Fullscreen HTML5Med Res (??MB)HTML4

Where’s my pneumatic car? Techno Talk Max the Magnificent Electric vehicles are a great idea, but the elements forming their batteries involve intensive and polluting mining operations and 70% of the electricity used to charge these batteries comes from nonrenewable sources, especially fossil fuels. Could pneumatic cars running on compressed air provide the answer? I f you look at a map of the world, it’s easy to visualise the various continents as being part of a gigantic jigsaw puzzle. A big clue is that – in addition to their mirror-image shapes – the geologies at the edges of continents like the east coast of south America and the west coast of Africa match up. The idea of continental drift was first espoused in 1912 by the German climatologist, geologist, geophysicist, and meteorologist, Alfred Wegener (I have no idea what he did in his spare time). However, it wasn’t until technology was brought to bear that the underlying mechanisms began to be properly understood. First, we discovered that the Earth’s magnetic field periodically reverses. Many rocks contain iron-bearing minerals that can act like tiny magnets. When these rocks are heated and cooled, these tiny magnets become aligned to the current orientation of the Earth’s magnetic field. According to the United States Geological Survey, these reversals can occur as often as every 10 thousand years or as infrequently as every 50 million years (the last reversal was about 780,000 years ago). Second, during the late 1950s and early 1960s, the magnetic fields associated with rock samples retrieved from the floor of the Atlantic Ocean reflected how new crust is forming along the underwater Mid-Atlantic-Ridge, thereby pushing South America and Africa apart. The amazing thing to me is that the theory of plate tectonics (the mechanism underlying continental drift) did not experience wide acceptance by most scientists in geology until around 1967, which is ten years after I was born, for goodness’ sake! Fancy a stroll? Bolstered by modern technology, scientists can tell us all sorts of interesting things. For example, we now know that during the last ice age about 18,000 years ago, what is now Manhattan in New York was covered by an ice sheet about 600m (2,000 feet) high. 8 So much of the world’s water was trapped in ice at that time that sea levels fell by around 120m (400 feet). As a result, it was possible for people to stroll from Europe to Britain. Over time, things started to warm, the ice melted, sea levels rose, and Britain returned to being an island, which is just the way we like it (and quite possibly for our neighbours too!). Got gas? Rising and falling temperatures are all part of the natural cycle. Sometimes these changes are extreme, with the world being much colder and hotter than it is today. For example, scientists currently believe that the entire planet has sometimes been completely covered with snow and ice. At other times, the world has been like a sauna. For example, researchers at the National Oceanic and Atmospheric Administration (NOAA) now believe that the global average temperature toward the end of the Neoproterozoic Era (around 550 million years ago) may have risen as high as ~32°C (90°F). The problem is that changes that would typically span hundreds of thousands of years are now transpiring in decades. Due to climate change, deserts are expanding, glaciers are retreating, permafrost is melting, sea levels are rising, heat waves and wildfires are becoming more common, and the world is experiencing more intense storms, droughts, and other weather extremes. Even worse, I don’t have anything suitable to wear. The primary cause of our current problems is the amount of greenhouse gases like carbon dioxide we are pumping into the atmosphere. And the primary source of carbon dioxide is burning fossil fuels like coal, oil and natural gas. Got wind? One way to at least begin to mitigate our current climate change woes is to use renewable energy sources like wind power. A recent report by the US Department of Energy (DoE) predicts that wind turbines will provide 20% of US electricity needs by 2030. These things can be huge. Each of the blades used in a typical modern landbased wind turbine are around 50m (170 feet) long, while China’s LZ Blades company currently holds the record with a wind turbine whose blades are 123m (404 feet) long! Are electric cars the answer? There are currently around 1.5 billion cars in the world. The vast majority burn gasoline or diesel, but the number of electric vehicles (EVs) is starting to rise. One’s knee-jerk reaction might be to think that our problems would be solved if all cars were EVs but – sad to relate – that’s not the case. The first issue is the batteries. Current automotive battery technologies are based on lithium, nickel, manganese, cobalt and graphite, along with a bunch of rare earth elements, all of which involve intensive and polluting mining operations. And I’m not even considering the problems associated with recycling and disposal when these batteries go end-of-life. The second issue is charging the little scamps. Renewable energy sources (sun, wind, hydro) currently account for only around 30% of global electricity generation. The rest comes from nuclear or – you guessed it – burning fossil fuels. Where’s my pneumatic car? For the past 20 years, I’ve been hearing about a novel French automobile company called Moteur Developement International that’s developing a pneumatic car that runs on compressed air. Admittedly, the range would only be around 100 miles on a full ‘charge,’ but that would cover 99% of my personal needs. Using a small pump located inside the car, its tank could be recharged for only a few pennies by plugging it into a regular wall outlet. Also, electricity to run the pump could come from solar panels mounted on the roof. Will this technology ever come to pass? I don’t know. I’m starting to lose hope. What I do know is that if these ever do go into production, I’ll be at the front of the queue! Practical Electronics | November | 2023