IES Energy Seminar Series Synopses

Richard Laine

Speaker: Richard Laine, University of Michigan: Agricultural waste derived anode for Lithium and Sodium ion batteries

Presented 2/6/2025, internally

Synopsis by Gagan Kumar Goyal, Postdoc Research Fellow in Naval Architecture and Marine Engineering

Professor Richard Laine, from the Department of Materials Science and Engineering of the University of Michigan Ann Arbor, presented a seminar titled “Agricultural waste derived anode for Lithium and Sodium ion batteries” on 06 Feb, 2025. 

His team’s research focuses on finding clean and green energy solutions to energy intensive industrial processes with an emphasis on the utilization of Carbon capture methods, mitigating CH4 generation, and eliminating fossil fuel consumption to set off the harsh global warming effects. One catastrophic incident that presented itself in the form of the Los Angeles fires in the USA, flooding, drought, and many other related repercussions observed across the globe. The motivation is to minimize the global supply chain restriction over certain critical components such as graphite and Silicon, which make a large proportion of materials required for renewable energy implementation.

To achieve this, they develop technologies to consume agricultural waste in chemically efficient ways to generate high purity Silicon for photovoltaic (SiPV) and electronic applications and find alternatives to graphite anode material in the batteries.

He highlighted the major challenges of producing Silicon in its pure elemental form using traditional methods, which include the usage of high temperatures in the range of 1800oC to obtain metallurgical grade 95-98% pure Silicon. This is treated with Hydrochloric acid to form Silicon tetrachloride (SiCl4), which is further treated to release the Silane gas, leading to the production of Silicon suitable for PV and electronic applications. The carbon-rich processes consume a high amount of energy. Thus, the requirement of developing alternate silica sources, amorphous in nature, to produce high purity Silicon was identified. Rice hull ash (RHA) is an agricultural waste that is being used as one such source. From 1M tonnes of the rice produced, nearly 200,000 tonnes of RHA is generated, which a company in California, Wadham Energy, uses to produce 200 GW/yr of energy. The RHA is also >90% high surface area silica, and ~10% Carbon without any heavy metals. Catalytic decomposition of this RHA90 generates silica depleted RHA60 (SDRHA60), which, after a cycle in an electric arc furnace, results in 99.999% purity SiPV. However, the current industrial processes set for SiCl4 impede the adaptation of this novel process.

With regards to the battery anode material, Dr. Laine made a comparison of the battery capacity and volume expansion between the traditional graphite (372mAh/g, dV=13%), and Silicon (4200mAh/g, dV=360%). While Si may improve the capacity,  the expansion volume is not practical for the applications, making graphite the most utilized anode material, currently. SDRHA compositions with 40-65% SiO2  could be one alternate anode material which is a SiO2/carbon nanocomposite with tunable ratios. Silicon carbide (SiC) from the SDRHA60 has a layered structure that may provide access to the Lithium ions in the interstitial sites and act as a potential anode material. From electrochemical cycling results, it has been shown that after nearly 600 charge-discharge cycles, the capacity may reach 1000mAh/g (3 times that of graphite) while a hard carbon (HC) composition forms during the cycling. In addition, the volume expansion is only 1%. Although 600 cycles mean a long time to charge the battery, which may be reduced to 250 cycles with an addition of 30% graphite to the anode material. Further, various characterizations (Raman, X-ray diffraction) confirm HC in the SDRHA compositions indicating it as a potential source as well. HC is also a potential candidate for not only the Li-ion batteries (>500mAh/g capacity) but also for the N-ion batteries (>200mAh/g capacity). SDRHA40, an improved version of the previous compositions, which may reduce the number of electrochemical cycles to 60, has been developed as well.

Reflecting on the seminar, Dr. Laine’s work opens energy solutions that may cater to the sustainability requirements without compromising on the material property related necessities for  Si production and battery anode materials. The research waste is practically a free commodity, utilization of which in turn mitigates the harsh effects of its irresponsible burning and rather solves the availability issues of geo-politically linked critical material’s supply chain. His work focuses on the RHA as a source, and it would be interesting if other types of agricultural waste could be utilized as well. Overall, this may be a start to a paradigm shift to newer methods, and continuous developments should be made to prepare new and existing industries to adopt and make commercialization possible.

Speaker: Ben Hobbs, Johns Hopkins: Green Power Procurement for Real Emissions Reductions: Accounting and Modelling in Complex Policy and Market Settings

Presented 2/20/2025, hosted by Vlad Dvorkin

Synopsis by Md. Rafiul Abdussami

The seminar on “How to Procure Green Power for Real Emissions Reductions? Accounting & Modelling in Complex Policy & Market Settings” was presented on January 20, 2025, by Professor Benjamin F. Hobbs, a leading expert in environmental management and energy market analysis. The talk focused on the challenges of ensuring corporate green power procurement translates into real emissions reductions. Prof. Hobbs emphasized the complexities of accounting, market structures, and policy interactions.

At the beginning of the seminar, Prof. Hobbs outlined the motivations for corporate green procurement, driven by corporate demand for sustainability (demand pull) and the need for struggling clean energy to find market value (supply push). He highlighted that voluntary corporate procurement has contributed to 40% of U.S. Variable Renewable Energy (VRE) additions in the past decade, which shows the growing influence of corporate actions on the energy market.

A critical part of the discussion centered on emissions accounting methods, particularly the GHG Protocol’s Scope 1, 2, and 3 classifications. Prof. Hobbs demonstrated how corporate sustainability goals often rely on Renewable Energy Credits (RECs) and Power Purchase Agreements (PPAs) to reduce Scope 2 emissions. However, he warned that traditional attributional accounting methods can misrepresent the actual emissions impact of green procurement, as they fail to capture market-driven changes in the power system. Instead, he explained consequential accounting, which assesses the impact of procurement decisions on real-world emissions. He emphasized the importance of accurately representing emissions in future decisions by distinguishing between short-run and long-run marginal emissions.

The talk then explored policy frameworks for decarbonization, contrasting first-best policies (carbon pricing on Scope 1 emissions) with second-best alternatives, such as sector-specific incentives, border adjustments, and corporate sustainability mandates. While systemic carbon pricing is theoretically ideal, incomplete sectoral and geographic coverage often necessitates a patchwork of second-best policies. A key modeling insight presented in the seminar was the role of market structures in green procurement effectiveness. Prof. Hobbs explored an equilibrium model illustrating how corporate procurement can influence market dispatch and emissions, investment in new capacity, and the integration of storage solutions. A notable takeaway from this discussion was that hourly green procurement might be more effective than annual targets, but it comes with higher storage costs if the Renewable Portfolio Standard (RPS) is binding.

In the end, Prof. Hobbs emphasized that second-best policies like the GHG Protocol should not be prioritized at the expense of efficient emissions trading and carbon pricing. While corporate procurement and voluntary programs play a role, relying too heavily on them without a systemic carbon pricing mechanism can divert resources to ineffective and complex accounting mechanisms rather than actual emissions reductions. He focused on the need for reliable, cost-effective GHG offsets that accurately reflect net emissions reductions and account for displacement, leakage, and long-term investment impacts for effective green procurement and emissions tracking. He also emphasized avoiding excessive complexity in emissions accounting, which shuffles emissions between sources rather than achieving real environmental benefits. 

The seminar provided me with a compelling deep dive into the subtle reality of corporate green power procurement. While companies increasingly engage in voluntary renewable purchases, the seminar emphasized that not all procurement strategies are equally effective in achieving real decarbonization. The discussion on attributional vs. consequential emissions accounting is fascinating to me, as it challenged conventional corporate sustainability reporting and stressed the importance of systemic modeling in evaluating green power impact. I found the discussion on marginal emissions and equilibrium models quite interesting. I agree with Prof. Hobbs that market-based policies alone are insufficient without proper accounting frameworks to measure their effectiveness accurately.