Assessing Factors Influencing Solar Energy Adoption among Small and Medium Enterprises in Mzuzu City, Malawi

One of the many renewable energy sources that offer advantages is solar energy, which also lowers energy prices and promotes environmental sustainability and energy security. Despite these advantages, various barriers, such as installation costs, have prevented small and medium-sized enterprises from investigating this invention. Malawi has a significant energy shortfall such that most businesses have been hindered from their profit maximization goals. The “Photovoltaic systems” (PV) that transform sunlight into electricity are the subject of this study. This type of solar energy system is situated on the building’s roof and generally produces electricity for businesses and even homes. Solar energy offers a great impact to small and medium enterprises in Mzuzu city with a cost-effective and dependable alternative to energy that has the potential to change the game. Therefore the aim of the study was to identify factors that encourage the adoption of solar energy among small medium enterprises in the city of Mzuzu city. And to identify some of barriers faced when adopting solar energy among small and medium enterprises in the city of Mzuzu. The research approach employed in the study was a survey. A survey is a type of research methodology in which primary data is gathered from a sample using a questionnaire. When information is to be gathered from a wider sample, a survey is employed. A bigger sample size was needed in this study in order to facilitate hypothesis testing. It is advised to apply a logical approach while using the survey. The survey utilized a five-point Likert scale. The study used convenience sampling to select study participants. The sample size in this study was determined using Cochran’s sample size formula. Statistical Package for Social Sciences (SPSS) and Microsoft Excel were used for statistical analysis. About 97.2% of the participants were aware of solar as a source of energy compared to 2.8 % who were unaware. The majority of participants use solar energy for lighting only, seconded by those who use electricity. The least number of participants use solar energy for cooling only. The majority of participants 21.5% indicated partnership and collaboration as the most motivating factor for the adoption of solar energy. This was followed by technical expertise 19.1 % the least number of participants 10.8% expressed that policy and regulatory frameworks were associated with the adoption of solar energy. This study found that there are no statistically significant factors influencing barriers to the adoption of solar energy. The price of solar energy adoption was identified as the least factor associated with the acceptance or rejection of solar energy. Nonetheless, the reasons given by the homes that had embraced solar technology aligned with the findings of other studies. This survey also found that although the public was aware of solar energy, and technology, there were still a number of factors that mattered, especially for non-adopters.

A New Heat-conduction Logging Technique and its Application

The results of a heat-conduction experiment with a central point source in a sand barrel shows that the temperature of the heat source increase much faster in sand saturated with oil and air （dry sand） than in water sand. During cooling the temperature of the central heat source goes down slower in oil- or air-saturated sands than in water sands. Based on the theory of heat-conduction in porous media and the experimental results, we developed a new heat-conduction logging technique which utilizes an artificial heat source （dynamite charge or electric heater） to heat up target forma- tions in the borehole and then measure the change of temperature at a later time. Post-frac oil production is shown to be directly proportional to the size of the temperature anomaly when other reservoir parameters are fairly consistent. The method is used to evaluate potential oil production for marginal reservoirs in the FY formation in Song-Liao basin of China.

量化短期弃电风险的小湾、漫湾水电站水光互补中长期优化调度研究

随着光伏不断接入流域水电并与水电打捆送出,水光互补优化调度对现有的流域梯级水电站水库群调度工作提出了新的要求。为解决已有的中长期水电优化调度规则并不能有效避免短期水光互补联合运行弃电风险这一实际运行问题,以澜沧江小湾、漫湾水电站水光互补为例,针对近期和远期2种光伏装机容量配置场景,对小湾、漫湾水电站长系列水文资料划分来水频率,具体量化短期弃电风险并嵌套绘制中长期水光互补优化调度图,得出该联合调度能有效降低不同来水条件,尤其是平偏丰来水年水光互补运行弃电风险的结论,可为实际调度规则的制订提供参考。

Solar System. Angular Momentum. New Physics

The most widely accepted model of Solar System formation, known as the Nebular hypothesis, does not solve the Angular Momentum problem—why is the orbital momentum of Jupiter larger than rotational momentum of the Sun? The present manuscript introduces a Rotational Fission model of creation and evolution of Macrostructures of the World (Superclusters, Galaxies, Extrasolar Systems), based on Overspinning Cores of the World’s Macroobjects, and the Law of Conservation of Angular Momentum. The Hypersphere World-Universe model is the only cosmological model in existence that is consistent with this Fundamental Law.

Propagation of large-scale solar wind events in the outer heliosphere from a numerical MHD simulation

Voyager 1 occasionally detected sudden jumps of the local interstellar magnetic field strength since its heliopause crossing in August 2012.These events were believed to be associated with outward propagating solar wind shocks originating in the inner heliosphere.Here we investigate the correlation between interstellar shocks and large-scale solar wind events by means of numerical MHD simulation.The solar wind is simplified as a symmetric flow near the equatorial plane,and the interstellar neutrals are treated as a constant flow with a fixed density distribution along the upwind direction of the local interstellar medium.The charge exchanges between the solar wind plasma and the interstellar neutrals are taken into account.At a heliocentric distance of 1 AU,the solar wind data from OMNI,STEREO A and B during the period between 2010 and 2017 are used as the inner boundary conditions to drive the simulation.The simulation results showed that the solar wind gradually merges into large-scale structures as the radial distance increases,consistent with observations by New Horizons.After propagating into the inner heliosheath,the shocks are fully developed and the corresponding pressure pulses roughly agree with the observations by Voyager 2 in the inner heliosheath.The arrival of the shocks beyond the heliopause is estimated and found to be consistent with the observed signatures of interstellar shocks by Voyager 1.The possible origins of interstellar shocks in the inner heliosheath are discussed based on the simulation.

Highly Thermo-Conductive Three-Dimensional Graphene Aqueous Medium

Highly thermo-conductive aqueous medium is a crucial premise to demonstrate high-performance thermal-related applications.Graphene has the diamond comparable thermal conductivity,while the intrinsic two-dimensional reality will result in strong anisotropic thermal conductivity and wrinkles or even crumples that significantly sacrifices its inherent properties in practical applications.One strategy to overcome this is to use three-dimensional(3D)architecture of graphene.Herein,3D graphene structure with covalent-bonding nanofins(3D-GS-CBF)is proposed,which is then used as the filler to demonstrate effective aqueous medium.The thermal conductivity and thermal conductivity enhancement efficiency of 3D-GS-CBF(0.26 vol%)aqueous medium can be as high as 2.61 W m-1 K-1 and 1300%,respectively,around six times larger than highest value of the existed aqueous mediums.Meanwhile,3D-GS-CBF can be stable in the solution even after 6 months,addressing the instability issues of conventional graphene networks.A multiscale modeling including non-equilibrium molecular dynamics simulations and heat conduction model is applied to interpret experimental results.3D-GS-CBF aqueous medium can largely improve the solar vapor evaporation rate(by 1.5 times)that are even comparable to the interfacial heating system;meanwhile,its cooling performance is also superior to commercial coolant in thermal management applications.

Solar System. Angular Momentum. Dark Matter Reactors

The developed Hypersphere World-Universe Model (WUM) is consistent with all Concepts of the World [1]. In WUM, we postulate the principal role of Angular Momentum and Dark Matter in Cosmological theories of the World. The most widely accepted model of Solar System formation, known as the Nebular hypothesis, does not solve the Angular Momentum problem—why is the orbital momentum of Jupiter larger than rotational momentum of the Sun? WUM is the only cosmological model in existence that is consistent with this Fundamental Law. The Nebular hypothesis does not solve Internal Heating and Diversity problems for all Planets and Moons in Solar system—why the actual mean surface temperature of them is higher than their effective temperature calculated based on the Sun’s heat for them and how could each one be so different if all of them came from the same nebula? The proposed concept of Dark Matter Reactors in Cores of all gravitationally-rounded Macroobjects successfully resolves these problems.

大规模新能源基地经特高压直流送出系统中长期运行方式优化方法

大规模新能源基地经特高压直流送出是我国未来新能源消纳的重要形式,合理优化特高压直流中长期运行方式,是提高新能源基地外送消纳能力的重要基础。提出了基于时序生产模拟的大规模新能源基地经特高压直流送出系统中长期运行方式优化方法。首先,考虑生产模拟计算准确性与复杂度的要求,建立了不同类型光热电站、火电机组和储能电站的聚合运行模型;然后,考虑特高压直流运行模式、灵活调节性能和受端电网负荷调峰需求,建立了不含整数变量的特高压直流运行模型。最后,建立了以新能源最大化外送消纳为目标,考虑各类电源与特高压直流运行约束的中长期运行方式优化模型,提出了基于逐周计算的全年8760h生产模拟计算方法。算例基于含风电/光伏/光热/火电/储能的大规模新能源基地开展测试,结果表明所提出方法能够优化特高压直流年/月运行曲线,实现新能源的最大化外送消纳,计算准确性与效率能够满足工程实用性需求。

关于太阳能热利用技术发展趋势探究

简要阐述了中国太阳能资源的概况,在分析中国太阳能热利用技术发展现状的基础上,分别对太阳能低温热利用技术和太阳能中高温热利用技术的应用现状和发展趋势进行了探究总结,以期为新时期背景下中国太阳能热利用技术的健康发展提供参考。

青岛某健身中心热水系统设计

通过青岛某健身中心热水系统工程实例,对同时存在泳池、公共浴室及地暖需求的健身中心的热水系统设计提供新的思路。

T160槽式太阳能中温集热器在工业领域的应用

随着2030年“碳达峰”以及2060年“碳中和”国家“双碳”战略的推进和实施,对工业领域绿色发展的紧迫性提出了现实考验。工业能耗占我国社会总能耗接近70%,其中约40%的能耗为热能消耗,即工业生产过程中大多数热能需求温度在80~150℃温度范围内。T160槽式太阳能中温集热器通过太阳跟踪、聚光等形式,可提供80℃以上的中高温热水,满足部分工业生产需求。

A new nonfullerene acceptor with an extended π conjugation core enables ternary organic solar cells approaching 19%efficiency

In organic solar cells(OSCs),it is an effective way to improve the power conversion efficiency(PCE)by adding a guest component with appropriate absorption and energy levels in the host system.Herein,a new nonfullerene acceptor(NFA)named TBF-2Cl was developed by the strategy of expanding theπconjugated core of 2,2’-(((4,4,9,9-tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b’]dithiophene-2,7-diyl)bis(methaneylylidene))bis(5,6-dichloro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile(IDT-4Cl)with two benzene rings.With increase of benzene units,TBF-2Cl exhibits higher lowest unoccupied molecular orbital(LUMO)level of-3.75 eV than that of one benzene unit based NFA IDT-4Cl and fluorene core based NFA F-2Cl,which facilitates enhancing the open-circuit voltage(V_(oc))of ternary devices.Moreover,TBF-2Cl film shows a medium optical bandgap with the absorption range from 500-800 nm,being well complementary with the wide bandgap polymer donor D18 and narrow bandgap NFA CH-6F.Accordingly,a remarkable PCE of 18.92%with a high short-circuit current density(J_(sc))of 27.40 mA·cm^(-2),a fill factor(FF)of 0.749,especially an outstanding V_(oc) of 0.922 V was achieved for the optimal ternary device based on D18:TBF-2Cl:CH-6F,surpassing the binary counterpart(17.08%).The findings provide insight into the development of new guest acceptors for obtaining more efficient OSCs.

中温太阳能集热器的参数数据库搭建

近年来随着已有技术的不断成熟,新技术不断涌现,中温太阳能集热器在生产生活中的应用越来越广泛。在此背景下,如果能够将目前市场上型号各异、效能不同的中温太阳能集热器进行归类整理,并结合具体应用场景和环境条件,创建一个中温集热器的参数信息数据库,对该设备的使用者和设计者都是十分有意义的。文章列举了当前国内常见的中温太阳能集热器,对相关参数进行了明确定义,提供了分类方法和效能计算方式,论证了创建中温集热器信息数据库的理论可行性。

风光储多源融合的中低压配电网架构及运行策略分析

文章研究了风光储多源融合的中低压配电网架构和运行策略,以应对可再生能源快速发展的能源转型。提出了综合性解决方案,通过多源融合和智能运行策略来优化电力系统性能。选取实际案例,通过仿真评估了系统性能。综合讨论中分析了结果,探讨了架构与策略关系,评估了应用前景和挑战。研究可为电力系统转型提供指导。

中国太阳能中温集热技术进展及应用

在分析太阳能热利用行业发展数据的基础上,对目前应用较为广泛的跟踪型和非跟踪型中温太阳能集热技术的发展研究及标准编制现状进行分析,介绍中温太阳能技术在供热采暖、空调、烟草等行业应用,明确了太阳能中温利用的温区,给出不同形式中温集热器性能提升的建议及应用展望。

聚光太阳能热发电系统关键技术研究综述

太阳能光热利用是目前新能源领域中自有技术含量最高、产业化发展最快、市场贡献最大的技术之一,与常规的光伏发电形式相比具有明显优势。考虑到太阳能具有能流密度较低及间歇性等特点,本文提出了基于有机朗肯循环发电的中低温太阳能利用形式,并从聚光集热、热功转换及蓄热技术3方面分别详细阐述了各自的工作原理、国内外研究及发展现状,并指出存在的问题,展示出太阳能热发电技术的广泛前景。

强化太阳池热性能实验研究

建立了两个表面尺寸2.4m×2.4m、深1.2m结构相同的小型盐水太阳池,通过向太阳池底部添加多孔介质、在太阳池表面加透明塑料膜盖,以及将太阳池与太阳能集热器相结合的方法,探索强化太阳池热性能的途径.实验结果表明:多孔介质用于太阳池可以起到降浊、蓄热的双重功效、加透明塑料膜盖可以有效降低太阳池浊度,减少表面散热,并影响下对流层温度分布;辅加太阳能集热器可以明显增加太阳池下对流层温度,但对非对流层和上对流层影响较小.

硝酸熔盐储热材料在太阳能利用中的研究进展

随着全球经济的快速发展,能源危机日渐凸显,太阳能作为可再生能源的一种,越来越受到人们的重视。因此,如何高效利用太阳能资源值得深究。熔盐具有良好的蓄热特性,在石化、电池及冶金行业中发挥着很大的作用,尤其可以作为传热蓄热介质应用于太阳能热发电和太阳能制氢中。其中硝酸盐的特性较为适合用于熔盐储热材料。主要针对硝酸熔融盐体系,一是介绍了硝酸熔融盐体系在太阳能方面的应用,二是介绍了国内外学者对此体系的物化性质研究,如工作温度范围、热力学性质及热稳定性等。通过对比,总结了不同混合熔融盐各项性能的异同。指出了硝酸熔融盐性能深入研究的方向,为硝酸熔盐在能源开发利用和环境保护等方面发挥更重要的作用提供了重要参考。

高温熔融盐斜温层单罐蓄热的热过程特性

以斜温层蓄热单罐设计理念为基础,采用硝酸熔融盐作为传热蓄热介质,锆质蓄热球与泡沫碳化硅陶瓷2种代表性的多孔介质填料作为固体蓄热体,构建了多尺度结构斜温层混合蓄热方法及系统,实验研究了多尺度结构中熔融盐的流动与蓄热特性。研究结果表明,由于斜温层的存在,系统理论蓄热效率小于80%;相对于熔融盐单相流体蓄热,采用锆质蓄热球与泡沫碳化硅的斜温层混合蓄热方式会导致系统的有效蓄热容量有所降低,但多孔介质填料的加入有利于保持熔融盐流体为理想的重力流或活塞流,并部分替代价格较高的熔融盐,需要结合蓄热容量以及经济性进行最优化设计。

太阳能热气流发电系统的传热与流动数值分析

建立了集热棚、烟囱以及多孔蓄热层的太阳能热气流发电系统传热与流动数学模型,分析了太阳辐射对蓄热介质的蓄热特性的影响。计算结果表明,在太阳辐射为200～800W/m^2的范围内,随着太阳辐射的增强,蓄热介质的蓄热比例先减小后增大;烟囱底部的最小相对压力显著减小,流动速度增大;系统内空气的温升增大,蓄热介质表面的温度也显著升高。