processes) HFCs (refrigerants) PFCs (refrigerants, industrial processes) Global Warming Potential (GWP) and CO2 Equivalance CO2 (1); CH4 (23); N2O (296); SF6 (22,200); HFCs (120-12,000); PFCs (5,700-11,900) Black and Organic Carbon Air Quality: SO2, NOx, HG, PM Regular updates through the EPA and the IPCC
5	An emission factor is a representative value that relates the quantity of a pollutant released to the atmosphere with an activity associated with the release of that pollutant. E = A x EF where: * E = emissions * A = activity rate * EF = emission factor as they say…the devil is in the details!
6	Emission Factors National Averages (1363lb CO2/MWh, 5.4lb SO2, 1.7-2.1lb NOx) Used for federal level assessments and modeling Sub-region Averages (AZNM WECC Southwest 1254lb CO2/MWh) Based on regional generation and transmission data, used by EPA Climate Leaders and other regional programs State Averages (1218lb CO2/MWh in AZ) Derived from generation data and fuel mix that is State specific Range from 700-3,600 lb CO2/MWh nationally) Facility Specific Direct emissions from on-site power generation and fuel combustion Higher level of complexity Fuel type, time of day Equipment efficiency and maintenance Technology used
7	The Process Identify your emission sources and data gaps (including key contacts…facility managers, finance office for billing records, fleet managers, procurement office) Determine emission factors to use (guidance from relevant program) Establish your baseline (year, which facilities, any sources to exclude, assumptions) Identify opportunities for mitigation (projections in growth help here) and anticipated emission reductions Implement your mitigation plan Monitor, measure, report, and evaluate
8	How Far Do We Go? Owned versus leased facilities Up-stream or down-stream emissions Embedded energy in capital investments Waste generation and management Water use Vehicle Fleet Staff travel (road and air) Off-site projects and/or offset purchases (including land-use, land use change, and forestry)
9	Key Data Points (1) Quality of data (metered, bills, estimates, projections, historical) Accuracy of emission factors Consistency of reporting (same units?) Consistency in data management
10	Key Data Points (2) Technology performance (e.g., on-site renewables monitoring is important in high penetration scenarios, actual impact of an energy efficiency measure) Time of use (e.g., baseload coal or peak gas?) Off-site (or out of State, out of country?) emission offsets and their emission factors Additionality (what would have otherwise occurred?)
11	Purchased Power (indirect) Generally measured in units of X lbs or kgs per kWh (electricity) or lbs or BTUs (steam) Data generally derived from utility bills but if you do not have site well metered, assumptions may be needed Data can vary significantly for kWh based emission factors depending on region and generation Quality of data is generally good nationally but factors like T&D losses and baseload versus peak generation not always very transparent
12	On-Site Generation (direct) Two-fold challenge: 1) Identify what your replacing: Meeting a new load? - (What would BAU look like?) Fuel switching to a cleaner source (e.g., biomass gasifier in place of natural gas fired boiler)? Offsetting purchased power (kWh reduction) 2) Measure and monitor EE or RE performance Is my technology performing as expected? http://www.azclimatechange.gov/docs.html Is my technology individually metered so I can calculate its energy production and the related emission reductions? Data variations by source depending on the technology, the fuel,system efficiency, operation, maintenance, etc.
13	Transportation (mobile) Mobile sources contribute to CO2, CH4, and N20 Small contribution for CH4 and N2O but up to 5% of total in gasoline and alternative fuel vehicles depending in large part on the emissions control equipment Maintenance and operation is a major factor Key data include fuel used, miles traveled, and vehicle type CO2 derived from carbon content in the specific fuel, the fuel density, and fraction of carbon oxidized for each fuel. For example for gasoline: Carbon Content Fraction Oxidized CO2/C ratio Emission Factor 2.42 kgC/gallon 99% (44/12) 8.79 kgCO2/gallon EPA and other sources provide top down derived emission factors for CH4 an N20 based on fuel type and vehicle (Inventory of U.S. GHG Emissions and Sinks)
14	Examples from EE Measures Scenario: Implement plan for facility wide incorporation of more efficient lighting replacing 1000 units of 75w incandescent light bulbs with 27w CFL lamps. Assume: 10 hours of use daily (no change in use) Emissions calculated on an annual basis Investment in higher upfront cost EE measures would not have otherwise occurred Using eGRID average emission factor for Arizona
15	EE Example Emissions Impact: 365 days x 10 hrs/day = 3650 hours per year 3650 hours x 48w (watt savings/lamp/hr) = 175,200 Wh/year 175,200 / 1000 = 175.2 kWh/year 175.2 kWh/year x 1000 units = 175,200 kWh saving (175 MWh) 175 MWh x 1,218 lb CO2/MWh = 213,150 lbs of CO2 213,150 lb CO2 / 2,205 = 96 metric tons of CO2 Questions to ask: Were the expected reductions realized and could we monitor that this investment was the actual source of reductions? Coupled with a staff awareness plan for EE or building design incorporating daylighting, what would relative impact be? What if we also purchase greentags from the utility, should reflect these cleaner kWh in our calculations?
16	Example of RE Measures Scenario: Install 100kW of roof top photovoltaics (PV) to meet part of our power needs on-site. Grid tied system but anticipate using all of PV generated power. Assume: System performs at stated capacity Annual average of 6 hours of energy production per day No performance degradation in initial years of installation
17	RE Example Emissions Impact: 365 days/year x 6 hours of power production/day = 2190 hours 2190 hours x 100kW = 219,000 kWh/year produced 219 MWh x 1,218 lb CO2/MWh = 266,742 lbs of CO2 266,742 lb CO2 / 2,205 = 120 metric tons of CO2 Questions to ask: Did we meter the PV to confirm actual KWh produced? Did we offset indirect electricity purchases or did the captive power needs offset other sources of energy that would have been used (efficient natural gas boilers or less efficient diesel gensets)?
18	On-Line Resources (1) Emission Factors: EPA EGRID: www.epa.gov/cleanenergy/egrid/index.htm EPA AP42: www.epa.gov/ttn/chief/ap42/index.html DOE EIA: www.eia.doe.gov/oiaf/1605/factors.html IPCC: www.ipcc.ch Methodologies: Arizona CC Action Plan: http://www.azclimatechange.gov/docs.html WRI GHG Protocol: www.ghgprotocol.org EPA Climate Leaders: www.epa.gov/stateply/ Conversion Tables: EPA: www.epa.gov/nonco2/units.html
19	On-Line Resources (2) Relevant Programs and On-Line Resources: Arizona Climate Program: www.azclimatechange.gov/ WRI GHG Protocol: www.ghgprotocol.org EPA Climate Leaders: www.epa.gov/stateply/ United Nations Framework Convention on Climate Change: www.unfccc.int WRI’s Climate Analysis Indicators Tool: http://cait.wri.org/ GREET Model (transportation): www.transportation.anl.gov/software/GREET/index/html Energy Information Agency: www.eia.doe.gov
20	Thank You Dan Bilello International and Environmental Studies Group National Renewable Energy Laboratory phone: (303) 384-7461 email: dan_bilello@nrel.gov