It sounds like a good idea: Use electricity to compress air, stuff it in a tank and use the power expelled by the air's release to power a vehicle. Seems like a good idea, certainly a lot easier to understand than nano-constructed cathodes on a lithium ion cell. And several companies have been actively attempting to build cars powered by conpressed air for quite some time. We at EcoGeek have been excited about them. The two biggest of these companies are MDI, a French company and Tata Motors, India's largest car company.

But I have bad news. Today, here at EcoGeek, we are declaring the air car dead. It's a question of physics, every conversion from one type of energy to another decreases efficiency. With battery electric vehicles, energy is converted into electricity and electricity is converted to motion. With air cars, energy is converted into electricity, electricity into compressed air and then compressed air into motion. Because of this, compressed air cars will always be less efficient than electric vehicles.

But Tata's goal of a 2008 release of an air car has, obviously, not been met. In 2009, Tata stated that the short range of the cars and issues with keeping them from freezing up (when compressed air is decompressed, temperatures drop dramatically) were proving them impractical.

So, I'm sorry my friends, we're all going to have to be happy with the much more technologically confusing (though also much more efficient) battery electric vehicles. The good news is, with the Leaf and the Volt already hitting the road, that's one technology that definitely isn't vaporware.

More on the disadvantages of air cars.

Researchers at the University of Michigan have created a color filter that could boost the efficiency of LCDs, the power hog of all your gadgets, by more than 400 percent, and no, I didn't add an extra zero there.

The researchers made an optical film that colors and polarizes the light that passes through an LCD, taking the place of the several layers of optical devices that typically serve the same function in an LCD.  Those multiple layers give rise to inefficiencies:  the best LCDs out today only emit eight percent of the light their backlights produce. The researchers found that the film allowed 36 percent of the light to make it through - a huge increase.

The color filter is made up of three ultra-thin layers -- two layers of aluminum enclosing a layer of insulating material -- and it only measures 200 nanometers thick.  The filter is etched with slits that produce different colors when illuminated by the backlight.  The slits are matched in scale to the wavelength of visible light and their length and distance apart determine the color produced.

This grating pattern is where the efficiency boost comes in.  In current LCDs, a polarizing filter absorbs half the light (the part with the wrong polarization).  The grating on the new filter doesn't absorb the light with the wrong polarization, it instead reflects it back towards a mirror that flips some of its polarization, letting more light pass through the filter.

Researchers are trying to improve the efficiency further and are coming up with ways to mass produce the filters, like with roll-to-roll printers.

via MIT Tech Review

It looks like supply and demand is working out in the consumers' favor when it comes to lithium-ion batteries.  Production has been ramping up for the batteries as more electric cars go into production and that has led to an oversupply that may just keep piling up.  Analysts are predicting a price drop of between 19 and 25 percent by the end of the year -- a slash that could also spell cheaper electric cars in the very near future.

Battery makers in Japan and Korea, like Samsung and Panasonic, account for 75 percent of the world's production, and they've been competing to get the largest share of a market that could triple over the next six years.  This production and pricing war has created a glut of batteries and, luckily for consumers, a falling price.

Many first generation electric vehicles are going on sale in the coming months.  I won't be surprised if the second generations, much like we've seen with later generation hybrids, include a cheaper price tag.

via Treehugger

image via GM

The U.S. Coast Guard has set a goal of a net zero carbon footprint for housing at their Southwest Harbor Base in Maine.  The base is using solar panels, solar hot water heaters and now a wind turbine for their energy needs.  Efficiency-boosting retrofits will also be done, including new electrical systems and better insulation.

The newly-installed wind turbine sits atop a 70-foot tower and provides power to a duplex housing unit located on the base.  The upgrades and retrofits will begin in October.

The Coast Guard is looking to install wind power at other bases in Maine and around the country.  This push toward renewable energy is part of a bigger program by the Department of Defense to get 25 percent of their energy from renewable sources by 2025.

As Capt. James McPherson of the Coast Guard said, "We want to be good stewards of the environment and we want to be careful how we spend tax payer dollars, but we also think the debate is over whether we need to go to alternative energy.”  Yes, it is.

via Inhabitat

The US Environmental Protection Agency has released its new vehicle fuel economy labels which are proposed to replace the current vehicle labels starting with the 2012 model year. The new labels provide consumers with additional information and a comparative ranking for new cars, with a comparison bar (not unlike what is now provided on appliances like refrigerators and clothes dryers) showing where the particular vehicle falls along the line from best to worst in fuel efficiency, greenhouse gasses, and other pollutants. Two alternative forms of labels (plus a third option which is not proposed for use at this time) are now open for public comment.

The new labels will help provide more useful comparison information for the increasing variety of vehicle options that are available. In addition to labels for gas and diesel vehicles, there will also now be labels for electric vehicles, plug-in hybrid vehicles, compressed natural gas vehicles, and flexible fuel vehicles. This will allow more direct comparisons between different vehicles with different kinds of fuels.

The proposed labels will still show the MPG, but will also include a fuel consumption value (which, instead of miles per gallon, is a better measure telling how many gallons of fuel per 100 miles are needed). Putting the extra information on the label is simple, and makes comparison of efficiency that much easier. But the familiar MPG number will still be there, too.

Information about greenhouse gas emissions and other exhaust pollutants would also be listed on these labels. Upstream emissions, such as the emissions from a power plant generating electricity to recharge a vehicle, would not be listed on the label, although a website with more information about these impacts would be included on the label.

The dual fuel label (for vehicles able to run on either gasoline or E85 ethanol) distills everything to a single number, rather than presenting alternatives for each fuel. Because a gallon of E85 ethanol has less energy than a gallon of gasoline, the miles per gallon number will be different.

But overall, we like the trend towards including more information on the labels. The new labels should address the gap in the current labels for dealing with 'advanced technology vehicles' and should help consumers evaluate the differences and the options that are now available.

EPA Press Release

via: GM-Volt.com and Treehugger

Starting tomorrow, you can officially order a Nissan LEAF, and I don't think it's a surprise to anyone that we've been pretty excited about this vehicle.  It will be the first mass-produced all-electric car on the market and, with federal and state incentives included, it will also be affordable.  But I'm getting a bit nervous as well.

As we've mentioned before, this crowning of the LEAF as the inaugural mass market electric vehicle is both a blessing and a curse for Nissan and those of us who strongly support electric cars.  The LEAF will enjoy a bit of fame, but a lot of pressure rests on its wheels to prove that electric cars can easily take the place of their gas-fueled counterparts.  And there's one particular feature that may hold it back.

The LEAF has been criticized by competitors and auto enthusiasts alike for lacking an active thermal management system for the battery pack.  It has a passive cooling system that features a single fan to distribute heat evenly over the pack.  The LEAF has an official range of 100 miles, but under extreme hot or cold weather conditions, without a competent system to keep temperatures in check, the range could plummet to as low as 40 miles.

Elon Musk has said that the LEAF's thermal management system is primitive and would lead to "huge degradation" in cold environments and that the battery pack would just "shut off" in hot environments.  If you live in Maine or Texas (as well as any other area that sees temperature extremes), that would be a major problem.

If the LEAF rolls out and enough people complain of limited range and consistency issues, it could be spell the end for the LEAF and could make convincing the average person to buy an all-electric an even harder feat.  I've got to believe that Nissan has fully tested the battery pack under extreme temperature conditions and hopefully this all amounts to a bunch of competitive gossip, but I'll be keeping my fingers crossed just in case.

Here at EcoGeek we've been long-time supporters of e-book readers. The publishing industry (including books, newspapers and magazines) is a serious environmental threat with a huge carbon footprint and raw materials that result in the harvesting of some 125 million trees per year.

So we were excited. But as the realities of ebooks set in, and they actually began to explode in popularity (with Amazon.com now selling more Kindle books than hard-covers) we got apprehensive. Would this new trend really be good for the environment? The answer...thankfully, is a resounding "Yes."

The Kindle device itself, of course, has a carbon footrprint caused by manufacturing and shipping all of its parts around. And it does use electricity (though, really, a very small amount compared with devices like laptops or even some cell phones.) But while I still love real books for a lot of reasons, I've got to give it to the Kindle. Authors are getting paid more, consumers are paying less, and (according to a study from The Cleantech Group) as long as the devices replace the purchase of more than 22.5 NEW (not used) books in the lifetime of the device, it will be a positive force for the environment. This seems to be roughly one year's use of the Kindle. Of course, if you're replacing newspapers and magazines with your Kindle chances are you'll go carbon negative faster than that.

But if you're thinking about getting a Kindle for green reasons, make sure you know you'll be replacing more than 20 new books on the thing before you upgrade, otherwise you're not just wasting your money, you're hurting the environment.

Concrete is not often the greenest material choice, particularly since concrete production is one of the largest single sources of carbon emissions globally. But, for wind turbine towers, the use of concrete bases can provide a number of significant benefits, including reducing the amount of concrete needed for the footings for a tower by more than two-thirds. Concrete bases can also be more economical to install and can provide faster construction times for wind towers and also can raise tower height to increase power production.

The wider footprint of the precast concrete base also adds stability to the foundation of the tower. With the precast concrete base, load is spread over a wider area, and a simpler ring footing can be utilized, which results in a 60% - 70% reduction in the concrete needed for the footing of the tower. This can result in a net reduction of the total amount of concrete used. The ring footing is easier to construct as well, since the problems associated with a mass pour can be avoided.

In addition to the construction benefits, the concrete bases increase the overall tower height to raise the turbine into more powerful winds or to allow the use of larger diameter blades. Metal towers are reaching limits for transportability and constructibility, but adding precast concrete tower base can add 30 meters (almost 100 feet) of height to the tower. This can allow larger diameter turbines to be used with existing metal towers.

Concrete tower bases can also be locally produced, rather than needing specialized manufacture as with steel towers. Precast concrete sections for these bases are actually more transportable, since they are produced in sections that are assembled together once on site. Concrete is also a sturdier product, which is less susceptible to damage and rusting and does not require regular painting like steel.

via: North American Windpower

The State of California has granted approval for a new solar thermal power plant. The 250-megawatt Beacon Solar Energy Project is the first solar thermal power plant to be licensed in the United States in nearly 20 years. Commercial operation is expected to start by the third quarter of 2011.

Several other solar projects are also in the pipeline and seeking approval by the end of the year, including the Brightsource 400 MW solar tower. More than 4 GW of other solar thermal projects are also pending with the state.

Beacon Solar will be an array of solar focusing parabolic troughs spread over a 2,012 acre site in Kern County, California. The approval process required a solution to local residents' objections to the great amount of water the project would require. The final agreement will have the project use recycled water from a nearby community instead of drawing directly from the local aquifer. The project expects to use nearly 1600 acre feet (1.97 million cubic meters) of water annually.

The state of California has mandated that 20% of its electrical power come from renewables by 2010. While it does not look like that target is going to be met, the approval of several hundred megawatts of solar thermal power will help get the state closer to that goal.