Clean Hydrogen Research Articles

Quantifying delayed climate mitigation benefits in electric and hydrogen fuel cell vehicle deployment for sustainable mobility

In the fight against climate change, transitioning to green transport is imperative. Our study evaluates the Greenhouse Gas Emission Breakeven Time (GBET) for Electric Vehicles (EVs) and Hydrogen Fuel Cell Vehicles (HFCVs) in China, the largest auto market globally. Emissions vary significantly across Chinese provinces due to differences in grid carbon intensity, hydrogen production methods, and vehicle usage. EVs show more than a 50 % difference in Well-to-Wheel (WTW) emissions regionally, which is also true for HFCVs, although they exhibit less interprovincial variability, suggesting a steadier reduction trend. These findings stress the need for regional considerations in Life Cycle Assessment (LCA) and introduce the concept of “climate debt” to evaluate the delayed benefits of emission reductions. HFCVs, benefiting from cleaner hydrogen production advancements, can repay their climate debt about 60 % quicker than EVs, presenting a caveat: the risk of short-term emission spikes if the initial greenhouse gas surplus isn't efficiently compensated. We found that the average GBET for EV-Cars is about 3.39 years and for EV-SUVs (Sports Utility Vehicle), 4.23 years. Comparatively, HFCV-Cars and HFCV-SUVs have shorter average GBETs of roughly 1.39 and 1.43 years, respectively, indicating faster environmental paybacks. Conclusively, our study endorses regional assessment frameworks and highlights HFCVs' role in China's path to a low-carbon future. It is essential for sustainable mobility stakeholders to adapt vehicle technology adoption and related policies to local energy contexts to meet climate goals. Our research provides crucial insights into how green vehicles can achieve emission targets, advocating for a localized approach in sustainable transportation strategies.

Feasibility of Scaling up the Cost-Competitive and Clean Electrolytic Hydrogen Supply in China

Scaling up clean hydrogen supply in the near future is critical to achieving China’s hydrogen development target. This study established an electrolytic hydrogen development mechanism considering the generation mix and operation optimization of power systems with access to hydrogen. Based on the incremental cost principle, we quantified the provincial and national clean hydrogen production cost performance levels in 2030. The results indicated that this mechanism could effectively reduce the production cost of clean hydrogen in most provinces, with a national average value of less than 2 USD·kg−1 at the 40-megaton hydrogen supply scale. Provincial cooperation via power transmission lines could further reduce the production cost to 1.72 USD·kg−1. However, performance is affected by the potential distribution of hydrogen demand. From the supply side, competitiveness of the mechanism is limited to clean hydrogen production, while from the demand side, it could help electrolytic hydrogen fulfil a more significant role. This study could provide a solution for the ambitious development of renewables and the hydrogen economy in China.

Obtaining clean hydrogen from waste plastics

Obtaining clean hydrogen from waste plastics

Feasibility analysis of virtual clean hydrogen plant platform: A case study on energy policy in S. Korea using stochastic programming

In S. Korea, high-density renewable and high-density load areas are separate. This separation has led to increased transmission constraints. As both Renewable Energy Source (RES) penetration and power demand simultaneously increase, RES saturation occurs. This phenomenon reduces both the benefits of power transactions and the acceptance of RES. Addressing this issue requires actions from Independent Power Producers (IPP) and policymakers. This paper suggests a Virtual Clean Hydrogen Plant (VCHP) platform design that consolidates the Photovoltaic (PV) energy from high-density renewable areas into a single power plant. The platform converts excess energy, generated by PV due to transmission constraints, into hydrogen and supplies it to the high-density load areas. The South Korean government plans to introduce a Clean Hydrogen Portfolio Standard (CHPS), which offers a fixed premium (FP) to private power generators that provide power through clean hydrogen. Consequently, the proposed benefit structure of the VCHP platform includes an FP, settled through CHPS. This paper's design and operation algorithm for the VCHP platform incorporates stochastic programming to analyze PV operation and deterministic optimization for the optimal scheduling of Fuel Cells (FC) that provide power and heat to high-density load areas. The simulation results demonstrate that the minimum subsidy required for CHPS benefits varies depending on how PV-coupled P2G technology is utilized. Specifically, engaging in net metering with VCHP over the course of one month can establish a cost-effective benefit structure, verified to require a subsidy ranging from a minimum of 0.2036 $/kWh to a maximum of 0.2416 $/kWh.

Modulating built-in electric field via Bi-VO4-Fe interfacial bridges to enhance charge separation for efficient photoelectrochemical water splitting

Photoelectrochemical (PEC) water splitting on semiconductor electrodes is considered to be one of the important ways to produce clean and sustainable hydrogen fuel, which is a great help in solving energy and environmental problems. Bismuth vanadate (BiVO4) as a promising photoanode for photoelectrochemical water splitting still suffers from poor charge separation efficiency and photo-induced self-corrosion. Herein, we develop heterojunction-rich photoanodes composed of BiVO4 and iron vanadate (FeVO4), coated with nickel iron oxide (NiFeOx/FeVO4/BiVO4). The formation of the interface between BiVO4 and FeVO4 (Bi-VO4-Fe bridges) enhances the interfacial interaction, resulting in improved performance. Meanwhile, high-conductivity FeVO4 and NiFeOx oxygen evolution co-catalysts effectively enhance bulk electron/hole separation, interface water’s kinetics and photostability. Concurrently, the optimized NiFeOx/FeVO4/BiVO4 possesses a remarkable photocurrent density of 5.59 mA/cm2 at 1.23 V versus reversible hydrogen electrode (vs RHE) under AM 1.5G (Air Mass 1.5 Global) simulated sunlight, accompanied by superior stability without any decreased of its photocurrent density after 14 h. This work not only reveals the crucial role of built-in electric field in BiVO4-based photoanode during PEC water splitting, but also provides a new guide to the design of efficient photoanode for PEC.

Towards building clean hydrogen supply chain network in Iran for future domestic demand and exports. Part I: Prioritization of scenarios

The first part of the current study highlights the importance of developing a clean hydrogen supply chain (CHSC) in Iran to enhance energy security and contribute to global efforts towards sustainable energy transition. Depending on whether the focus is on domestic consumption or export of hydrogen, the study provides valuable insights into the prioritization of CHSC development pathways via multi-criteria decision-making tools (AHP, AHOP-TOPSIS, and AHP-VIKOR). The results show that for domestic hydrogen consumption (internal scenario), the best path of the supply chain includes blue hydrogen from steam methane reforming coupled with carbon capture and storage, H2-carriers (ammonia and methanol), natural gas grid for transportation and distribution, and industry sector as the end user. In the external scenario, however, the best path of the CHSC consists of green hydrogen production based on solar energy, and the other parts of the path include liquid hydrogen as the storage method, ship as the distribution and transportation, and industrial sector as the end user. By identifying the most suitable methods and technologies for each stage of the supply chain, this paper offers a comprehensive analysis that can guide decision-making in CHSC development.

Research progress on electronic and active site engineering of cobalt‐based electrocatalysts for oxygen evolution reaction

AbstractElectrocatalytic water splitting has been identified as a potential candidate for producing clean hydrogen energy with zero carbon emission. However, the sluggish kinetics of oxygen evolution reaction on the anode side of the water‐splitting device significantly hinders its practical applications. Generally, the efficiency of oxygen evolution processes depends greatly on the availability of cost‐effective catalysts with high activity and selectivity. In recent years, extensive theoretical and experimental studies have demonstrated that cobalt (Co)‐based nanomaterials, especially low‐dimensional Co‐based nanomaterials with a huge specific surface area and abundant unsaturated active sites, have emerged as versatile electrocatalysts for oxygen evolution reactions, and thus, great progress has been made in the rational design and synthesis of Co‐based nanomaterials for electrocatalytic oxygen evolution reactions. Considering the remarkable progress in this area, in this timely review, we highlight the most recent developments in Co‐based nanomaterials relating to their dimensional control, defect regulation (conductivity), electronic structure regulation, and so forth. Furthermore, a brief conclusion about recent progress achieved in oxygen evolution on Co‐based nanomaterials, as well as an outlook on future research challenges, is given.

A high-efficiency photocatalytic hydrogen evolution system based on nickel-quinoxaline dithiolate complexes and water-soluble CdSe quantum dots

Photocatalytic water splitting of water for hydrogen evolution is one of the effective methods to obtain clean hydrogen energy. In the present work, the following materials were synthesized: two nickel quinoxaline thiolate complexes [NBu4]2 [Ni(qdt)2] (1, Bu = n-butyl, qdt = quinoxaline-dithiol), [NBu4]2 [Ni(qdt)2(NO2)2] (2) and water-soluble MPA-CdSe quantum dots (MPA-CdSe QDs, MPA = 3-mercaptopropionic acid). Subsequently, an efficient three-component photocatalytic hybrid system for hydrogen evolution was developed and tested under visible light irradiation, in which one of the target complex 1 or 2 was used as the catalyst, triethylamine (TEA) was used as the sacrificial electron donor, and MPA-CdSe QDs were used as the light harvesting reagent. The turnover numbers (TON) for H2 evolution of 8974 (vs. complex 1) and 6532 (vs. complex 2) were obtained under the optimal conditions with TEA concentration of 5 %, pH = 12, and concentration of complex 1 or 2 of 1 × 10−5 mol L−1 after 13 h of irradiation (λ > 420 nm) in pure water. The mechanism investigation indicated that critical steps of hydrogen production was formation of hydride intermediates Ni(II)-H and Ni(I)-H spices, followed by the reaction of two Ni(II)-H or Ni(I)-H species with protons generating H2 molecules and regenerating the catalyst Ni(II).

Unlocking the potential of hematite photoanodes in acidic electrolytes: Boosting performance with ultra‐small IrOx nanoparticles for efficient water splitting

AbstractPhotoelectrochemical (PEC) water splitting offers a promising route for harnessing solar energy to produce clean hydrogen fuel sustainably. A major hurdle has been boosting the performance of photoanode materials within acidic electrolytes—a critical aspect for advancing PEC technology. In response to this challenge, we report a method to augment the efficacy of hematite photoanodes under acidic conditions by anchoring IrOx nanoparticles, replete with hydroxyl groups, onto their surface. A remarkable and steady photocurrent density of 1.71 mA cm−2 at 1.23 V versus RHE was achieved, marking a significant leap in PEC efficiency of hematite in acidic media. The introduction of the IrOx layer notably expanded the electrochemically active surface area for more active sites, fostering improved charge separation and transfer. It also served as an effective hole capture layer, drawing photogenerated holes from hematite to facilitate swift migration to the active sites for the water oxidation process. This advancement has the potential to fully harness the capabilities of hematite photoanodes in acidic environments, thereby smoothing the path toward more effective and sustainable hydrogen production through PEC water splitting.

On-site hydrogen refuelling station techno-economic model for a fleet of fuel cell buses

Fuel cell electric buses (FCBs) have proven to be a technically viable solution for transportation, owing to various advantages, such as reliability, simplicity, better energy efficiency, and quietness of operation. However, large-scale adoption of FCBs is hindered by the lack of extensive and structured infrastructure and the high cost of clean hydrogen. Many studies agree that one of the significant contributors to the lack of competitiveness of green hydrogen is the cost of electricity for its production, followed by transportation costs. On the one hand, to reduce the investment cost of the electrolyzer, high operating hours should be achieved; on the other, as the number of operating hours decreases, the impact of the electricity costs declines. This paper presents an innovative algorithm for a scalable hydrogen refuelling station (HRS) capable of successfully matching and identifying the most cost-efficient levelized cost of hydrogen (LCOH) produced via electrolysis and connected to the grid, based on the HRS components' cost curves and the hourly average electricity price profile. The objective is to identify the least-cost range of LCOH by considering both the electric energy and the investment costs associated with a hydrogen demand given by different FCB sizes and electrolyzer rated powers. In addition, sensitivity analyses have been conducted to quantify the technology cost margins, and a cost comparison between the refuelling of an FCB fleet and the recharging infrastructure required for an equivalent fleet of Battery Electric Buse (BEB) has been performed. An LCOH of around 10.5 €/kg varying from 12 €/kg (2 FCB) to 10.2 €/kg (30 FCB) has been found for the best-optimized configurations. The final major conclusion of this paper is that FCB technology is currently not economically competitive. Still, a cost contraction of the electric energy price and the electrolyzer capital investment would lead to a 50% decrease in the LCOH. Furthermore, increasing renewable energies into the grid may shift the electricity cost curve, resulting in higher prices when the BEB recharging demand is more significant. This impact, in addition to the peak power load and longer recharging times, might contribute to bridging the gap with FCBs.

A systems thinking approach to reimagining innovation models: The example of clean hydrogen

AbstractAs global temperatures, ocean heat and greenhouse gases reach record levels, transitioning to renewable energy systems offers hope for climate stabilisation. Globally, renewable capacity rose by 50% from 2022 to 2023. Clean hydrogen is attracting strong investment, yet its development is challenging as it requires supply chain‐wide innovation. Sustainably transitioning to hydrogen will require thinking and acting systemically, as opposed to current business‐as‐usual innovation. Whilst hinting at non‐linear relations and feedback loops, prevailing representations of innovation theories remain largely devoid of the feedback structures evident in transitioning socio‐technical systems. In this paper, generational innovation theories are recast as causal loop diagrams (CLDs), and the Success to the Successful archetype is modified to reflect the multi‐level perspective on transition theory. The outcome is twofold: to promote thinking systemically when innovating and diagnosing issues, and to show how CLDs can help elucidate the factors and interactions influencing hydrogen's trajectory.

Changeable Active Sites by Pr Doping CuSA-TiO2 Photocatalyst for Excellent Hydrogen Production.

Photocatalytic water splitting for clean hydrogen production has been a very attractive research field for decades. However, the insightful understanding of the actual active sites and their impact on catalytic performance is still ambiguous. Herein, a Pr-doped TiO2-supported Cu single atom (SA) photocatalyst is successfully synthesized (noted as Cu/Pr-TiO2). It is found that Pr dopants passivate the formation of oxygen vacancies, promoting the density of photogenerated electrons on the CuSAs, and optimizing the electronic structure and H* adsorption behavior on the CuSA active sites. The photocatalytic hydrogen evolution rate of the obtained Cu/Pr-TiO2 catalyst reaches 32.88mmolg-1h-1, 2.3 times higher than the Cu/TiO2. Innovatively, the excellent catalytic activity and performance is attributed to the active sites change from O atoms to CuSAs after Pr doping is found. This work provides new insight for understanding the accurate roles of single atoms in photocatalytic water splitting.

Optimal coordination of power to gas-linked energy systems: Focused on energy policy in South Korea

In this paper, the role of Power to Gas (P2G) technology in securing contributions from policy and economic perspectives is explored. The potential of P2G-linked energy systems to enhance the output of uncontrollable Renewable Energy Sources (RES) is examined, thereby ensuring more effective power rates from RES and achieving policy-mandated clean hydrogen production targets. From the perspective of policymakers, the integration of P2G technology represents a significant advancement toward achieving policy objectives. Furthermore, this paper investigates how new business models leveraging P2G technology can develop innovative benefit structures and strengthen economic contributions. The feasibility of P2G integration is analyzed from the viewpoints of policymakers, who aim to achieve policy goals, and Energy eXchange Aggregators (EXA), the investment entities responsible for the practical implementation of P2G technology. The research findings confirm that as the capacity of RES increases, the performance of P2G technology significantly improves. Compared to systems not utilizing P2G, the application of P2G technology results in an increase of up to 25 % in the maximum effective power rate from RES and a numerical improvement of approximately 22 % in the benefits derived from RES. While this paper focuses on energy policy factors in South Korea, its findings and implications can be extended to a global context, assuming a mandatory increase in the share of clean hydrogen production and RES globally in the future.

Advancing Hematite Photoanodes for Photoelectrochemical Water Splitting: The Impact of g‐C3N4 Supported Ni‐CoP on Photogenerated Hole Dynamics

AbstractThe increasing demand for clean hydrogen necessitates the rapid development of efficient photoanodes to catalyze the water oxidation half‐reaction effectively. Here a strategy is introduced to fabricate photoanodes that synergistically combine and leverage the properties of porous Ti‐doped hematite (Ti‐Fe2O3) and graphitic carbon nitride (g‐C3N4) nanosheets anchored with in situ grown Ni‐doped CoP co‐catalyst (Ni‐CoP). The resulting hybrid photoanodes exhibit >7 times higher photocurrent density at +1.23 VRHE compared with Ti‐Fe2O3 photoanodes. Comprehensive characterization techniques, including ambient photoemission spectroscopy, intensity‐modulated photocurrent spectroscopy, and transient absorption spectroscopy complementarily reveal the key impact of g‐C3N4 in these composites with enhanced solar oxygen evolution reaction: The incorporation of g‐C3N4 leads to enhanced charge separation through a type‐II heterojunction, thereby increasing the hole flux at the surface, and extending the charge carrier lifetime to the ms‐s range needed for water oxidation. Additionally, g‐C3N4 facilitates efficient transfer of photogenerated holes to the fine Ni‐CoP nanoparticles confined in the graphitic matrix for a boosted oxygen evolution reaction. These findings highlight the advantages of complex heterostructure photoanodes and demonstrate a new application of g‐C3N4 as a multifunctional support of co‐catalysts for future photoanodes with enhanced performance.

Development of Transition Metal Phosphates NiCoP/NF and Evaluation of Their Hydrogen Evolution Properties

Energy and the environment are one of the most important global issues in the 21st century. In order to avoid the excessive destruction of the environment and human settlements by fossil fuels, and achieve sustainable development of the Earth, clean energy carrier hydrogen shows its application value. Facing the challenges in preparing transition metal phosphides, in this study, transition metal salts and urea were used as raw materials to react under hydrothermal conditions. The transition metal basic carbonate NiCo2(CO3)1.5OH3 was grown in situ on nickel-foam (NF) substrates. After low-temperature phosphating treatment, NiCoP alloy phosphide electrocatalysts (NiCoP/NF) grown on nickel-foam substrates were obtained. The electrochemical hydrogen evolution performance was tested in 1 mol/L KOH alkaline electrolyte solution. Experiments show, NiCoP/NF heterostructure catalyst has excellent hydrogen evolution performance. In an alkaline medium, the overpotential required to obtain the catalytic current density of 10 mA/cm2 is only 93 mV, and the Tafel slope is 118 mV/dec. This is largely due to: 1) the good dispersion of NiCoP/NF nano-catalyst on the Nickel Foam substrate increased the number of active sites exposed; 2) the heterostructure promotes the electron interaction between NiCoP and NF; 3) theoretical calculations show that the construction of NiCoP/NF heterostructure can effectively reduce the dissociation barrier of water, promote the dissociation of water, the kinetic reaction process of electrocatalytic hydrogen evolution is accelerated. Therefore, the construction of NiCoP/NF nanostructured heterogeneous catalysts enriches the application of non-noble metal nanomaterials in the field of hydrogen production from water electrolysis.

Techno-economic analysis of a novel concept for the combination of methane pyrolysis in molten salt with heliostat solar field

Methane pyrolysis has emerged as a promising low-carbon hydrogen production method, serving as a bridge from conventional fossil fuels to renewable energies (REs). A recent technique for sustainable hydrogen production involves the process of methane pyrolysis in molten salt. To better understand the potential of sustainable turquoise hydrogen production, this paper presents a techno-economic assessment of methane pyrolysis in molten salt combined with a high-temperature heliostat solar field. In addition, a high-temperature thermal energy storage (HTES) unit is utilized to ensure uninterrupted hydrogen production during periods of solar unavailability, thereby contributing to the economic viability of the overall system. The proposed system can produce about 9 tons of H2/day and 27 tons of solid carbon/day with a round-trip efficiency of 49.8 % and a levelized cost of hydrogen (LCOH) of 1.93 $/kg. To further decarbonize the process, the feasibility of utilizing REs as the source of electricity for the HTES was analyzed, yielding a synergistic achievement of clean and economic hydrogen production. This configuration resulted in a LCOH of 1.25 $/kg, after including the United States (US) clean hydrogen production tax incentives. The proposed system shows the potential to achieve the US Department of Energy target of 1 $/kg of hydrogen with a 20 % reduction in the cost of RE infrastructure.

Laser-Printed Photoanode: Femtosecond Laser-Induced Crystalline Phase Transformation of WO3 Nanorods for Space-Efficient and Flexible Thin-Film Solar Water-Splitting Cells.

Despite its potential for clean hydrogen harvesting, photoelectrochemical (PEC) water-splitting cells face challenges in commercialization, particularly related its harvesting performance and productivity at an industrial scale. Herein, a facile fabrication method of flexible thin-film photoanode for PEC water-splitting to overcome these limitations, based on laser processing technologies, is proposed. Laser-induced graphene, a carbon structure produced through direct laser writing carbonization (DLWC), plays a dual role: a flexible and stable current collector and a substrate for the hydrothermal synthesis of tungsten trioxide (WO3) nanorods (NRs). To facilitate water-splitting, a femtosecond-pulsed laser (fs laser) is focused on the WO3 NRs, converting their crystalline phase from pristine orthorhombic to monoclinic structure without thermal damage. With NiFe layered double hydroxide (LDH) catalyst, the flexible thin-film photoanode exhibits good PEC performance (1.46mAcm-2 at 1.23 VRHE) and retains ≈90% of its performance after 3000 bending cycles. With its excellent mechanical properties, the flexible photoanode can be operated in various shapes with different curvatures, enabling space-efficient PEC water-splitting by loading larger photoanode within a given space. This study is expected to contribute to the advancement of large-scale solar water-splitting cells, introducing a new approach to enhance H2/O2 production and expand its application range.

Design and modeling of a co-flow reactor for turquoise hydrogen production

This work focuses on the design of a reactor for producing clean hydrogen from methane pyrolysis in the form of the so-called “turquoise hydrogen”. In addition to its simple geometry, the fundamental concept and the main novelty of the proposed method rely on using part of the methane to produce the required heat needed for the thermal decomposition of methane (TDM). The reactor configuration for hydrogen production is shown to produce significant advantages in terms of greenhouse gas (GHG) emissions. A reactive flow CFD model incorporating also soot formation mechanism has been first developed and validated with experimental results available in the literature and then used to design and characterize the performances of proposed reactor configuration. 3D CFD simulations have been carried out to predict the behavior of the reactor configuration; a sensitivity analysis is used for clearing the aspect related to key environmental parameters, e.g., the global warming impact (GWI). The real potential of the proposed design resides in the low emissions and high efficiency with which hydrogen is produced at the various operating conditions (very flexible reactor), albeit subject to the presence of carbon by-product. This suggests that this type of methane conversion system could be a good substitute for the most common hydrogen production technologies.

Integrated Heterogeneous Engineering with the Vacancy Defect of Porous CoPv-MoxPv Nanosheets for an Accelerated Hydrogen Evolution Reaction.

Electrochemical water splitting is a possible way of realizing sustainable and clean hydrogen production but is challenging, because a highly active and durable electrocatalyst is essential. In this work, we integrated heterogeneous engineering and vacancy defect strategies to design and fabricate a heterostructure electrocatalyst (CoPv-MoxPv/CNT) with abundant phosphorus vacancies attached to carbon nanotubes (CNTs). The vacancy defects enabled the optimization of the electronic structure; thereby, the electron-rich low-valent metal sites enhanced the ability of nonmetallic P to capture proton H. Meanwhile, the heterogeneous interface between bimetallic phosphides and CNTs realized rapid electron transfer. In addition, the Co, Mo, and P active species in the electrocatalytic process exposed increased amounts of active sites featuring porous nanosheet structures, which facilitated the adsorption of reaction intermediates and thus enhanced the hydrogen evolution reaction performance. In particular, the optimized CoPv-MoxPv/CNT catalyst possesses an overpotential of 138 mV at a current density of 10 mA cm-2 and long-term stability for 24 h. This work offers insights and possibilities for the engineering and exploration of transition metal-based electrocatalysts through combining multiple synergistic strategies.

Three strategies to revive teetering clean hydrogen dreams

A global effort is underway to realize long-held visions of a diversified clean hydrogen (H2) economy. In the United States, the Department of Energy has selected seven clean H2 hub proposals into which it plans to invest $7 billion, along with another $1 billion to stimulate demand for the molecules. Coupled with generous production subsidies, these moves are intended to support early-movers to prove business models, initiate the build-out of distribution infrastructure, and catalyze further scale-up efforts. Major public support programs are also underway in Europe, Asia, the Middle East, North Africa, and Australia. Despite this unprecedented level of public funding, there is a growing risk that follow-on commercial adoption could be mostly limited to substitution in existing uses, new entrants will struggle to gain traction, and private capital will remain on the sidelines for emerging applications. Drawing on insights from senior stakeholders from across the clean H2 value chain and investment community, we explain why the long-term prospects for most clean H2 use-cases remain moribund, and show how public support can address the underlying “system-level” gaps that must also be overcome to truly unlock large-scale growth. In particular, there is an opportunity and need for public support to help resolve three underlying issues: (i) clarifying fit with the broader clean energy ecosystem; (ii) bridging “chicken-and-egg” barriers; and (iii) harnessing incumbency without being captured by it.