Climate change: 4 storage systems that may help fulfill Elon Musk’s dream

Clean energy can help reduce global emissions — but without energy storage systems, it could cause chaos.

During Tesla’s September 2020 “Battery Day” presentation, CEO Elon Musk outlined a plan to massively increase battery production and enable the transition toward renewables. Sources like solar energy and wind power sound good, but they’ll only produce energy at certain times of the day. It’s no good trying to power a house at night if all your energy is from solar, for example.

“That unstable network grid system is supplied with intermittent renewables,” Jonas Eklind, CEO of energy storage firm Azelio, tells Inverse. “This together really is a recipe for chaos.”

Want to know more about what we’ll need to tackle the clean energy transition, why long-duration energy storage is vital, and how Eklind envisions the future energy grid? Read the full interview, only in MUSK READS+.

So what is the solution? Musk’s proposal was to massively increase battery production.

• To fully electrify transportation, battery production for electric vehicles would need to increase 100-fold above current levels, estimated at 0.1 Terawatt-hours, to reach 10 Terawatt-hours.
• To electrify other high energy use industries, battery production for applications other than electric vehicles needs to jump 1,600-fold above current levels, estimated at 0.006 Terawatt-hours, to reach 10 Terawatt-hours.

But there’s a wide variety of energy storage systems out there, all of which can be used to facilitate what the International Energy Agency described as a “complete transformation of the global energy system.”

Here are a few of the energy storage solutions out there, including a few that could beat lithium-ion on key metrics like cost and longer-duration storage.

4. Lithium-ion batteries — Tesla’s favored means of energy storage. The United States Environmental and Energy Study Institute claims that lithium-ion batteries account for 90 percent of battery storage used in the global grid today.

Large-scale installations include Tesla’s South Australia battery, finished in December 2017, offering 100 megawatts of storage capacity. But that battery only offers 129 megawatt-hours, which means that it can only supply its full 100 megawatts of capacity for just over one hour. Great for balancing the grid’s workload — tests show the battery saved the South Australia grid — but not so great for supplying energy for much longer.

3. Pumped hydropower — The current reigning champion. The United States Environmental and Energy Study Institute notes that pumped hydro currently accounts for 95 percent of the United States’ utility-scale energy storage.

Note that pumped hydro is not classed as a battery, which uses chemicals in a power pack to store electricity. Instead, hydro pumps water from a low reservoir into a high reservoir. It’s released when it’s needed, and the energy is used to move a turbine and power a generator.

These can run for a bit longer. The Energy Storage Association claim they can typically supply power for six to 20 hour. In 2017 they supplied around two percent, or 23 gigawatts, of the total electricity supply system.

2. Thermal energy — The less popular one. A phase change material is used to move from solid to liquid as heat is applied, storing the energy. When the energy is needed again, the heat is released and the material returns to a solid.

Azelio has developed the TES.POD with this use in mind. The pod heats up an aluminum alloy to around 600 degrees Celsius, and then the heat energy is transferred as required.

Although Azelio’s pod can supply 13 hours of electricity, it only started construction on its first commercial installation in February 2021, making it one of the less prevalent systems on the list.

Thermal energy storage can also combine with concentrated solar panels, which focus the sun’s rays onto a receiver. This can be used to melt salt, which is then stored ready as it’s needed.

1. Compressed air — Another potential storage system. This idea takes in air, compresses it into tanks or underground caves, then releases it when it’s needed.

“Nothing that exists or is in development can store energy as well, and as cheaply, as compressed air,” Seamus Garvey, professor of dynamics at the University of Nottingham, wrote in October 2018. Garvey noted, however, that the technology is “grossly undervalued.”

Perhaps the biggest issue, Garvey notes, is that it has a similar problem to pumped hydro: it’s better suited for long-term energy storage. For short-term responses, the lithium-ion battery may still reign supreme.

Far from a single solution for every situation, energy storage of the future may require a wide range of ideas — especially if intermittent sources are going to play a big role in the future.

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