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Community Choice Aggregation Feasibility Analysis Alameda County <br />June 2016 vii MRW & Associates, LLC <br />Greenhouse Gas Emissions <br />As modeled, there are no greenhouse gas benefits for Scenario 1—in fact there are net incremental emissions. This is because both the CCA and PG&E are meeting the same RPS <br />requirements, but over 40% of PG&E’s supply portfolio is made up of nuclear4 and large hydro <br />generation, both of which are considered emissions-free. <br />The Alameda CCA’s GHG emissions under Scenario 2 are much lower than those under <br />Scenario 1. This is due to the higher renewable content in the CCA’s generation mix under Scenario 2, but more importantly, the 50% hydro content in the non-renewable generation mix. <br />Figures ES-5 compares the GHG emissions from 2017-2030 for the Alameda CCA under <br />Scenario 2 with what PG&E’s emissions would be for the same load if no CCA is formed. <br />PG&E’s GHG emissions are initially comparable to, the CCA’s emissions. The expected <br />retirement of Diablo Canyon in 2025 increases PG&E’s emissions by approximately 30% in 2025. Following this, PG&E’s emissions are expected to decrease from 2026 to 2030 as PG&E <br />procures renewables to meet its mandated RPS goals. However, they still remain higher than the <br />CCA’s expected GHG emissions. <br />The results of Scenarios 1 and 2 illustrate that if the CCA wants to reduce is net carbon <br />emissions, it must include hydroelectric (or other low- or carbon-free resources) in its portfolio. <br />Note that the analysis assumes “normal” hydroelectric output for PG&E. during the drought <br />years, PG&E’s hydro output has been at about 50% of normal, and the utility has made up these <br />lost megawatt-hours through additional gas generation. This means that our PG&E emissions are <br />the PG&E emissions shown here are lower that the “current” emission. If, as is expected by <br />many experts, the recent drought conditions are closer to the “new normal, then PG&E’s GHG emissions in the first 8 years would be approximately 30% higher, resulting in GHG savings for <br />Scenario 2 rather than parity. <br />Similar to Scenarios 1 and 2, under Scenario 3 the Alameda CCA’s GHG emissions first increase <br />from 2017 to 2019 as the CCA is phased in into the entire county. However, in Scenario 3 this increase is partially offset by the increasing renewable content in the CCA’s supply mix (Figure ES-6). Thus the CCA’s emissions in this scenario grow at a slower rate from 2017 to 2019 than <br />in the first 2 scenarios, then decrease until 80% renewable supply is achieved in 2021, and <br />remain flat thereafter. The CCA’s GHG emissions under this scenario are lower than PG&E’s <br />expected emissions for the same load if no CCA is formed, for all years except for 2017 for which the emissions are comparable. <br /> <br />4 40% of PG&E portfolio is nuclear and hydro 2017-2024; in 2024 the Diablo Canyon retires and is replaced by gas-fired generation.