This paper gives an overview on the SolarPACES guideline for Bankable STE Yield Assessment which was published in January 2017 by SolarPACES. After summarizing the history of the standardization activity behind this document, on overview on the content and its key elements is given. The paper ends by addressing the various players involved in STE yield assessment and how they can make benefit from applying this guideline in their day-to-day work. The document is available for free download from SolarPACES at http://www.solarpaces.org/yield-analysis-guideline.

Given the increasing demand for sustainable agricultural practices and energy conservation, advanced technologies for electric agricultural machinery (EAM) are critically needed. This paper provides a comprehensive review and analysis of powertrain systems and energy management strategies (EMSs) for electric tractors (ETs), a key representative of EAM. Specifically, this paper: (1) outlines the current development status and research significance of ET powertrains, including single-energy powertrains (SEPs), diesel-electric hybrid powertrains (DEHPs), and hybrid energy storage systems (HESSs); (2) offers an in-depth analysis of EMS approaches—covering rule-based, optimization-based, and learning-based strategies—and evaluates their performance in terms of energy efficiency, adaptability, and cost reduction; (3) identifies future research hotspots, such as intelligent data-driven EMSs, multi-source energy integration, and advanced energy optimization algorithms to improve the adaptability, efficiency, and reliability of ET power systems. The findings of this paper highlight the critical role of hybrid powertrains and advanced EMSs in enhancing the operational range, energy efficiency, and economic viability of ETs, offering insights and guidance for the further development of sustainable agricultural technologies.

Concerning solar flux densities during the operation of a concentrated solar power tower plant, their uneven distribution on a central receiver not only leads to abrupt variations of thermal gradient on the receiver surface but also makes it possible for the receiver to break down. Specific to such problems, a “concentrating-receiver” coupling system of a 1 MWe concentrated solar power tower plant in Yanqing was selected as the research object. On this basis, a spliced heliostat model was firstly established in this paper. The model was used to investigate solar flux distribution on the receiver surface. Considering that heliostats in different positions make diverse contributions to receiver surface energy and the incidence cosines of adjacent heliostats are similar to each other, a new grouping method for heliostat fields was subsequently proposed; moreover, focal point selection criteria were designed for the receiver surface according to solar spot sizes. Finally, an optimized dispatch and operation strategy was established based on the genetic algorithm for the heliostat field. Therefore, a standard deviation of solar flux distribution can be minimized. To verify the reliability of the established model and the proposed strategy, a small-scale heliostat field was adopted to check the simulation results by means of experiments. It has been demonstrated that a heliostat field subjected to optimized dispatch makes solar flux densities distribute more uniformly on the receiver surface. Hence, the safe and steady operation of the receiver is guaranteed.

California has some of the key agricultural regions in the United States. One of these key regions, San Joaquin Valley, frequently experiences severe droughts leading to shortage of irrigation water. This has a significant impact on the agricultural based economy of the region. It is imperative to develop new strategies to reduce overall water consumption in agriculture without affecting crop yield. A large fraction of irrigation water is lost due to the evapotranspiration (ET) process in the crops and the soil. The classical Penman-Monteith model has been used in the present work to analyze the effect of different environmental variables and water saving strategies on the ET. Some of the scenarios considered show potential for significant water savings without much reduction in the amount of sunlight available to facilitate crop growth. The central idea considered in this study is the use of canopy shading to cover the crop field resulting in reduction in the ET. Among the strategies considered, the most promising strategy is to partially cover the crop field for a certain part of the day by employing a partially covering retractable canopy. Based on numerical calculations, total reduction in ET is calculated to be 37% from June to August for the partially covering retractable canopy.

The establishment of a reliable simulation system for a solar tower power plant can greatly increase the economic and safety performance of the whole system. In this paper, a dynamic model of the 1MWe Solar Tower Power Plant at Badaling in Beijing is developed based on the “STAR-90” simulation platform, including the heliostat field, the central receiver system (water/steam), etc. The dynamic behavior of the global CSP plant can be simulated. In order to verify the validity of simulation system, a complete experimental process was synchronously simulated by repeating the same operating steps based on the simulation platform, including the locations and number of heliostats, the mass flow of the feed water, etc. According to the simulation and experimental results, some important parameters are taken out to make a deep comparison. The results show that there is good alignment between the simulations and the experimental results and that the error range can be acceptable considering the error of the models. In the end, a comprehensive and deep analysis on the error source is carried out according to the comparative results.