One of the biggest challenges with using renewable energy for electricity generation—specifically wind and solar power—is intermittency. The wind doesn’t always blow and the sun doesn’t always shine. Affordable, reliable, and deployable storage is seen as the holy grail of renewable energy integration, and recent advances in storage technology are getting closer to finding it.

The current electricity grid has virtually no storage—pumped hydropower is the most prevalent, but is largely location dependent. As higher levels of solar and wind energy are added to the grid, however, storage will become increasingly fundamental to ensuring that the power supply remains stable and demand is met. Utilities and businesses around the globe are starting to use large-scale batteries to complement their renewable energy generation: in Texas, for example, Duke Energy installed a 36 megawatt lead-acid storage system to balance its wind power.

Storage system ratings

Credit: Energy Storage Association

Storage technologies not only provide utilities with grid reliability for renewable integration, but also offer additional benefits such as ancillary services, ramp rate control, frequency regulation, and peak shaving, which can lower costs and improve the performance of the transmission system. Power system operators have always had to match electricity demand with supply, and energy storage is an additional tool in their grid-management toolbox.

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batteries, CAES, compressed air energy storage, electricity, electricity grid, intermittency, lithium-ion batteries, pumped-hydro storage, renewable energy, solar power, Storage, wind power

This entry is the latest in a Worldwatch blog series on innovations in the climate and energy world.

Soon to be obsolete?

The Nissan Leaf proudly advertises that it can go 100 miles on a single charge. Chevrolet, Toyota, and other car companies have promoted their plug-in gas-electric hybrids as the more rational alternative, since you can switch to the gasoline option when you need extra range. But what if charging your electric car were as easy as filling your gas tank?

For electric vehicles to become the dominant mode of personal transportation, the charging process will have to evolve: it will need to be either much faster, or far less frequent. In a recent article in Nature Nanotechnology, scientist Paul Braun and his research team at the University of Illinois at Urbana-Champaign describe their blueprint for a new battery with a greatly reduced charging time. Their most successful lithium-ion prototype reaches a 90 percent charge in just two minutes.

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battery, electric vehicles, Innovation, lithium, lithium-ion batteries, nickel-metal hydride batteries, Nissan Leaf, technology series

Rare earth minerals and lithium: two ingredients of a clean energy future that have gotten special treatment in the media and enviro-sphere this past month. (Not to mention the essential ingredients, oil and gas, which also received some “special treatment” from the Obama Administration.) The central question with all of these resources is: Can we import enough of them to meet our energy, energy efficiency, and transport needs? And if not – there is ample risk ahead in international competition for these resources – how can we produce more of them within our borders?

If you missed some of the buzz about rare earths and lithium or are confused about details, here’s a quick and simple run-down:

Rare Earth Elements


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Molycorp’s Rare Earth operation in Mountain Pass, California

Rare Earths are a group of 17 elements with funky names (like yttrium, gadolinium, and neodymium) and similar reactive properties that make them useful for electronics, catalytic converters, and permanent magnet generators, the latter being a key technology for efficient wind turbines. Despite their many applications, rare earths – true to their name – are rarely found in economically extractable quantities, and only a few major mining operations exist across the world.

Last month, the U.S. government made known its concern about the future of rare earth supply. The House of Representatives held a hearing on the topic and focused especially on China’s dominance of rare earth production. The Department of Energy began crafting a rare earths strategy, and Congressman Mike Coffman (R-Colo.) introduced The Rare Earth Supply-Chain Technology and Resource Transformation (RESTART) Act.  

All of these initiatives called for new and diverse supports for rare earth mining within U.S. borders. Currently, only a single U.S. company has rare earth mining and separation capabilities. Molycorp, based in Mountain Pass, California (pictured), has operated intermittently in the past decade due to environmental and regulatory problems. Thus, the U.S. joins the rest of the world in near-complete dependence on China for its rare earth supply. In 2008, China supplied 96 percent of world demand for rare earths. Australia is the only other country with potentially massive stores of rare earths, but extraction there is also underdeveloped. 

Rare earths were a buzz topic in March, as cleantech advocates woke up to the great importance of these elements, which are used in renewable energy generation and energy efficiency technologies. Apart from wind turbines, rare earth-containing products include fluorescent lamps and some batteries. Now that concern over this issue has gone public and the government has been kicked into action, rare earth elements will remain a topic of intense research and debate.  

Lithium


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Lithium brine operation in Silverpeak, Nevada

Concerns over lithium supply all come back to batteries. Lithium-ion batteries are currently the most cost-effective tool for powering the massive fleet of electric cars that is supposedly on the horizon. Lithium concerns boiled to the surface recently as a slew of articles covered the massive lithium resource in Bolivia – a potential 5.4 million tons, the largest in the world and more than ten times the United States’ lithium resource. This created a buzz about Bolivia being the “Saudi Arabia” of lithium. However, Bolivia currently extracts and exports zero tons of lithium, even if the government has expressed its intention to develop a lithium industry. In a situation similar to that of rare earths, the United States has only one domestic facility that separates and produces usable lithium – the Chemetall Foote lithium brine operation (pictured).

Much like our dependence on foreign oil, the United States relies on imports to meet more than half of its lithium demand. These imports come largely from Argentina and Chile, and a small portion from China. Lithium is set to be an even hotter topic as the American-made Chevy Volt and Japanese Nissan Leaf – all-electric vehicles powered by lithium-ion batteries – hit the road in 2010.

Despite this similarity to our oil-based relationship with Saudi Arabia, the situation differs greatly in other respects. Lithium recycling technologies are on the horizon, alternatives to lithium-ion batteries are in development, and the U.S. vehicle fleet will not be fully electric for a long time. The International Energy Agency predicts that even with climate and energy legislation in place, less than 20 percent of new U.S. vehicle sales will be electric by 2030. Finally, the company American Lithium claims it is eying other parts of the U.S. Great Basin for lithium production sites.  

Besides simply ramping up domestic lithium production, the United States might also consider boosting R&D of lithium alternatives.

bolivia, China, electric vehicles, energy security, lithium-ion batteries, neodymium, rare earth elements, wind turbines