So often when I am talking to someone who has noticed that my car is electric, I have to explain that it is ALL electric..there is no petrol engine at all.
Most people are basically familiar with the concept of the hybrid…Toyota has popularised the concept with its Hybrid Synergy Drive vehicles, the best known being the ubiquitous Prius that many love to hate.
The Prius however, is not the only type of hybrid, nor is it the best. But it was the first on the market.
The fundamental difference between a hybrid and an EV is that an EV drives purely on electricity, supplied from a rechargeable battery, and is powered only by an electric motor.
A hybrid uses an electric motor and batteries, as well as some other form of energy…usually a petrol (occasionally diesel) internal combustion engine.
A hybrid can be classed either as a series hybrid…meaning that all of the driving is done with an electric motor and the petrol engine is there only to run a generator to produce power (most railway locomotives are series hybrids) or as a parallel hybrid…where the petrol engine is connected to the wheels and the electric motor is there to give assistance with hills and acceleration.
The Prius (and the Camry hybrid, the Lexus hybrids, and all vehicles using Toyota’s Hybrid Synergy Drive) is a parallel hybrid. The petrol motor is running all the time (unless stopped in traffic or creeping along at low speed) and the electric motor is there to give assistance with climbing hills or accelerating. The battery pack is small, just enough to give a few minutes of assistance. The idea is to allow a smaller petrol engine to be used without compromising performance. The power used by the electric motor is generated by burning petrol. This type of vehicle cannot be classed as an Electric Vehicle, as all of the power used to move it ultimately comes from burning fossil fuels, it just uses the fossil fuels a bit more efficiently than a conventional car.
A more recent type of hybrid development, is the Plug-in Hybrid Electric Vehicle (PHEV).
These use a larger battery pack, generally enough to allow 40-60km of electric driving. There is a petrol (or diesel on the Volvo V60 PHEV) engine connected to a generator, and when the battery gets low the petrol engine starts and provides power.
A PHEV is much more efficient than the Prius style hybrids, as the engine only ever runs when the batteries have been used up and it runs always at the most efficient speed and only as long as needed. All driving is done with electric motors which are more efficient.
The first PHEV on the Australian market was the now discontinued Holden Volt. More recently we have seen the Mitsubishi Outlander PHEV, with Mitsubishi committing to rolling out a range of PHEVs over the next few years, Audi has launched the A3 eTron, and BMW has a “range extended” variant of the i3. Overseas there are a whole
raft of PHEVs, with VW offering a Golf PHEV overseas (but have said that for now they are not planning to sell any of their EV range in Australia…) and Volvo recently announcing that their entire model range will be available as PHEV by 2019.
A PHEV is recharged just like a fully electric EV, and for most people in ordinary commuting it will always run on electricity. The petrol engine only cuts in when you drive further than the electric range.
The benefits of a PHEV over an EV are that PHEVs are more convenient for long trips. Refuelling is faster than recharging. Filling a petrol tank takes 2-5 minutes while a fast charge will give 80% battery fill in around 20 minutes. Fast chargers are being rolled out on major routes, but they aren’t everywhere yet…
On the downside, a PHEV is always carrying around an engine, generator, fuel tank, and all of the associated parts required to run a petrol engine. This means extra weight, reduced efficiency, and a smaller battery pack. While battery EVs on the Australian market can go 150km or more per charge, PHEVs generally go around 60km before needing a recharge or the petrol engine kicking in.
This petrol engine also means more maintenance and associated costs. On the other hand, EVs have no oil to change, spark plugs to swap, fuel and air filters, exhausts to rust out, or any of the “stuff” that is needed for a petrol engine. Servicing an EV is pretty much checking to make sure nothing is bent or broken underneath, checking brakes and wipers and tyres, and perhaps running a computer diagnostic check.
Right now, if you rarely make long trips you are better off having an EV, and either swapping cars with a friend or family member, or hiring one, when you need to do long trips.
If you do long trips regularly then the PHEV is a good stepping stone, and makes an ideal second car to an EV in a two car household.
As charging networks improve, and more fast chargers are rolled out along major routes, the relevance of PHEVs will decrease until at some point in the future they will be viewed as an anachronism belonging to a past era…