LEADERSHIP
Faculty Co-Director
Faculty Co-Director
Managing Director
REPORT WRITERS
Philaphon Sayavong PhD Candidate Department of Chemistry Stanford University
Sofia Catalina PhD Candidate
Materials Science & Engineering Stanford University
Sang Cheol Kim PhD Candidate
Materials Science & Engineering Stanford University
PhD Candidate
Materials Science & Engineering Stanford University
Yi Cui
Will Chueh
Jimmy Chen
Louisa Greenburg
8:30AM - 9:00AM
9:00AM - 10:15AM
STORAGEX ANNUAL CONFERENCE AGENDA
May 3rd, 2022, 8:30AM - 6:30PM PST MacKenzie Room, Huang Engineering Center, Stanford University
WELCOME
PROFESSOR YI CUI, Director, Precourt Intitute for Energy
PROFESSOR WILL CHUEH, Co-Director, StorageX Initiative
PANEL 1: CIRCULAR ECONOMY / SUPPLY CHAIN
Presenter:
PROFESSOR WILL TARPEH, Stanford University
Panelists:
YUAN GAO, Board Director, Lithium Americas Corporation
KERSTIN SCHIERLE-ARNDT, Vice President Research Inorganic Materials and Synthesis, BASF
STEVEN CAI, CTO, Gotion
VIVAS KUMAR, CEO & Co-Founder, Mitra Chem
10:15AM - 10:30AM
10:30AM - 11:45AM
11:45AM - 1:00PM
1:00PM - 2:15PM
BREAK
PANEL 2: CHARGING FOR MOBILITY
Presenter:
PROFESSOR YI CUI
Moderator:
PROFESSOR WILL CHUEH
Panelists:
JIM CUSHING, General Manager, Applied Materials
MADHUR BOLOOR, Manager, Toyota
HEINO SOMMER, Director of Development, CellForce Group
IONEL STEFAN, CTO, Amprius
LUNCH
PANEL 3: LONG DURATION STORAGE
Presenter:
PROFESSOR ARUN MAJUMDAR, Jay Precourt Provostial Chair Professor, Stanford University
Panelists:
DAN REICHER, Senior Research Scholar, Stanford Woods Institute for Environment
MATEO JARAMILLO, Co-founder & CEO, Form Energy
ANDREW PONEC, Co-founder & CEO, Antora
FONG WAN, Senior Vice President of Energy Policy & Procurement, PG&E
CLYDE LOUTAN, Principal of Renewable Energy Integration, CAISO
2:15PM - 3:45PM
STORAGEX ANNUAL CONFERENCE AGENDA
May 3rd, 2022, 8:30AM - 6:30PM PST MacKenzie Room, Huang Engineering Center, Stanford University
STANFORD HEADLINE RESEARCH
SLAC, Johanna Nelson Weker
YI CUI LAB, Fang Liu
BAO RESEARCH GROUP, Zhiao Yu
SIMONA ONORI’S GROUP, Muhammad Aadil Khan
TARPEH GROUP, Sam Bunke
CHUEH GROUP, Grace Busse
3:45PM - 4:00PM
4:00PM - 4:40PM
4:40PM - 5:10PM
4:45PM - 5:30PM
5:10PM - 6:30PM
BREAK
ENERGY STORAGE START-UPS
NOON ENERGY - Ultra low-cost carbon battery for long-duration storage (LDS), Chris Graves, Founder & CEO
BLUE CURRENT - Silicon Elastic composite solid-state battery, Ben Eiref, CEO
AIONICS - AI/ML for discovering new materials, Austin Sendek, Co-Founder & CEO
ENERVENUE - Ni-Hydrogen battery for LDS, Brad Dore, Senior Director of Marketing
ANTHRO ENERGY- Novel safe polymer electrolyte, Joe Papp, CTO
POSH ROBOTICS - Universal, scalable, and safe battery packs renewal, Wesley Zheng, Founder & CEO
RENEWELL - Gravitational LDS, Kemp Gregory, Co-Founder and CEO
FIRESIDE CHAT
DREW BAGLINO, Senior Vice President, TESLA
STUDENTS NETWORKING / RECRUITING
GENERAL RECEPTION
FIRESIDE CHAT WITH DREW BAGLINO
Moderated by Yi Cui and Will Chueh, StorageX Co-Faculty Directors
The StorageX Initiative Annual Conference concluded with a Fireside Chat with Drew Bagliano (CTO, Tesla), Yi Cui (Director, Precourt Institute for Energy, Stanford University), and William Chueh (Associate Professor, Stanford University, Faculty Director, Stanford StorageX Initiative). In this Fireside Chat, these leaders and experts in the energy storage field discussed the most exciting developments and the most pressing challenges to meeting a 300TWh energy storage goal and how academia and industry can partner to accelerate an electrified clean energy transition. The panelists emphasized how the future of energy in the United States and beyond is one of innovation, technical challenges, and manufacturing complications. As the electrification of cars, buildings, and the electric grid itself becomes paramount to addressing climate change, an estimated 300-500 Terawatt-hours (TWh) of energy storage is needed to account for the intermittency of renewable energy sources. The world’s current energy storage capacity is in the single digits of Terawatt-hours. In order to reach the 300-500TWh
goals in the next twenty years, an enormous amount of growth in energy storage technologies, from basic science to mining and refining the raw materials to manufacturing battery cells to designing battery packs for safety and longevity. These areas of development are both broad and deep and will require the partnership of academia, industry, and governmental and regulatory agencies to bring about this change. Yi Cui poses the question: How can we scale up? Drew Bagliano has dedicated his career to the development of scalable battery technology, and as he describes the challenges the energy storage industry faces in the next twenty years, two words come up again and again: mining and refining. Current lithium-ion batteries (LIBs) rely on a highly refined transition metal cathode, which introduces a massive challenge of mining and materials availability. Additionally, the graphite anode and electrolyte originate from byproducts of petrochemical processes. Thus far, the acquisition of battery materials has occurred on the coattails of other materials industries.
However, to continue with the exponential growth of LIBs, the battery industry must develop its own processes to source all of the components needed for scalable development. Drew describes the battery raw materials supply chain as being the fundamental bottleneck and biggest risk area. Without an independent supply of the necessary components to LIBs, further development will be curtailed by materials availability. The critical issues of mining and refining battery materials also present exciting areas for development to improve the way these raw materials are obtained. For example, lithium mining has many areas of improvement, including better ways to extract lithium from brines and water, more extensible resins for ion exchange membranes for purifying lithium, oil field lithium extraction, removing fossil fuel inputs from the lithium refining process, and sequestering CO2 in the lithium extraction process. There is extensive ground to cover, and academic
and industry partnerships in the often overlooked areas of mining and refining will be critical to the development of a dedicated battery supply chain. Even with a reliable supply chain for the Li-ion battery chemistry, there are still abundance, cost, and ethical roadblocks to reach 300TWh of energy storage. As such, a “Lithium or bust” mindset may not be feasible, and the development of alternative chemistries is an exciting area of research. Sodiumion batteries (NIBs) are often considered as a sisterchemistry to lithium-ion batteries, as they also rely on the intercalation of the working ion into a carbon host structure. While they typically have higher cost and lower energy density, they also deliver better safety and could reach similar performance to LIBs while using more abundantly available chemicals. Drew mentions that if NIB performance can rival LIB’s, then using the sodium-based chemistry for grid-scale energy storage, where energy density is not as critical, would greatly reduce the pressure put on the lithium industry. While not discussed in depth in this session, the development of other electrochemical energy storage devices such as metal-air batteries and flow batteries and of mechanical energy storage are additional cuttingedge areas of development. The energy storage landscape of a 300TWh system will likely be greatly varied, with many technologies meeting many different use cases. Will Chueh noted that in his tenure as a professor, he has seen the interests of students transition from working on cool science to working on science that matters.
Thus the question was posed to Drew: What are the questions and capabilities that research universities can uniquely contribute? Drew notes that the problems that industry works on in their own research and development are not necessarily headline grabbing or flashy, but are still important problems. In industry, the problem might be one of ensuring an airtight seal over many years or perfecting the performance of a pump. Engineering issues like sealing, maintaining head pressure, and materials swelling are important to confidently establish the lifetime of batteries. Academia has the ability to accelerate the pace of iteration, enabling products to get better and costs to get lower over time. For example, FEA analysis done in academia has hugely improved the electric motor. Industry research and development can also greatly benefit from the investment of time, energy, and capital in analytical tools specifically built for the investigation of batteries and electrolyzers. In this way, academic and industry partnerships benefit both institutions and the energy storage community as a whole, academia providing scientific breakthroughs and detailed understandings of underlying mechanisms
and industry providing high-quality, highthroughput energy storage design for reproducibility and performance. Concluding, the panelists agreed that addressing big problems like global-scale electrification requires not only a cohesive effort between academia, industry, and government, but most importantly an understanding of the true bottlenecks. To reach 300TWh of energy storage, major efforts in the mining and refining of lithium ion battery components, developing alternative battery chemistries, and commitment to working together are necessary.
PANEL 1: CIRCULAR ECONOMY / SUPPLY CHAIN
The first panel of the StorageX Initiative Annual Conference on the circular economy and supply chain began with an opening talk by Prof. Will Tarpeh. The Biden administration recently allocated $3.16B to support the infrastructure of domestic manufacturing and supply chain. As such, there is a growing emphasis to build sustainable supply chains to keep pace with the growing battery industry. However, currently 95% of lithium-ion batteries (LIBs) end up in the landfill, which can cause pollution issues and the loss of valuable metals such as lithium, cobalt and nickel. Recycling of metals is especially important when the demand for lithium is expected to outpace the supply, and the gap needs to be filled through other means—one solution being recycling. For example, we discovered that recycling LIBs provide much higher value than conventionally recycled plastics and recycled cans. Therefore, converting the linear economy into a circular economy is integral to the sustainability and the economics of the battery industry. There are many ways to recycle batteries. Pyrometallurgy uses
heat to disintegrate the battery into its components. This method is easy to scale up, but has high energy demand, high cost and loss of metals. Hydrometallurgy uses aqueous solutions to separate metals, which has high recovery rates and product purity, but uses corrosive solutions that can cause environmental concerns. Direct recycling recovers materials without decomposition, which retains the original structure and therefore can be cost effective, but also involves complicated separation and post-treatment processes. There are several start -up companies working on these various methods reinventing battery recycling to be more energy efficient and practical. After the opening talk, the first panel discussion with leaders in the battery industry took place. Panelists included Steven Cai (CTO of Gotion), Vivas Kumar (CEO and co-founder of Mitra Chem), Kerstin Schierle-Arndt (Vice President of Research at BASF), and Yuan Gao (Board of Directors at Lithium Americas).
The first topic of discussion was on the opportunities and barriers to the transition from a conventional to circular economy. Kumar remarked that there are new opportunities that emerge as the volume increases. For example, lithium iron phosphate (LFP) materials were deemed to be too low in value for recycling. However, the economics change as the production changes in scale. LFP production volume is growing 25% y/y, and now there are research efforts into recycling LFP. As the battery industry grows, new opportunities for recycling will emerge. Schierle-Arndt highlighted the consensus that our community has on the importance of recycling as a driving force towards a circular economy. This involves pressure from the public as well as government regulations, which will eventually drive the industry to a more sustainable one. She stressed that the challenge is implementation. The transition necessitates large CapEx investments and that the challenge is implementation. The transition necessitates large CapEx investments and commitment from corporations and government. Implementation is important because scale-up will open doors for additional innovation. Gao added another perspective that the current supply chain has many inefficiencies that can in turn provide opportunities for innovation. For example, when he was working at FMC in the mid-90’s producing about 30 tons of cathode materials per month and the company was considered a major player. Now, the global cathode market has grown to the scale of millions of tons per year and by 2030, each major player will need to produce at least a million tons to be considered a major player. As volume increases,
the impact of inefficiencies becomes magnified. For example, only a fraction of the energy input during the calcination step is used in heating up the materials. These inefficiencies can be opportunities, where innovations can lead to more efficient processes. Cai urged that battery cell and pack design need to take into account recycling and reuse for a system-level design. For example, the reuse of automotive packs for grid-scale storage applications needs special design considerations that enable easy disassembly and reassembly. He also commented that uncertainties such as government regulations (for example, treating battery packs as a hazard will increase transportation costs) as well as volatile metal prices makes recycling a challenge from an economic point of view. The panel discussion moved onto a second topic, which was one engaging various stakeholders such as government and clients. Gao commented that cooperation with automakers is important, as understanding a battery pack is instrumental to recycling. Information on the design and the components of the pack is important to recycling, which makes cooperation with automakers a critical step to recycling.
Schierle-Arndt agreed that cooperation is key, and the fact that many parties including the OEMs are committed to recycling is a big opportunity for recycling. However, issues such as confidentiality remain as challenges that need to be parsed out.
Cai commented on creative business strategies as a solution to engaging various stakeholders.
As an example, he mentioned Gotion’s case of cooperation with a power generation company to exchange electricity used in graphite production for grid-scale energy storage systems. He commented that energy is the biggest cost factor in manufacturing graphite and in many parts of the world with significant renewable energy generation, electricity is discarded to waste because of surplus generation. Cooperation such as this can be drivers to carbon neutrality. Kumar added that sharing of information across regions is also important to making recycling more efficient and practical. Feedstocks of used batteries come from around the globe whereas the production sites are focused in particular regions, which makes information sharing across countries and continents is key to making recycling more efficient and practical. The discussion turned to questions from the audience, and the first question was on what makes a site attractive for building facilities for recycling. Kumar remarked that access to cheap power, particularly renewable electricity, is a key consideration, and SchierleArndt added that site-selection is a multifaceted problem, where factors such as materials supply chain, business opportunities and partnerships are important. Following the question on lessons that can be learned from lead-acid battery recycling, Gao had an interesting insight that maturity is a key factor. Because LIB market is growing fast, supply and demand of used batteries are not matched, and there will always be batteries manufactured from new materials. Another factor he raised was government regulation, which pushed the recycling of leadacid battery and may be a valid driving force
for lithium-ion counterparts. Cai also added that the small size of lead-acid batteries enabled carowners to return and recycle the batteries with financial benefits. However, for LIBs the size makes it difficult for individuals to recycle, which means that institutions must play bigger role. Also, he stressed the importance the design of consumer electronics; because laptop and smartphone batteries are not designed to be disassembled by consumers, it makes recycling much more difficult. Another question was on the role of academic battery research. Cai commented that building safer batteries can help the industry in many different aspects, such as battery transportation and recycling. He also added that data-driven approaches could be developed to identify battery user locations, and the information could be used in deciding the battery collection sites. Gao highlighted the importance of fundamental understanding. The complexity of the battery has led to the industry R&D practice being more of an art than science. He believes that deeper understanding of the fundamentals can make the development process more efficient. The last question was on the possibility of sodium-ion batteries, which utilize abundant metals such as Ti, Fe, and Mn, resolving the sustainability problem. Gao commented that as lithium prices go up, sodium can be an alternative. However, he believes that sodium cannot replace lithium in all applications due to lower energy density and high temperature cyclability.
PANEL 2: CHARGING FOR MOBILITY
The second panel discussion at the StorageX Initiative Annual Conference, titled “Charging for Mobility”, considered the significance and implication of battery charging in the path to electrification of transportation from different perspectives. To start off the discussion, Prof. Yi Cui (Director, Precourt Institute for Energy, Stanford University) outlined key areas of focus that are crucial for the electrification of transportation. He stresses that battery fast-charging (5 minutes of charging to full charge) is a multifaceted issue involving different aspects of research, ranging from battery cell- and pack- level engineering to charging station design. Afterwards, he handed over the discussion to the panelists. This includes experts from different key industries, including panel moderator Prof. William Chueh (Associate Professor, Stanford University, Faculty Director, Stanford StorageX Initiative), Jim Cushing (General Manager, Energy Storage Solutions, Applied Materials), Madhur Boloor (Manager, Carbon Neutral Program at Toyota Research Institute), Heino Sommer (Director
of Development, Cellforce Group) and Ionel Stefan (Chief Technology Officer, Amprius). Prof. Chueh (Moderator) started the panel discussion by talking about what fast charging means from the EV consumer’s perspective. According to Mr. Boloor and Mr. Sommer, commercial EV consumers are generally more concerned about charging time after purchase, instead of range. Overall, Mr. Boloor stated that there is a general push, both from public investments and legislative support, for fast charging capabilities that can achieve full charge after about 30 minutes of charging. However, different consumer groups may have vastly different needs from one another. Mr. Sommer stated that the customers in the highperformance EV market prefer < 10 min of charging time to reach full state of charge. This indicates that while fast charging is generally desired, it strongly depends on the use case scenarios and consumer groups. In addition to consumer’s needs, all panelists agreed that the language used to communicate charging capabilities with customers can be less ambiguous.
Even within the industry itself, there is no concrete definition distinguishing slow charging, fast charging, and extreme fast charging from one another. The metrics used by the industry to measure charging rate are generally too complicated for consumers to comprehend (e.g. c-rate, charging time per % battery capacity, MW power). Instead, Mr. Sommar and Boloor both suggested that a more intuitive metric like miles/min should be used to inform consumers about charging capabilities. Overall, all panelists agree that FC can be made more accessible to consumers through improvements in charging infrastructure and communication. Another important topic that came up during the discussion is about charging infrastructure for fast charging capabilities. Panelists agree that fast charging is not only limited by battery cell architecture, but also current available EV charging infrastructure as well. For instance, Mr. Sommer stated that battery cells being developed by his company can reach full charge within 12 minutes of fast charging. However, they realized there is no available charging station in the world that can reach the charging power required for their cell architecture. In fact, such fast-charging stations can be as much as 10 times more expensive to implement compared to slower charging stations, according to Mr. Boloor. This means that it is important to drive down the cost of stations capable of fast charging to make it more affordable for consumers to operate. Another great point brought up by the panelists is the standardization of charging stations. Standardization is very important for developers as it removes another layer of complexity in the implementation of
charging stations. For example, standardizing the plug-type used for charging have been shown to ease deployments of charging stations in the European market, according to Mr. Boloor. He stated that this has made charging more accessible and seamless for the consumers of EVs. Aside from the charging station infrastructure, fast-charging can also significantly affect power supply at grid-scale level. High power charging can be a problem, as it can be demanding and unpredictable for the grid power supply. Mr. Sommer and Mr. Boloor both suggested that a way to circumvent this issue is to implement smart charging at strategic time periods of the day to alleviate the energy demand on the grid. Another solution suggested by Mr. Stefan and Mr. Cushing is to provide customers with incentives to charge during time periods when energy is the cleanest and low in demand. This would not only alleviate the energy demand on the grid, but also minimize the overall carbon footprint for the whole process. A major factor to consider for battery fast charging is the cell chemistry and architecture. There are many tradeoffs to consider in order to achieve fast charging at the battery cell design level. For instance, cell components will need to be thinner to accommodate fast charging. This means that the energy density of the battery (therefore range) will have to suffer, according to Mr. Stefan.
On the other hand, Mr. Cushing suggested that if the cells can achieve sustainable fast charging capabilities, EVs may not need to rely on high energy batteries as much to achieve long range. This is because charging would be less time consuming for EV consumers.
He further suggested that this could in fact enable entry level commercial EVs to be more competitive, as they generally have smaller battery and range to lower costs. Other tradeoffs that come with fast charging are safety and battery health. Mr. Stefan stated that charging at high rate can degrade batteries faster, decreasing its cycle and calendar life. In addition, he said that fast charging can make battery management systems more complex. This is because the battery would heat up more when fast charging, requiring a more sophisticated battery cell cooling system to avoid thermal runaway. In addition to cell architecture designs, Mr. Stefan and Mr. Sommer both agree that switching the anode material of the battery to Silicon would be beneficial for fast charging. Silicon has significantly higher specific capacity compared to current carbonbased anode, allowing thinner electrodes to be achieved without sacrificing EV range as much. In fact, Mr. Sommer believes that Silicon-based anode technology will soon be widely implemented into commercial battery packs within the next three years. Overall, panelists agree that there are still room to improve to minimize the tradeoffs that come with fast charging, especially the safety aspect of the problem. Fast charging is a complex topic that requires further research and development in multiple fields ranging from cell chemistry and battery pack architecture to designs of charging and grid infrastructure. Panelists agree that it is a very challenging problem that needs optimization at the systems level to make fast charging sustainable, efficient, and safe. Looking forward, Prof. Chueh believes that the amount of data that are being
gathered from the increasing deployments of EV charging stations will help inform providers with useful insights on their use case profiles. This will help strategic deployment of charging stations to enable a more sustainable and accessible EV charging experience.
PANEL 3: LONG DURATION STORAGE
The Grid is Changing
In the third panel of the day, Arun Majumdar, the Jay Precourt Provostial Chair Professor at Stanford University, moderated a panel on long duration storage, one of the most demanding issues we are facing in the clean energy transition. Majumdar kicked off the panel by detailing how the grid is changing. For the last hundred years, the grid’s architecture has remained largely unchanged; turbo machinery generates electricity that goes to transmission lines, to substations, to distribution networks and to the customer. This had been a oneway process with balancing done in real-time, using frequency as a proxy. Jurisdictional boundaries were created around this paradigm, with wholesale markets on the transmission side that are regulated federally. On the retail side, there is state regulation and electricity utilities, such as PG&E. Panelist Fong Wan, Senior Vice President of Energy Policy & Procurement at PG&E, emphasized the simplicity of this one-way energy flow process. He was able to baseload renewables, use gas units over evening hours, and use Helms pumped storage. Now,
Majumdar stated, as the United States looks for clean energy to play an increasingly large role, the grid is changing dramatically. Majumdar informed the audience about initial goals of 50% renewable energy in the electric grid, with some calling for ultimate renewable penetration of up to 80-100%. Yet, the grid was never designed for fluctuating generation. As a result, we see duck curves, meaning there is extensive generation in the middle of the day and a massive ramp up when the sun goes down in the evening, causing all kinds of issues on the grid. On the other end of the grid, Majumdar noted that we are seeing different use patterns such as more electric vehicles coming on, whose load when charging can be about 5-10 times that of a single home on average. In addition, with other systems like distributed generation from solar, systems can be connected to the cloud and can provide services on the grid. Wan emphasized the challenge of the duck curve.
Then, customers are drawing back power overnight when there is no longer any solar. Tesla power packs and electric loads lead to worries about big spikes in power needs. Majumdar added that the regulatory environment and technology is all coming along at the same time while we try to adapt to and embrace more renewable energy on the grid. Majumdar highlighted that as we go to higher penetration of renewables, cost of storage must come down. As we approach 80% penetration, we will have some occasions where 100 hours of storage or more are needed, and with even deeper penetration, storage demands will be even more extreme. Today, the Lithium-ion battery is about $100/kWh in capital cost, but storage technology may need to get below $10/kWh to enable higher penetration of renewables. Notably, Majumdar adds, the market and performance requirements are always changing, and we must be able to adapt accordingly.
The Challenge of Grid Operation
Panelist Clyde Loutan outlined some key energy storage issues that he faces as Principle of Renewable Energy Integration at California ISO. Loutan stressed the need for long-term storage to address extended periods with minimal wind and solar production. For example, in January, there are often multiple cloudy, rainy days, resulting in very little wind and solar, and still a lot of snow, meaning minimal hydropower. In such a month, there is a greater reliance on thermal plants and gas units. In comparison, Loutan pointed out, months in the middle of the year have a lot of wind, solar, and snow
melt for hydro, meaning the thermal fleet must be backed down. This variability presents a tremendous challenge according to Loutan, who pointed out the importance of frequency control. He noted that with the amount of rooftop PV and grid connected solar that we see, the grid can change by about +/- 1000- 2000MW in ten minutes, which is a lot of variability. In the old days, Loutan continued, there was controllable supply and predictable demand which made for easy control. Today, from the grid perspective, variable supply and unpredictable demand make for a big challenge, forcing grid operators to be largely reactive.
Buying and Distributing Electricity in the Clean Energy Transition
Wan described his optimism for California renewables but noted that great challenges remain. Californians, Wan stated, are fortunate to have more renewable resources than anywhere in the world, and as a result, he is confident we can get our renewable numbers up, especially because prices have come down significantly in recent years. The next issue, however, is facing renewable curtailment. Wan described how PG&E first operated with renewables: most of his renewable contracts are signed with fixed prices, and PG&E pays for how much is produced. Yet, he quickly figured out that these renewables were not generating at the right times, and dispatchable features were necessary to get them to generate at the load profile required, according to the duck curve.
In his contracts, Wan stated, he cannot turn down units, and when renewables are curtailed, PG&E still pays for that energy regardless. They even ship excess renewable energy at low or negative prices during times when they do not need it themselves. Wan described the process of curtailment as “painful” but necessary to make the whole energy system balanced.
The Need for Long Duration Storage
From the perspective of the California ISO, Loutan stressed that the need for storage is tremendous, particularly to provide frequency control. If operating with a low gas fleet, downward flexibility becomes a big problem; if wind or solar picks up, there is not much to back off, leading to high frequency control problems. Loutan relayed that they control the system frequency every minute and must balance the grid every four seconds. As a
result, we need many types of storage, both long and short term, that can provide frequency control and more flexibility. Wan agreed with Loutan that long duration storage is crucial. He shared that PG&E has already been very involved in buying storage, including bringing 1000 MW of lithium-ion batteries (LIBs) online last year and another 500 MW this year. These batteries have only four-hour durations, however, leading to the question of whether PG&E should buy more LIBs. Wan believes it may be time to switch to longer duration, citing the need for batteries that can provide a longer duration of storage than LIBs can provide. While an eight-hour duration would be an improvement, Wan said that eventually we will need storage across days, months, and even seasons.
Long Duration Storage Technologies
There are many technologies that can be further developed for long-duration storage. In this panel, three options were highlighted: pumped storage, batteries, and thermal energy storage. Dan Reicher, Senior Research Scholar at Woods Institute for Environment, spoke about the exciting developments in pumped storage. Mateo Jaramillo, co-founder and CEO of Form Energy, shared his excitement about batteries, and specifically his company’s iron-air technology, for meeting long duration storage needs. Andrew Ponec, co-founder and CEO of Antora Energy, shared how his company’s thermal energy storage system can provide long duration storage for both heat and electricity in industry.
Panel moderator Majumdar noted that while these three technologies are competing in some senses, it is more likely that we will need some combination of technologies depending on need.
1. Pumped Storage Pumped storage has been well-developed, but it’s being modernized, and Dan Reicher explained how a new form of pumped storage is primed to make a big impact. Traditionally, pumped storage hydropower has been open-loop, involving a dam on a river and a reservoir at the top of a hill. Today, this form of pumped storage provides almost 90% of U.S. electricity storage. However, this method presents a large issue to the environmental community, Reicher noted, because of the need for a dam, which largely hindered further pumped storage development. Today, pumped storage is now getting a second look for several reasons. Most importantly, Reicher told the audience, there is a new pumped storage method called off-river, closed-loop pumped storage, which does not require a dam, and both reservoirs are built off-river. This improvement has brought increasing support from the river conservation community. Secondly, pumped storage can store large quantities of variable solar and wind energy. Finally, it provides the grid with many key attributes such as long duration peaking capacity, critical balancing services, energy arbitrage, and black start capability. Today, Reicher notes that there are about 90 proposed U.S. pumped storage projects in the development pipeline that would total about 80 GW of capacity. A few of these projects have gotten Federal Energy Regulatory Commission (FERC) licenses, while the rest remain in earlier
development stages. Despite the exciting potential for new pumped storage, Reicher outlined some key challenges: the need for water in a time when some U.S. regions are facing drought, major upfront capital costs, extensive timeframes for development, valuation issues in the face of electricity market uncertainty, and opposition from environmentalists and river conservationists. He does note, however, that off-river closed-loop pumped-storage recirculates the water and tends to lose very little, and that this new form is enjoying increasing support from the environmentalists after reaching a major agreement between the hydropower industry and the river conservation community in late 2020. From the audience, Jay Precourt asked how PG&E felt about these exciting developments, to which Wan replied that while he loves pumped storage, he is worried about the certainty of construction costs, and he cannot take a deal with an unknown cost structure to his regulators or his customers. Precourt believes private investors, who are more risk oriented, will be enthusiastic about pumped storage now that there will be less pushback from environmentalists in the modern system.
2. Batteries Mateo Jaramillo explained to the audience that his motivation to start Form Energy came from thinking about what kinds of energy storage would allow for the replacement of thermal resources during multi-day events without significant wind or solar power. Jaramillo and his cofounders have been developing an iron-air battery that enables the crossing point between 100-hour duration and less than $20/kWh.
Jaramillo revealed that the active material cost is less than $1/kWh, meaning the system must be designed very intelligently to drive inactive costs down. Jaramillo reported that Form Energy is on the path to commercialization, aiming for hundreds of MWs in projects by the middle of the decade to achieve a reliable, renewable, affordable electric system. Jaramillo also stressed that there is no holy grail solution to reach these metrics, so while Form Energy’s technology is being developed to provide multi-day storage cost-effectively, it also has two major tradeoffs: cycle life and efficiency. However, due to the long-duration storage capability of the system (about a week to charge and a week to discharge), Jaramillo explains they do not need to provide thousands of cycles like a LIB. And, as we curtail renewables and spill electricity all the time, Form Energy believes one should be giving up the right amount of efficiency in pursuit of the low CAPEX cost. He cited coal and natural gas, each with poor thermal efficiencies, as examples of lower efficiency systems that work for this application. Jaramillo emphasized that their long duration electrochemical storage will not work for a car or
for a laptop, but it is right for the moment today and for the future of the grid, which he believes will ultimately reach 100% penetration of renewable energy.
3. Thermal energy storage Andrew Ponec told the audience about Antora’s mission to decarbonize industry, which is responsible for over 30% of global emissions. Ponec noted that more of these emissions come from generating heat than generating electricity, so it’s important to address both halves of that problem. Ponec stated that just like we need long duration storage to turn variable renewables into consistent reliable energy, we also need long duration storage to turn variable renewables into reliable heat. The problem for electricity and heat is essentially the same, akin to solving for weather, and the same storage durations matter. Antora’s system works by taking inexpensive electricity when it’s available from wind and solar and using it to resistively heat cheap carbon blocks, storing energy in sensible heat of carbon. The carbon blocks are put in insulated blocks without heat leaking into the environment and can be stored for days or weeks.
To get the energy back out, Ponec explained, an insulated shutter on the side of that box is opened, allowing a beam of white light to exit the system. This light can do one of two things: firstly, it could be used to generate heat for industry. Or, alternatively, the light can be converted directly into electricity using a PV cell in a one-step, inexpensive, scalable process. Like Form Energy, Antora is targeting the same 100-hour duration and under $20/kWh for electricity, but Ponec highlighted that some of those costs are offset by being able to sell heat out of the same system using energy that may otherwise have been curtailed or underutilized. Risks, Bankability, and Scaling With each promising technology comes risk and the challenge to prove its reliability, especially at scale. Jaramillo shared that there are many risks when commercializing a new battery chemistry, but at Form Energy, they instead think about their mission as commercializing a bankable asset. The threshold for bankability, Jaramillo
described, is the ability to get low-cost financing to back a project. Jaramillo said that with the current need to bring new technology to market quickly, there are also new pathways to prove a technology is bankable. The LIB demonstrated that with a lot of data and testing at a system level for a wide range of operating and environmental conditions, decades of reliable performance is no longer necessary to become a bankable technology. Jaramillo also spoke about the need to reach a technology readiness level (TRL) of seven. Ponec added that Antora’s situation largely overlaps with Form Energy’s: more than just developing a new technology, they need to have a large amount of solid data. Ponec also highlighted the benefit of looking for industrial analogs that are already bankable. By incorporating such systems, such as graphitization furnaces for example, into their own processes, they can point to over twenty years of data that has already been collected, which strengthens their own data as well. Wan noted that PG&E is better off leaving innovation to others. PG&E, Wan claimed, should spec out business needs, write good contracts, and let the capital market and innovation prove the reliability of new technologies. Wan said that he is open to giving new technologies a try if he is approached with a great contract. If the other side fails to deliver, PG&E will not pay. This is different, however, than investing in large capital projects such as pumped storage, which would be much higher risk for PG&E and not a project that they would be willing to take on. Reicher agreed that such pumped storage projects would rarely be done by utilities, and instead are better suited for private developers.
Jaramillo added while Wan might sign a more speculative contract, doing a one-off contract and failing to deliver is not the goal. Form Energy is focused on building an asset that can be deployed at large-scale. Ponec emphasized a big difference between Antora and Form Energy is that Antora is going after industrial customers first, which does provide Antora with more flexibility. On the flip side, however, there is much greater offtake risk with industrial partners than with a partner such as PG&E who commits to buying electricity for a specified time. In the Q&A section, Will Chueh raised the issue of new technology often being a single much larger installation rather than hundreds of millions of units to manufacture, making it challenging to bring costs down, and he asked how this concept played into the risks of each technology. Jaramillo agreed that achieving significant scale is important for bringing down costs, but that their technology is still making cells, which then turn into modules and then packs, which get deployed in the field. Form Energy is thus actually using the same concept as LIBs and solar cells in terms of units manufactured, because it’s a concept that has been proven many times.
Ponec added that Antora’s case is very similar: using PV cells as power generation, their system closely resembles solar. They too, aim to scale cells and modules and then put everything together into the whole system, in a way that looks very similar to a utility scale solar plant. Wan added that if you can sell him a dream that might start off as more expensive for the first hundred units, but you can explain how efficiency and cost reduction can be done, PG&E will buy into the dream with you, if your dream is legitimate. To close the panel, Loutan gave a reminder to the audience: whatever technology you develop, please make sure that it something you can control.
