Energy storage provides continuity in alternate energy systems, supplying power when wind and sun are not available.
Batteries are second only to the solar array in cost of the photovoltaic system, and are completely necessary for reliable and continuous performance of the electrical unit.
Energy storage is expensive and with the prices of electronic controls and photovoltaic panels continually dropping, lowering battery costs is the next logical step both in the progression of technology for the reduction of initial expenditures.
The highest cost of production for a battery is the manufacture of the anode, and cathode.
Electrical current is produced by the movement of ions, namely protons and electrons; it starts when the protons flow from the anode though the electrolyte, to the cathode.
To balance this movement, the negatively charged electrons flow through an external circuit hooked to the same two electrodes and in doing so performs work.
Usually these electrodes are made of lead, zinc, nickel, or in the newer designs lithium, all are expensive elements that are not in abundant supply.
Enter lignin, one of the two main components found in wood; the other being cellulose. Lignin is found in abundance, most commonly in a by-product of the paper making process known as black liquor.
Lignin has a high concentration of a group of chemicals known as phenols and from these phenols another chemical group can be extracted.
Known as quinones these specific chemicals interested Grzegorz Milcarek, and Olle Inganas, two scientists researching organic compounds for storing charge. Quinones allow the lignin derivatives to shed a proton and store an electrical charge in its place.
Another chemical, polypyrrole holds on to that proton until the electrical charge is released and the proton returns to the quinone.
Working in conjunction, these two chemicals form the ion receptors which allow the protons and electrons to flow, creating the basis of a cathode.
Preliminary testing shows a charge density of 496 mAh/ g which when compared to a lithium system’s 344 mAh/g, is a favorable output.
With an abundant supply of cheap materials, large batteries could be developed and wind and solar farms could store energy during the day for release during those inevitable times of low energy production.
The inescapable ice on the door step handicapping these developments falls to the fact that so far only a cathode has been developed using these chemicals.
The anode question needs more research. Another proverbial wrench in the developmental gearbox lays in the rate of discharge.
The two researchers developing this technology feel that with more experimentation these deficiencies can be adequately addressed, and are not insurmountable.
Energy storage using cheap renewable biopolymer materials that are nontoxic, safer, operate in water, and can be used on an industrial scale, will help address the problem of energy storage shackling wind farms and other sources of alternate energy production.
Although nowhere near fabrication, it is worth noting, the world is not sitting on its hands, waiting for solutions to fall from the sky.
Lorne Oja is an energy consultant, power engineer and a partner in a company that installs solar panels, wind turbines and energy control products in Central Alberta. He built his first off-grid home in 2003. His column appears every second Friday in the Advocate. Contact him at: lorne@solartechnical.ca.