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New Process May Make Renewable Energy Reliable at Last

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Solar energy is virtually limitless, generates no planet-warming greenhouse gases — and is useless between sunset and sunrise. Wind energy is also plentiful and emits no carbon, and it can be harvested day or night, but not when the air is calm.

A discovery announced in Thursday’s issue of Science may offer a way around these daunting problems, however. Chemists at the University of Calgary, in Canada, have found an efficient way to turn electricity from wind and solar energy into hydrogen, which itself can be used as a fuel, emitting nothing more harmful than water vapor, when the wind stops blowing or the Sun is below the horizon. “Essentially, we’re using hydrogen as a storage mechanism for electricity,” said co-author Curtis Berlinguette in an interview.

Credit: aismist/flickr

Without such a mechanism, electric utilities need to keep conventional power plants as backup, and if those plants burn coal or natural gas, they vent heat-trapping CO2 into the atmosphere. But the storage techniques energy experts have come up with so far — pumping water uphill when the sun is shining or the wind is blowing, then letting it flow down again to generate power, or storing the electricity in batteries, or using it to compress air that can run generators — are all quite inefficient.

Until recently, the same has been true of hydrogen storage. The way this technology works is that an electric current is run through water, splitting the H20 into oxygen (the O) and hydrogen (H). The downside, Berlinguette said: “It takes a lot of electricity.” You can speed the process by using a catalyst, which helps split water molecules, but so far, the best catalysts available have been made from rare metals with a layered, crystalline atomic structure.

That structure, however, keeps the water from making maximum contact with the catalyst. “It’s a bit like lasagna,” Berlinguette said. “If you pour sauce over layers of flat pasta [the crystalline metals], it has trouble penetrating all the way through.”

The chemists’ answer was to use cheaper metals, including plain old iron oxide (a.k.a. rust) in an amorphous, non-crystalline form. “It’s more like spaghetti,” Berlinguette said, and that makes the process far more efficient. It’s not nearly efficient enough if your end goal is simply to produce hydrogen: for that, an established process known as methane reforming is much better.

But if you’ve got a solar plant in the desert or a wind farm on the Nebraska (or Alberta) prairie, and you need somewhere to stash excess energy until it’s needed, hydrogen appears to be better than the other options. “The energy density of hydrogen,” — that is, the amount of energy it holds per pound of material — “is about a hundred times more than batteries or compressed air or the rest,” Berlinguette said.

The Calgary team’s new work improves upon a similar discovery made by MIT chemists a few years ago, and their new catalysts are the best available, doing the job better, and with cheaper materials.

While converting renewable electricity into hydrogen is currently far more expensive than these other methods, the higher efficiency and thousandfold-cheaper materials in this new process could finally make it competitive. 

A company formed by the chemists to commercialize their new technology is planning to have a utility-scale working model on the market sometime next year, with a homeowner-size model, the size of a large refrigerator, by 2015. If that comes to pass, a house equipped with solar panels or a wind turbine could be entirely energy self-sufficient, around the clock.

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Comments

By Jack Clock (Harrison, Ohio 45030-9456)
on April 1st, 2013

I think this is a great idea.

There is a quaker farmer by the name of Ralph Dull who lives in Brookville, Ohio. He has been green for 30+ years. He has every form of renewable energy on his farm, including a hydrogen generator. The hydrogen generator is hooked up to 2 Bergey 10,000 watt turbines. Whenever the turbines are turning they generate electricity. This electricity is used to generate hydrogen.

The hydrogen generated is stored in a large tank until it is needed. The hydrogen is used to operate farm equipment and to fuel the heaters in the corn silos. Nothing goes to waste. He even has a hydrogen pump on his farm. This allows people with hydrogen operated vehicles and equipment to get a hydrogen fill-up.

In addition to the hydrogen, Ralph has 4 more Bergey Turbines that are grid tied. He also has SolarPV and Solar Thermal on the roof of his office. He is now in his 80’s and has been green before it was the in thing.

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By Greg D (Denver)
on April 2nd, 2013

Look up MOLTEN SALT SOLAR THERMAL COLLECTORS. This article just points out the simple fact that renewable energy in america is simply a jobs program to be given lip service.

The fact is that while oil is traded in dollars it is against US policy to actually become energy independent and show the rest of the world it can be done. Sadly once the rest of the world stops trading oil in Dollars the currency will collapse and the idea of being able to invest in a sustainable future will seem like a fairy tale. it’s going to be countries with real need for renewable energy that will make it happen(india/china)

The technology already exists to be free of fossil fuels for energy and transportation it simply requires the leadership to organize the infrastructure. Sadly the free market isn’t effective at creating sustainable renewable standards.

Like most things it’s going to take local organizing to force change that should already be common sense. Everything on the surface of the planet lives on solar energy and so can humans.

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By Nothing New Here (4015)
on May 14th, 2013

There is nothing new here, In fact in 5 weeks time an educational building in Brisbane will open that demonstrates this technology. Its daily power will be delivered by Solar with excess power stored as Hydrogen. It is estimated the building will run for 3 days off the hydrogen reserves.

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