One hop is better than two

March 11, 2020


Spring is just over a week away. The snow is melting, a winter’s worth of dog poop is appearing, the crocuses aren’t far away, and my youngest daughter is counting the days until the Easter Bunny visits. A certain electricity is in the air. That electricity is about to make its way into our city buses.

In January Guelph welcomed local, provincial, and federal government representatives and welcomed the exciting news they brought to town. We will soon be receiving 35 electric buses, with another 30 to follow, along with a facility to clean, maintain, and charge them. The feds and the Province are both kicking in dollars to help.

Like many people, you’ve probably never even seen an electric bus, much less ridden on one. You may not be sure whether they’re a good idea. They sound cool, high tech, and clean, but are they really? These are all important questions.

First, let’s talk about how they change things for riders. If you’ve ever waited at the downtown terminal or at a stop serving more than one route, you’re familiar with diesel fumes. They’re awful. When a diesel bus pulls away, it leaves a bad taste in your mouth and probably pushes you into a coughing fit. Those fumes harm your health, especially if you’re a child. Electric buses produce no exhaust, so the air around them is as clean as spring. That’s a plus.

The e-bus riding experience is also an improvement. Every time a diesel bus changes gears, it lurches, which leaves you with an uncomfortably jerky ride. You really notice this when it’s standing room only, like the 99 Express toward UofG first thing in the morning or away from it at the end of the school day. Electric buses accelerate smoothly, without pitching you around every time the driver works the clutch.

Then there’s the noise, or the lack of it. Diesel buses are loud beasts, since they run by making a small amount of fuel explode inside a metal cylinder more than a dozen times each second. That noise is displeasing both inside the bus and out. The brakes can also produce an ear-splitting squeak, especially if they’re in need of maintenance. Electric buses, by comparison, are virtually silent. The motors hum a little, but it’s barely noticeable. The brakes often have no physical contact happening at all, since they convert the forward motion of the bus back into stored electrical energy in the battery. This magnetic process, called regenerative braking (more on that later), is as quiet as a mouse.

So the e-bus rider experience is head and shoulders better than the diesel one. How do things look to Guelph Transit?

First, the costs are different. Electric buses have a higher sticker price than diesels by quite a margin. Throw in the chargers, and the upfront cost is higher still. However, electric buses cost far less to run than diesels. Electric vehicles (EVs) are inherently more energy efficient than internal combustion engine (ICE) ones; they convert 80-90% of the battery energy into torque, compared to 30% or less for ICEs. They will typically charge up at night, when electricity is cheap. As mentioned above, EVs have regenerative braking, which charges the battery back up when the vehicle slows down. ICE vehicles just produce heat and maybe that squeaky noise mentioned earlier, both of which are wasted energy. ICE vehicles have 100 times more moving parts in the drivetrain than electrics, meaning a whole lot more things to maintain and a whole lot more things that can go wrong. That makes maintenance a lot cheaper for EVs.

Still on the topic of fuel, with e-buses, you can “grow your own”. Put solar panels on the roof of the garage, build a solar carport over your outdoor parking lot, and set up a few more in a nearby field, and you can supply some - maybe even all - of the power you need to run your fleet. Try that with diesel. (Well, actually you can, with biodiesel - but it’s very tough to scale up to supply an entire transit fleet, and you can only mix so much biodiesel with regular diesel before engine trouble starts.)

Another consideration is environmental liability. Transit operators store diesel fuel in large tanks, often underground. These tanks can leak. This leaves behind a significant cost for environmental remediation down the road. Electric vehicle chargers don’t come with this risk.

There’s also the contribution to climate change. In Ontario, we shut down all our coal-fired generation plants a few years back, so our electricity produces minimal emissions. This means that e-buses - directly or indirectly - emit virtually none of the greenhouse gases that are heating our planet.

Let’s not forget the folks in the transit garage. They’re very skilled at maintaining diesels, but electrics are a completely different animal. So retraining them will be another consideration, and another cost. Again, the biggest cost will be the initial one, as the entire maintenance staff complement will have to learn how to tend the new buses.

Finally, there’s the question of what to do with the e-bus batteries when they are too old to cut the mustard. Some folks raise concerns about the environmental cost of disposing of these batteries. But that’s missing an important point - these batteries still have plenty of life left, they’re just not good enough to keep on the road. There will be buyers - electric utilities or their suppliers. They will use the batteries to buy and store electricity at night when rates are low, and sell it back during the day when rates are high. Buy low, sell high. So it will be a very long time before those batteries get tossed, and even then their component parts and materials will make them attractive to recyclers. (This buy-low-sell-high idea may even be a money-making opportunity for Guelph Transit, when a new idea called Vehicle-to-Grid becomes available.)

To sum up, electrics cost more initially but less if you look at their entire service life. So the trick is to spread the initial cost over time. Cities can do this by borrowing, but another option is to lease the batteries. The jury’s still out on whether that’s a good deal or not. My bet is that it’s not, since I find it hard to believe that a bus manufacturer can get cheaper money than the city can.

E-buses aren’t the only next-generation bus tech game in town. Another option is natural gas, specifically compressed natural gas (CNG). Compared to diesel, CNG looks pretty good. But compared to e-buses, not so much. CNG burns cleaner than diesel; although CNG bus fumes are much better than diesel, they still can’t match fume-free e-buses. CNG bus riders still have to put up with the lurches whenever the driver changes gears. CNG buses are a bit quieter than diesels, but not as quiet as electrics. So for the rider, CNG isn’t much to get excited about.

CNG buses have a lower sticker price than electrics, but you still have to splash out for CNG filling stations, and those don’t come cheap. Those filling stations will become a stranded asset if we opt to switch to electric buses after using CNG ones for a decade or two. CNG buses are even less energy efficient than diesels (and don’t have regenerative braking), so they’re actually a step backwards on that score. And their engines are every bit as complicated as diesels, and will make it necessary to invest in training staff on the new tech, so no maintenance savings

There is a “grow your own” option for natural gas, namely renewable natural gas. Sewage sludge, green bin waste, closed landfill sites, and farm wastes can all be used to make this stuff. However, we’re extremely dependent on climate-changing natural gas as it is. We’ll have to dramatically reduce our consumption, and the alternatives aren’t very promising. Renewable natural gas potential is low, and there’s an upper limit to how much hydrogen you can add before it causes problems with the devices that use the fuel. 

Adding another mouth to feed from the same larder would be a huge mistake. British Columbia has imposed an aggressive renewable natural gas goal, stretching the slim pickings of RNG sources to the breaking point. CNG vehicles will be in direct competition with established natural gas uses for the same scarce sources of renewable fuel.

To put this in perspective, the World Resources Institute estimates that the potential for renewable natural gas production in the US is the equivalent of 6 billion gallons of diesel per year. However, the US consumes more than seven times that amount of diesel - 46 billion gallons - each year (and 377 billion gallons of gasoline). So RNG is a drop in the bucket. Or the barrel.

On a smaller scale, Surrey BC uses green bin waste to produce renewable natural gas. This is enough to fuel the city’s fleet of garbage trucks, but that’s as far as it goes. Fuelling transit? Forget about it.

We will never be able to produce much renewable natural gas. That means that if we opt for CNG buses, we will be locked in to fuelling the buses with fossil natural gas, which - per a report from the California Air Resources Board - produces just as much globe-warming gases as diesel. To make matters worse, a natural gas supply chain - whether it is based on fossil or renewable sources - inevitably produces leaks, and natural gas is 25-34 times more potent a greenhouse gas than carbon dioxide. Electricity has no such issues.

Another wildcard is tax. CNG is cheaper than diesel because it is exempt from the gas tax. That may change. However, it isn’t exempt from the carbon tax, and the plan is to increase that tax over time. Taxes will make the CNG choice look worse and worse with each passing year.

CNG is an intermediate technology at best, like the IBM Selectric typewriter was an intermediate technology between mechanical typewriters and personal computers running word processing software back in the eighties. We have the choice to hop twice, stopping for a while on CNG before eventually moving to electric, or just once. Edmonton and Toronto have opted to make big investments in battery electric buses. The leadership at the City of Guelph is making the right choice to do the same, moving directly to a permanent solution, and we salute them for it.


Alex Chapman