As illustrated in Figure 5 , the return on investment to the Authority for the incremental cost of an electric bus depends on the level of grant we receive . Using the ZEV guidelines for a 50 % grant on the cost of an new EV bus plus an electric charger results in a grant award of $ 356,000 . 17 As indicated by the red dot in figure 5 , this indicates that we would recover our incremental investment for a new electric bus in approximately 4.5 years . Any grant equal or less than $ 100,000 implies we do not recover our incremental investment within the estimated 15-year useful life of the bus . We calculate our net incremental upfront investment for a new EV bus after a 50 % grant to be approximately $ 114,500 . 18 With an estimated payback of 4.5 years , our analysis is showing savings of approximately $ 25,000 per year by choosing an electric bus over a diesel bus .
It is worth highlighting that the analysis reflects current pricing for buses as well as for the cost of both diesel fuel and electricity . But as noted earlier , given the dramatic slowdown in air travel , our current bus fleet is highly underutilized , allowing us to use our most efficient buses to cover our passenger needs at both airports and sideline those with high maintenance requirements . As a result , we can defer investments in new buses until air travel returns to levels that we experienced pre-COVID . When appropriate , analyses may be updated with current costs and to confirm assumptions .
Greenhouse Gas Emissions
If the Authority converts diesel buses to electricity , electric buses will have a positive impact on what are known as our Scope 1 GHG emissions . In the diesel-to-electric scenario , 1,929 metric tons ( MT ) of CO 2 e would be eliminated per bus over its 15-year life , or 129 MT per year . 19 129 MT per year is equivalent to removing 28 passenger cars from the road for an entire year . 20 Further detail is provided on what constitutes Scope 1-3 emissions in the GHG Inventory section of the Plan .
Operating Risks
In addition to the air quality benefits and the potential for financial savings associated with electrification , we do need to incorporate certain operational risks into our decision-making process .
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Given the winters we can experience in the Metro DC area , we need to consider the impacts of colder weather on battery range which can lead to more frequent charging . Frequent charging
17 The base price for the EV bus for the analysis is $ 670,000 plus an additional $ 43,000 for the charger . Therefore ,
50 % of the total cost equals approximately $ 356,000 ( rounded up ). The cost used for grant calculations is less than the $ 890,500 as this higher amount includes an extended range battery at a cost of $ 100,000 , a 12-year extended batter warranty for $ 75,000 and $ 2,500 to add an extra charging port to the bus ; modifications we feel are necessary for on-site conditions at Dulles International . These additional costs are considered modifications to the underlying base bus cost and thus not included in the calculation of the grant . 18 We arrive at $ 114,500 by taking the all-in bus cost of $ 890,500 and subtracting the $ 356,000 grant . This leaves
us with $ 534,500 which is $ 114,500 higher than the $ 420,000 we would have paid for a diesel bus . In addition , our analysis included the cost of the additional investments in parking infrastructure that we would need at Dulles International to accommodate a fleet of EV buses . We estimate an additional $ 800,000 for 6 EV buses or $ 133,000 per bus . Amortized over 30 years , it reduces our savings from migrating to EV buses by approximately $ 4,400 per year per bus . 19 This does not include GHG emissions associated with electricity generation to power the buses ( Scope 2 ). 20 Greenhouse Gas Equivalencies Calculator . Accessed on August 12 , 2020 at
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