OPINION
This series is designed to help people to understand modern technology, and become more confident in using computing devices. It is not designed to educate experts.
The author is involved in tutoring older students at SeniorNet, a New Zealand wide organisation. SeniorNet hopes that students will feel more confident in using their computing devices as a result of the learning opportunities offered. This series of articles shares that hope.
Disclosure: I don’t own an electric vehicle. If Lotto comes in on Saturday I may consider it. Our use case would suggest a PHEV as the best choice, but as we have not even test-driven one yet that choice may not be well informed.
We’ve all heard how electric vehicles are changing the world. So I thought I would look under the hood, and see what it’s about. This article is concerned with passenger cars, so I won’t be looking at trucks, buses, milk floats or other non-passenger vehicles. If I mention a vehicle I mean “car”.
These are not new. Grandma Duck (Donald Duck’s grandmother) drove a Baker Electric, which was produced between 1899 and 1914.
There are four types of electric vehicles:
Battery Electric Vehicles,
Plug-In Hybrid Electric Vehicles,
Hybrid Electric Vehicles,
Hydrogen Vehicles.
Let’s look at each of these in turn.
Battery Electric Vehicles (BEV’s). These are vehicles that derive all their motive power from electricity. You plug them into the grid, charge the battery and then drive. When the battery is depleted the vehicle stops. The great claim for these vehicles is they produce no harmful emissions when they drive down the highway. No emissions, no CO2. This puts aside any discussion on how the electricity is generated and how ‘dirty’ the process is.
Looking at the most common USA makes, the range is between 100 miles (Mazda MX30) and 520 miles (Lucid Air Dream Edition). The make we hear most of the talk about is the Tesla. There are five models shown in my reference chart, ranging from 267 miles (Model 3) to 396 miles (Tesla Model S Plaid).
Plug-in Hybrid Electric Vehicles (PHEVs). These vehicles have both an engine and an electric motor to drive the car. Like regular hybrids, they can recharge their battery through regenerative braking. They differ from regular hybrids by having a much larger battery and being able to plug into the grid to recharge. While regular hybrids can (at low speed) travel 1–2 miles before the gasoline engine turns on, PHEVs can go anywhere from 10–40 miles before their gas engines provide assistance. So they are halfway between BEVs (above) and hybrids (below).
Here is an extensive list of vehicles that fall into this category available in New Zealand. Some of the prices are eye-watering!
Questions that I would ask:
- What is the range on electric before petrol kicks in?
- Does the gas power the wheels or just generate electricity?
- What is the price difference between the PHEV and the regular old gas-guzzling model?
- What private data does the vehicle provide to the vehicle maker?
- Are there any extras already installed, that would be turned on with a software switch? (e.g. heated rear seats)
Hybrid Electric Vehicles. (HEVs) Hybrid electric vehicles are powered by an internal combustion engine and one or more electric motors, which use energy stored in batteries. A hybrid electric vehicle cannot be plugged in to charge the battery. Instead, the battery is charged through regenerative braking and by the internal combustion engine. The extra power provided by the electric motor can potentially allow for a smaller engine. The battery can also power auxiliary loads and reduce engine idling when stopped. Together, these features result in better fuel economy without sacrificing performance.
So you effectively end up with a conventional vehicle with some battery assist. But it costs more upfront, so there is a payback period until the fuel savings cover that extra cost. Here is a calculator (in US$ unfortunately) to assist with that calculation. Use the table function to best view this information.
Hydrogen Vehicles. Fuel cell electric cars are powered by the most abundant element in the universe: hydrogen. Although a fuel cell car runs on electricity, it does so differently than battery-powered or plug-in hybrid cars. In a fuel cell, hydrogen reacts electrochemically to produce electricity to power the car.
Fuel cell cars are powered by compressed hydrogen gas that feeds into an on-board fuel cell stack that doesn’t burn the gas but instead transforms the fuel’s chemical energy into electrical energy. This electricity then powers the car’s electric motors. Tailpipe emissions are zero, and the only waste produced is pure water. Refuelling is quick (under 5 minutes). The first four stations are due, or under construction in 2023. Auckland, Tauranga, Hamilton, Palmerston North. Anywhere else and you are out of luck.
Hydrogen has had a bad safety rap ever since the Hindenburg airship blew up in 1937.
The question is, is it safer to have a hydrogen-powered bomb or a lithium-powered bomb parked in your garage?
Which Type of EV is best for you? There are differences between the various types which make one type better than another, depending on circumstances.
This site sets out to try and answer that question, and you are probably best to study it instead of having me try to reproduce the information here. The information is in the PDF, which you can read online or download. Bear in mind this is government-sponsored and produced propaganda, with its inevitable political bias. But at least it’s New Zealand-produced propaganda.
Each user will have their own use case, and this would affect which of these would best suit. A good, long test drive and an extended maths session should precede any buying decision. We also need to remove the politics from this decision, as the Greens have heavily politicised this, and we are led to believe (incorrectly) that hydrocarbon supplies are nearly exhausted.
Range and Range Anxiety
A note about the published range figures. A vehicle’s published range is based on standardised testing performed on a dynamometer in a test facility. However, as EV drivers know, the officially listed range is best taken as a guideline. In the real world, you have start/stop driving, hills, temperature, and wind, and that doesn’t even account for BMW drivers!
Thinking of the New Zealand landscape, does altitude affect electric vehicle mileage? Fortunately, electric cars work well at high altitudes. In fact, electric cars perform much better than combustion-based vehicles in regard to reduced air pressure at high altitudes. EVs are powered by a chemical battery that is unaffected by air pressure.
And what about temperature? As you turn the temperature up or down, however, the loss of range is apparent. At 5 °F (-15 °C), EVs drop to 54% of their rated range, meaning a car that is rated for 250 miles (402 km) will only get on average 135 miles (217 km). Cold gets a bad rap, but it turns out heat is also culpable.
When global warming (or driving in Australia) makes it uncomfortably hot, that also has an effect on the battery performance. The range drops as it gets hotter. The best-performing temperature turns out to be 21.5 °C, or 70 °F in olden days temperatures. Around NZ’s average temperature, so we may be the best place in the world to own an electric.
These are the effects on the battery. Don’t forget that you also add to the effects by using AC (air conditioning). These systems also affect the battery in EVs (and draw energy in your vehicle powered by dead dinosaurs and decomposed plants). But heating may be partially offset in traditional vehicles by using some of the waste heat going out the exhaust pipe.
There is more information about range/temperature here. Towards the bottom of the article are some interesting hints on getting better range, worth reading if you don’t want the embarrassment of calling out a petrol-powered ute dragging a diesel generator to the middle of the Desert Road, or some of those sparsely populated areas of the South Island.