Musings on sustainable/affordable transport

Archie has generated a discussion I find interesting over at his site on the subject of petrol prices. Metro makes a valid point about this pushing us toward cleaner technology such as electric vehicles.

I want to make the point up front that I’m totally in favour of that.

People often say things to me like “electric vehicles are awesome because they don’t pollute and they’re cheap to run.” I thought I’d put up a post exploring that statement in a wider sense because sustainability is a subject dear to my heart.

At face value, the statement about electric vehicles is mostly true. The vehicle has no emissions except hydrogen during charging (with present lead-acid-type battery technology). That will likely change. In terms of cost, the cost of a usable kilowatt of electricity is less than the equivalent kilowatt of petrol.

Let’s explore these factors in a more holistic sense within the framework of a nation. I’ll use New Zealand.
How about this question: by switching all vehicles in NZ from petrol or diesel to electricity do we eliminate the burning of carbon fuels in our country and their carbon emissions?

Answer: no.
NZ relies on a wide range of energy sources, mainly hydro-electric, gas, coal, geothermal and wind in descending order of market share. There is a limit to how much power we can generate sustainably (and when it is needed in the grid) from geothermal and wind. Hydro-electric is our major component, but our dams are already near their generation capacity and the idea of flooding more valleys/damming more rivers is fairly abhorrent to most NZers. Oh, and hydro apparently produces large amounts of greenhouse gas too.
30-40% of our present generation comes from gas and coal. Mostly gas. By adding a massive new energy demand to the grid from everyone charging vehicles, we need to burn more gas/coal. Despite modern co-generation plants like the Southdown Plant, this still means a lot of new plants. New Zealand is strongly anti-nuclear. I support that, along with most of the country, and it’s unlikely to change. Having said that, I have seen studies arguing that coal is even more environmentally damaging than nuclear. I’m not exactly sure that’s true, but I do know that coal is extremely damaging and it could be true.

Verdict: Assuming we make up the shortfall of energy by adding gas or oil stations, we may save a percentage of emissions by burning more efficiently. We need to make massive investment in new power infrastructure. We are still burning large quantities of carbon fuel that we have limited resources of.

Let’s look at costs. At today’s electricity prices it would be cheap to operate an electric vehicle. How about when everyone has electric vehicles? Massive demand on the energy grid for a limited supply would see a major price increase, plus the costs of expanding the infrastructure would be factored into either the retail price or taxes depending on whether the government foots the bill. Either way, society pays for it.

This is all very negative I know. It’s not intended to be. This shift might occur over the next fifty years. Electric vehicles might not be particularly widespread until fifty years from now. They may never be. Another better technology may present itself that avoids these issues. I sincerely hope that’s the case.

Other developing technology may reduce the amount of energy required to get from point A to point B. Take this example: A guy driving to work in an average four-door car. Around 4% of the energy produced by the engine goes into moving the driver himself. Even with four people in the car you’re only up to about 14%. The rest goes into moving the mass of the car itself, is lost to heat/friction etc. If we could improve the car by, say, reducing it’s weight (without sacrificing structural integrity) could we reduce the energy it uses? Absolutely. This has already been happening for some time, but continuing advancements in materials technology may make even more substantial gains. That’s a conventional example. How about something more sci-fi like a relativity drive? This could potentially produce a hovercar if it ever actually works. Despite apparently violating fundamental laws of physics I’m suspending judgement until it’s peer reviewed. At the very least it proves that we’re not yet out of ideas.

There is some deep thinking around energy sustainability. Far too much to cover in a single post. There may be more on this in the future. Watch this space. In the meantime I welcome any healthy debate.

For now, I leave the fundamental point: Moving things or people from point to point requires energy. That energy needs to come from somewhere. All the sustainable forms of it that I can think of are driven by either solar or gravitational sources. We just need to figure out how to employ them efficiently and effectively. I believe we’ll manage it somehow.


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