Category Archives: Energy

Car Powered Using Compressed Air

car powered using compressed air

Jules Verne predicted cars would run on air. The Air Car (link broken, so it was removed) is making that a reality. The car is powered by compressed air which certainly seems like an interesting idea. Air car ready for production (link broken, so it was removed, sigh, when will site stop failing the web so badly?):

Refueling is simple and will only take a few minutes. That is, if you live nearby a gas station with custom air compressor units. The cost of a fill up is approximately $2.00. If a driver doesn’t have access to a compressor station, they will be able to plug into the electrical grid and use the car’s built-in compressor to refill the tank in about 4 hours.

The car is said to have a driving range of 125 miles so by my calculation it would cost about 1.6 cents per mile. A car that gets 31 mpg would use 4 gallons to go 124 miles. At $3 a gallon for gas, the cost is $12 for fuel or about 9.7 cents per mile. I didn’t notice anything about maintenance costs. I don’t see any reason why the Air Car would cost more to maintain than a normal car.

The air car was named one of Time magazine’s best inventions of the 2007.

Five-seat concept car runs on air

An engineer has promised that within a year he will start selling a car that runs on compressed air, producing no emissions at all in town. The OneCAT will be a five-seater with a fibre-glass body, weighing just 350kg and could cost just over Â£2,500.
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Tata is the only big firm he’ll license to sell the car – and they are limited to India. For the rest of the world he hopes to persuade hundreds of investors to set up their own factories, making the car from 80% locally-sourced materials.
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“Imagine we will be able to save all those components traveling the world and all those transporters.” He wants each local factory to sell its own cars to cut out the middle man and he aims for 1% of global sales – about 680,000 per year. Terry Spall from the Institution of Mechanical Engineers says: “I really hope he succeeds. It is a really brave experiment in producing a sustainable car.”

Grand Challenges for Engineering

Here are the Grand Challenges for engineering as determined by a committee of the National Academy of Engineering:

* Make solar energy economical
* Provide energy from fusion
* Develop carbon sequestration methods
* Manage the nitrogen cycle
* Provide access to clean water
* Restore and improve urban infrastructure
* Advance health informatics
* Engineer better medicines
* Reverse-engineer the brain
* Prevent nuclear terror
* Secure cyberspace
* Enhance virtual reality
* Advance personalized learning
* Engineer the tools of scientific discovery

Committee members included: J. Craig Venter, President, The J. Craig Venter Institute; Dean Kamen, Founder and President, DEKA Research and Development Corp; Raymond Kurzweil, Chairman and Chief Executive Officer, Kurzweil Technologies, Inc and Larry Page, Co-Founder and President of Products, Google, Inc.

The web site (which by the way fails to even display the text on many pages without javascript – phb design) goes into more details on each challenge and will chronicle the ideas the public shares based on the challenges.

Clean Clothes Without Soap

photo of eco washing balls

The Soap-free Green Laundry Revolution by Tania Rabesandratana:

Then, there’s the sheer weirdness of entirely eradicating washing powders in favor of such an intangible washing concept. “The balls are made of a special kind of plastic,” explains Steve Jones, the founder of Ecotopia, which sells a variety of washing balls he believes are top of their league, and a scientific breakthrough. “It is the chemical reaction between the plastic and the agitated water that actually does the washing,” he says. The product’s blurb says the balls “produce ionized oxygen that activates the water molecules naturally and allows them to penetrate deep into clothing fibers to lift dirt away.”

Right. Let’s go back to washing basics. Our machine works by combining three actions. First comes chemical action. Here, detergents act as surfactants: they lower the water’s surface tension, making it more likely to mix with oil, so that yucky grease and grime can be removed during rinsing. Second comes the mechanical action from the spinning of the washing machine drum. And finally, there is heat action, which consists of dunking your laundry in hot water.

The eco balls mostly increase the mechanical action so that you can do without the chemical action, thereby saving money and avoiding the use of evil pollutants. The increase of mechanical action also does away with the need for heat action, which in turn conserves electricity and water, which is good for your wallet and your planet.

Pretty cool, if they actually work. I think I might have to try these out. For the next stage of the process, DryerMax Dryer Balls claim to cut the drying time by 25% and soften the fabric. Some other cool gadgets and gizmos.

Biofuels use Could Worsen Global Warming

Biofuels use could worsen warming (site broke link so link removed)

The biofuels themselves produce less greenhouse gases than fossil fuels, but not nearly enough to offset the carbon dioxide that is released when land is cleared and plowed up to produce crops, the studies said. Carbon dioxide is one of the leading contributors to global warming.

One of the studies released Thursday by the journal Science estimated that ethanol would nearly double the greenhouse emissions over a 30-year period if the impact of land conversion is taken into account.

Geothermal Power in Alaska

Geothermal Power in Alaska Holds Hidden Model for Clean Energy, how it works:

1) 165 F water, pumped three-quarters of a mile from Chena’s 700-ft.-deep production well, enters the evaporator. After circulating through pipes, the water, now 135 F, is reinjected into the reservoir at a well 300 ft. from the power plant.
2) The refrigerant R-134a fills the shell of the evaporator. Heat transferred from the 165-degree water causes the refrigerant to vaporize without the two liquids actually coming into contact.
3) The vapor is expanded supersonically through the turbine nozzle, causing the turbine blades to rotate at 13,500 rpm. This turns a generator at 3600 rpm, producing electricity.
4) 40 F water, siphoned from a shallow well 33 ft. higher in elevation than the plant, enters the con-denser without the aid of a pump. It circulates through pipes before being returned 9 degrees warmer to Monument Creek.
5) Vapor exiting the turbine fills the shell of the condenser, where the 40 F water returns the refrigerant to liquid form.
6) A pump pushes the refrigerant back to the evaporator, generating the pressure that drives the entire cycle so that it may start anew.

Sails for Modern Cargo Ships

photo of Sky Sail in action

Kite-powered ship sets sail for greener future

A cargo ship pulled by a giant, parachute-shaped kite will leave Germany on Tuesday on a voyage that could herald a new “green” age of commercial sailing on the high seas.
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During the journey from Bremen to Venezuela, the crew will deploy a SkySail, a 160 square metre kite which will fly more than 600ft above the vessel, where winds are stronger and more consistent than at sea level. Its inventor, Stephan Wrage, a 34-year-old German engineer, claims the kite will significantly reduce carbon emissions, cutting diesel consumption by up to 20 per cent and saving Â£800 a day in fuel costs. He believes an even bigger kite, up to 5,000 square metres, could result in fuel savings of up to 35 per cent.

From the Sky Sails site:

The planned product range contains towing kite propulsion systems with a nominal propulsion power of up to 5,000 kW (about 6,800 HP). On annual average fuel costs can be lowered between 10-35% depending on actual wind conditions and actual time deployed. Under optimal wind conditions, fuel consumptions can temporarily be reduced up to 50%.

Go Engineering!

Super Soaker Inventor Aims to Cut Solar Costs in Half

[Lonnie ] Johnson, a nuclear engineer who holds more than 100 patents, calls his invention the Johnson Thermoelectric Energy Conversion System, or JTEC for short. This is not PV technology, in which semiconducting silicon converts light into electricity. And unlike a Stirling engine, in which pistons are powered by the expansion and compression of a contained gas, there are no moving parts in the JTEC. It’s sort of like a fuel cell: JTEC circulates hydrogen between two membrane-electrode assemblies (MEA). Unlike a fuel cell, however, JTEC is a closed system. No external hydrogen source. No oxygen input. No wastewater output. Other than a jolt of electricity that acts like the ignition spark in an internal-combustion engine, the only input is heat.

Here’s how it works: One MEA stack is coupled to a high- temperature heat source (such as solar heat concentrated by mirrors), and the other to a low-temperature heat sink (ambient air). The low-temperature stack acts as the compressor stage while the high-temperature stack functions as the power stage. Once the cycle is started by the electrical jolt, the resulting pressure differential produces voltage across each of the MEA stacks. The higher voltage at the high-temperature stack forces the low-temperature stack to pump hydrogen from low pressure to high pressure, maintaining the pressure differential. Meanwhile hydrogen passing through the high-temperature stack generates power.

“It’s like a conventional heat engine,” explains Paul Werbos, program director at the National Science Foundation, which has provided funding for JTEC. “It still uses temperature differences to create pressure gradients. Only instead of using those pressure gradients to move an axle or wheel, he’s using them to force ions through a membrane. It’s a totally new way of generating electricity from heat.”

Very cool and yet another example of the benefits of educated engineers. The positive externalities are large for engineering education.

Aptera Prototype – Over 230 Miles Per Gallon

Aptera - photo of the new electric vehicle

They have a goal to begin production in 2008 and initially the Aptera will be available only in California. It is classified as a motorcycle but they are planning to aim for passenger car safety standards. The Electric only version will have a range of 120 miles and the hybrid version is estimated at 300 mpg. More interesting details from the Aptera web site:

We decided not just to meet many of the requirements for passenger cars, but we chose to exceed them. Industry safety standards are very different for passenger cars and motorcycles; we are choosing to go well beyond the industry safety standard for passenger cars so Aptera drivers can feel safe in any driving situation.
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The approximate price for the all electric version is $26,900 and the plug-in hybrid $29,900. These prices are subject to change any time before we begin production.
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Operating Prototype achieved over 230 Miles per gallon

via: Aptera Test Drive A Success!

Bigger Impact: 15 to 18 mpg or 50 to 100 mpg?

This is a pretty counter-intuitive statement, I believe:

You save more fuel switching from a 15 to 18 mpg car than switching from a 50 to 100 mpg car.

But some simple math shows it is true. If you drive 10,000 miles you would use: 667 gallons, 556 gallons, 200 gallons and 100 gallons. Amazing. I must admit, when I first read the quote I thought that it must be an wrong. But there is the math. You save 111 gallons improving from 15 mpg to 18 mpg and just 100 improving from 50 to 100 mpg. Other than those of you who automatically guess that whatever seems wrong must be the answer when you see a title like this I can’t believe anyone thinks 15 to 18 mpg is the change that has the bigger impact. It is great how a little understanding of math can help you see the errors in your initial beliefs. Via: 18 Is Enough.

It also illustrates that the way the data is presented makes a difference. You can also view 100 mpg as 1/100 gallon per mile, 2/100 gallons per mile, 5.6/100 gpm and 6.7 gpm. That way most everyone sees that the 6.7 to 5.6 gpm saves more fuel than 2 to 1 gpm does. Mathematics and scientific thinking are great – if you are willing to think you can learn to better understand the world we live in every day.

Turning Trash into Gas

Frank Pringle has found a way to squeeze oil and gas from just about anything

Everything that goes into Frank Pringle’s recycling machine—a piece of tire, a rock, a plastic cup—turns to oil and natural gas seconds later.
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The machine is a microwave emitter that extracts the petroleum and gas hidden inside everyday objects—or at least anything made with hydrocarbons, which, it turns out, is most of what’s around you. Every hour, the first commercial version will turn 10 tons of auto waste—tires, plastic, vinyl—into enough natural gas to produce 17 million BTUs of energy (it will use 956,000 of those BTUs to keep itself running).
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Or rather, he had extracted it. Petroleum is composed of strings of hydrocarbon molecules. When microwaves hit the tire, they crack the molecular chains and break it into its component parts: carbon black (an ash-like raw material) and hydrocarbon gases, which can be burned or condensed into liquid fuel. Pringle figured that some gases from his microwaved tire had lingered, and the cold air in the shop had condensed them into diesel. If the process worked on tires, he thought, it should work on anything with hydrocarbons. The trick was in finding the optimum microwave frequency for each material—out of 10 million possibilities.