LCA of Electricity Production and Consumption from Two Technologies In this problem estimate the life cycle impacts of producing electricity from 2 technologies. This data will then be used to estimate the life cycle impacts of California's electricity system. Much of the data has been pre-calculated for you to help shorten the homework problem. Please note, entire problem by hand, but we have provided a spreadsheet for you to do the calculations. If you aren't comfortable solving the problem only in the spreadsheet, try solving the problem by hand and then figuring out how you would do it in the spreadsheet. Do NOT hardcode answers in the spreadsheet. See the resources on Canvas for help if you're unsure about what this means and how to avoid it. Part 1: LCA of electricity from two technologies GOAL: To estimate the life cycle environmental impacts of electricity produced from natural gas and solar photovoltaics (PVs) given the data provided. SCOPE: The analysis includes the fuel production and electricity generation (for natural gas electricity), and the technology production and electricity generation for solar photovoltaic. The functional unit is 1 MJ of electricity (at the power plant), and the impacts of interest are: water use, global warming potential, and smog formation potential. Use the following Global Warming Potentials: GWP100 of CO2 = 1, GWP100 of CH4 = 30 (all methane is fossil), and GWP100 of N2O = 265. METHODS: Use the figures and data below to calculate the impacts of generating 1 MJ of electricity from each of these technologies. In this part of the problem you will IGNORE transmission and distribution. Natural Gas Electricity Production System 1 The natural gas production system is broken into two main stages; natural gas production and electricity generation. The power plant has a 50% conversion efficiency of fuel to electricity. The figure and data below include all of the data required for your calculation. Note that the "input" of natural gas reported in the Table for Generation of 1 MJ of Electricity reflects the 50% efficiency (in other words, for 1 MJ of electricity, 2 MJ of natural gas are needed)

Natural Gas Production Electricity Transmission Generation and Distribution Extraction and Transport Power plant Line losses Production Processing and Storage operation Natural Gas Production Generation of 1 M of Electricity Flow Quantity Unit Flow Quantity Unit Input Water use 4.00E-05 m water Water use 7.80E-03 m water Inputs 2.00 MJ Smog formation potential 6.05E-04 kg O,eq Natural Gas Smog formation potential 7.40E-03 kg O,eq Carbon dioxide 8. 70E-03 kg CO Outputs Carbon Dioxide 4.80E-01 kg CO, Methane ( Fossil) 1.75E-04 kg CHA Outputs Methane (Fossil 170E-03 kg CH4 Nitrous Oxide 1.60E-07 kg N,O Nitrous Oxide 2.40E-06 kg NZO The Natural Gas LCI datasets are adapted from the GaBi and Ecoinvent databases. LCA Homework - ECI 123 Photovoltaic (PV) Electricity Production System This is a utility scale PV system which uses 4400 m of PV panels mounted on a 1-axis tracking system [meaning the panel's tilt (its angle relative to the flat ground) changes as the sun moves across the sky]. The major impacts associated with PV electricity include PV panel production, PV plant construction, and maintenance, which is mostly water use for panel cleaning. Once installed, the system will generate 910 MJ per m per year and have a 22 year lifetime. PV Production Power Plant Electricity Transmission Construction Generation and Distribution Power plant PV PV Plant Transport operation (22 Line losses Manufacturing Construction years) *................. PV Panel Production (per 1 m' PV] Utility Scale PV Plant Construction (per 1 m' PV) Flow Quantity Uni How Quantity Unit Inputs Water use 4.006+03|m' water Input Water use 4.506+03 m water Smog formation potential 1.126+01 kg Osec Smog formation potential 1.80E+01 kg Orec Carbon Dioxide 1926+02 kg CO. Carbon Dioxide .758+02 kg CO. Methane (Fossil] 6.006-01 kg CHA Methane (Fossil) 9.0DE-01 kg CHA Quputs Nitrous Oxide 5.0DE-03 kg NO Outputs Nitrous Oxide 6.20E-03 kg N-O Utility Scale PV Plant Operation Flow Quantity Uni Input Cleaning water (per 1 m'/year) 2.00E-02 m' water/year Output Electricity Generated (per 1 m'/year) 9.10E+02 MJ/yearH3 A B C D E F G H I J K L M 14 15 Conversions & Constants 16 GWP CO2 (kg CO2e) 1 17 GWP CH4 (kg CO2e) 30 18 GWP N20 (kg CO2e) 265 19 1 kWh 3.6 MJ 20 1 kWh 1000 Wh 21 1 year 365 days 22 23 24 Part 1: LCA of electricity from two technologies 25 26 Electricity produced from natural gas (NG) 27 28 Power plant efficiency 50% 29 30 Table 1. Natural gas electricity production 31 Natural Gas Production Electricity Total per 1 MJ per 1 MJ per 1 MJ per 1 MJ 32 Natural Gas Electricity Electricity Electricity Production Generated Generated Generated 33 4.00E-05 7.80E-03 Input Water (m3) 34 Natural Gas (MJ) 0.00E+00 2.00E+00 35 Smog (kg 03 eq) 6.05E-04 7.40E-03 36 Carbon Dioxide (kg CO2) 8.70E-03 4.80E-01 37 Output Methane (kg CH4) 1.75E-04 1.70E-03 38 Nitrous Oxide (kg N20) 1.60E-07 2.40E-06 39 GWP (kg CO2e) 40 41 + LCA Assignment +Electricity produced from solar photovoltaics (PVs) Annual generation (MJ/yr/m2) 910 System lifetime (years) 22 Table 2. Solar PV electricity production Panel Production Plant Construction Plant Operation Total per 1 MJ per 1 MJ per 1 MJ per 1MJ Electricity Electricity Electricity Electricity per 1 m2 PV Generated per 1 m2 PV Generated per yr/m2 Generated Generated Water (m3) 4.00E+03 4.50E+03 2.00E-02 Input Natural Gas (MJ) 0.00E+00 0.00E+00 0.00E+00 Smog (kg 03 eq) 1.12E+01 1.80E+01 0.00E+00 Carbon Dioxide (kg CO2) 1.92E+02 2.75E+02 0.00E+00 Output Methane (kg CH4) 6.00E-01 9.00E-01 0.00E+00 Nitrous Oxide (kg N20) 6.20E-03 5.00E-03 0.00E+00 GWP (kg CO2e)