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7.A. - Page 72 of 285 2019 Energy Efficiency Ordinance Cost-effectiveness Study For a package to qualify, a minimum EDR Margin of 0.5 was required. This is to say that a package that only achieved an EDR Margin of 0.4, for example, was not considered. An EDR Margin less than 0.5 generally corresponds to a compliance margin lower than 5% and was considered too small to ensure repeatable results. In certain cases, the Reach Code Team did not identify a cost-effective package that achieved the minimum EDR Margin of 0.5. Although some of the efficiency measures evaluated were not cost-effective and were eliminated, the following measures are included in at least one package: • Reduced infiltration • Improved fenestration • Improved cool roofs • High performance attics • Slab insulation • Reduced duct leakage • Verified low leakage ducts in conditioned space • Low pressure -drop distribution system • Compact hot water distribution system, basic and expanded • High efficiency furnace, air conditioner & heat pump (preempted) • High efficiency tankless water heater & heat pump water heater (preempted) 3.1 PV and Battery System Sizing The approach to determining the size of the PV and battery systems varied based on each package and the source fuel. Table 7 describes the PV and battery sizing approaches applied to each of the four packages. For the Efficiency Non -preempted and Efficiency — Equipment, Preempted packages a different method was applied to each the two fuel scenarios. In all mixed fuel cases, the PV was sized to offset 100% of the estimated electrical load and any electricity savings from efficiency measures were traded off with a smaller PV system. Not downsizing the PV system after adding efficiency measures runs the risk of producing more electricity than is consumed, reducing cost-effectiveness and violating NEM rules. While the impact of this in most cases is minor, analysis confirmed that cost-effectiveness improved when reducing the system size to offset 100% of the electricity usage as opposed to keeping the PV system the same size as the Standard Design. In the all -electric Efficiency cases, the PV system size was left to match the Standard Design (Std Design PV), and the inclusion of energy efficiency measures was not traded off with a reduced capacity PV system. Because the PV system is sized to meet the electricity load of a mixed fuel home, it is cost-effective to keep the PV system the same size and offset a greater percentage of the electrical load. For the Efficiency & PV case on the all -electric home, the Reach Code Team evaluated PV system sizing to offset 100%, 90% and 80% of the total calculated electricity use. Of these three, sizing to 90% proved to be the most cost-effective based on customer utility bills. This is a result of the impact of the annual minimum bill which is around $120 across all the utilities. The "sweet spot" is a PV system that reduces electricity bills just enough to match the annual minimum bill; increasing the PV size beyond this adds first cost but does not result in utility bill savings. 19 © 2019-08-01 324