As soon as the unconstitutional Federal monopoly that protects oil-powered infrastructure from competition, we will power urban mobility within a solar budget, achieving what Thomas Edison noted as practical in 1910:
"Sunshine is spread out thin and so is electricity. Perhaps they are the same, Sunshine is a form of energy, and the winds and the tides are manifestations of energy.”
“Do we use them? Oh, no! We burn up wood and coal, as renters burn up the front fence for fuel. We live like squatters, not as if we owned the property.
“There must surely come a time when heat and power will be stored in unlimited quantities in every community, all gathered by natural forces. Electricity ought to be as cheap as oxygen...."
Solar collectors mounted over JPods rails gather about 5 megawatt-hours per mile of rail per day. This equates to about 40,000 vehicle miles of power per mile of rail per day.
We can adjust the width of the solar collectors over the rails to assure we gather enough extra energy to store for night and cloudy days.
Odd as it may seem, those opposed to using solar claim the sun is "intermittent". The truth is the sun shines 100% of the time. The earth rotates and hides the sun from them sometimes ;-). Also, clouds, seasons, and other atmospheric events varies the amount of energy that can be collected on any given day. Trees do not die at night. So to power our lives within a solar budget requires we be as clever and foresightful as trees. Like good farmers, we must gather and store energy when it is available so we can have what we need when we wish.
JPods reduces the parasitic waste of moving a ton to move a person. This cuts the energy required to move people and cargo in cities by 90%. This in turn, reduces the amount of energy we must harvest and store.
Energy in excess of what is need to operate vehicles will be converted into methane for storage and distribution:
Transporting a passenger one mile per US DOE
by car requires 3447 BTUs = 1.01 kW-hr
by bus requires 4118 BTUs = 1.21 kW-hr
by rail requires 2520 BTUs = 0.75 kW-hr
by JPods requires = 0.062 kW-hr
Combine this DOE data with MassDOT's cost per passenger-mile:
To understand the physics of why JPods waste so little energy, the costs for four components and formulas for calculating them are provided based on a 7.5 mile trip:
- Steady Speed
The amount of energy used depends upon how long the JPod waits from the time it stops to unload a passenger until it is reloaded and begins to move. The minimum rate of energy use was found to be 1025 W (1.025 kW). A waiting JPod will consume 1.03 kW-hr for each hour it sits idle. At $0.10 per kW-hr., this costs 10 cents per hour.
During acceleration, energy is used both to do the acceleration and also to overcome the air drag force.
D = .5Cd ρ V^2 A
Where the speed, V, depends upon the time, t.
V = at
The force needed for the acceleration, a, is
Facc = ma
The combined Drag and Accelerations Forces are
Fcombined = .5Cd ρ (at)^2 A + ma
The work done at any time when traveling an incremental distance Δd
ΔW = Fcombined Δd = .5 Cd ρ (at)^2 A Δd + ma Δd
At any time the incremental distance traveled during a small time step is
Δd = V Δt
= at Δt
The incremental work is
ΔW = .5 Cd ρ (at)^3 A Δt + ma^2t Δt
The total work performed is
∫dW = .5 Cd ρ a^3A ∫t3 dt + ma^2 ∫t dt
W = 1/8 Cd ρ a^3A t^4 + ma^2 (1/2 t^2)
In Part 1 the time for the acceleration to 30 mph was calculated to be 6.84 seconds.
In Part 1 the continuous energy use of a JPod at 30 mph in still air was found to be 1446 W (1.446 kW).
One hour of steady speed operation uses
1.466 kW-hr of energy.
At $0.10 per kW-hr., this costs 10.5 cents.
When decelerating, the JPod will not use any more energy than when idle. If the bogie wheel motor have regenerative capability, the motors can behave as generators and put electricity back into the JPod batteries.
An idle JPod will consume 1.03 kW-hr for each hour it sits idle. The deceleration time is about the same as the acceleration time, 6.84 seconds.
At $0.10 per kW-hr., this costs
1.03 kW * 6.84 sec * 1 hour/3600 seconds * $0.10/kw-hr = $0.0002
The total energy use is
Waiting 3 min/60 min/hr * 1.03 kW-hr/hr = 0.052 kW-hr
Accelerating = 0.0402 kW-hr.
15 min/60 min/hr * 1.47 kW-hr = 0.368 kW-hr
Decelerating = 0.002 kW-hr.
TOTAL ENERGY = 0.462 kW-hr
At $0.10 per kW-hr., this trip costs 4.6 cents for 7.5 miles --- or --- 0.061 cents/per mile
Allocating 7 times the travel energy for creature comforts of airconditioning, heating, etc... the cost is estimated at $0.04 per mile.