The 16kWh battery is just a place to store electrical energy. If you plug in the car, it gets the energy from the electrical grid. If the 53 kW generator is charging it, it gets the energy from the burning of gasoline. If the regenerative brakes charge it, it gets the energy from recaptured kinetic energy.

If you plug in the Volt, you charge the battery to 80% state of charge(SoC). You drive, using the battery energy, until the battery drains to 30% SoC. You have used up the energy from the electrical grid. Now it is a simple series hybrid, similar to the Prius (which is a parallel hybrid: the Prius can drive the wheels with either the gas engine or the electric motor). The SoC will now vary around 30% (I think it is 25% to 30% ? I’m not quite clear about this detail. Maybe 30% to 35%, or 27.5% to 32.5% )

In ‘charge sustaining mode’ the gasoline engine/generator is basically using the battery as an energy buffer for peak power requirements (just as the Prius does). The 53 kW generator can power the 110kW electric motor directly, most times, but for a power surge, the battery can supply up to 57 kW for short bursts. Then, the generator slowly recharges the battery again, to be ready for the next burst of power.
The Prius uses about 0.4kWh of battery ‘buffer’ to supplement their 76 hp gas engine to perform like a 110 hp car. The Volt will be using about 0.8kWh battery buffer to supplement their gas engine/generator to drive their 150 hp electric motor. It’s the same concept: you can get by on a smaller gas engine, because the peak power requirements are assisted by a battery energy buffer.

The battery is never “depleted”. It has different States of Charge, but the generator charges it while driving, as does coasting downhill, or braking. It stays in a “band” of SoC, ready to assist the 53kW generator whenever more power is needed.

In ‘charge sustaining mode’, all the energy is coming from the gasoline, ultimately. Just like a regular car, or a regular hybrid. The headlights, radio, aircon – yup, they all use energy, and will all be supplied by the gasoline, just like regular cars and hybrids. Yup, most cars weigh a lot.
Capturing lost kinetic energy back into the battery only helps – in a regular car, all that ‘slowing down’ energy is just lost as heat. Hybrids like the Prius capture a fraction of the lost kinetic energy, as well. It is not a source of energy, just a way to better use the kinetic energy of the car which was the result of burning gasoline.

The battery is never ‘depleted’ as long as you have gasoline. You could drive the Volt cross country as a series hybrid (just means the gasoline engine drives only the generator, not the wheels too). I drove a Prius cross country – its the same idea, slightly different drivetrain design.

I’ve been reading comments over the last year or so (but not participating), and I’ve noticed that (some) folks are making conjecture without baselining their remarks against real world values – such as the specific energy of gasoline, or the system efficiency of an ICE automobile compared to an all-electric vehicle.

The EV trumps an ICE vehicle, except for one hang up…electrical energy storage. The good news is that’s changing.

An ICE has the advantage of a high-energy density found in petroleum (the 47 MJ/kg I mentioned earlier), but cannot fully take advantage of its entire energy content…and never will.

Barring a breakthrough in thermo-electric conversion, we’ve squeezed as much performance from an internal combustion engine, as we ever will. In fact, an ICE’s system performance (20%) is pathetic compared to that of an electic motor (90% to 96%), and that’s something most people don’t fully comprehend.

Likewise, if there is ever a breakthrough in “room temperature” superconductivity (273 K or higher), an electric motor’s mass will plummet for the same performance, making an EV all the more attractive.

Many people wrongly think that and ICE automobile is using most of the energy content in gasoline, when nothing could be further from the truth. So, we consume tremendous amounts of gasoline to move us from point A to point B.

Don’t get me wrong. After 100 years, the ICE is a marvel of engineering, but it’s been the only game in town…until now.

We’re witnessing the advent of something that is going to profoundly change the world – the introduction of mass-produced electric vehicles for personal use that has, until now, been hindered by the lack of progress in the development of massive electrical energy storage.

For comparison:

Clock Spring (or Torsion Spring) = 0.0003 MJ/kg
Standard Capacitor (0.3 F to 0.6 F) = 0.002 MJ/kg
Lead Acid Battery = 0.11 to 0.18 MJ/kg
Nickel Metal Hydride (NiMH) Battery = 0.22 to 0.43 MJ/kg
Lithium Ion Battery (Present Energy Density) = 0.4 to 0.6 MJ/kg
Lithium Ion Battery (Predicted Energy Density) = 0.54 to 0.9 MJ/kg
Ultracapacitor (31 F from EEStor, 2008) = 1 MJ/kg
Lithium Ion Battery (with nanowires) = 2.54 to 2.72 MJ/kg

Gasoline Benchmark (20% ICE system efficiency) = 9.9 to 10.6 MJ/kg

Lignite Coal = 14 to 19 MJ/kg
Bituminous Coal = 23 to 35 MJ/kg
Ethanol = 27 to 30 MJ/kg
Gasoline = 46.5 to 48.3 MJ/kg
Methane (Natural Gas) = 50 to 55.5 MJ/kg
Hydrogen = 143 MJ/kg
Enriched Uranium (3.5% U235 in Light Water Reactor) = 3.456 TJ/kg
Nuclear Fission (of U235 in Nuclear Power Plants) = 88.25 TJ/kg

As you can see, massive electrical energy storage reaches far beyond automotive applications.

For example, electrical power generation will be able to take advantage of nighttime (off peak) energy storage, where today, coal and nuclear power plants cannot throttle back sufficiently to match the dropoff in baseload demand.

In other words, the steam turbine (and generator) spins, whether or not there’s load to match generation, and we can’t shut these plants down to conserve that energy (in coal or uranium). Typical “blackstart” times are the following:

Natural gas-fired (Combined Cycle) Plants: 30 minutes
Nuclear (Fission) Plants: 5 to 8 hours
Coal-fired Plants: 8 to 10 hours

But back to my original thought:

Another point to consider is that it doesn’t matter whether we’re discussing a Toyota Prius or a Dodge Durango SUV. They both have the same efficiency when in ICE mode exclusively – maximum 20%, but more often than not 17%.

The difference between the two vehicles is the amount of fuel each can carry and their respective mass: 11.9 gallons for the Prius (1317 kg) versus 27 gallons for the Durango (2112 kg).

A Toyota Prius has a fuel economy rating of 46 mpg (combined). It’s range is approximately 547 miles, assuming all fuel is consumed.

A Dodge Durango gets a fuel economy rating of 15 mpg (combined). It’s range is approximately 405 miles, assuming all fuel is consumed.

Taking into account their respective masses, the Durango’s fuel economy would climb to approximately 24 mpg were it possible to reduce its mass to that of the Prius while keeping the same fuel volume (27 gallons).

Conversely, the Prius’s fuel economy would fall to approximately 29 mpg were we to increase its mass to that of the Durango, while keeping the same fuel volume (11.9 gallons).

The issue of the ICE auto versus the EV hinges on mass, energy density/specific energy (MJ/kg), utility (end use), and system efficiency (20% vs. 90% to 96%). The EV will eventually win over those apprehensive about range anxiety.

To think, we currently burn fuel to go get fuel, whereas electrical energy is readily available everywhere hundreds, if not thousands of miles, from the generation source…in a millisecond, and has been for more than 60 years thanks to rural electrification.

People will have the freedom to use their electrical energy for moving to a “desired” location, as opposed to making a “required” trip to a filling station to get the energy needed to go to their “desired” location.

Electrical energy is readily available everywhere. The smart money is on the EV (all variants).