Renewable Energy Storage

April.09.2012

New storage methods make renewable energy a more viable option

Renewable Energy StorageEven though renewable energy has been gaining traction in the world energy arena, progress has been slow. One of the main reasons for this is the one fatal flaw that renewable energy presents; it’s inconsistent. The wind doesn’t always blow and the sun doesn’t always shine and, even when they are producing energy, the amount and duration are not consistent. This means that to provide base load energy requirements, sources such as natural gas, coal and nuclear need to be utilized; sources that are consistent, that are cheap and that can be increased or decreased to meet demand. Now, thanks to an unlikely gooey brown liquor, all that is about to change.

Brown gets down

Brown liquor, like yellow cake, is an innocuous-sounding misnomer which deals with very scientifically advanced products. Brown liquor is the by-product of the sulfite process which is used when producing wood pulp. This process involves soaking wood chips in sulfurous acid in pressure vessels to break down the fibers in the wood and extract the lignan. The resultant brown goo is a mixture of lignan and hemicellulose. Traditionally, the brown liquor is burned to generate steam in paper mills, but scientists at Linköping University in Sweden have found a much more interesting use for it.

Grzegorz Milczarek, a researcher at the University of Poznan in Poland teamed up with Olle Inganas, a professor of biomolecular and organic electronics at the University of Linköping in Sweden to discover that brown liquor makes a pretty impressive cathode. What do cathodes have to do with renewable energy? If renewable energy is going to be a constant and reliable source of energy, we must be able to store it. Batteries, the storage devices of choice, are too expensive to make this proposition viable on a large scale. The element most responsible for the high price of batteries is the cathodes which are traditionally made from rare and expensive materials such as cobalt.

Answers from nature

When faced with the problem of creating cheap batteries, Inganas turned to nature for the answers, researching how the photosynthetic process stores the sun’s energy. Brown liquor consists mostly of the Renewable Energy Storagebroken cell walls (lignin) resulting from the pulping process. If these cell walls can be broken down even further to form quizones, or molecules that can transport electrons. Combine the quizones with a polymer known as polypyrrole, and voilà – you have the first low-cost, environmentally friendly battery.

Still in the prototype phase, the batteries need further development to make their way into the commercial market. Using batteries to store renewable energy is becoming a more attractive prospect as battery technology improves. Silicone batteries have already exponentially improved the viability of solar panel installations. Aside from increased battery capacity, silicone batteries also boast longer life spans, double the number of recharges of lead acid batteries and they are recyclable.

Alternatives to batteries

There are other options too; pumped storage hydroelectricity is a system whereby water is pumped from a low elevation reservoir to one at a higher elevation during times when electricity is cheap and plentiful. When demand outstrips supply, the water is released and flows through turbines which produce electricity.

Another storage method is to use excess energy to produce hydrogen from water and utilize it for energy creation in times when renewable energy production is low. Researchers at MIT also copied processes that occur during photosynthesis to split water molecules and create hydrogen. Professor Ernst Chain had this to say about the creation of hydrogen as a way of storing energy: “The importance of their discovery cannot be overstated since it opens up the door for developing new technologies for energy production thus reducing our dependence for fossil fuels and addressing the global climate change problem.”

Each of these methods represents exiting developments that bring renewable energy into the next generation. With countries like Germany committing to 100% renewable energy by 2050, more is being invested into research and development. All of the answers have been supplied by Mother Nature herself, which is jolly decent of her, considering.

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