As we consider an e-bike vs. a car purchase, I'm trying to assess return on investment (ROI). My cost factors are, in order of priority, time, money, and carbon footprint.
- I travel 20 miles daily, 5 days/week, over moderately hilly terrain in a temperate zone with four-season weather.
- I drive a ten-year old car that gets 45 mpg and has low annual maintenance costs.
The car trip takes 20 minutes on avg., so time cost is 40 minutes/day, 178 hours/year, or 37 days in 5 years.
At a fuel cost of $2.30/gal, daily fuel cost is $1.02, or $267/year.
- To buy another car like the one I own, according to Kelly Blue Book, I would pay $3,250. For sake of argument, I'll assume the car will last five more years.
- Insurance costs are $552/year.
- Maintenance costs include oil and filter changes and unexpected repairs. On average this has been about $800/year.
Cash outlay the first year is $4,869. Subsequent years would be $1,619. Estimated five-year financial cost is $11,345.
Estimated carbon footprint is 2,296 lbs of C02, or 11,480 lbs in 5 years.
- Testing e-bikes, trip time is ~40 mins. Daily packing prep time, a shower, and a clothes change add 25 mins. Normal time cost is 105 minutes/day or 467 hours/year.
- Because of weather, I can't bike-commute daily. Of the 267 work days/year, I'll Uber on 30 of them. At 20 minutes per trip, Uber time is 20 hrs per year.
Adjusting for Uber, annual time cost is 435 hrs, or 90 days in 5 years.
With moderate motor assist, I consume approximately 300 Wh of electricity daily. Cost per kWh is $0.13, so fuel cost is $0.04/day or $10/year.
- Speaking to local bike shops, the high side of annual maintenance costs is ~$150.
- The e-bike I'm considering costs $3,000. Adding high quality waterproof panniers ($150), a pump ($20), tube ($5), seat post bag ($10), rain jacket ($100), lock ($50), and clothing ($300) brings the kit cost to $3,635. I will not add additional insurance.
Uber costs $22/trip, so 60 trips per year (30 days) is $1,320.
Adjusting for Uber days, cash outlay the first year is $5,115. Subsequent years would be $1,480. Estimated five-year financial cost is $11,035.
For the bike alone, estimated carbon footprint is 110 lbs of C02/year. Adjusting for Uber rides (265 lbs/yr), that translates to 363 lbs/yr, or 1,813 lbs for 5 years.
Over 5 years, the car is >2x better in terms of time. The e-bike + Uber mode breaks even with the car in terms of money. The e-bike + Uber mode produces less than 1/6th the CO2.
I'm not surprised about the time or carbon footprint, but I thought the finances would look more attractive. Where am I making incomplete or unsafe assumptions, and how should I modify these calculations?