Battery Energy Storage – An Unsustainable Solution in a Zero Carbon Future

When most people get involved in a discussion about greener, more sustainable energy sources, they often fail to address the elephant in the room; how do you keep the lights on after sunset or when the wind stops blowing.

The world is awash with natural energy, but most is wasted even when available. And then we have the challenge of storing enough energy to power civilization when the sun isn’t shining, there’s a week-long bout of overcast weather, or the wind stops blowing.

Without an equally environmentally sustainable means to store excess energy when it is available, many green power solutions turn to battery energy storage. However, there are plenty of reasons batteries are a poor choice for reducing humanity’s carbon footprint.

Why Battery Energy Storage for Renewables is Not Sustainable

Lead-acid batteries are still in widespread use for storing solar and wind energy. However, a short service life, heavy weight, and requirement to micromanage so they don’t overcharge means that lithium-ion batteries are becoming the dominant choice over lead-acid. The lithium-ion based Tesla Powerwall is an excellent example of lithium’s growing dominance in energy storage.

The push to put more electric vehicles (EVs) on the roads is causing the demand for lithium batteries to skyrocket. Lithium is abundant in the earth’s crust, but there is a lengthy, complicated, and resource-hungry process to extract it. For instance, acquiring one metric ton of lithium requires approximately 500,000 gallons of water.

Toxic Lithium Mining

More than half of the world’s lithium supplies are found in South America’s Lithium Triangle, which encompasses parts of Chile, Bolivia, and Argentina. The metal sits just below the salt flats, which are, unfortunately, some of the driest places on earth. More than 65 per cent of Chile’s Salar de Atacama’s water supply was used for the lithium extraction process.

Of course, such dramatic water use has an extreme impact on the local farmers, who are often forced to go further afield to sustain their thirsty crops and livestock.

Straining the world’s dwindling freshwater supplies is not the only issue lithium miners face and the communities they impact. Vast quantities of hydrochloric acid are also necessary during the extraction phase.

As lithium extraction uses large evaporation pools, there is always the risk that a significant volume of hydrochloric acid and other waste products filtered out of the brine can leak into the local area’s freshwater supply. This issue is one that many Tibetans have faced over the years.

Developing countries are not the only ones at risk. For example, researchers discovered that fish populations 150 miles downstream from a Nevada lithium processing facility had been affected by toxic waste leaking into the local water system.

If you need more proof that lithium mining is too heavy a price for the environment to pay, residents in Argentina blame lithium processing plants for ruining the soil and contaminating the streams needed for irrigation and livestock. In Chile, lithium mining is responsible for creating an eerie, lifeless, alien landscape of mountains of discarded salt and canals and lakes with water that has a pretty but unnatural blue hue.

Can You Recycle Lithium Batteries?

Lithium cathodes degrade with use, so they cannot be recycled into new batteries. Roughly only 3% of Australian lithium batteries are recycled, and a significant portion are not disposed of properly. Many end up in landfills, where they can leach toxic chemicals into the soil.

Manufacturers are also secretive about the materials they use in their batteries. It’s challenging to recycle potentially dangerous chemicals when you don’t know what they are. Most recovered cells are shredded, and the metals are separated using pyrometallurgical techniques, an inefficient process that wastes a lot of lithium.

The ecological challenges we face with lithium batteries are dire as they stand now. However, consider a world that runs on electric vehicles and the many billions more batteries about to go into circulation to power them. Battery energy storage could prove to be a significant headache for the environment, especially considering they require replacing when they reach 70% efficiency (about ten years with normal use).

We expect that EVs will become another throw-away item when people are faced with the expense of putting new batteries costing many thousands of dollars into a ten-year-old vehicle.

What are the Eco-Friendly Alternatives to Battery Energy Storage?

The good news is that battery energy storage is not the only option for storing green energy. A range of technology solutions with a zero, or close to it, net carbon footprint are in the research phase or starting to enter mainstream use. Just a few of the potential candidates include:

Compressed Air Energy Storage (CAES) – Compressed air energy storage is a large scale energy storage system that uses excess electrical energy during low demand periods to inject air into a natural gas reservoir. The compressed air is allowed to escape and run turbines during peak demand.

Pumped Heat Electrical Storage (PHES) – Electrical energy drives a storage engine connected to two thermal storage compartments which transfer heat from the cold side to the hot side. Reversing the process uses the stored heat to power turbines that convert the stored energy into electricity.

Kinetic Energy Storage – Out of all the green energy solutions, flywheel energy storage is proving to be the most practical and energy-efficient. An electrical source, such as a solar panel array, spins up a heavy flywheel to store the excess electrical energy as kinetic energy. When the solar panels go dark after sunset, the flywheel energy storage switches to generator mode to keep power flowing to the grid.

Flywheel energy storage has been around for a long time, but recent technological developments were necessary before they could be considered a worthy alternative to batteries. In previous generations of flywheels, friction between the spindle and its supports would waste most of the stored kinetic energy as heat.

Today’s flywheel spindles are supported via powerful magnets and rotate inside a vacuum housing. The result is almost zero friction and a flywheel capable of spinning and supplying energy to the grid for hours rather than minutes.

Who is Leading the Way in Flywheel Energy Storage?

Amber Kinetics is a clear front runner in flywheel energy storage as a viable zero-carbon alternative to lead-acid and lithium-ion batteries. They are the only provider of grid-scale kinetic energy storage systems, delivering durable, efficient flywheels that balance energy output from green energy sources to keep electricity flowing around the clock.