125 research outputs found
Structural and Functional Analysis of the Reaction Center Complexes from the Photosynthetic Green Sulfur Bacteria
The reaction center (RC) complex of the green sulfur bacterium Chlorobaculum tepidum is composed of the Fenna-Matthews-Olson (FMO) antenna protein and the reaction center core (RCC) complex. The RCC complex has four subunits: PscA, PscB, PscC, and PscD. The structure of the intact and functional FMO-RCC complex was studied by chemically cross-linking the purified sample followed by biochemical and spectroscopic analysis. The interaction sites of the cross-linked complex were also studied using LC-MS/MS. A structural model is proposed based on those results. In addition, the RCC complexes were purified, both the PscA-PscC complex from the Chlorobaculum tepidum and the PscA-PscB complex from Prosthecochloris aestuarii. The intact FMO-RCC complex and the RCC complexes were further studied comparatively by steady-state and time-resolved fluorescence and femtosecond time-resolved transient absorption spectroscopies to elucidate the pathway of FMO-to-RCC inter-protein energy transfer as well as RCC intra-protein energy and electron transfer
Spatiotemporal Arbitrage of Large-Scale Portable Energy Storage for Grid Congestion Relief
Energy storage has great potential in grid congestion relief. By making
large-scale energy storage portable through trucking, its capability to address
grid congestion can be greatly enhanced. This paper explores a business model
of large-scale portable energy storage for spatiotemporal arbitrage over nodes
with congestion. We propose a spatiotemporal arbitrage model to determine the
optimal operation and transportation schedules of portable storage. To validate
the business model, we simulate the schedules of a Tesla Semi full of Tesla
Powerpack doing arbitrage over two nodes in California with local transmission
congestion. The results indicate that the contributions of portable storage to
congestion relief are much greater than that of stationary storage, and that
trucking storage can bring net profit in energy arbitrage applications.Comment: Submitted to IEEE PES GM 2019; 5 pages,4 figure
Sector coupling via hydrogen to lower the cost of energy system decarbonization
There is growing interest in hydrogen (H) use for long-duration energy
storage in a future electric grid dominated by variable renewable energy (VRE)
resources. Modelling the role of H as grid-scale energy storage, often
referred as "power-to-gas-to-power (P2G2P)" overlooks the cost-sharing and
emission benefits from using the deployed H production and storage assets
to also supply H for decarbonizing other end-use sectors where direct
electrification may be challenged. Here, we develop a generalized modelling
framework for co-optimizing energy infrastructure investment and operation
across power and transportation sectors and the supply chains of electricity
and H, while accounting for spatio-temporal variations in energy demand and
supply. Applying this sector-coupling framework to the U.S. Northeast under a
range of technology cost and carbon price scenarios, we find a greater value of
power-to-H (P2G) versus P2G2P routes. P2G provides flexible demand
response, while the extra cost and efficiency penalties of P2G2P routes make
the solution less attractive for grid balancing. The effects of sector-coupling
are significant, boosting VRE generation by 12-55% with both increased
capacities and reduced curtailments and reducing the total system cost (or
levelized costs of energy) by 6-14% under 96% decarbonization scenarios. Both
the cost savings and emission reductions from sector coupling increase with
H demand for other end-uses, more than doubling for a 96% decarbonization
scenario as H demand quadraples. Moreover, we found that the deployment of
carbon capture and storage is more cost-effective in the H sector because
of the lower cost and higher utilization rate. These findings highlight the
importance of using an integrated multi-sector energy system framework with
multiple energy vectors in planning energy system decarbonization pathways.Comment: 19 pages, 7 figure
Shaping future low-carbon energy and transportation systems: Digital technologies and applications
Digitalization and decarbonization are projected to be two major trends in the coming decades. As the already widespread process of digitalization continues to progress, especially in energy and transportation systems, massive data will be produced, and how these data could support and promote decarbonization has become a pressing concern. This paper presents a comprehensive review of digital technologies and their potential applications in low-carbon energy and transportation systems from the perspectives of infrastructure, common mechanisms and algorithms, and system-level impacts, as well as the application of digital technologies to coupled energy and transportation systems with electric vehicles. This paper also identifies corresponding challenges and future research directions, such as in the field of blockchain, digital twin, vehicle-to-grid, low-carbon computing, and data security and privacy, especially in the context of integrated energy and transportation systems
- …