mdrejhon
Senior Member
That's not a deep cycle -- with a 3x-4x safety margin, you can keep it in the sweet spot SoC (State-of-Discharge).
This isn't the "first 5km past Union" scenario.
This is the "Completely Catenary-Electrified All The Way To Aldershot Scenario".
If you are familiar with lithium battery management, you already know maintaining roughly a middle SoC (State of Charge) is the best. I've already sized the battery for an expected shallow discharge cycle. Approximately 200KWh capacity per BiLevel-equivalent coach should be sufficient for very shallow discharge cycles during what will usually be only 2 to 3 minutes of power-mising MP40-diesel-like acceleration and rest easy 10min-ish of speed-maintaining a coast (it takes relatively little power maintain speed on level grade, just merely the power difference between coasting versus maintaining speed), while consuming roughly only one-quarter of the battery's life for an average Aldershot-Hamilton. A good trip may use only one-sixth and a bad trip might use one-half, and a really terrible trip (GO shutdown) may use up more than a half. Most of the time, it would be shallow discharge, with the safety margin used up rarely, during long stuck periods that requires multiple accelerations and extended climate-control usage. It should be no problem, to hover approximately near 60% of the battery's capacity, and avoiding fully recharging the battery unless necessary (e.g. extremely cold winter days where extra heater operations are needed). One can get well over 10,000 charge cycle equivalents out of a lithium battery with some very tight cycling margins (e.g. bouncing discharge-recharge in the 40%-to-60% SoC instead of the typical 500-1000 for a 100%-to-0% that most smartphone users do). Not only in the count of back-and-fourth charge-discharge, but also the total watt-hours-discharged ever. (i.e. With good SoC and battery management, you can do more than 10x 25% shallow charge-discharge cycles and it damages less than a single 100%-to-0% deep discharge). For the really cold winter days and really hot summer days where climate control demands are rather extreme, it may be needed to charge the battery more fully all the way to 100% (giving a ~5x+ safety margin), but this move can be avoided most of the year.
Since the freight companies own Hamilton trackage that they don't want to sell, this can be a potentially more inexpensive alternative to building half-a-billion-dollar (probably way more by then) -- of freight-separating, when eventually extending 15-min electrified Lakeshore West RER to Hamilton -- we electrify as much as possible with catenary, and bridge this small gap with an affordably-sized battery that still has a sufficient safety margin.
See Figure 1. below:
Figure 1. The token CP section for running on battery power.
(Catenary to Aldershot is assumed in this scenario, but only on the two southmost tracks of the corridor between Aldershot and Burlington, with some trackwork required to make CN happy)
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