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The spheres, which resemble tiny Death Stars (or, perhaps for a more niche Star Wars reference, normal-sized training remotes), are 30 times smaller than solar panels, with 7.5 times the output. Astoundingly, she said they are more than 200 times more efficient.

These are the basic stats on US annual fuel consumption:
137,240,000,000 gallons of finished motor gasoline consumed in the US during 2023.
56,261,100,000 gallons of distillate fuels consumed in the US during 2023.
3,200,000,000,000 total miles driven by all US drivers per year.

Now Let's consider the energy required to "charge" air powered cars that weigh about 1,000kg:
85,000kPa = 850bar
100kPa = 1bar (sea level atmospheric pressure)
3,600J / 3.6kJ = 1Wh

kJ = (P2 - P1) * V
kiloJoules = (Final Pressure in kPa - Initial Pressure in kPa) * Volume (in m^3)
kJ = (85000kPa - 100kPa) * 0.253 = 21,479.7kJ = 5,967Wh

We'll assert that our compression process is about 80% efficient.  Some compressors might be more or less efficient, but 80% is a good value to use for industrial scale air compressors.  That implies actual compression energy is about 7,458Wh.  That amount of energy provides about 100 miles of driving range for our air powered car.

32,000,000,000 * 7,458Wh = 238,656,000,000,000Wh = 238.656TWh

Constant power output of about 27,243,835,616Wh is required.  This is equal to the output of 27 1GWe nuclear reactors.  Spread across all 50 states, about 545MW, which is equal to the output from two large commercial electric power gas turbines.

However, we want to do this without consuming hydrocarbon or nuclear fuels or specialty metals, so we won't be converting any of that solar thermal power into hydrocarbon fuels or electricity.  President Biden's administration blocked environmental permits for proposed new Copper and Lithium mines here in the US, so they clearly don't want EVs, either.  Maybe someone in his administration finally figured out how much worse EVs are for the environment compared to burning oil.  At the same time, Democrats block all new nuclear reactor permits, and see it as their duty to ensure that no new reactors are built.  In conjunction with President Biden's continuation of the trade war tariffs with China, that's driven a stake through the heart of photovoltaics, wind turbines, and battery production expansion attempts.  They're being taxed, tariffed, or otherwise regulated out of existence.  We're essentially left with nothing, and unsurprisingly, we're not happy.

In an earnest attempt to both skirt around Democrats' apparent unwillingness to do anything constructive to reduce hydrocarbon fuel energy reliance, while actually addressing a minor aspect of climate change in a cost-effective way, I'm proposing using solar thermal power to compress air so we have workable and affordable energy to use to power our vehicles.  I would think that this solution is the most environmentally benign of all options presented.  It requires far less specialty metals input from Russia or China, unlike EVs.  It's the option with the longest service life and lowest total cost of ownership.  It's a poor man's solution to a rich man's silly game.  The new "fuel" (compressed air) will be taxed to pay for the roads and bridges, since our haughty EV owners don't contribute anything to their upkeep.

Solar thermal requires quite a bit of steel and some Aluminum coating material to reflect and thermalize photons, as well as salt to store thermal power at night to continue production at a reduced rate.  My materials of choice are steel, concrete, salt, air, and water in a closed loop subsystem for waste heat recovery from air compression, for purposes of additional mechanical power generation to improve overall air compression efficiency.  Maybe we can improve overall energy utilization efficiency during compression to about 85%.  Alternatively, we could supply flash-evaporated fresh water.

If our drivers had an affordable alternative to a gasoline powered vehicle for their daily commutes, then the US could potentially reduce our annual gasoline consumption by about 95%.  We'll still need gasoline for light aircraft, power tools, and some off-road uses, but the quantity consumed will plummet.  Providing a cheaper alternative to gasoline is the only viable way to end our reliance on it.  Price sells cars and energy.  EVs don't sell because they're too expensive for what they provide to most owners- a commuter type vehicle.

At 33,700Wh per gallon, we consume 4,624,988,000,000,000Wh worth of gasoline per year.  That's about 19.38X more energy than compressing enough air to charge the tanks of air powered cars.  This is not to suggest that the energy was used inefficiently, because the total weight being moved was not reflected in the top line energy consumption figures, merely that a light vehicle powered by air would consume a lot less energy.

At 250Wh/mile, if every vehicle on the road was a Tesla Model 3, then we need to supply 800,000,000,000,000Wh of electricity for our drivers to cover 3.2 trillion miles.  That's about 3.35 times more energy than 1,000kg air powered cars would require.  All their electrical and electronic gadgetry eats up a lot of power, and battery operated vehicles are almost twice as heavy, which is part of why they cost more and consume more energy.  Heavy vehicles require more energy to operate, period.  This also suggests that air powered vehicles could be made twice as heavy while still consuming no more energy than EVs.  Air powered cars can't beat EVs on range or acceleration, but across every other metric EVs are toast, even before they self-immolate.

Let's use a real-world example.  Since those tanks from the link in my prior post were being charged to 875bar and discharged to 20bar, let's assert that we can charge our 253L tank to 850bar using the latest fiber and resin matrix technology with a CNT additive to improve inter-laminar sheer strength.  The goal here is not to make the storage tank any lighter, it's to make it seriously strong and thus better able to resist many thousands of pressure cycles, for ultimate durability / longevity in operation.  I will assert that the tank and fittings will weigh about 200kg, and store 215m^3 of air, which would weigh about 277kg if it was completely dry.  With 10% moisture, we're looking at 305kg.  That leaves 495kg for the rest of the car (chassis, suspension, wheels, tires, brakes, cabin, air motors, flywheel energy storage system, electrical system, etc).  Using fiber filled plastics or composites for the chassis, that should be doable.

Deprag makes an air tool equipped with a 4.5kW / 6hp air motor.  It's a grinder, but the entire tool weighs 4.2kg.  The air motor is only half of that, but 2kg vs 4.2kg makes little difference to the performance of the car.

At max output, or "fully loaded" as DePrag describes it, this turbine consumes 117cfm /  of air and the tool speed is 6,400rpm.  The free turbine speed likely falls somewhere between 60,000rpm and 120,00rpm.  Idling, the air consumption rate is 42.4cfm.

In our example 1,000kg air powered car, we require 1.1627hp or 867W of power to maintain 75mph.  That is "typical highway speed" here in Houston, whether the speed limit says 60mph or not.  That's about 20% of the turbine's maximum output, so I will guess that's also 56% of max airflow rate based upon idle air consumption to keep the turbine spinning, or 1.855m^3 per minute.  At that flow rate, our air supply will last about 95 minutes.  That means our max range at 75mph is about 118.75 miles.  If I'm 20% off of what the actual is, then range may only be 95 miles at 75mph.  Either way, we should have enough power to maintain 75mph, if required.  Most driving in Houston or Los Angeles happens at walking speed during rush hour, with 60mph being about as fast as you can drive at any point in time along any of the major freeways during rush hour.  That said, "weekend speed" with light traffic will be 75mph, so that's how fast an air powered car must go to merely keep up with traffic.

Whilst cruising along a perfectly flat stretch of highway using minimal air motor power is all well and good, with only 12hp on tap from a pair of air motors, our acceleration rate would pose a danger to ourselves and others, if the vehicle's acceleration rate was limited by such pint-sized powerplants.  We really need a flywheel to store the required power.  The total energy consumed by an acceleration rate of 0-60 in 6 seconds is rather small, about 107Wh.  However, the release rate would either require a much larger and more powerful air turbine (about 64kW) that also consumes far more air, and would thus be far more expensive to build, or we need an energy storage mechanism to convert turbine power into stored kinetic energy.  Flywheels are capable of transferring enormous amounts of power over very brief periods of time.

A 10kg flywheel with a 10cm radius, spun up to 60,000rpm, about the same as what I would guess the free turbine speed is, it would store about 548Wh worth of rotational energy.  That is more than enough power to accelerate to 75mph from a dead stop, and likely twice as large as it really needs to be, so significant weight and cost savings are available for trade studies.  It could easily beat the Tesla Model S Plaid's 0-60 time if the flywheel was capable of transferring all that power in 2 seconds or less.  I think the tires and vehicle weight will rapidly become limiting factors, though.  Regardless, an air powered could still be a fun vehicle to drive, even with a "measly" 12hp.

The overriding point is that a pair of 6hp turbines for cruising and light acceleration, which are effectively tiny 2kg air tool motors, backed up by a flywheel, would provide the best overall vehicle performance under real world driving conditions, at the lowest total weight.  I would estimate about 35kg for the entire powerplant (pair of power turbines, flywheel energy storage system, and transmission or direct drive to the powered axle.