• Energy Research
• 7. Clean energy close
• DE close
• UA close
• Chinese Academy of Sciences close

Project: GCOS Earth Heat Inventory - A study under the Global Climate Observing System (GCOS) concerted international effort to update the Earth heat inventory (EHI), and presents an updated international assessment of ocean warming estimates, and new and updated estimates of heat gain in the atmosphere, cryosphere and land over the period from 1960 to present. Summary: The file “GCOS_EHI_1960-2020_Earth_Heat_Inventory_Ocean_Heat_Content_data.nc” contains a consistent long-term Earth system heat inventory over the period 1960-2020. Human-induced atmospheric composition changes cause a radiative imbalance at the top-of-atmosphere which is driving global warming. Understanding the heat gain of the Earth system from this accumulated heat – and particularly how much and where the heat is distributed in the Earth system - is fundamental to understanding how this affects warming oceans, atmosphere and land, rising temperatures and sea level, and loss of grounded and floating ice, which are fundamental concerns for society. This dataset is based on a study under the Global Climate Observing System (GCOS) concerted international effort to update the Earth heat inventory published in von Schuckmann et al. (2020), and presents an updated international assessment of ocean warming estimates, and new and updated estimates of heat gain in the atmosphere, cryosphere and land over the period 1960-2020. The dataset also contains estimates for global ocean heat content over 1960-2020 for different depth layers, i.e., 0-300m, 0-700m, 700-2000m, 0-2000m, 2000-bottom, which are described in von Schuckmann et al. (2022). This version includes an update of heat storage of global ocean heat content, where one additional product (Li et al., 2022) had been included to the initial estimate. The Earth heat inventory had been updated accordingly, considering also the update for continental heat content (Cuesta-Valero et al., 2023).

Long-duration gamma-ray bursts (GRBs) release copious amounts of energy across the entire electromagnetic spectrum, and so provide a window into the process of black hole formation from the collapse of massive stars. Previous early optical observations of even the most exceptional GRBs (990123 and 030329) lacked both the temporal resolution to probe the optical flash in detail and the accuracy needed to trace the transition from the prompt emission within the outflow to external shocks caused by interaction with the progenitor environment. Here we report observations of the extraordinarily bright prompt optical and gamma-ray emission of GRB 080319B that provide diagnostics within seconds of its formation, followed by broadband observations of the afterglow decay that continued for weeks. We show that the prompt emission stems from a single physical region, implying an extremely relativistic outflow that propagates within the narrow inner core of a two-component jet.

Abstract Operational stability is becoming one of the most crucial parameters for commercialization of perovskite solar cells (PSCs). However the stability issue of PSCs is currently far from being resolved due to complicated and still unclear degradations. In this work, we systematically demonstrate the degradation of metal cathode PSCs under operation conditions. Discussions about influence of intrinsic factors i.e. light illumination, voltage and current, on device degradation are conducted. It is concluded that metal cathode stripping/plating behavior (electrochemical metallization effect) due to current together with perovskite degradation could dominate the device degradation. It is deduced that electrochemical cell in the PSC system could be formed by metal/counter electrodes and perovskite electrolyte. Both cells accelerate degradation of metal electrode and perovskite in working conditions, hence device degradation. These insights into the degradation and mechanisms can help further understand the working principle and solve the instability problem of perovskite-based optoelectronic devices.

Energy dissipation in the plasma edge is key for future tokamaks. The potential of neon as radiating seeding species in disconnected double null (DDN) configuration is assessed in EAST discharges in high confinement mode (H-mode). As the separation between the two separatrices in the studied DDN discharges is minimum 1.5 cm, the configuration is effectively a single null configuration, and the benefits of the double null topology are minimal. Neon seeding, on the other hand, has a favourable effect: both the target heat flux and the divertor temperature decrease more than five-fold with increased seeding rate in high-recycling conditions. Interpretive edge plasma simulations with SOLPS-ITER in support of ongoing transport analysis are presented. For the unseeded case the numerical results agree with the experimental data within a factor two for the target temperature conditions and measured neutral pressures in the active divertor. The key for achieving good agreement is a suitable selection of coefficients for anomalous transport and neutral conductances between the upper cryopump and the main chamber.

Wind power can help ensure regional energy security and also mitigate both global greenhouse gas and local air pollutant emissions, leading to co-benefits. With rapid installation of wind power equipment, it is critical to uncover the embodied emissions of greenhouse gas and air pollutants from wind power sector so that emission mitigation costs can be compared with a typical coal-fired power plant. In order to reach such a target, we conduct a life cycle analysis for wind power sector by using the Chinese inventory standards. Wind farms only release 1/40 of the total CO2 emissions that would be produced by the coal power system for the same amount of power generation, which is equal to 97.48% of CO2 emissions reduction. Comparing with coal power system, wind farms can also significantly reduce air pollutants (SO2, NOX and PM10), leading to 80.38%, 57.31% and 30.91% of SO2, NOX and PM10 emissions reduction, respectively. By considering both recycling and disposal, wind power system could reduce 2.74×104 t of CO2 emissions, 5.65×104 kg of NOX emissions, 2.95×105 kg of SO2 emissions and 7.97×104 kg of PM10 emissions throughout its life cycle. In terms of mitigation cost, a wind farm could benefit 37.14 US$ from mitigating 1ton of CO2 emissions. The mitigation cost rates of air pollutants were 7.94 US$/kg of SO2, 10.79 US$/kg of NOx, and 80.79 US$/kg of PM10.Our research results strongly support the development of wind power so that more environmental benefits can be gained. However, decentralized wind power developers should consider not only project locations close to the demand of electricity and wind resources, but also the convenient transportation for construction and recycling, while centralized wind power developers should focus on incorporating wind power into the grids in order to avoid wind power loss.

Abstract Recently discovered novel π-SnS (cubic phase) has gained much attention due to suitable nature for several optoelectronic devices and thermoelectric applications. Local density approximation (LDA) and generalized gradient approximation (GGA) with ultra-soft pseudo-potential (UPP) technique within density functional theory (DFT) are used to study the structural, electronic, optical, and elastic properties of π-SnS. The structural properties show good consistency with previous results. The band structure study shows that its nature is indirect with bandgap 1.073/1.37 eV (LDA/GGA). The calculated elastic constants satisfy the Born stability criteria which are determined for the first time as per our knowledge. On the basis of Voigt-Reuss-Hill approximation, bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, Lame’s coefficients, average sound velocity and Debye temperature are determined. In LDA/GGA the value of Bulk modulus is estimated 55.32/20.98 GPa, which is in good agreement to that calculated with Birch-Murnaghan equation of state (EOS). The 2D and 3D surface visualization of bulk, shear and Young’s moduli suggest that π-SnS is elastically anisotropic. In LDA/GGA the value of Debye temperature (θD) is estimated as 361.01/299.39 K. The thermal conductivity of π-SnS could be high due to high Debye temperature (θD) relative to α-SnS (θD ∼ 270 K). Additionally, for the first time transversal and longitudinal wave velocities in [1 0 0], [1 1 0] and [1 1 1] directions are calculated. In the view of present studies π-SnS could be suitable candidate for exploitation in optoelectronic, thermoelectric and energy storage devices.

AbstractFused‐ring electron donors boost the efficiency of organic solar cells (OSCs), but they suffer from high cost and low yield for their large synthetic complexity (SC > 30%). Herein, the authors develop a series of simple non‐fused‐ring electron donors, PF1 and PF2, which alternately consist of furan‐3‐carboxylate and 2,2′‐bithiophene. Note that PF1 and PF2 present very small SC of 9.7% for their inexpensive raw materials, facile synthesis, and high synthetic yield. Compared to their all‐thiophene‐backbone counterpart PT‐E, two new polymers feature larger conjugated plane, resulting in higher hole mobility for them, especially a value up to ≈10−4 cm2 V−1·s for PF2 with longer alkyl side chain. Meanwhile, PF1 and PF2 exhibit larger dielectric constant and deeper electronic energy level versus PT‐E. Benefiting from the better physicochemical properties, the efficiencies of PF1‐ and PF2‐based devices are improved by ≈16.7% and ≈71.3% relative to that PT‐E‐based devices, respectively. Furthermore, the optimized PF2‐based devices with introducing PC71BM as the third component deliver a higher efficiency of 12.40%. The work not only indicates that furan‐3‐carboxylate is a simple yet efficient building block for constructing non‐fused‐ring polymers but also provides a promising electron donor PF2 for the low‐cost production of OSCs.

Reinjection of geothermal water into reservoirs could help maintain the reservoir pressure but may lead to thermal breakthrough. Therefore, the calculation of an optimal distance between the production and reinjection wells is required to balance the changes of pressure and temperature in the reservoir. In this work, a procedure has been designed to optimize well-doublet placement by integrating numerical simulations and economic analyses. The procedure is composed of two subsequent steps, which makes the method more flexible. The first step is the numerical simulation, which incorporates the geological and physical processes. The second step is to optimize the cost by varying the well distance. An example shows that it is better to place the reinjection well in the downstream of the production well. A distance of 400 m between the wells was found to be optimal for the given scenario. Through a further comparison with economic parameters in different countries, the optimal distance was found to be more relevant to the ratio of heat price over electricity than a single parameter for heat or electricity prices.