Thursday, December 29, 2011

Souped up photosynthesis produces H2


Scientists have taken photosynthesis to the next level, by creating a tiny solar-powered device that works twice as fast as nature to produce hydrogen biofuel.
But the researchers add further research is needed before we can start using it to fuel our cars.
Hydrogen is seen as an alternative fuel source because it burns to produce water as waste. However, sources of hydrogen are difficult to tap.
Some scientists are turning to biomimicry, designing devices based on photosynthesis to use light to split water into oxygen and hydrogen.
"I think there's good prospects for using some of these biological photosynthesis systems to produce biofuels for the future," says Professor Donald Bryant, of Pennsylvania State University and co-author of a paper appearing inProceedings of the National Academy of Sciences.
In nature, a light-capturing enzyme known as Photosystem I uses light energy to energise electrons. Those electrons are moved, relatively slowly, to another enzyme known as FNR. The FNR enzyme combines these electrons with a biological molecule (NADP+) and a hydrogen ion to produce an energy-storage molecule called NADPH, which is used to make sugars.
To make their biofuel device the reserachers at Pennsylvania State University replaced the FNR enzyme with hydrogenase, an enzyme that combines two electrons with two hydrogen ions to make molecular hydrogen.
To increase its efficiency the hydrogenase was 'tethered' directly to the Photosystem I enzyme with a carbon chain. This chain, which acts like a molecular wire, speeds up the movement of electrons between enzymes, boosting hydrogen production.

Useful for other enzymes

Lead author of the study, Dr Carolyn Lubner, also of Pennsylvania State University, says the design can be adapted for other enzymes.
"For example, we could potentially use formic acid dehydrogenase to make formic acid, which is also a biofuel," she says.
Beyond biofuel, using light to inject single electrons one by one into enzymes gives scientists a unique ability to study the process of photosynthesis, says Bryant.
"For example, the hydrogenase enzyme has to accumulate two electrons, and they come one at a time - even in natural settings," he says. "What happens when one electron comes, and where it goes, is something that is currently unknown."
Lubner adds that "the more insight we can gain into enzymes found in nature, that make compounds ... such as hydrogen or ethanol, the better we can design mimics of them."
Associate Professor John Stride, of the University of New South Wales, says it makes sense to look to nature when designing new processes. "Nature has had millennia to solve problems, and photosynthesis is very efficient."
"One can imagine a biogenerator of hydrogen fuel that works just by using sunlight," he says. "Though they do have to feed it sodium ascorbate [vitamin C], so it's not quite energy for nothing."
Bryant says that while they used ascorbate in this experiement, "We can feed it electrons from anywhere, including the ground. We just have to have electrons from 'somewhere'."

Sunday, December 25, 2011

Researchers develop cheap and easy to mass-produce "solar-paint"

From Gizmag:

Researchers develop cheap and easy to mass-produce "solar-paint"
19:55 December 21, 2011
Mixtures using cadmium sulfide produced yellow paint, cadmium selenide produced dark brown...
Mixtures using cadmium sulfide produced yellow paint, cadmium selenide produced dark brown, while a mixture of the two - which offered the best conversion efficiency - was light brown (Photo: ACS Nano)

A team of researchers from the University of Notre Dame in Indiana is reporting the creation of a "solar paint" that could mark an important milestone on the road to widespread implementation of renewable energy technology. Although the new material is still a long way off the conversion efficiencies of commercial silicon solar cells, the researchers say it is cheap to make and can be produced in large quantities.
In an effort to find an alternative to silicon-based solar cells, the Notre Dame researchers turned to quantum dot materials. They started with nanoparticles of titanium dioxide (TiO2) and coated them with either cadmium sulfide or cadmium selenide - both compounds that can absorb photons. A photon of the right energy hitting the cadmium compounds causes an electron to escape, which is absorbed by the TiO2.
The resultant particles were then suspended in a water-alcohol mixture to create a paste. The cadmium sulfide mixture produced a yellow paste, while the cadmium selenide mix produced a dark brown. The most efficient was a mixture of the two that produced a light brown paste.
When the paste was brushed onto a transparent conducting material and exposed to light, it created electricity. To replenish the electrons lost by the cadmium and test the conversion efficiency of the paint-on electrode, cathodes made from other materials and additional compounds were used.
"The best light-to-energy conversion efficiency we've reached so far is 1 percent, which is well behind the usual 10 to 15 percent efficiency of commercial silicon solar cells," explains Prashant Kamat, an investigator in Notre Dame's Center for Nano Science and Technology (NDnano). "But this paint can be made cheaply and in large quantities. If we can improve the efficiency somewhat, we may be able to make a real difference in meeting energy needs in the future."
Kama and his team have christened the new paint "Sun-Believable" and plan to study ways to increase its conversion efficiency and improve its stability. The Notre Dame team's paper is published in the journal ACS Nano.

Thursday, December 15, 2011

JP Morgan expands deployment of FPGA-based supercomputer -

This is how to get really efficient computing.
There was a Russian book I found on systolic computing.  Brilliant stuff, really inspirational for me.  It's applications in video and image processing were immediately obvious.

Is living off the Grid now a crime?

Monday, December 12, 2011

earthCell | the renewable battery by Jason Rugolo — Kickstarter

Indoor solar energy harvesting: a platform to (finally) get some numbers

Mathieu] was interested in using more solar cells for his everday electronics. He looked around but couldn’t find much information about using pholovoltaic for small indoor devices. We remember hearing some of the same things from [Dave Jones] in one of his EEVblog installments from a few years ago which looked at solar calculators; the only indoor solar gadget we can think of.

The quest for knowledge was on and [Mathieu] decided to build this indoor solar cell test platform. It’s a stable piece of hardware that allows him to run reliable tests in many different conditions. It’s designed to compare two identical cells. One is charging the Lithium cell, the other is driving a load directly. A second battery powers the platform separately from the solar circuits so that it can be used as a data logger. He collects, dumps, and graphs info from his test runs, then discusses his findings. We won’t spoil it, but the results are not great. Mostly you need sunlight to get real results as it’s just so much more powerful than artificial lighting.

Thursday, December 8, 2011

Fwd: Home Performance Nightmare

---------- Forwarded message ----------
From: ss
Date: Tue, Dec 6, 2011 at 6:00 PM
Subject: Fwd: Home Performance Nightmare

Energy efficiency.


         Home Performance Nightmare

Greetings Planetsavers

Tonight we're diving in to fixing the worst Home Performance nightmare I've ever seen.  That's right, it's the house I just bought in Virginia!  Over the last few weeks I've shown you some pictures but today I took my first blower door reading... 7800 cfm50... and it never even got to 50! Actually it got to 34 with an open fan. We'll talk about what that all means and what can be done about it... on this house that the DOE wants real tight.

BTW I met some neighbors and they told me that the home had over $1,000 electric bills. We mentioned the insulation disaster a few weeks ago (shown above) but now we know how big a disaster that was.

This is actually a case where the Home Performance Failure actually cost the owner his home as the Utility Bill certainly contributed to them losing it in foreclosure!

Check in at 6 pacific and we'll take on this challenge. Hint: greater measures will be required than we discussed last week.
Also I've already implemented some of last weeks suggestions from the audience. I'm getting excited about this one.

See you tonight,

Dave Robinson

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Upcoming Educational
Energy Wise Investing by Dave Robinson
PGE Classes are pending. Check back for further details.

   Field Trip
Fresno CA
 Dec 10th, 2011
On his trips from Virginia, Dave tries to leave time for a Fresno "Field Trip."  Those wishing to see Energy Wise Renovation in process should watch here for upcoming details.
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Visit our New completely remodeled Beta Site by clicking here or link at top of page.  Let us know how you like all the  changes!
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View the video "Welcome to Energy Wise House Flipping of Foreclosed Homes" by  clicking here.
Green Earth Equities...  
Saving the Planet One Foreclosed House at a Time


Monday, December 5, 2011

Consumers turn to smart-meter alternatives for energy management

The pricing of smart meters offered by utilities is making many consumers seek out alternative products for energy management and monitoring, Cassandra Sweet writes in The Wall Street Journal. This article surveys several products, including General Electric's Nucleus, which can now work without a smart meter, and the Nest Learning Thermostat.

Watch Your Energy

New monitoring gadgets may help reduce utility bills