Critics of solar and wind power are correct in that each is an intermittent source of power. But in more recent years the emphasis has been on batteries and other forms of energy storage to enable either of these two forms of green energy to carry the whole load. The current standard is the lithium-ion battery. But l.i. batteries have several issues that call for the world to look for better alternatives. L.I. batteries can overheat and explode if charged too rapidly. They have a limited number of charge-recharge cycles. They are flammable. Extracting the required cobalt from mines, and processing the raw materials into l.i. batteries is a highly water- and energy-intensive process. Cobalt mining all too often takes place under unsafe conditions, and using child labor. 70% of the known cobalt reserves are in one 3rd-world country – the Democratic Republic of the Congo, or DRC. 76% of l.i. batteries are produced by one country – China.
Emerging Battery and Energy Storage Technologies (Alphabetically)
Aluminum-sulfur battery. Donald Sadoway’s battery design based on aluminum, sulfur and molten salt. Known as the Avanti battery. “Aluminum-sulfur Battery Promises Low Cost Energy Storage”. www.cleantechnica.com 8/26/22. “Local Researchers Are Aiming to Create the Perfect Battery”. www.bostonglobe.com 9/26/22. The article concerns MIT’s Donald Sadoway and his Avanti battery.
Battery Storage in General. “Energy Storage is Important to Creating Affordable, Reliable, Deeply Decarbonized Electricity Systems”. www.pvbuzz.com 5/17/22. “How Energy Storage Policies Can Allow Grids to Run on Renewables”. www.climate-xchange.org 8/26/22. “Storage Technology: Five New Ways to Store Energy”. www.strive2thrive.earth 11/15/21.
Brick & Rock Batteries. Learn “How a Brick & Rock Battery is Changing Energy Storage”. www.youtube.com From Matt Ferrell’s “Undecided” Channel.
Compressed Air Energy Storage (CAES). During periods of excess power, ambient air or another gas is compressed and stored under pressure in an underground cavern or container. When electricity is required, the pressurized air is heated and expanded in an expansion turbine driving a generator for power production. www.energystorage.org/why-energy-storage/technologies/compressed-air-energy-storage-caes/ A company called Hydrostor in Toronto has developed what it calls Advanced Compressed Air Energy Storage (A-CAES). www.hydrostor.ca The McIntosh Power Plant in Alabama uses CAES as its storage technology, as does the Huntorf Plant in Germany, which dates from 1978.
Carbon Dioxide (CO2) Battery. “Energy Dome Launches World’s First CO2 Battery for Long-duration Storage of Wind and Solar Power”. www.euronews.com 9/6/22. “CO2 Battery – Long Duration Storage/Energy Dome”. www.youtube.com “Energy Dome Introduces its Carbon Dioxide Energy Storage System on Sardinia”. www.cleantechnica.com 6/10/22. Describes its 10-hour duration, and how it is made from off-the-shelf parts and equipment.
Embedded Batteries. Batteries embedded into structural materials – buildings, automobiles, etc. “Batteries of the Future are Weightless and Invisible”. www.wired.com 11/6/20.
Flow Batteries. Flow batteries work through the reaction that happens when two specialized liquids flow adjacent to each other, separated only by a thin membrane. Scaling is simply a matter of building larger tanks to keep the liquids apart until needed. Learn about Lockheed-Martin’s Grid Star Flow long-duration energy storage technology: www.lockheedmartin.com . Also: “ESS Makes 12+ Hour Flow Battery for Sustainable Energy Storage”. www.cleantechnica.com 2/11/21. “Hybrid Membrane Edges Flow Batteries Toward Grid-scale Energy Storage”. www.newatlas.com 11/11/21. “ESS Inks Largest-ever US Flow Battery Purchase With Sacramento Utility”. www.canarymedia.com 9/27/22. And learn about grid-scale energy storage at a San Diego Gas & Electric substation: “Microgrid Project Using Vanadium Redox Flow Battery”. www.pv-magazine-australia.com . While there are some variations among flow batteries, they generally share similar advantages over lithium-ion batteries. They have longer life. They provide a much longer output duration, up to 3 times that of l.i. batteries. They are non-flammable, non-toxic, and have no explosion risk. Unlimited cycle life and no capacity degradation over an expected 25-year operating life. L.I. batteries typically provide only about 7000 cycles during an expected lifetime of from 7 to 10 years. Flow batteries have a greater tolerance to a wide range of ambient temperatures, between 14F up to 140F. Flow batteries’ cost of ownership is about 40% less than with lithium-ion batteries.
Flywheel Energy Storage (FES). FES works by accelerating a rotor – the flywheel – to a very high speed and maintaining the energy in the system as rotational or kinetic energy. When energy is needed, the spinning force drives a device similar to a turbine to produce electricity, slowing the wheel’s rate of rotation. www.energystorage.org/why-energy-storage/technologies/mechanical-energy-storage/ Read the California Energy Commission Report of the subject: “Flywheel Systems for Utility Scale Energy Storage”. January 2019. Companies offering this technology include: Beacon Power www.beaconpower.com; Power-Thru www.power-thru.com; Vycon Energy www.vyconenergy.com; and Omnes Energy www.omnesenergy.com. Some key advantages of FES are low cost, low maintenance, long life (up to 175,000 full depth discharge cycles), and negligible to no environmental impact. Flywheels can bridge the gap between short-term ride-through power and long-term energy storage. Very short recharge time. Operates at between 85 – 90% efficiency.
Gravity-based Energy Storage. Gravity storage is raising something heavy up to a certain level, when energy is cheap or not in great demand, or by intermittent green energy sources, such as solar or wind, and then letting the force of gravity bring that heavy something back to ground level, generating electricity in the process. One of the oldest methods of using gravity in this way is pumped storage. Water is pumped up to a higher level; then, when power is needed, or has greater value, the water is released to flow through a turbine, generating electricity in the process. A utility-scale version of pumped storage is underway in Switzerland. This 1 gigawatt Swiss pumped storage “battery” operates on the height difference between two lakes. At full buildout it will be able to supply all the electricity needs of one million Swiss homes. See “Could This Be the Most Extreme Power Plant in the World?” at www.ge.com 6/6/16. There are numerous pumped storage facilities around the U.S.: the 400MW Gordon Butte project in Montana; the 1300MW Eagle Mountain project in California; and the 800MW Dominion Energy project in Virginia. Another way of doing this, without water, is with stacked concrete blocks. Heavy concrete blocks are raised up to a certain level, then lowered, running a generator, when power is needed. Read “India’s Largest Power Company Relies on Energy Vault”. And visit www.energyvault.com . Gravity can also be used in high-rise buildings in a manner similar to how regenerative braking recharges the battery in hybrid and electric vehicles. Read “Turning High-rise Buildings Into Batteries”. www.cleantechnica.com/2022/06/03/turning-high-rise-buildings-into-batteries/ and www.newatlas.com/energy/lift-energy-skyscraper-batteries/ 3/31/22. Companies involved in this technology include www.gravitricity.com , www.energyvault.com , and www.aresnorthamerica.com . The advantages of using gravity storage are many: gravity is a force found everywhere on earth, at all times of day and throughout every season. The pumped hydro version of gravity storage is the world-wide most common form in existence, and has been utilized for about a century. During periods of low demand, and usually, lower cost, the upper portion of the device is recharged, with either conventionally-generated power or with available renewables. Gravity-powered storage plants can respond to large electrical load changes within seconds. They are cheap to build and to operate, and are virtually indestructible. With regard to the still-evolving raised block gravity storage systems, read www.helena.org/projects/energy-vault Also: “Gravity Batteries: Any Nation Can Do It at Scale Using Rocks”. 7/27/22. www.energypost.eu Also “Gravitricity Battery Generates First Power at Edinburgh Site”. 4/21/21. www.bbc.com www.gravitricity.com
Iron-air Batteries. Form Energy (www.formenergy.com) is one of many companies seeking to develop a battery that is free of the many limitations and hazards of lithium-ion batteries. It has developed a battery which operates on iron and air. Iron is widely available around the world, as is, of course, air. A recent article in Canary Media covers the basics of iron-air batteries quite nicely: “Form Energy Wins $450M to Rust Iron for Multiday Energy Storage”. www.canarymedia.com . 10/4/22. The article describes how the company’s battery will store energy so cheaply that a power plant can deliver emissions-free energy (if the source was renewable, carbon-free energy) around the clock for days on end. Form Energy is described as graduating out of the venture capital space and is now drawing growth equity money from some massive financial organizations, including TPG Rise Climate, Singapore’s GIC, and the Pension Plan Investment Board of Canada. Also have a look at: “Form Energy to Build Novel Iron Batteries in West Virginia Steel Town”. www.canarymedia.com 10/22/22. Of note: Form Energy’s CEO is Mateo Jaramillo, who built Tesla’s energy storage business before joining forces with MIT battery expert Yet-Ming-Chiang. More on the promise of iron-air batteries: “Four Ways to Store Sunlight”. www.steelforfuel.substack.com/p/four-ways-to-store-sunlight And “Enabling a True 24/7 Carbon-Free Resource Portfolio For Great River Energy With Multi-Day Storage. www.formenergy.com
Liquid Air Energy Storage (LAES) also known as Cryogenic Energy Storage (CES). LAES/CES uses electricity to cool air until it liquifies, stores the liquid air in a tank, brings the liquid air back to a gaseous state – by exposure either to ambient air or with waste heat from an industrial process – and uses that gas to turn a turbine and generate electricity. Plants of this type can provide large-scale, long-duration energy storage, with hundreds of megawatts of output. They can use industrial waste heat and cold from widely found sources such as thermal generation plants, steel mills, and LNG terminals. LAES/CES uses existing and mature components with proven long lifetimes, performance, and O&M costs. See “Liquid Air Energy Storage (LAES)” at www.energystorage.org . The largest liquid air battery built so far, and in practical use, is located near Manchester, England UK. Read about it at “Construction Begins on World’s Biggest Liquid Air Battery” at www.theguardian.com 6/18/20. Also “Grid Battery Using Regular Old Ambient Air”. www.hackaday.com 7/24/20.
Liquid Metal Batteries. (known as the Ambri battery) Like the aluminum-sulfur (Avanti) battery described above, the Ambri battery is the result of research carried out by MIT battery whiz Donald Sadoway. His Ambri battery utilizes a liquid calcium alloy anode, molten salt electrolyte, and a cathode made of solid particles of antimony. When the cell is heated to 500C (932F), the metal and salt melt, creating a liquid metal battery. This non-flow battery has a claimed 20-year life expectancy. Because of the weight of liquid metal batteries (significantly greater than lithium-ion) they are targeted at stationary battery storage markets. For a full description of an early practical application of Prof. Sadoway’s Ambri battery, read: “TerraScale to Deploy Ambri Liquid Metal Battery at Energos Reno Project”. www.datacenterdynamics.com 11/27/20. Terrascale has also signed an agreement to provide Ambri batteries for Earth & Wire in South Africa. Keep up with the rapidly expanding adoption of this technology at www.ambri.com/news/ .
Long-Term Battery Storage at Scale. “Solving the Clean Energy and Climate Justice Puzzle”. “How Multi-Day Energy Storage Can Cost-Effectively Replace Long-Running Peakers”. From Form Energy. www.formenergy.com
Manganese & Aluminum Batteries. Batteries without lithium, cobalt, or nickel from Alsym Energy, Woburn MA. Alsym has developed a process, about which it says very little on its website, to make large-size rechargeable batteries that deliver the performance of lithium-ion at half the price. The company is selling them to many ocean shipping companies and to one automaker. “Alsym Energy Emerges From Stealth Mode” www.pv-magazine-usa.com 6/15/22. Alsym does say that its team is working to ensure that their batteries not only meet performance expectations at reduced cost, but also avoid most of the supply chain challenges associated with lithium-ion technologies. www.cleantechnica.com/2022/06/16/alsym-energy-debuts-low-cost-water-based-batteries/ 6/16/22. Also see: “New Water-based Battery”. www.cleantechnica.com 6/12/22.
Oxygen-Ion Batteries. “New Batteries That Are Safer, Cleaner, and Last Longer Than Lithium-Ion”. 5/14/23. www.thecooldown.com These are regenerative oxygen-ion batteries. Developed at the Vienna University of Technology. Also: “New Invention: The Oxygen-Ion Battery”. 3/22/23. www.eurekalert.org/news-releases/983590
Peaker Plants. Peaker plants, usually powered by fossil fuels, are activated onto the grid at times when demand is greatest, and without which, blackouts might occur. Peaker plants everywhere, however, are under siege as battery power of one sort or another is proving to be both greener and cheaper. The green energy provisions of the 2022 Inflation Reduction Act are strong incentives to deactivate peaker plants and to substitute energy storage instead. “The Drive to Replace Summer-only ‘Peaker’ Power Plants”. www.wired.com. 5/19/220. And “Report: These Rarely Used, Dirty Power Plants Could Be Cheaply Replaced by Batteries”. www.grist.org 6/11/20.
Sand Storage. More often referred to as Hot Sand Storage. Sand is found everywhere. It is dirt- (sand-) cheap. It doesn’t melt, off-gas, or create any kind of toxin or health danger. It is non-flammable. Its temperature can be raised to very high levels without incurring a phase change, as occurs with the raising of the temperature of water above the boiling point. It is highly self-insulating, and at large volumes, loses thermal energy quite slowly. As a result of these characteristics, hot sand is finding its way in many energy storage situations. In Finland, a company called Polar Night Energy is showing how well hot sand, stored in silos, works in a Finnish city’s district heating system. “First Commercial Sand-based Thermal Energy Storage is in Operation”. www.renewableenergymagazine.com 7/7/22. Or watch the video – “Dirt Simple Energy Storage” at www.youtube.com/watch?v=tm7spMGOch8 “An Italian Company is Turning Hot Sand Into Clean Energy” www.magaldi.com/en/products-solutions/csp-concentrating-solar-power All components are universally available, inexpensive, completely recyclable, eco-compatible, and highly reliable over time. The 600C hot sand produces steam which generates electricity. Want to learn more?: “New Thermal Energy Storage Methods Using Hot Sand” at www.azocleantech.com 10/7/21. And “Using Hot Sand to Store Energy”. www.cleantechnica.com 8/31/21. And www.solarpaces.org/nrel-results-support-cheap-long-duration-energy-storage-in-hot-sand/ 1/8/22.
Silicon. SC555 is a new silicon-carbon composite that can improve the energy density and charging time of the lithium-ion batteries in everything from smartphones to EVs to earbuds. Its fast-charging feature means that an EV could potentially be charged in 10 minutes. Porsche is an investor, and expects SC555 to power its EVs in 2024. An invention of Group14. See www.group14.technology/en/ . SC555 was selected by TIME Magazine for inclusion in its “Best Inventions 2022” edition. Along the same lines: Silicon Anode Battery. “New EV Battery Offers 50% More Energy Density Than Traditional Lithium-Ion Batteries”. 2/10/23. www.pv-magazine-australia.com A rapid charge can power 80% of the battery’s capacity in 10 minutes. Can undergo 1000 charge cycles while retaining nearly 90% of its original capacity. The company is Ionblox. www.ionblox.com Located in Fremont CA.
Sodium-ion Batteries. Sodium-ion batteries have many advantages over lithium-ion batteries, as explained in: “United Plans to Electrify Airport Operations With Sodium-ion Batteries”. www.canarymedia.com 11/30/22. The batteries are made by Natron Energy, of Santa Clara CA. www.natron.energy Natron states that its cells do not rely on rare earth materials like cobalt nor do they have a long, questionable supply chain like lithium. Their battery materials are mainly aluminum, iron, manganese and sodium-ions. Natron’s sodium-ion batteries have a high peak capacity, a wide temperature operating range, and the flexibility to scale quickly. The batteries can cycle 50,000 times, recharge in 8 minutes, are UL-approved, and are not a fire hazard.
Thermal Energy Storage. There are numerous ways for thermal energy to be stored and used directly as heat, converted to electricity in the grid that serves your community, or used in individual buildings or complexes of buildings. Some of these are as follows: “Thermal Batteries Could Efficiently Store Wind and Solar Power in a Renewable Grid”. www.science.org 4/13/22. “Thermophotovoltaic Efficiency of 40%”. www.nature.com 4/13/22. “A Better Heat Engine”. www.technologyreview.com 6/29/22. “Vattenfall Starts to Fill Up 200MW Thermal Storage Tower in Berlin”. www.energy-storage.news 7/4/22. “A Battery For the Grid That Stores Electricity by Heating Refractory Materials”. www.solarimpulse.com/solutions-explorer/stolect-carnot-battery Thermophotovoltaics/Thermal Battery Corporation. www.thermalbattery.com “Capturing Light From Heat at Record 40% Efficiency, NREL Makes Big Strides in Thermophotovoltaics”. www.cleantechnica.com 5/21/22. “Seasonal Underground Thermal Energy Storage”. www.hydrosolar.ca “5 Reasons Why Thermal Storage May Finally Be Set to Take Off”. www.canarymedia.com 1/23/23.
Zinc Aqueous Hybrid Cathode Battery Storage Systems. “EOS Got US $258 Million Orders for its Zinc Battery Storage in Q2 2022”. www.energy-storage.news Also, at the EOS website: “EOS Cube” www.eose.com
Zinc Batteries. “Scientists Led By an Oregon State University Researcher Have Developed a New Electrolyte That Raises the Efficiency of the Zinc Metal Anode in Zinc Batteries to Nearly 100%”. 3/26/23. www.oregonstate.edu This achievement is considered a breakthrough on the way to an alternative to lithium-ion batteries for large-scale energy storage.
3D-Printed Batteries. “3D-Printed Solid-State Battery”. 2/16/23. www.cleantechnica.com A company called Sakuu has announced that it has successfully 3D-printed solid-state batteries in custom shapes that include cooling channels. With these batteries having twice the energy density, and 30% less weight than existing Li-ion cells, they have a great ability for use in energy storage in residential and industrial applications.