Renewable energy – solar and wind – works like a charm when the wind is blowing strongly enough to whip windmill blades into a frenzy, or the sun is baking down onto strategically-placed solar panels. The trouble, of course, is that the power they produce is intermittent. Wind has an annoying habit of dying down, as does the sun in hiding behind clouds.
Harnessers of wind and solar power face another dilemma, and that is how to store the energy they produce, before it is fed into the electricity grid. A good example is what is happening in Hawaii. The island state is the ideal location for solar energy, not only because of the amount of sun it gets, but because its remoteness and lack of fossil fuels makes the cost of electricity three times the U.S. average. To cut their power bills, 10 percent of Hawaiians have installed solar panels on their roofs. All good so far.
But last year, the state’s power monopoly Heco started refusing to hook up solar panels purchased by some residents, due to fears that the grid could become swamped by a glut of mid-day power, when the sun’s rays are strongest. The same thing is happening in sun-drenched California, where the bulk of solar power is generated between noon and 4. That’s great for residents working from home, but not the majority whose energy needs peak in the evening, when lights, fridges, air conditioners and microwaves all power up around the same time.
What these states really need is a way to store this power until it’s most needed during peak loads, and to release it gradually if too much comes in at once.
One way is through pumped-hydro. The Bath County Hydro Pumped Storage Facility, in Virginia, is the largest pumped-hydro station in the world, and also its largest “battery”. Two reservoirs, one 1,200 feet above the other, act as a kind of hydroelectric dam to generate power when demand is high, and store power during low-use periods. Click here for an interesting video on how the facility works.
Pumped-hydro is proven (it's been around for over 100 years) and well-used (there are 40 such stations in the U.S.), but expensive, hard to site and even more difficult to build. The Bath County facility cost $1.6 billion, and that was in 1985.
Another alternative has more recently come to the fore, with the technology originating from a metal most have never heard of: vanadium. Named after the Norse goddess of beauty, Vanadis, vanadium's primary use is for strengthening steel. Dropping a bar of vanadium into a batch of steel allows the steelmaker to use 40 percent less material. The metal is also used in super alloys and in aerospace applications, which require 99.9 percent purity. Henry Ford used it in the first Model T.
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Chemists have discovered another use for vanadium, one whose applications are far-reaching. When an electrical current is passed through two tanks of vanadium dissolved in sulfuric acid, it creates a type of rechargeable battery called a “vanadium redox battery”. The battery's chief advantages are its stability – it can be recharged up to 20,000 times without losing performance, meaning a potential decades-long life – and it can be discharged while retaining nearly all of the vanadium electrolyte. Vanadium redox batteries are also scalable, meaning they offer nearly unlimited capacity by simply scaling up to larger storage tanks.
While the technology is still nascent and expensive, one company is charging ahead with ambitions to open the first vanadium mine in the United States and become the lynchpin of a new power storage market in North America.
American Vanadium plans to use vanadium mined from its Gibellini project in Nevada as feedstock for vanadium electrolyte used in vanadium flow batteries; last year the company showed the seriousness of its intentions by announcing a deal with Gildemeister AG. Under the agreement, American Vanadium will market and sell the German company's CellCube redox flow battery, used to recharge electric vehicles and to store solar and wind power.
Ron MacDonald, American Vanadium's former chairman, said in a 2012 interview with MINING.com that he sees energy storage as “a massive new industry, a trillion-dollar industry globally,” that has already begun in Asia and will migrate next to the United States.
As evidence, MacDonald pointed to China, which has set a target to achieve storage of 5 percent of their total electricity generation, not just renewables. He said that industry analysts have pegged anywhere between $400 billion and $1 trillion worth of investment will flow into the industry, “because these technologies are commercially feasible.”
MacDonald said that once its mine is up and running, American Vanadium will “walk the walk” by installing a 5 MW solar field. The solar energy used to run the mine would be stored in a vanadium-flow battery, utilizing mined vanadium as feedstock for the electrolyte. “We're going to be energy self-sufficient,” he predicted.
By Andrew Topf of Oilprice.com