Minimal Transportation

08-09-15 A laptop version:

WalkCar



03-23-15 - And another:

OneWheel

10-27-10 - The Yike Bike has been trumped!  Not as powerful or fast, but quite impressive in it's minimalism.

Video Link

Liquid Piston's New Engine Design

It's fascinating to see the various ways of converting liquid fuel to horsepower.  The Otto piston has long dominated, but is famously inefficient.  Wankel was a nice challenge, but suffered from low compression and its oil squeegee valves burned more than they wiped.

The LiquidPiston guys set out solve the problems of both designs, and they may be getting close with this inverse Wankel approach.  The picture above is of the older X1 design and the text at this link is distracting, but watch the video for a quick visualization:

Autoevolution on the LiquidPiston X Mini Engine

Here's a much better presentation of the technology:

Gizmag on the LiquidPiston X2 Engine

And here is a description of their early prototype:

MIT Technology Review of the X0 LiquidPiston

It will be interesting to see how this technology evolves.

Another weight and space efficient engine:

The Duke Axial

A better movie

Amazing New Air Car - It's NOT About the Air!

Updates:

09-18-14 - Another radical light car for Paris.  This one is 2100 lbs and uses Air/Hybrid to get 141 MPG.  Are the French on a roll?

01-25-13 - Peugeot Cirtoen to Introduce Compressed Air Hybrid by 2016

09-07-12 AIRPod

09-07-12 Tata AIRPod


07-05-11 - Tata Air Powered Car to be Introduced in India

02-26-09 - Yet one more way to use compressed air for braking recovery from ETH Zurich

First posted 01-19-08:







And it's not even about the car!

(note - whoever owned the MDI page when I posted this blog has diverted it to a new investment group and broken some of the links below. I have redirected them to the French or Guy pages as well as possible for now - thanks to Chris from Future Net.)

Every now and then a an idea comes along that will change the world - and gets mostly ignored. Some of you have heard me talking about this new air powered car from MDI (Moteur Developpment International) in France which is now to be manufactured by Tata Motors of India.

MDI did a press release a few weeks back and it was handled like, well, another press release. The automotive press paraphrased a few paragraphs, but I wonder if they actually THOUGHT ABOUT what they wrote?

And when Tata Motors introduced their more conventional yet inexpensive Nano at the Detroit Auto Show last week, it got amazing coverage, but not ONE mention of this new air car to be manufactured by the very SAME company!

The highly touted Tata Nano is a cute little bug that will get more than 50 MPG - cool. But the MDI OneCat which is about the same size will go more than 3 TIMES farther on the same gallon of fuel! Did no one actually READ the spec sheet on the OneCAT?

To be fair, the objective of the Nano is low price, not mileage. And the OneCat is much lighter, which helps, but surprisingly, that's not the key to it's mileage advantage. Here's how they do it...

As almost everyone knows, the standard internal combustion engine is only about 30% efficient under the very best of conditions. This means 70% of the energy in a gallon of gasoline leaves the car as wasted heat.

The only heat that produces power is that narrow band of highest temperature that causes rapid expansion of air when the spark plug fires. Once the piston reaches the bottom of it's cycle, all the lower temperature energy from that cycle is wasted and must be pumped out the exhaust pipe.

If you add MORE heat at the point of ignition (higher octane), you get more power. But Carnot and his second law of thermodynamics limits us from using any of the heat BELOW the temperature of ignition. THAT is the primary reason for the INefficiency of the internal combustion engine. But what if we COULD use ALL of that heat?



CAT - Compressed Air Technology

Guy Negre of Formula 1 fame and his company, Moteur Developpment International have spent the last 14 years developing a new type of engine for automobiles.

Compressed Air Technology has been described as using air as fuel, but that's not quite right. The air works more like a battery. Guy's design actually uses a carbon-fiber air tank with up to 300 times normal atmospheric pressure driving a piston to give the car a range of 100 Km. You can think of this system as a standard compressor motor and air tank - except it's running backwards. The air tank drives the compressor, instead of the other way around.

So far, no big deal. Any advantage is a matter of strength, weight and volume per unit of energy stored in the "battery" - the carbon-fiber tanks helps some. But if a short range compressed air car is all they had, it wouldn't be very impressive. The next refinement is the key and I now believe it was created in response to the problem of freezing the engine as the air was decompressed. Whenever air pressure drops from 300 Bar to 1, the gas laws say the heat in that original volume is now spread out over a much greater area thus dropping the temperature. Guy's "fix" to this problem had a side-effect that I believe to be the biggest advancement in thermal energy extraction since the invention of the Otto-cycle in 1860! It effectively uses "wasted heat".





Bi-Energy Breakthrough

Guy Negre's brilliant innovation is to add a small fuel burner between the air tank and the motor. The heat from this burner not only keeps the engine from freezing up, it also extends the range for the compressed air tank by increasing the pressure of the air even more on it's way to the motor. Properly insulated, this burner could approach 100% conversion efficiency of the burned fuel. Here's the reason...

Small amounts of heat are not enough to turn over a reciprocating motor. But when you add a compressed air tank, it provides a pressure bias great enough to drive the motor on it's own. Now add the burner. Per the gas laws, the pressure increase is proportional to the heat added - it doesn't require a critical temperature of ignition! You could run it tepid or boiling - ANY heat adds power. It's just a matter of how much.

If you double the burn rate, you'll double the added expansion. Since there's no point of ignition, there's no critical temperature before this energy is extracted. ANY heat added by a burner (or other source) will simply add proportional expansion and energy extraction. Theoretically, most of the energy from a gallon of gasoline (or stack of firewood) could be used to drive the motor.



Check the spec sheet above. I assume these are actual measurements. The OneCAT will go 100 Km on air alone, but another 700 Km on only 10.5 (1.5 Liters per 100 Km x 7) liters of fuel! That works out to almost 157 MPG!



More Than JUST an Amazing New Car

MDI has a good chance of creating an amazingly efficient little car, and that's cool. But what's REALLY exciting are all the other potential industrial applications.

Considering generation and line losses when producing electricity, it may even now be more efficient to run Bi-Energy motors at the site of the application instead of buying electricity. Or we could boost mechanical power from solar heating. Or hot sewer water for that matter! ANY source of heat could be used. It's just a matter of degree and effectiveness.

OK. You'll still need electricity to provide the compressed air bias, but the rest of the energy would be more efficiently extracted - the hotter, the better. What about recycling the heat from air conditioners to drive their OWN motors? I'm not talking about perpetual motion here. There's no free ride. It's just that the heat is no longer has to be totally wasted. This approach provides an excellent possibility of dramatically increased efficiency in anything that needs a rotating motor and has wasted heat available. (Note - MDI was WAY ahead of me - I just found this link on their site... Further Applications - WOW!)

These ideas are worth more than just a press release.

It's a whole new way of thinking about energy!


More Air Car Energy Links...

Guy Negre Page

MDI and Indranet

Dr Louis Arnoux Interview

Future Net

ZevCat

Wiki


Others are picking up on using waste heat in this fashion - The VGT RoundEngine

06-20-20 Liquid Air Battery

10-13-25 Liquid Air Storage

VW Redefines "Car" With A 261-MPG Diesel Hybrid

As you can read, light efficient cars have been one of my favorite topics for a long time:

07-04-06 1974 VW Dasher

Update 03-06-13:

The Volkswagen XL1 just debuted in Geneva and claims a range of 261 mpg, with a curb weight of about 1,750 pounds. Its coefficient of drag is extremely low at 0.189. It’s powered by a 47-hp, two-cylinder turbodiesel paired with a 27-hp electric motor. VW says it will make 250 examples with a price near $100,000

Autoblog Roadtest

Top Gear First Drive: the VW XL1

Update 01-25-11:

Formula XL1 Concept 

First posted on 02-18-10:

Finally!

261-MPG Diesel Hybrid 

09-16-14 - Renault's 880 pound answer to the VW XL1!

09-18-14 - Another radical light car for Paris.  This one is 2100 lbs and uses Air/Hybrid to get 141 MPG.  Are the French on a roll?

Back to the Future with Motorcycles

When I was a kid, our family had a number of small motorcycles for trail riding.  They were light, agile and got great gas mileage.  My favorite was a 1965 Yamaha Trailmaster 80.  I spend lots of time exploring the mountains of Norther California on that "bike".

Unfortunately, the same thing happened to trailbikes that happened to cars - over the years, they got heavier. Then motors got bigger to carry that extra weight, which made everything heavier still.  Unlike cars, this weight had more impact on handling, especially on rough ground.  It's not easy getting a 300 lb motorcycle over a log.

I'm still waiting for a modern version of the 1978 VW Rabbit which weighed 1880 pounds dry.  With modern technology it should be able to get 100 MPG.  In the mean-time, it looks like Yamaha may be thinking the same thing.  It's only a concept, but it's headed in the right direction:

Yamaha shows retro lightweight 125cc motorcycle that gets 220 mpg

Bring it on!

The Energy Star / CFL Efficiency Myth

If you still want incandescents:

Newcandescents

First posted on 02-01-07:

For years the Federal Energy Star program has perpetuated the myth that if you buy appliances (or any electrical device) for the home that uses less energy, you'll see proportional savings in your monthly power bill. This is rarely the case.

Other eco-writers do similar simplistic math to calculate savings in money, energy, and carbon. A recent example is Charles Fishman's September 2006 article in Fast Company magazine about WalMart's CFL project, "How Many Lightbulbs Does it Take to Change the World?".

The claim is made that if a single light bulb using 45 watts less is placed in 100 million homes, 6.57 billion Kilo-Watt-Hours will be saved. The fact is, unless you are cooling your house, there is often ZERO savings. Charles focused on the bulb, but forgot about the home. His entire premise is based on a false assumption. The savings are grossly exaggerated for most homes.

"Wasted" energy takes the form of heat. And this heat helps keep you warm, if only just a small amount. For most of America, for much of the year, that 45 watts will be automatically added back in by the home heating system to maintain the same level of comfort. If the home is heated with electricity, the savings in dollars, energy and carbon production is literally ZERO.

The only time energy is actually saved is when the air conditioning is running or you have the windows open to cool the house. With the air conditioning on, the savings can even be a little greater than 45 watts, but for most of America, that's a small part of the year. What are the savings for the rest of the year?

ZERO!

If you are not cooling your home, EVERY light bulb and appliance is 100% efficient.

Here's why...

The second law of thermodynamics demonstrates that "wasted" energy tends to disperse evenly. And if this "wasted" energy is in your house, it simply keeps you warm. More importantly, it keeps your normal heat source from turning on. Let's see how it plays out in a real home and why saving energy by turning off the lights is mostly an illusion.

If you have a home in the northern latitudes which is electrically heated much of the year, you are a net consumer of heat. And the nice thing about heat is that It doesn't matter where it comes from. And that's the key.

Take a light bulb that's only 10% efficient. That means 90% of its energy is converted directly to heat. So what happens to that heat? It spreads out through your house and slightly delays your normal heating system from clicking on.

And what about the 10% of the energy in the form of visible light? Virtually all of it strikes objects in the house. It too is converted to heat. The ONLY ineffectiveness of a light bulb in a northern home in the winter is the light that escapes through the windows, which is a VERY small amount. Even THAT can be stopped with curtains making ANY light bulb 100% effective at producing heat. Here's how Wiki explains it... Efficiency versus Effectiveness.

Why do I qualify this with northern homes and winter? Because if you have to open the windows to be comfortable, you lose the advantage. And if you have to turn on the air conditioning, this "effectiveness" actually becomes a small liability. So those of you in Florida and south Texas... never mind.

It's all about heat, where it moves and how we store it. But for most of America, much of the year, energy efficiency is very much an illusion. Effectiveness rules the day because we actually USE that "inefficient" heat.

And if your windows are closed but your heat is NOT turned on? Or not turned on until later at night? Those appliances are still 100% effective. That's because they are helping keep the house warm. They are one reason your electric heat hasn't come on yet. If that heat doesn't come from one source, it has to come from another.

But what if you're a bit on the warm side in the late afternoon but you haven't opened the windows? Again, it doesn't matter. This thermal inertia will delay heating later on. As long as you don't have to cool your house, everything is 100% effective. Let's take a couple more examples.

Electric blanket - 100% effective. If you turn it off, the electric wallboard heating will kick up 100 watts to compensate: net cost of blanket electricity for the same comfort level - zero.

TV, DVD & computer - Left on all the time? No problem, as long as the air conditioning doesn't kick on.

Hair dryer - 100% effective (and only used for short periods anyway), so get every hair in place.

Electric toothbrush - Yep. Even its charger is a perfect machine in this context.

Refrigerator - 100% effective. This is one of my favorites. What does a refrigerator do? That's right. It compresses gas to pump heat from the inside to the outside of the icebox. Where does that heat go? It heats the kitchen! Even the compressor is 100% effective! Once again, it saves energy that might come from electric heat.

Why do I keep referring to electric heat instead of oil or gas? That's because in the past gas has been far cheaper than electricity per BTU. This made electrical devices a little less "effective" (and a little more expensive) in producing that "wasted" heat. Unfortunately, cheap gas is history (update - well, it was in 2007). The cost of oil and gas heating now approaches that of electricity (at least during the price spikes which are likely to be more common in the future). So for many, there's no big difference. Leaving your TV on is almost as cost effective as buying natural gas.

Another even more significant exception is if you warm your house with a heat pump. Heat pumps with a good source are three times more effective than electrical resistance heat so two-thirds of the stated saving ARE real. CFL and Energy Star DO represent significant saving in this case even though one-third of the savings is still an illusion. Your mileage may vary but it will always be less than claimed by these "expert" sources.

With electrical resistance heat, this "effectiveness" creates the strange situation where you could turn EVERYTHING in the house OFF (except for the electric heat) and set in the dark for a winter month with no entertainment or hot food - and your power bill would be EXACTLY same. Try it sometime. You'll see.

This also means you could go out and buy the most efficient light bulbs you could find and all new Energy Star appliances; STILL, the power bill would be EXACTLY the same. So enjoy your gadgets and think twice before spending extra for "efficiency". Spend your money where it counts.

And where might that be? If there's little advantage to "efficient" appliances, how can we save energy and money? That's another blog post but start by taking a look at the heat leaving your home through the walls or down the drain as hot water. Those two are your biggest loses.

Heat and air conditioning use 50% of home energy. Better insulation and sealing can save up to 25% of your energy cost for the typical home. But make sure the house still has reasonable ventilation - especially in radon areas. And hot water is about 13% of your energy use, so again, use it carefully. It's not effective to heat up the sewer drains.

Which brings up one important exception to this "effectiveness" rule - the clothes dryer. It blows it's heat outside and also brings in cold air - you lose. It's a good reason to get a clothesline. Or use the dryer sparingly.

And if you still want to buy some of those CFL bulbs, put them outside. That's one place where ALL the savings count.

There you have it. Now you can sleep better (and warmer) knowing your heat isn't as "wasted" as you thought.

OK. If you still want to know how much of that 65.7 KWH you would save by buying that bulb, multiply it by the ratio of cooling days over days in a year (365.25). The extra air conditioning load will be offset by less probable need for light in the summer. For me in Reno, Nevada that extra efficiency can be used about a quarter of the time (in the summer) which is probably about average for America. This makes WalMart's claim overstated by four times - you decide if that bulb still makes sense.

But why would Fast Company, WalMart and Energy Star not point this out? Simple. It would make the story less exciting, WalMart would sell fewer light bulbs and... and... and I don't know WHAT'S wrong with the Federal government.

So from now on, don't let some slick magazine make you think a new light bulb will solve all your problems; don't expect WalMart to always save you money. And finally, don't expect the government to set them both straight. When you hear about efficiency, think also about effectiveness.

And quit worrying about your household appliances. They are almost perfect machines much of the year. No matter what their efficiency rating. Please leave a comment if I've missed something.

11-30-11 - The best counterpoint to my post that I've seen so far:

The Math Changes on Bulbs - Wall Street Journal

03-12-12 Ready for $50 Light Bulbs?

Minicars Get Maxied

Posted to Car and Driver Forum on 07-04-06

Csaba Csere, you hit the nail on the head with your August Column, "Minicars? I don't see no stinking minicars". But you stopped short of defining the problem. And you didn't clarify the solution. Still, your examples pointed us in the right direction.

Just like the forties changed the way cars looked, the seventies changed the way they worked. The gas crisis gave us the first major advancement in functional body design since the twenties.

Like you, I recall the mid-seventies well. Until then I owned American cars and loved the torque of the small block V-8s. Then I compared my Chevy to the specs for the 1974 VW Dasher. I was impressed. When I traded up, I discovered how much weight was a factor in acceleration, handling, braking and economy - even with less power. I became addicted to the idea of light and efficient cars.

The Dasher was so much fun, I bought a Scirocco when it came out. It was a fantastic ride at the time. Two years later I traded in the Dasher for a 1978 Rabbit for my wife. At 1880 pounds, it got 38 MPG with reasonable performance.

Giorgetto Giugiaro made history with these little cars in creating an excellent light-weight package that still held five people when needed. The VW Rabbit was state of the art in 1978. Unfortunately, art doesn't advance it's state at a steady pace.

Later I bought a 1985 Honda CR-V. It weighted only 2000 lbs and had lots of room. Twice, I actually hauled a standard sized refrigerator (no I couldn't get the tail-gate closed). This car also got mileage in the high thirties, but not better.

And now Toyota, Honda and Nissan are all introducing new economy cars. But they still only 38 MPG! And Nissan will struggle to get that.

What's the deal? Has there been no technical progress in the last 30 years? No, that's not it. Engines and transmissions are definitely more efficient. Could it be the few hundred extra pounds these "small" cars have gained? Yep. The improved drive-train efficiency has been totally eclipsed by the increasing weight of the cars. New does not always mean improved.

Think what could be done if we dropped window lifts, electric door locks and butt warmers. Then scale the whole car back so everything can be lighter. Focus on active safety instead of building tanks that tend to roll over anyway.

If Honda combined the body of the 1985 CR-V with today's drive-trains, they could be getting 50 MPG instead of only 38 in that little fat Fit. Don't get me wrong. Not withstanding a name borrowed from a rabid dog, Honda has done a wonderful job on Fit's package. They get a lot in a reasonable space. It just WEIGHTS too much.

Another "Mini" that's been "maxied" is the one from BMW. A car that small should weight half as much, and get twice the mileage. They could have at least IMPROVED on the original after all this time.

And why did Toyota replace the Echo weighing 2055 lbs with the Yaris which weighs 2326 pounds? Two hundred pounds LIGHTER than the Echo and it would have come in at 50 MPG instead of the high thirties. It may not be obvious, but 271 pounds can make a LOT of difference in such a small car.

It seems these masters of auto technology have forgotten the basic purpose of a car - to move a human from one place to another. How many tons of steel does it take to deliver a 150 pound person? With all the new light-weight materials at hand, we should have an effective ONE thousand pound car by now.

I also owned a 1975 MG Midget (I told you I got excited about light cars). At only 1300 pounds, it was so much fun to drive, I forget the mileage. One evening I left the lights on and had to push start it in a 30' driveway. Yes, I got it started... AND stopped before hitting the garage door. Try THAT with their Yaris, Fit or Versa.

But it's not all bad news. Lotus has shown the way forward in the sports segment with the new Exige. Colin Chapman would be proud to see them living out his creed - "Simplify and add lightness". WHEN will the rest get a clue? And more importantly, WHY haven't they done it yet?

Do they own too much oil stock? Would it upstage their complex hybrid solutions? Are the Fed safety trolls just too hard to deal with? There are lots of good questions at the heart of this problem. And we're about to be in desperate need of some good answers.

Someone has to lead the charge.

Csaba, you have their ear.

Tell 'em who we are.

10-29-09 Here's some good data on weight effects of milage...

Drill into the PDF from the link above. Also included are the weight's effects on performance, as well as showing how much weight DOESN'T matter much once you exceed 65 MPH. Great stuff.

04-28-10 Lotus comes out swinging for lighter, more efficient vehicles 


Finally, someone conclusively demonstrates the key to automobile efficiency is light weight - the video says it all.

09-16-10 Ultra-Light Cars Reap Rewards of X Prize 

06-26-13  New VW Golf TDI BlueMotion is 'most fuel-efficient ever' with 73.5 mpg

03-11-14 Will Citroen be the first to build a fuel-efficient car? 

12-26-14 Suzuki Alto Goes Back to Basics at 1345 lbs and 104 MPG

X-Prize Winner : Gas Powered Edison2

11-10-10 Interesting how the car that won the X-Prize was named the Edison2, yet is gas powered.  They tried electric, but discovered all the had to do was get the weight down to 830 lbs and success was theirs.  So do we really need electric / hybrid complexity?  Or will just doing more with less be the ultimate energy transportation solution?

06-12-13 Finally an X-prize contender headed for production? - Aptera

Wave-Disk Engine Advances Efficiency?

All very nice, but we need more details!

Wave-Disk Engine

Wiki Wave-disk Entry

King Tut and Colin Chapman

This picture made me realize how minimal transportation can be.  In Tut's time, horses were too small for a man to ride.  It took TWO of them just to get pulled around.  Which makes this chariot maybe the best example of Colin Chapman's, "Simplify and add lightness".

King Tut's Ride

Now, if we can just get a modern low-cost car under 2000 lbs.

The Rocky Mountain Plan - Water Enough for All

OK.  I admit it.  I have a weakness for grand solutions to grand problems.  I first heard about this back in the 80s and out of curiosity thought I'd Google to see how progress was coming along.

Considering the state of environmental politics not to mention international boundaries, I'm sad but not surprised to report, not much has happened since I first read about it.  Here's the only reference I could find...

The Rocky Mountain Plan


So what IS the Rocky Mountain Plan?  It's nothing less than diverting water all the way from the Arctic Circle, and spreading it across the mid-western United States and even into California, Texas and Mexico.  Here's a summary.  I'm posting it here because grand ideas shouldn't die just because they are grand (note the 2200 foot drop for energy production).


"The Rocky Mountain Plan, conceived by William G. Dunn, Consulting Engineer, is a potential massive, international water and power development project that would distribute water and power throughout the West from Canada to the Mexican border.

Principal sources of water are the Peace, Athabasca, and Smoky rivers in northern Alberta (Canada), and upper tributaries of the Mackenzie River in northern British Columbia, which flows into the Arctic Ocean. Additional sources of water are the Kootenai and Flathead rivers and Clark Fork in western Montana, which are upper tributaries of the Columbia River. Water would be diverted for use within the Yellowstone, Missouri, and the Snake rivers in the northwestern United States, and upper tributaries of the North and South Saskatchewan rivers in Alberta.

The water distribution system would include several large reservoirs with a total storage capacity of nearly 100 million acre-feet. Project yield would range from 12 to 25 million acrefeet per year, depending on aqueduct and reservoir sizing. This water would be distributed through more than 5,850 miles of aqueduct for use in southern Alberta, Montana, Idaho, Wyoming, all of the western states on both sides of the Rocky Mountains including west Texas and California, and northern New Mexico in the Colorado River and Rio Grande valleys.

New energy developed under the Rocky Mountain Plan would come from a huge hydroelectric project called the Whitehorse-Skagway Division, collecting water from the upper tributaries of the Yukon River and releasing it through a 2,200-foot power drop into an interior inlet of the Pacific Ocean near Skagway, Alaska. The 33 billion kilowatt hours of power produced by this system would be conveyed in a 2,000-mile transmission line to Alberta, British Columbia, and the Pacific Northwest for general use in the power market, and for project purposes. Three large storage reservoirs with a total storage potential of 60 million acre-feet are proposed within the Columbia River Basin. These reservoirs would include large pumped storage facilities that would reregulate the power developed in the Columbia River plants and in the project power plants, and that also would produce some new power.

The entire Rocky Mountain Plan, including power facilities, was estimated to cost between $40 and $50 billion in 1977 dollars. One of the significant advantages of the Rocky Mountain Plan is that it could be staged to provide significant water and power benefits during early development."

"Simplify and Add Lightness"

I've written here before how lowering weight is the single greatest factor to improve acceleration, braking, handling, price and economy of operation in an automobile.

Here is a great example of what can be done if you follow Colin Chapman's advice and, "Simplify and add lightness". This British movie and review is impressive. Check it out.

Tata Nano Review Film

There is hope for rational design.

Climate Change Recalculated

This was an email to me of Stewart Brand's notes from Saul Griffith's Long Now presentation - on, "Climate Change Recalculated".

Man-made global warming or not, the numbers are amazing. Will we find the conviction to change before we are forced? Or not? And what happens when we discover it was wasted effort as nature self-corrects?

I'm not yet convinced about man-made global warming, but I AM very much in favor of using less energy as well as finding effective alternatives. If we don't start now, cost will force us to in the near future in any case. I have doubts about accomplishing what he projects and suspect reality will be some kind of moving mix of new energy sources, yet short of this goal over the next 25 years.

In any case, this is an interesting read...



Engineer Griffith said he was going to make the connection between personal actions and global climate change. To do that he's been analyzing his own life in extreme detail to figure out exactly how much energy he uses and what changes might reduce the load. In 2007, when he started, he was consuming about 18,000 watts, like most Americans.

The energy budget of the average person in the world is about 2,200 watts. Some 90 percent of the carbon dioxide overload in the atmosphere was put there by the US, USSR (of old), China, Germany, Japan, and Britain. The rich countries have the most work to do.

What would it take to level off the carbon dioxide in the atmosphere at 450 parts per million (ppm)? That level supposedly would keep global warming just barely manageable at an increase of 2 degrees Celsius. There still would be massive loss of species, 100 million climate refugees, and other major stresses. The carbon dioxide level right now is 385 ppm, rising fast. Before industrialization it was 296 ppm. America's leading climatologist, James Hanson, says we must lower the carbon dioxide level to 350 ppm if we want to keep the world we evolved in.

The world currently runs on about 16 terawatts (trillion watts) of energy, most of it burning fossil fuels. To level off at 450 ppm of carbon dioxide, we will have to reduce the fossil fuel burning to 3 terawatts and produce all the rest with renewable energy, and we have to do it in 25 years or it's too late. Currently about half a terrawatt comes from clean hydropower and one terrawatt from clean nuclear. That leaves 11.5 terawatts to generate from new clean sources.

That would mean the following. (Here I'm drawing on notes and extrapolations I've written up previously from discussion with Griffith):

"Two terawatts of photovoltaic would require installing 100 square meters of 15-percent-efficient solar cells every second, second after second, for the next 25 years. (That's about 1,200 square miles of solar cells a year, times 25 equals 30,000 square miles of photovoltaic cells.) Two terawatts of solar thermal? If it's 30 percent efficient all told, we'll need 50 square meters of highly reflective mirrors every second. (Some 600 square miles a year, times 25.) Half a terawatt of biofuels? Something like one Olympic swimming pools of genetically engineered algae, installed every second. (About 15,250 square miles a year, times 25.) Two terawatts of wind? That's a 300-foot-diameter wind turbine every 5 minutes. (Install 105,000 turbines a year in good wind locations, times 25.) Two terawatts of geothermal? Build 3 100-megawatt steam turbines every day-1,095 a year, times 25. Three terawatts of new nuclear? That's a 3-reactor, 3-gigawatt plant every week-52 a year, times 25."

In other words, the land area dedicated to renewable energy ("Renewistan") would occupy a space about the size of Australia to keep the carbon dioxide level at 450 ppm. To get to Hanson's goal of 350 ppm of carbon dioxide, fossil fuel burning would have to be cut to ZERO, which means another 3 terawatts would have to come from renewables, expanding the size of Renewistan further by 26 percent.

Meanwhile for individuals, to stay at the world's energy budget at 16 terawatts, while many of the poorest in the world might raise their standard of living to 2,200 watts, everyone now above that level would have to drop down to it. Griffith determined that most of his energy use was coming from air travel, car travel, and the embodied energy of his stuff, along with his diet. Now he drives the speed limit (no one has passed him in six months), seldom flies, eats meat only once a week, bikes a lot, and buys almost nothing. He's healthier, eats better, has more time with his family, and the stuff he has he cherishes.

Can the world actually build Renewistan? Griffeth said it's not like the Manhattan Project, it's like the whole of World War II, only with all the antagonists on the same side this time. It's damn near impossible, but it is necessary. And the world has to decide to do it.

Griffith's audience was strangely exhilerated by the prospect.

--Stewart Brand

04-25-12   'Gaia' scientist James Lovelock: I was 'alarmist' about climate change