Sunday, November 11, 2012

Cleantech News from CleanTechnica

Cleantech News from CleanTechnica

Link to CleanTechnica

Entire Cities Could Run on Compressed Air

Posted: 10 Nov 2012 08:09 AM PST

LightSail compressed air energy storageThe company LightSail Energy started out a few years ago with a student’s modest idea for a compressed air scooter, and now it has just raised $37.3 million in private funding to bring utility scale, compressed air energy storage to the market. That’s a big leap not only for the company but for compressed air technology itself, which has long been eyed for its clean energy potential. The problem has been to make the process efficient enough to deliver power at a commercial scale, so let’s take a look and see how LightSail solved the problem.

The Compressed Air Conundrum

As aptly described by writer Rachel Metz over at the MIT Technology Review, half of the compressed-air equation is simple enough from a clean energy perspective. You can use any form of alternative energy such as solar or wind to generate electricity, which in turn powers a motor that compresses air in a tank.

The  hard part kicks in when you try to store large quantities of compressed air. Compression adds energy in the form of heat (almost 1,000 degrees centigrade, according to Metz) and that leads to enormous complications.

The Indian car manufacturer Tata Motors has apparently found at least a partial solution for small scale compressed air, but LightSail is going down an entirely different road.

LightSail’s Compressed Air Solution

Danielle Fong, Chief Scientist and co-founder of LightSail, is the former student who dreamed of a compressed-air scooter. She solved part of the problem by designing two related features into the system. One involves using mist to cool the air, and the other involves recapturing energy from the spent mist, in the form of heat.

According to Metz, Fong and her partners also identified a compound that could be used to manufacture tanks strong enough to store bulk quantities of compressed air above ground, in relatively inexpensive facilities, leading to the conclusion that “there are no technical barriers to building units large enough to power entire cities.”

As for whether it works or not, the new round of funding indicates a pretty high degree of confidence. It was spearheaded by legendary investor Peter Thiel of PayPal fame, and it included early investor Khosla Ventures as well as Bill Gates and Innovacorp among others.

Compressed Air Meets Wind Power

As a side note, compressed air technology is also expanding its role in the alternative energy field through the avenue of wind power.

One example is a compressed-air wind turbine that is designed like a funnel, with no exposed blades, in order to cut down risks for birds.

Along similar lines, an Air Force veteran has come up with a low cost wind turbine  that uses a steady stream of compressed air from silos. The design is aimed at enabling small farmers on a budget to leverage their existing infrastructure, including silos and grid connections.

Alternative Energy and Democracy

Environmental and financial issues usually dominate the conversation about clean energy, but in announcing the new round of funding, LightSail CEO and co-founder Steve Crane teased out the truly transformative potential of alternative energy from a social and political perspective:

“We want to democratize energy – to enable renewable sources to supply energy on demand locally and at a lower cost than centralized fossil-fuel based generation."

That’s the piece missing from the fossil fuel puzzle, the ability of a democratically organized community to make decisions about its primary sources of energy, just as it makes decisions about roads, zoning, schools, public safety and a host of other issues that are fundamental to the quality of life.

Image: Some rights reserved by ewan traveler

Follow me on Twitter: @TinaMCasey


Jay Leno Tours The Proterra Ecoliner Electric Bus (Video)

Posted: 10 Nov 2012 04:00 AM PST


Late night funny man (or unfunny depending on who you ask) Jay Leno in the video above tours the Proterra Ecoliner Electric Bus, which has been cruising the streets of LA for more than a year.

Electric buses are become more popular with sales expected to rise 26 percent annually through 2018. It’s nice to hear that this bus is actually in operation and not just a prototype that may never hit the road.

Check out the video for details about the clean energy credits purchased to off-set the electricity the bus uses; the durable, noncorrosive, lightweight balsa wood/figerblass bus structure; and two-speed transmission, 200 horsepower engine propelling the people mover.

At about the 13 minute mark in the video, feel free to move on with your day. That’s when Leno gets behind the wheel and gushes about how much he loves the bus, followed by passengers awkwardly applauding his driving skills. Stick to your day job, Jay.

Source: Climate Crocks

Man Lights House with Toyota Prius

Posted: 10 Nov 2012 02:00 AM PST

An enterprising New Jersey man used his Toyota Prius as a generator to run his home’s lights, laptops, and a television because he lost power due to the recent Sandy outages. For one week he used an inverter and some extension cords to produce power for his home while only using 75% of one tank of gas.

At one point, as you probably know, millions of homes were without power in New York and New Jersey.


There are instructions online explaining how to use a Prius as a generator. WikiHow has a six-step process, including a tip about proper ventilation, because car exhaust can be deadly if it accumulates in a space where people or animals are breathing.

The New Jersey man is not the only person to have used a Prius to power devices in his home. Last year, a man in Massachusetts did as well. “When it looked like we were going to be without power for awhile, I dug out an inverter (which takes 12v DC and creates 120v AC from it) and  wired it into our Prius… These inverters are available for about $100 many places online,” the man said. He only used five gallons of gas to power his home appliances for three days.

Many backup generators use two-cycle engines, which are known to create large amounts of air pollution, though they certainly are much cheaper than a Prius. Some electric vehicle owners also have solar panels on their homes and generate all or a portion of their own power.

The 2012 Prius has been rated at 536 miles per tank.

Image Credit: S 400 HYBRID

Ascent Solar Technologies Selected By U.S. Air Force For Advanced Flexible Lightweight Photovoltaics

Posted: 10 Nov 2012 01:00 AM PST

Ascent Solar Technologies was selected for the Air Force SBIR (Small Business Innovative Research) Phase 2 award to demonstrate its next flexible lightweight photovoltaic technology built upon its existing flexible, monolithically integrated, thin-film CIGS (Copper Indium Gallium Diselenide) one.

The Air Force SBIR Phase 2 program is expected to operate for 24 months with a program value of up to $750,000.

Ascent Solar Powered Phone Charger.

"Solar cells perform best at lower temperatures, but they can get hot during normal operation," stated Victor Lee, President and CEO at Ascent Solar Technologies, a developer of flexible, thin-film solar technology.

"Modifying our existing technology can improve its performance at higher temperatures. This Air Force program builds upon significant work already conducted by our team in this area. After program completion, we envision a new product that will perform over 30% better under some operating conditions that utilize process modifications that can be used in our existing manufacturing line."

Looks promising.


The Problem With Solar Panels

Unfortunately, solar panels need to receive as much sunlight as possible, and some sunlight turns into heat when it reaches the panel, while the rest is converted into electricity. More sunlight translates to more heat, and lower efficiency, but still a greater power output.

Fortunately, power output can be increased more by cooling the solar panels using heat sinks, or liquid cooling systems. Heat sinks can be helpful without using any electricity if they are passive, but the active type performs much better. The active type utilizes a fan to pass air through it to help dissipate the panel’s heat faster.

Another innovative idea is to get the most out of electricity-generating solar panels by utilizing the heat they absorb from the sun to heat water, increasing their overall energy yield.

Otherwise, improvements in performance like those Ascent Solar is delivering are certainly helpful.

Source: Business Wire
Photo Credit: Ascent Solar Website

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