Solar Power isn't Feasible!

Solar Power isn't Feasible!
This cartoon was on the cover of the book "SolarGas" by David Hoye. It echoes the Sharp Solar slogan "Last time I checked nobody owned the sun!"

Saturday, September 8, 2007

Barium titanate: Better living through chemistry?

Every so often we non-specialists out here in the "general public" get wind of a sea-change possibility that gives us a sniff of fresh hope in the malodorous air that is inexorably filling our hydrocarbon- tainted atmosphere. You have to look hard and keep your eyes peeled, but the hunt pays off from time to time.

For all those of us who really are worried about climate change and the increasing threats of radioactive elements and chemical carcinogens in our environment (and that should be all of us, no?) , the recent announcement of Toronto´s Zenn Motors liscencing EEStor's barium titanate based ultracapacitor technology is one of those payoffs.

A good popular article on the announcement can be found here:

In summary the argument goes like this: The single greatest impediment to the use of renewable energy, which is often intermittent in supply, and to the use of clean electric cars, which need long ranges between fuelings to be accepted by the public, is said to be ENERGY STORAGE.

Ultra-capacitors made from barium titanate can solve that problem and replace batteries. "Punkt", as we say here in Germany.

Dispersed and intermittent energy sources (like the sun, the wind and seasonal micro-hydro) must be accumulated before they can be practically used. Of course, for that matter, so must all energy sources: Practical cars today rely on sunlight that accumulated chemically for millions of years in the form of fossil fuels. So they are really using solar energy. Using oil as their solar energy storage substance, cars have acheived considerable ranges. But although the public would never be willing to wait the eternity necessary to refill their tanks if they had to wait for new oil to form, they still balk at the thought of recharging a battery for a few hours so they can drive to work and back (most of us only drive 60 miles per day on average, which is about what even a home built electric car using standard lead acid batteries will give you on a full charge!).

So, while we will be forced to re-accumulate sunlight once the oil runs out (assuming we are sane enough to avoid the temptation of using the enormous energy accumulated in unstable radioactive metals!) , the relatively slow process of accumulating energy in the chemical bonds of what we call "bio-fuels" and "batteries" will inevitably impede a quick and easy transition to renewable energy supplies in the years before the fossil fuels disappear.

The Zenn Motors announcement augurs a change from all that. They are proposing to use ultra-capacitors instead of batteries. Ultra-capacitors accumulate, store and release energy very quickly. On the order of seconds and minutes rather than hours. You are probably already familiar with capacitors -- they are usually sheets of a conductive metal sandwhiched between sheets of a semi-conductive material like salted paper. Basically they accumulate and store electrons, building up a charge that can become quite powerful. You yourself have probably experienced a few shocking moments as a human capacitor -- every time you rub your feet on a carpet, electrons build up on your skin, and when you touch a metal doorknob -- zap! -- you discharge the electricity you stored with a pop that can be audible and even painful. It is enough to make your hair stand on end -- literally!

Increasingly capacitors have found their way into rechargeable items, replacing short lived batteries. Their beauty is that they hardly wear out at all -- unlike batteries they don´t go dead over time. Since they are basically just surfaces that build up a static charge, they can be used over and over and over again without any change in the substance itself.

Perhaps you have seen rechargeable flashlights like this:

This is the "Mini Shake Flashlight Magnetic Induction Bright LED Rechargeable Flashlight" found in shops all over the world these days (like this one:
We used them at the Wadi Environmental Science Center in Egypt to teach kids about how magnetic induction works because they are clear and you can see through the case to watch the magnet move through the copper coils to create the electricity that lights the LED. But few people stopped to ask "why does the LED stay lit for up to 30 minutes when you are not shaking it if there are no batteries". The secret is, of course, that it contains an internal capacitor that slowly discharges electrons to the LED. Shake it again and you recharge the capacitor. Simple, effective, clean, durable.

There was also an article on the web at one time by a guy who built his own bicycle generator so that he could allow his kids to watch TV without turning into couch potatoes. The idea was that they were allowed to watch TV as long as they could supply the energy for it. So they would get on the bike and pedal and generate electricity for the TV and if they got too tired, they would have to quit. I tried the same technique myself, and bought a 75 watt TV (13 " AC/DC Color TV for campers) that ran on DC power. I hooked up to a bicycle generator I bought from Windstream Power
When I set up my generator I learned that while I was perfectly capable of generating the needed power (a biker can generate up to 150 Watts at full speed for a short while, and can sustain 35 to 75 watts for an hour ; see and ) the problem was that the picture would glow and diminish in brightness just like an old light bulb in a horror movie, depending on how hard I was pedalling. I also learned that you can fry your television if you pedal too fast or too slow -- the thing wants the correct operating voltage!

Obviously something had to be put in between to regulate the voltage. Being ignorant, I went out and bought a heavy deep-cycle rechargeable battery, and a charge controller, just like you would for a typical wind or solar energy system. Then I would pedal to charge the battery and the battery would supply the energy. The battery only lasted a couple of years, and died an early death because I got tired and stopped pedalling and took the temptation to watch a video all the way through using what remained of my battery power. I let the battery discharge, and stupidly, because I was lazy, I didn't get on the bike to fully recharge the battery. I let it sit there discharged for months, thinking "one of these days, when I'm not busy and have more energy, I will get on the bike and recharge the thing." But I never did, and that is how I learned that if you leave lead acid batteries discharge for too long the lead sulfate crystals become irreversible (or something along those lines -- perhaps an expert can post the real mechanism here).

At any rate, I killed the battery by leaving it discharged. It was then that I learned that one can use capacitors in place of batteries, capacitors like the one's sold here:

(I should mention, for the safety fanatics out there, that, as pointed out on the Pedal Power website , if you pedal too fast you can make a capacitor "explode", but then again, you can also cause the acid in a battery to boil out, generating hydrogen which can lead to explosions and... well, there are risks to everything. But since you are only dealing with a 1 Farad capacitor, if you take precautions (and use a voltage regulator) this should not be a worry (just as batteries in a well-ventilated enclosure have never caused me problems! The "Hindenburg" myth has been used by oil addicts for long enough to scare us away from hydrogen power; let us not use "capacitor explosion" fears to make us refrain from using these marvelous devices -- we aren´t talking bombs here!!!! At any rate I doubt many people can pedal that fast and that hard and that long while watching TV.)

This is all besides the point though. The point here is that capacitors are known to be good battery replacements. What the world has been waiting for has been a capacitor large enough, powerful enough and durable enough to replace the batteries in electric cars and in home power systems.

And it appears that thanks to patent number 7,033,406 filed by Austin based EEStor (standing for Electrical Energy Storage, perhaps?) the world won't have to wait much longer. Using Barium Titanate as its medium for high voltage energy storage, EEStor claims the days of big batteries are behind us.

If Zenn Motors is successful in their tests of the barium titanate ultracapacitor, we could see light weight electric cars with the same ranges as fossil fueled cars, and no toxic waste to be recycled or put in the landfill at the end of the car's useful life. And for those of us who are "off the grid", it isn't hard to imagine that we could also use Barium titanate ultra-capacitors for home power, charging them whenever the sun shines and the wind blows and the water flows.

No doubt energy insiders are watching this very closely. Those of you who have seen "Who Killed The Electric Car" will not be surprised if we hear all sorts of "Hindenburgian" scare-monger nonesense about "the danger of exploding ultra-capacitors" or "the danger of getting a lethal electric shock from accidentally touching the capacitor in the wrong way"(anybody who ever serviced CRT screen TV sets or computer monitors will remember the "danger from death by electric shock" warnings on the insides of those devices. We taught students at Jefferson High School in South Central Los Angeles to respect the big capacitors in the monitors when they disassembled them, and then taught them how to use a screwdriver to short them and safely discharge them). Hollywood will doubtless join the oil industry in a campaign against ultracapacitor electric cars because, without a flammable fuel in the gas tank, they won't explode after a car chase. How boring.

But for the rest of us, members of the general public, worried as we should be by global warming, radiation and cancer (to say nothing of terrorist threats), the wonderous barium titanate ultra-capacitor cars are a much awaited example of the better living through chemistry that was promised us after the last world war. Seems it is close at hand with this innovation, and THAT is EXCITING!

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