New vanadium-flow battery delivers 250kW of liquid energy storage

New vanadium-flow battery

Imergy Power Systems announced a new, mega-sized version of their vanadium flow battery technology today. The EPS250 series will deliver up to 250kW of power with a 1MWh capacity. We’ve talked about a number of different battery chemistries and designs at ET, from nanobatteries to metal-air, to various lithium-ion approaches, but we’ve not said much about flow batteries — and since this new announcement is a major expansion for the company (their previous battery was a 30kW unit) it’s an opportunity to take a look at the underlying technology.

Feel the flow

A flow battery can be thought of as a type of rechargeable fuel cell. The electrolyte fuel, in this case, is kept in large external tanks that can be pumped through a reactor. One of the characteristics of a flow battery is that the energy storage can be decoupled from the energy output. The size of the reactor determines how much power can be released at once, while the size of the storage tanks determines how much total power can be stored.

This, in turn, makes it theoretically much easier to expand the size of a flow battery installation as compared to a lithium-ion battery. Doubling your battery life is theoretically as simple as doubling the size of the storage tank. Flow batteries can charge and discharge rapidly — refilling the tank with “charged” electrolyte can be as simple as opening a nozzle and pumping in the replacement fluid while the original electrolyte is recharged in a separate container.

There are different types of flow batteries and multiple compatible battery chemistries, but Imergy’s designs all use vanadium for both electroactive elements. The ability to fill both ‘sides’ of the equation is an unusual property of vanadium and it simplifies certain aspects of the reactor design. Vanadium flow batteries are extremely stable — leaving the battery in a discharged state causes no damage, and the battery has an estimated lifespan of 30-50 years and supports thousands to tens of thousands of discharge cycles — far more than lithium-ion can manage.

The disadvantage of flow batteries is that the total energy density of the solution is rather low energy density and the complexity of the storage and pumping mechanisms. Research into improving vanadium’s energy density is underway, a team at the Pacific Northwest National Laboratory has found a way to boost the energy density of vanadium batteries by up to 70% by switching to a different electrolyte formulation.
The long-term market

Much of the debate over the long-term usefulness of battery technology in the US centers around whether or not batteries can be combined with solar and wind power while still matching the cost of our existing natural gas, coal, and nuclear plants. What’s often ignored is that these equations look very different in other parts of the world, particularly in Africa or Indonesia where import costs are high, infrastructure limited (or nonexistent) and natural deposits of fossil fuels are low.

Africa also has enormous renewable energy potential — it receives huge amounts of solar power, its hydropower generating capability is largely untapped, and its geothermal and wave power are both abundant. The East African Rift in particular has high potential as a long-term geothermal power source.

Vanadium flow batteries could potentially augment renewable power in many areas across the continent, and Imergy is focusing its efforts on both the developing and the developed world. The company claims it can deliver power for a levelized cost as low as $300 per kWh, which would put it in competition with lithium-ion costs — including, possibly, in competition with Tesla as that company scales up its own industrial battery efforts.

New vanadium-flow battery delivers 250kW of liquid energy storage

2:27 PM energy, Flow Battery, Vanadium

Poll shows giant gap between what public, scientists think

The GAP Between Scientist views And Public Views

we are not talking about underdeveloped or developing countries. This about very developed countries. The views of common public is totally different from that of the scientist of the country.

Why there is a huge gap in their views ? Is the knowledge is not properly reached the public ? Or public is not ready to change from what they beliefs ?

What ever may be the case, it directing towards some new level of discussion. The science s for public life, it suppose not to end with publishing discoveries, rather the public should be educated and must give confident to them to change their mind set. This is very much required for the fearsome world of this generation. If this is the case of highly developed nations, I am not dare enough to think about the situations in developing and under developed countries. So think of it ... and read further to find the real statistics-- and realize the ocianic gap between public and scientist. 

.


WASHINGTON (AP) — The American public and U.S. scientists are light-years apart on science issues. And 98 percent of surveyed scientists say it's a problem that we don't know what they're talking about.


Scientists are far less worried about genetically modified food, pesticide use and nuclear power than is the general public, according to matching polls of both the general public and the country's largest general science organization. Scientists were more certain that global warming is caused by man, evolution is real, overpopulation is a danger and mandatory vaccination against childhood diseases is needed.

In eight of 13 science-oriented issues, there was a 20-percentage-point or higher gap separating the opinions of the public and members of the American Association for the Advancement of Science, according to survey work by the Pew Research Center. The gaps didn't correlate to any liberal-conservative split; the scientists at times take more traditionally conservative views and at times more liberal.

"These are big and notable gaps," said Lee Rainie, director of Pew's internet, science and technology research. He said they are "pretty powerful indicators of the public and the scientific community seeing the world differently."

In the most dramatic split, 88 percent of the scientists surveyed said it is safe to eat genetically modified foods, while only 37 percent of the public say it is safe and 57 percent say it is unsafe. And 68 percent of scientists said it is safe to eat foods grown with pesticides, compared with only 28 percent of the general public.

Ninety-eight percent of scientists say humans evolved over time, compared with 65 percent of the public. The gap wasn't quite as large for vaccines, with 86 percent of the scientists favoring mandatory childhood shots while 68 percent of the public did.

Eighty-seven percent of scientists said global warming is mostly due to human activity, while only half of the public did. The figures for scientists are slightly different than past academic studies because of wording of the question and the fact that AAAS members include many specialties, but they tell the same essential story, said Pew associate director Cary Funk.


In this Monday, Oct. 31, 2005, picture, a harvester works through a field of genetically modified co …

What to do about climate change is another issue. Nearly two-thirds of scientists favored building more nuclear power plants, but only 45 percent of the public did. But more of the public favored offshore drilling for oil and fracking than scientists did.

More than four out of five scientists thought the growing world population will be a major problem, but just less than three out of five members of the public did.

Pew polled 2,002 adults in August and did an online survey of 3,748 AAAS members in the fall. The margin of error is plus or minus 3.1 percentage points for the public and 1.7 percentage points for the scientists.

In 2009, Pew asked only a handful of questions like these to both scientists and the public and the gap hasn't changed much since, Funk said.

"On the whole, as compared to most members of the public, scientists are likely drawing from a larger scientific knowledge base — and thinking more scientifically — about each of these issues," George Mason University communications professor Edward Maibach said in an email. "Therefore, their views appear to be more in line with a completely dispassionate reading of the risks versus the benefits."

Alan Leshner, chief executive officer of AAAS, said the gap between the way the public and scientists look at issues is a cause for concern.


A sign from an environmental group pushing a bill proposing man …

"Science is about facts; science is not about values," Leshner said. "Policies are made on facts and values and we want to make sure that the accurate, non-distorted facts are brought in to any kind of discussion."

The trouble is that scientists don't think the public knows the facts. The survey said 84 percent of the scientists said it is a major problem that "the public does not know very much about science" and another 14 percent said it is a minor problem.

And 97 percent of the scientists criticized the educational system. Three-quarters of the scientists said not enough science and math education is a major problem and another 22 percent said it was a minor one.

"It's not about being smart or dumb," Leshner said. "It's about whether, in fact, you understand the source of the fact and what the facts are."


Online:

Pew Research Center: http://www.pewresearch.org/

American Association for the Advancement of Science: http://www.aaas.org/

Journal Science: http://www.sciencemag.org


Seth Borenstein can be followed at http://twitter.com/borenbears

Poll shows giant gap between what public, scientists think

2:03 PM energy, GM crops, Nuclear plants, public view, scientist

Artificial Leaf. Will it be the Energy source of the future ?

Artificial Leaf: the new ways of producing energy

At the very beginning of the human race, concurring the energy source was the ultimate target. And still we are racing behind a renewable, affordable energy source. We already witnessed wars and fight for capturing energy sources and witnessed the rise of economical power of the world  from scratch  just becuse of having the natural energy resources.

The world is and will be highly worried about the avaialbility of the natural resources. The depresiation of the resources is really an unforgatable thoughts. But still we are not able to come up with a replaceble source for natural resources. One advantage of liquid fuel is propotrion of stored energy in it  and storage space required.  To use elctric current insted of liquid fuel to fly a flight, just imagine the amount for batteries required to store the power. So the real though is to come up with a real alternate energy source  which is to be efficient, cheap and robust. And it is the ultimate challenge for the existance of the entire humnity.

In recent publication of Nature, discused about a concept of Artificial leaf. This leaf is just not a leaf made of synthetic material, the artifical part is the functionality of the leaf. Yes we are trying to mimic the function of a leaf 'the photosysnthesis'. Ultimately the energy source we are looking for the solar energy.

The concept of artificial photosynthesis goes back to 1912, but the push to achieve it did not start until 1972, when Japanese researchers outlined what a device would need to take in sunlight and use it to split water into oxygen and hydrogen fuel2. Progress was slow. In 1998, Turner reported3 a complete system that showed a major advance — it stored 12% of the incoming solar energy as fuel, compared with 1% of energy stored as biomass in real leaves. But it cost more than 25 times too much to be competitive, and its performance dropped off after 20 hours of sunshine.

In the process, to create a system that is much cheaper than just splitting water with electricity from a solar panel. At the heart of JCAP's artificial-leaf design are two electrodes immersed in an aqueous solution. Typically, each electrode is made of a semiconductor material chosen to capture light energy from a particular part of the solar spectrum, and coated with a catalyst that will help to generate hydrogen or oxygen at useful speeds (see 'Splitting water'). Like many other artificial-photosynthesis devices, JCAP's system is divided by a membrane to keep the resulting gases apart and reduce the risk of an explosive reaction.

Once the water has been split, the hydrogen is harvested. It can be used as a fuel by itself — perhaps in hydrogen-powered cars.

Making any one of the artificial leaf's components work well is a challenge; combining all of them into a complete system is even harder. Much of the difficulty comes down to finding the right materials. Silicon, for instance, makes a good photocathode — the electrode that produces hydrogen gas — but is stable only when the solution around it is acidic. Unfortunately, the situation is reversed with photoanodes, which produce oxygen: the good ones are stable only when the solution is basic, not acidic. And the best catalyst for the oxygen-producing electrode, iridium, is both rare and expensive, which makes it unsuitable for commercial-scale devices.

Light industry

Another entrant in the artificial-photosynthesis field is the Japan Technological Research Association of Artificial Photosynthetic Chemical Process (ARPChem), a consortium of universities and companies that has government funding comparable to JCAP's grant — although over ten years rather than five — to develop a bag-based approach. Kazunari Domen, a chemist at the University of Tokyo and leader of ARPChem's water-splitting group, says that one of the companies in the consortium has been working on a membrane to separate the hydrogen and oxygen products.
Other projects are making photoabsorbers from organic molecules, rather than semiconductors. Some are building molecular assemblies inspired directly by the photosynthetic apparatus of plants. And in the past few years, a class of materials called perovskites has drawn the attention of the solar-photovoltaic community for its high energy-conversion efficiency; some researchers think that the materials also have potential in artificial photosynthesis.
Daniel Nocera, a chemist at Harvard University in Cambridge, Massachusetts, launched Sun Catalytix to develop his work on a low-cost catalyst. But the company announced last year that it has put that research on hold to pursue a less challenging product with prospects of turning a profit for investors sooner. The decision underscores the challenges of bringing a commercially viable artificial-photosynthesis system to market.


 

Artificial Leaf. Will it be the Energy source of the future ?

9:47 PM Artificial leaf, energy, fuel, solar energy, splitting water