An Exploration of Key Topics Shaping the Future.

Should You Buy A Hybrid: ICE, Hybrid, Plug-In Hybrid, Range Extender, or Electric?

This is an exploration comparing standard gasoline and diesel vehicles, with hybrids, plug in hybrids and battery electric vehicles. There is a separate exploration of hydrogen vs battery electric cars, so this page is focus on comparison with battery electric.

This page is currently in the process of being reviewed.

Contents:

  • ICE (Internal Combustion Engine: Gasoline/Petrol or diesel).
    • The Case For ICE / Internal Combustion Engines.
    • The Case Against
    • On Balance Winner so far: ICE.
  • Hybrids (Non-plugin)
    • The case for Hybrids over Non-Hybrids.
    • The case against
    • On Balance Winner so far: Hybrid.
  • Plug In Hybrids.
    • The case for adding the plug.
    • The case against
    • On Balance Winner so far: PHEV (provided you can plug in at home).
  • Range Extender.
    • The Case For Plug In Hybrids
    • The Case Against
    • On Balance Winner so far: Range Extender.
  • Battery Electric
    • The Case For Plug In Hybrids
    • The Case Against
    • On Balance, Overall Winner: BEV
  • Conclusion

ICE (Internal Combustion Engine: Gasoline/Petrol or diesel).

The Case For ICE.

Low Energy Weight: The key benefit of combustion engines is that combustible fuels such as gasoline/petrol or diesel have a far better energy per kg ratio than any electrical storage mechanism available to date.

A car with a 70 litre (18.5 US gallon) tank holds around 618 kwh of energy. Fitting a 618 kwh battery to a car is way beyond what is practical with batteries today.

If you want more stored energy, it is relatively low cost to increase the fuel tank size, or add an extra tank. Accessory long range fuel tanks are available for some vehicles, either as aftermarket or in some cases from the original brand, and some aftermarket companies will fit custom long range fuel tanks. Fitting a 60 gallon (227 litre) fuel tank would provide over 2,000kwh of energy.

Fast Refuelling. While battery recharging can take hours and even over a day in some cases, refuelling an internal combustion engine takes mere minutes.

The Case Against ICE.

The negatives are quite well established:

  • Internal combustion is very inefficient, with at least around 70% of energy lost as heat, and dealing with that heat also presents significant costs and and challenges to reliability.
  • Fuels for internal combustion engines are volatile and present a challenge to storage and significant risks in the event of an accident.
  • Gasoline itself a known carcinogen, as are the fumes from diesel engines.
  • Internal combustion engines produce significant amounts of greenhouse gasses as well as toxic nitrous oxides.

On Balance: ICE

When the Model T Ford was introduced in 1908, internal combustion engine vehicles were compelling. At the time, the electric grid infrastructure was not yet in place, and “gas stations” were easier to make into a business than recharging stations. In simple terms, while electric cars could be “city cars”, the internal combustion engine car could also be road trip capable. That won the day for ICE vehicles, at least back in 1908 and the next few decades! While Henry Ford did plan to introduce an electric vehicle in partnership with his friend of many years Thomas Edison, battery cost make the project uneconomical at the time.

The problem so far has been to build a storage battery of light weight which would operate for long distances without recharging. Mr. Edison has been experimenting with such a battery for some time.

Henry Ford, 1914.

Non-Plugin Hybrids, Or “Self-Charging Hybrids”.

Overview.

All hybrids combine both an internal combustion engine, and an electric generator, motor and battery as a second power source.

A “self charging hybrid” gets the power for charging from gasoline/petrol or diesel. Part of the duty of the internal combustion engine is to act as a generator to charge the battery. All energy comes from fossil fuels. The marketing term “self charging” can be misleading, and almost suggest this is a technological advance over plugin hybrids, but it is not. While all hybrids do some “self charging” in capturing energy from their own internal combustion engine, those labelled “self charging” at least be called “self charing only”, or as some would prefer, “fossil fuel charging only”.

The case for Hybrids Over Standard Internal Combustion Engine Vehicles.

So why bother to charge a battery if the energy all comes from the internal combustion engine? There are three good reasons:

  1. Some of the energy generated by the ICE would be lost if not “harvested” by a generator when decelerating, and by capturing and later using this energy, fuel consumption can be significantly reduced.
  2. A smaller capacity internal combustion engine can be provided, as peak power is achieved by the internal combustion engine boosted by extra power from the electric motor. So for example, an 200 kilowatt car could have a 150 kilowatt combustion engine, combined with a 50 kilowatt electrical motor.
  3. The car can operate for short distances on electric power alone, providing silent, pollution free motoring for short distances.

All modern vehicles with an electric motor, EV, hybrid, plugin hybrid, range extenders included, harvest energy that would otherwise be lost under braking. Some of the energy the vehicle produces to accelerate the car, needs to be “absorbed” during deceleration. Conventional brakes convert this energy to heat, which produces wear and is not desirable. Vehicles with an electric motor use the motor as generator during deceleration, capturing that energy as electricity instead of heat. This is known as “regenerative braking” and provides two benefits:

  • Less heat and wear during deceleration.
  • Recovered energy can be used to reduce fuel consumption.

The case against Hybrids.

Limitations:

  1. There are times, such as in “bumper to bumper” traffic, or on long trips on freeways, where there will be little energy available from when decelerating, and without “free energy” economy improvements can only arise from using a smaller internal combustion engine.
  2. Use of both engines to boost performance of the combustion engine alone cannot be used for extended periods such as driving at maximum speed on the autobahn.
  3. Electric only range is very low at typically up to 5 kilometres or up to 3 miles, has performance usually suitable only for “shared zones” at very low speeds, and is not even available on “mild hybrids”.
  4. Adding an electric motor and battery can add to weight and cost.

Limitations 1 and 2 are rarely relevant, and number three, the “limited electric only range”, while a limitation, is not a limitation relative to internal combustion vehicles. Generally, limitation 4, the added cost and weight is the only negative relative to internal combustion vehicles.

On Balance, Winner so far: Hybrid.

There is no real downside, particularly if combustion engine size can be reduced due to the availability of the power boost from the electric motor. Neither vehicle cost, nor weight, needs to be increased substantially now the technology is mature, and it likely almost all internal combustion engine vehicles would evolve into at least mild hybrids eventually.

Plug-In Hybrids or PHEV (Plugin Hybrid Electric Vehicles).

Overview.

All that is required in theory to convert a hybrid vehicle to a plug in hybrid, is an charging connector and circuitry to allow charging the battery.

In practice, it is generally only considered worthwhile bothering to plugin to charge, if the battery can provide a “worthwhile” range when running electric only, and the motor can provide acceptable performance when running electric only.

Moving to a plugin hybrid shifts the balance from a hybrid which is an internal combustion engine vehicle that is more economical because it is hybrid, to a PHEV that can be used as an electric vehicle on shorter distance trips consuming zero gasoline, petrol or diesel, and regular hybrid on road trips, overcoming the range limitations of most of todays EVs.

The dream is the best of both worlds, an electric vehicle with limited range for use on local trips, and a high performance long range vehicle on longer trips.

Where the dream falls short, is the electric vehicle experience is highly compromised.

As long as the owner of a PHEV accepts they will still be using fossil fuels even on shorter trips, they can benefit from using significantly less fossil fuel on these trips, provided they can charge at home, and the trips are short.

Ownership Experience: Its Not An EV, So Just Don’t Expect One.

Poor ‘Pure Electric’ experience: In practice, the ideal mix of providing the normal trips as pure electric, and reserving the Internal Combustion Engine for long trips is often unattractive because the experience in pure electric mode is too compromised. Consider, for example, the Volvo XC60 T8. 235kW of gasoline power, and 65kW of electric power. Which engine is the priority? How good is the experience when driving in pure electric mode? A comparable pure electric vehicle, the Jaguar I-Pace, has more than 4.5 times the kW (295kW) and almost 3 times the torque of the T8 in pure electric mode. Despite a comparable price, only when the T8 is fully using both engines does the T8 provide close to a similar experience.

Plug In Hybrid Identity Crisis: Is a plug in hybrid a part-time electric vehicle, or a performance boosted gasoline powered vehicle? Consider the Volvo XC60 T8. Underpowered in pure electric mode, but with sports car acceleration when using both gasoline and electric motors. While no SUV handles fully like a sports car, the cornering of the XC60 T8 is further compromised by the weight of the heavy battery. As a sports car, the T8 simply has a battery that is too large and too heavy for the role as a ‘sports SUV’, yet as a plug in hybrid, although the large battery provides the necessary range, the driving experience encourages use as primarily a gasoline powered car with extra power available from the electric power. The Volvo, and many other plug-in hybrids, are more comfortable as ‘sporty’ (or fast accelerating but heavy) gasoline powered vehicles with electric motors boost performance, rather than being suited to spending most regular commutes in ‘pure electric’ mode.

Most PHEV do not provide for recharge during road trips, refuel instead.

The Road Trip Benefit: The big payback for not being an EV, is that when on road trips the PHEV can become an ICE vehicle, refuelling briskly at conventional fuel stops, and never requiring a charging station. An real EV used in locations with good infrastructure, and with an EV with the range expected from 2022 models, would match the PHEV experience on road trips, but it buying a vehicle today in 2019 that will be used frequently for road trips, a PHEV could be very compelling.

If You Don’t Plug In, Some PHEVs Are Just Hybrids: Will you really plug in at home? About 50% of people are not set up to plug in at home, and perhaps surprisingly, it feels like that number rises to 90% for motoring journalists:

Unfortunately, without the ability to frequently charge, I spent most of my test time with the Outlander operating as a conventional hybrid, leaving me with 27.2 observed mpg after a week of testing.

A plug-in SUV that lacks appeal: Review of a plugin without plugging in.

It may seem obvious, but if you don’t plug in, then economy from a plugin hybrid will be no better than from a hybrid that cannot plugin. Some PHEVs, such as the Volvo XC60 T8, deliver performance that will please even motoring journalists who do not plugin, but others such as the Mitsubishi Outlander PHEV, are designed for the benefit of being a PHEV to be fuel economy, and that benefit is lost if you do not plug in.

Implementation Varies: PHEVs Are New And Evolving.

  • Compare the Mitsubishi Outlander, the Volvo XC60 and the Kia Sorrento PHEVs:
  • Outlander PHEV uses same ICE as and adds a low power electric motor.
  • Volvo XC60 T8 uses same ICE and add higher power electric motor to create a performance car.
  • Kia Sorrento PHEV use 1.6Turbo motor in place of 3.0L, and adds higher power electric motor to compensate.

These are three different formulas, to defining a PHEV, and the results are quite different. This in part reflects the fact that PHEVs are much newer than conventional hybrids, with the BYD PHEV-60 and Volt PHEV launched around 10 years after the Toyota Prius. Of the formulas above, the Kia Sorrento is the most successful at achieving a vehicle that is most practical for use primarily as an EV and delivers best fuel economy even on road trips.

The case for Plug In Hybrids over regular hybrids.

While a PHEV is not an EV, it does give a taste of owning an EV that cannot be experienced with a regular hybrid. There are two categories of PHEV. Those like the Volvo T8 models use the bigger motor and battery to deliver a performance result, and those such as the Mitsubishi Outlander PHEV that are focused on delivering economy.

All plugin hybrids offer substantially longer range, and more useable power when driving as a ‘pure’ EV, providing a taste of the potential of a full EV, and better ability to comply with pollution free zones that are in place in some European cities.

This gives three potential benefits over regular hybrids, but only performance PHEVs will provide any benefit to the 50% of the population that cannot easily plugin each night.

The case against Adding A Plug To Hybrids

The only read downside to adding the plug is cost.

On Balance: Adding The Plug.

Is the additional cost justified? In some cases the additional performance alone can justify the price, although some wanting a PHEV are seeking EV mode, not performance. The biggest caveat to the benefit of adding the plug is whether a driver has access to a plug at home.

Series Hybrid or Range Extender PHEV.

Overview.

With conventional PHEVs, as with conventional hybrids, both the electric motor and ICE can operate in parrallel, with both engines sending power to the wheels.

Alternately labelled a “series hybrid” or “serial hybrid” or “range extender” is a vehicle where only an electric motor drives the wheels, and an ICE operates as an onboard generator to recharge the battery for the electric motor, but does not drive the wheels.

Thus a Series Hybrid is an alternative type of PHEV, which shifts the balance between ICE and EV even further to the EV. While in regular PHEVs, the ICE is the primary engine and the electric motor provides only a boost when driving at full power. As seen in the BMW i3 (not all i3 models), Chevrolet Volt from 2010 and the to be introduced in 2022 Mazda MX-30, a range extended vehicle is a full EV, and has full power even when the ICE is not in use. When the EV battery is depleted, the generator activates and generates electricity to recharge the battery while driving, enabling range beyond the range of the battery alone. Since the ICE does not drive the wheels, a series hybrid/range extender, drives as a fully electric vehicle, and offers full power even when the ICE is not running.

Most series hybrid end dropping the ICE engine all together and moving to be full electric vehicles as battery technology and charging networks improve, but series hybrids could remain viable in areas with gasoline/petrol or diesel but no charging infrastructure.

The Case For Series PHEVs over Conventional parallel PHEVs.

In city driving for local trips, a series PHEV delivers full performance without using any fossil fuel. This allows a series hybrid to operate as full EV almost all driving, given that almost all trips are are local trips.

The Case Against Series PHEVs.

Consider a PHEV with a 150kw electric motor and a 50kw ICE. As a parallel hybrid, this vehicle would have 200kw of peak power available rather than the 150kw available as a series hybrid.

On Balance: Series Or Parallel PHEV: Series PHEV.

As Toyota has correctly identified, even providing any PHEV technology leads to consumers choosing EVs, which Toyota believes is will lead to job losses and lost revenue to the automobile industry. For consumers the normal balance between road trips and local trips, and with the ability to charge at home but not road trips, a series PHEV can deliver the ultimate experience. However, it still loses on that peak power specification.

Battery Electric.

Limited ‘Pure Electrc Range’: To achieve the optimal result of electric power for days with regular distances travelled, the electric range must provide sufficient distance. In 2019, vehicles with pure electric range of 40-40kms are common, but previously distance were often inadequate. In fact, 50km range, while adequate for some, does not enable this to be viable electric travel for a significant number of others.

The Case For Battery Electric

Efficiency: Conventional batteries are highly efficient, and the entire pathway from energy supply to electric propulsion is the most efficient system available.

Charging at home: Convential batteries are simple to charge anywhere there is time and electricity. This allows for charging at home using the well established and efficient utility electicty grid. It has even been suggested ‘off peak’ charging of EVs cpould improve grid utilisation and potentially even lower electricty pricing per kw/h to homes.

Best Solution for Predominant use case: For many people, battery electric provides the optimum solution with lost cost and convenient refuelling for almost their entire use of a car, even with short range batteries. Longer range batteries are only needed by most people for very rare long road trips.

The Case Against Battery Electric.

Road Trips (Charging away from home): Charging when parked other than at home is a challenge, but one with a variety of solutions. The biggest challenge is charging during a journey. There are recharging stations, but the time to recharge means these stations would need an enormous number of bays to service the same number of vehicles currently serviced at petrol/diesel fuel pumps. Consider a current fuel stop with, for example, 8 busy pumps. If the same number of vehicles are to be refuelled, and it takes ten times as long per vehicle, then 80 ‘pumps’ would be required. Currently it can take over 20 times as long per vehicle, even with the fastest recharging, and distance per refuel is lower, so vehicles need ‘refuelling’ more often.

Internal Combustions to best cover long trips: The usage pattern discussed in ‘range’ under ‘the case against battery electric’. A 50km range needed for almost every day, but a much longer range required to cover the rare need for a longer range. The advantage of the plug in hybrid is capablity for the infrequent longer range trips could be 700 or even 1,000 kms, a range not possible with any battery EV as of 2019, where over 400km range is rare, and beyond 500 not available. A further advantage is that refuelling a plug in hybrind on those longer trips is using current well established and high availability refuelling.

Range: With charging during a journey problematic, range becomes extremely important. But range comes at a cost in terms of weight. While fossil fuelled or hydrogen fuelled vehicles have carry capacity for long journeys, a large battery is heavy, and just as heavy even when not charged. A common car usage pattern would be 9 out of 10 days requiring only 50km range, and the maximum available range (for example for an electric vehicle say 400km) would only be needed less than 1 day in 30. Despite only being needed 1 day in 30, a vehicle will typically need to provide for that maximum range. This means the extra battery weight to provide the rarely needed extra 450km of range needed must be carried as ‘dead weight’ or ‘insurance’ 9 days out of 10. This ‘rarely needed’ range has a negative impact on efficiency.

Range Anxiety: Anxiety is where the worry or stress felt is beyond the level appropriate for a problem or possible problem. While balancing actual range against weight is a real problem, there is also ‘range anxiety’ is disproportionate fear of insufficient range. Imagine you had always only been able to charge your mobile phone once per week, and then were given typical new mobile, that requires charging at least every two days, and in practice most people charge every day. Switching to an Electric Vehicle is a similar change, as most people refuel internal combustion cars about once per week, so they need range for an entire week, which charging an Electric Vehicle at home is like charging a phone so enough range for two days would normally be adequate. We have been trained by past habits to need more range do to the refuelling process and the change can create anxiety. There is a real problem for infrequent long trips, and an imagined problem on normal days.

On Balance: Battery Electric

Perfect for every day use, but with question marks for the rarer days kilometres (or miles) travelled with exceed 2/3 of vehicle range- or around 250km (or 150 miles) for long range battery electric cars, and shorter trips for shorter range vehicles.

For a two car family, the case is very clear for one car to be electric. But for singles or one car families, there is a question over refuelling on those long trips.

Conclusion

Right now, to run electric the best choice pure battery electric vehicle. Plug-in hybrid currently available are lost in an identity crisis, and offer a sub optimal experience unless you plan to use fossil fuel as the main power source. Certainly all hybrids offer fuel savings compared to having the same performance without the hybrid, but the still run on fossil fuel.

Hydrogen could be used together with battery electric in future, given the established recharging network it is going to require a big step. Perhaps there is hydrogen in the future, but it does happen, it will still not make battery electric redundant.

Share

Table of Contents

Categories

Our Journey To A Finite Planet.

Hasn’t The Planet Always Been Finite? The Finite Planet Of The 21st Century Pre-1650 and “Sustainability”, A Seemingly Infinite Planet. The Economics of Finite Planet.

Share
Read More »
No more posts to show