Hydrogen-powered cars

There is a lot of talk and much advertising recently on the subject of water being expelled from hydrogen-powered cars instead of C, CO and CO2 (as well as the other stuff). This all sounds great. Fuel cells convert hydrogen and oxygen directly into electricity and water. How cool is that? Clean, simple and expensive. Oh sorry, that's supposed to be cheap except that it isn't. The cost is only one of the problems. There are two much bigger issues with hydrogen-powered cars and they have nothing to do with storing the hydrogen or how a hydrogen pump station will work or safety or even cost. The first issue is that electric cars cannot function directly from a fuel cell very well. The fuel cells are OK at generating a constant power level but cars need short peaks of power to get up to speed and this means you need some form of electrical storage. Until we get really huge capacitors with adequate life, we are stuck with rechargeable batteries and these are both heavy and costly to make in terms of pollution. The extra weight increases the mass of the car which means it needs more torque to accelerate and bigger brakes to stop. The batteries themselves are generally made from materials which are nasty pollutants if the batteries are not properly recycled and they need to be every year or so because the lifetime isn’t that great. Even if we ignore the battery issues - let's say we can make big enough super-capacitors in the next 5 to 10 years from materials like grass, corn and sea water; we still have to deal with making the hydrogen. Hydrogen is made (typically) by electrolysis. This is the process that uses an electric field to cause the H and O ions in a solution to migrate apart from each other towards the electrodes supplying the potential. This ion movement constitutes a current and requires energy to make it happen. In a big generation plant this means pulling lots of power from the grid or perhaps building a power station nearby. And the power station is fueled by what? That would be predominantly coal or gas in the US with a sprinkling of nuclear power thrown in so we don’t look too backward to the French. So the bottom line is that your nice new hydrogen-powered car might cause just as much of exactly the same pollution (C, CO, CO2, S, H2SO4, etc) as the gas-powered car does now. But as a purchaser you can walk with your head held high knowing that your tail pipe only spits out water.