2-wheel PRT: Calculation inputs concerning energy consumption

Assumed vehicle and route characteristics

• Vehicle mass:
  • Vehicle itself: 150 kg [331 lb] (standard version) / 300 kg [661 lb] (enlarged version). Most similar vehicles found as examples for estimation: TWIKE (Wikipedia): 246 kg [542 lb] and CityEl (Wikipedia): 280 kg [617 lb]
  • Thereof battery: 20 kg [44 lb] (standard version) / 40 kg [88 lb] (enlarged version)
  • User and luggage (average including empty redistribution rides): 75 kg [165 lb] (standard version) / 130 kg [287 lb] (enlarged version)
• Rolling resistance:
  • Rolling resistance coefficient: 0,015 Examples for estimation: Rolling resistance of tires generally (Wikipedia): 0,01 - 0,015; Rolling resistance of motorcycle tires (Wikipedia): 0,02 but increasing with speed
  • Standard gravity: 9,81 m/s²
• Aerodynamic drag:
  • Cross sectional area: 0,91 m² [9,9 sqft] (standard vehicle) / 1,25 m² [13,6 sqft] (enlarged vehicle) The dimensions of the enlarged vehicles are estimated according to standard wheelchair dimensions
  • Aerodynamic drag coefficient: 0,25 Examples found for estimations: Automobile drag coefficient (Wikipedia)
  • Air density at standard conditions: 1,29 kg/m³ Density of Air (Wikipedia)
• Engine and battery efficiency
  • Engine & Battery efficiency (Plug-to-wheel): 72% European Association for Battery Electric Vehicles - estimation rather better, because of technical progress since 2009 and probable less auxiliary consumption of the small vehicle
  • Regenerative braking efficiency (Wheel-to-battery): 75% assumed as slightly better than plug-to-wheel because no AC/DC converter necessary
  • Density of energy stored in battery: 167 Wh/kg [76 Wh/lb] (Same energy density as in the Tesla Model S 90)
• Assumed route characteristics
  • Average trip length: 20 km [12,4 mi]
  • Thereof on backbone road (80 km/h): 18 km [11,2 mi]
  • Thereof on feeder road (30 km/h): 2 km [1,2 mi]
  • Number of acceleration / deceleration sequences: 1 between 0 and 30 km/h [between 0 and 19 mph], 2 between 30 and 80 km/h [between 19 and 50 mph]
  • 0,5 km [0,3 mi] with 10% gradient on backbone road

Consumption data of compared vehicles and means of transportation

• Individual consumption data
  • Tesla Model S
  • VW Golf (e-Golf, VW Golf VII, 1.6 TDI, 66 kW)
  • VW Phaeton 3.0 V6 TDI, 180 kW
  • Average CO₂ emissions of new cars in the EU 2015 (per car-km, only direct emissions without those from refinery)
  • Diesel regional rail passenger Services: Reference 1 , Reference 2 , Reference 3 - average: 87 g / Pkm
  • Specific energy consumption in regional rail transport with and without capacity optimization
  • Fuel consumption of standard sized bus in regional transportation , Average capacity utilization in regional bus transportation
  • Electric regional rail passenger Services: Reference 1 , Reference 2 - average: 71 g / Pkm
  • Average car occupancy: Reference 1 (Austria) , Reference 2 (Germany) , Reference 3 (US); assumed average: 1,4
• Conversions between units of energy economics
  • CO₂ emissions of diesel fuel (direct): 2,62 kg/l (Wikipedia)
  • CO₂ emissions of diesel fuel (including refinery): 2,95 kg/l (Austrian Environment Agency)
  • Calorific value of diesel fuel: 35 MJ/l (Wikipedia)
  • Average CO₂ emissions of EU electricity generation: 558 g/kWh (European Environment Agency)