Thursday, 29 May 2008

What shall we do when the oil runs out?

Crude oil has hit $135 a barrel (a barrel is about 35 gallons and can be used to make 15 gallons of petrol plus other stuff) and the prices at the pumps in the UK hover around £1.10 for a litre of unleaded.

Some say that this extraordinary price is more indicative of speculation than any actual shortage. This may be true for the near term but the oil is going to run out sooner or later - it would be a good idea to have some sort of plan in place for when it does.

Of course, the oil is never really going to run out completely. Think of it like this: when God created the world He supplied it with 3 trillion barrels of oil. The first trillion barrels were easy to access, you just dug your pickaxe into the ground and a great black gusher came up and you were rich. Unfortunately that trillion barrels has all gone now. We're working our way through the second trillion. This oil is hard to access, you need to dig deep and suck hard. Worse, for every 5 barrels you get out you're burning another barrel just to run the rig. We're a long way into this trillion barrels and known reserves are falling. Saudi production will probably start to fall in 2010. Iraq and Nigeria could produce more but they are in the grip of local wars. (Interestingly Saudi could produce more now but to do so they would have to invest in more wells--why spend the money when all it would do is reduce the price they then get for the stuff?)

As for the 3rd trillion barrels; it's not really liquid at all. It's bound up in rocks and tar sands. We would have to be desperate to try to extract that oil. You would be burning two barrels for every one you extracted and for some of it you would literally have to burn more oil than you ended up with--so completely pointless even to attempt.

During the oil price peak of the 1970s the oil companies did some investment in getting oil out of shale rock, but the oil price fell again and they lost their shirts. Since then they've been reluctant to try.

So, one way or another the oil is going to run dry, or at least get too expensive to use. What will we do then?

There are people who think the oil running out wouldn't be such a bad thing. Think of the environment, the clean air, when there's no oil being burned. Of course we'd have to live like it was the Middle Ages all over again--but were the Middle Ages really so bad? Commute on horseback, goods delivered in carts, sailing ships for international travel and candles to light your way to bed. No pollution, a simpler life.

The down side is that about 30 million people in the UK would die of starvation without mechanised agriculture and the other 30 million would have a life expectancy of about 30 years due to disease and malnutrition.

So it might be a good idea to find some sort of oil replacement before the oil is gone.

Let's look at what we use oil for.

The world requires about 80 million barrels of the stuff a day. It goes about one third to run cars and trucks and planes and ships - transport basically, one third is used to generate electricity for industrial and domestic use, and the last third as an ingredient in manufactured goods, including plastics, clothing, fertiliser and even food.

Let's start with the "generating electricity" side of things. There are lots of other ways to generate electricity: solar power, wind power, tidal power, geothermal power. Of course you can also burn other stuff like coal or gas, but since they're running out just like oil there's probably not much point gearing up to use them. (And it would be nice to have a "green" replacement.)

The trouble with all these options is that none produces enough power reliably enough. Solar? When the Sun isn't shining you have no power. Wind? Same problem. Tidal power is of course very predicable but there are only two high tides a day and what do you do for juice the rest of the time? (This problem isn't totally insurmountable. There are "multi-basin" solutions which let you eke out your tide over the course of a day.) However even capturing every high tide in every nook and cranny of the UK wouldn't give us enough electricity to replace our oil consumption.

Geothermal requires the Earth's subcrustal heat to come to the surface and in the UK it mainly doesn't.

There are always biofuels, but then 3rd worlders starve.

Frankly it's going to have to be nuclear.

Now nobody likes nuclear, and nobody wants a massive nuclear plant near them. But technology has moved on since the 1950s and nuclear doesn't have to be like it was. Check out this dinky little reactor:

Dinky reactor

It's completely sealed and self-contained and good for a 100 megawatts. 100MW, how much juice is that? Well the UK really needs about 50 gigawatts so 500 of those babies would keep the lights on when the oil's gone.

It's a breeder reactor and runs on uranium 238. We could go for a more conventional reactor using U235 but although there's enough U235 in the world to keep the UK supplied forever; let's face it, the rest of the world will be going nuclear as well and U238 is at least 100 times more plentiful. Unfortunately the UK doesn't actually have any uranium mines but the world's reserves are mainly in Canada and Australia - politically stable and friendly countries.

The reactors would be dotted all over the country; buried underground of course for safety and concealment and nobody could be a NIMBY because everybody would be getting one. There would be an added benefit that the 10%-20% power loss that happens when the national grid shunts electricity around the country would be reduced by widely distributing the generators.

These reactors would never be opened on site. The local operators would do little more than guard them and polish them. If maintenance or refueling were required the whole reactor would be lifted out of its silo and trucked to a remote facility such as Sellafield.

Who would make these reactors for us? Well, Rolls Royce do a nice line in reactors for submarines so I suggest these wouldn't over-tax them.

Which brings us to transport.

How will we fuel our cars when the oil is gone?

Assuming we have plentiful electricity thanks to an investment in nuclear power there are a few options. Let's look at them.

Hydrogen-powered cars: Hydrogen is easily extracted from water by running a current through it. It can then be "burned" to reform water and release energy. It takes about 50 kilowatt hours to produce 1 Kg of hydrogen (that's 180 megajoules) but on the plus side hydrogen has an energy density slightly higher than petrol, per Kg. Unfortunately that doesn't mean the tank can be smaller because it will require massive pressurisation and hydrogen cars will be very heavy bombs waiting to happen.

Nitrogen-powered cars: We're talking liquid nitrogen here. You can condense it out of the atmosphere which is about 80 percent nitrogen, put it in an insulated tank, and power a car by drawing some off and heating it whereupon it will expand and turn a turbine. To cut a long story short your car will be safe (nitrogen is inert) have a top speed of 30 mph and conk out after ten miles.

Iron-powered cars: Yes, you can burn iron, believe it or not. It has to be in the form of filings or dust with particles of exactly the right size: too large they won't burn, too small they explode. The energy density is higher than petrol. I think this one is a non-starter but I put it in just to show there are some weird possibilities out there.

Battery-powered cars: These are good for lightweight vehicles over a short range. The best lithium-ion batteries like you get in laptops have an energy density of 750 kilojoules per Kg. Contrast that with the energy density of petrol which is about 150 megajoules per gallon. As you can see a battery the size of your petrol tank would struggle to propel your car for more than a couple of miles. (By the way, a "joule" is a measure of energy equal to a watt-second. You'll need to know that when we work out how many extra reactors we need to run our electric cars.) So successful battery powered cars need to be light, devote an inordinate amount of their interior space to battery, and not go very far. A maximum range of 150 miles perhaps. The other big problem with batteries is they have a strictly limited number of recharges before they need substantial reconditioning.

Capacitor-powered cars: We're talking super-capacitors here, not the tiny little things you see on circuit boards. Unlike batteries which use a chemical reaction to store energy capacitors store their juice as raw electrons. They can be charged and discharged millions of times without loss of capacity, and the recharge time will be minutes. The best, admittedly experimental, capacitors have an energy density up to 1 megajoule per Kg. So if your car's petrol tank were replaced with a capacitor of the same size you'd be able to go at least three miles extremely fast.

So I think the root problem is clear: the only power-storage technology we have is either too dangerous, or too limited. We can generate plenty of electricity but how to store it in the car, or bus, or truck, or train?

Wait a minute! Electric trains don't carry their juice around with them, they are supplied from the track, either by overhead cables (the continental solution) or in the UK using a third rail which people can walk on and kill themselves.

Could we do the same with cars? The overhead cable idea is obviously out, how would cars overtake or go off-road? But a power cable could be buried in the road surface under the tarmac and the car could pick up the power by induction. The road would be safe to walk on provided you didn't dig down to the cable.

Power cables would need to be buried in all the motorways, A-roads and B-roads. That's about 60,000 miles of road. The car would also need to have perhaps a 100Kg capacitor onboard for use when it wasn't over a power cable. That would give it an independent range of about 30 miles. The capacitor would charge itself up whenever the car was in contact with a power cable. The power cables wouldn't need to be continuous, for example, you could skip junctions for ease of laying the cables.

Now wiring up the country's roads would be a hideously expensive and disruptive exercise. Worse even than all the digging that happened to put cable TV in, but once it was done the whole energy storage problem goes away.

For billing purposes each electric car would have a secure meter like the odometer but recording how much juice the car had sucked out of the public roads. Once a year, say, it would be read, eg at the MOT, and you'd get a bill. It wouldn't be a vast bill since electric cars only cost one or two pence a mile to run.

Off the top of my head I think another 500 of those breeder reactors would be sufficient to fuel every car, truck, bus in the land.

Aircraft would still need to the fueled by oil, and we would still need oil for manufacturing. But with our consumption down by at least two-thirds oil's last day would be postponed quite substantially. I suspect we will still have to restort to bio-oils to some extent, the 3rd-worlders will just have to eat cake.


Sir Henry Morgan said...

Off topic.

Just read your comment on South Africa Sucks. I too am a daily reader.

I do comment there occasionally. And it's from there that I've picked up two wonderful words:


which I use on a daily basis.

Used them when talking to a bunch of about a dozen teens the other day (obout 16yrs old). They were amazed to hear that there adults out here who think that in their own country they should come first, not moboons (they raised the subject, not me; and yes, they actually said they felt second class. They don't now.Managed to sell two 'Asylum: don't unpack you're going back' lapel badges. And I was amazed to discover they didn't know there were such things as nationalist political parties. Well they do now, along with the new vocabulary they picked up.

Keep up your good work.

Jeff ( Va. Rebel ) said...

Hey guys ... good to hear you're getting the message out to our young folks . I'm sure alot of them have no direction or hope anymore . Gret job !!
Yall take care ...