A flexible thin-film membrane with broadband Ag@TiO2 nanoparticle for high-efficiency solar evaporation enhancement

Synergistic Tandem Solar Electricity-Water Generators

A Hybrid Electric and Thermal Solar Receiver

Sustainable solar-powered seawater desalination enabled by phosphorene-decorated watermelon-like phase-change microcapsules

Establishing a transient model of double-layer porous media interfacial evaporation system to reveal the relationship between porous media parameters and evaporation performance

Enhancing solar steam generation using a highly thermally conductive evaporator support

Self-Healing Hydrophilic Porous Photothermal Membranes for Durable and Highly Efficient Solar-Driven Interfacial Water Evaporation

Solar thermal energy (STE) technology refers to the conversion of solar energy to readily usable energy forms. The most important component of a STE technology is the collectors; these absorb the shorter wavelength solar energy (400-700nm) and convert it into usable, longer wavelength (about 10 times as long) heat energy. Depending on the quality (temperature and intensity) of the resulting thermal energy, further conversions to other energy forms such as electrical power may follow. Currently some high temperature STE technologies for electricity production have attained technical maturity; technologies such as parabolic dish (commercially available), parabolic trough and power tower are only hindered by unfavourable market factors including high maintenance and operating costs. Low temperature STEs have so far been restricted to water and space heating; however, owing to their lower running costs and almost maintenance free operation, although operating at lower efficiencies, may hold a key to future wider usage of solar energy. Low temperature STE conversion technology typically uses flat plate and low concentrating collectors such as parabolic troughs to harness solar energy for conversion to mechanical and/or electrical energy. These collector systems are relatively cheaper, simpler in construction and easier to operate due to the absence of complex solar tracking equipment. Low temperature STEs operate within temperatures ranges below 300oC. This research work is geared towards developing feasible low temperature STE conversion technology for electrical power generation. Preliminary small-scale concept plants have been designed at 500Wp and 10KWp. Mathematical models of the plant systems have been developed and simulated on the EES (Engineering Equation Solver) platform. Fourteen candidate working fluids and three cycle configurations have been analysed with the models. The analyses included a logic model selector through which an optimal conversion cycle configuration and working fluid mix was established. This was followed by detailed plant component modelling; the detailed component model for the solar field was completed and was based on 2-dimensional segmented thermal network, heat transfer and thermo fluid dynamics analyses. Input data such as solar insolation, ambient temperature and wind speed were obtained from the national meteorology databases. Detailed models of the other cycle components are to follow in next stage of the research. This paper presents findings of the system and solar field component.

Vapor generation using solar energy is emerging as an efficient technology for wastewater purification and seawater desalination to relieve global water crisis. However, salt deposition on the evaporation surface seriously impairs the long-term steady water evaporation performance. Herein, the flexible salt-rejecting photothermal paper comprising reduced graphene oxide (rGO) and ultralong hydroxyapatite nanowires (HNs) has been developed for high-performance solar energy-driven water evaporation and stable desalination of seawater. The rGO/HN photothermal paper has advantages such as the hierarchical porous structure, interconnected channels, high mechanical strength, high efficiencies of solar light absorption and photothermal conversion, fast water transportation, and good heat insulation and salt-rejecting properties. Furthermore, the hydrophilicity and hydrophobicity of the rGO/HN photothermal paper can be adjusted by regulating the thermal treatment time. The water evaporation rate and energy efficiency of the hydrophilic rGO/HN photothermal paper are 1.48 kg m-2 h-1 and 89.2%, respectively, under 1 sun illumination (1 kW m-2). The hydrophobic rGO/HN photothermal paper shows a long-time stable water evaporation and salt-rejecting performance in the process of seawater desalination. The flexible salt-rejecting rGO/HN photothermal paper can produce clean water from wastewater and seawater with high rejection rates of organic dyes, metal ions, and salt ions, and it is promising for applications in water purification and seawater desalination.

Flexible engineering of advanced phase change materials

The mechanism for solar irradiation enhanced evaporation and electricity generation

Prediction of global solar irradiance based on time series analysis: Application to solar thermal power plants energy production planning

Energy is considered as a prime agent in the generation of wealth and a significant factor in the economic development. The development scale of any country is measured by few parameters among which per capita energy consumption holds the most significant. With the depletion of nonrenewable energy resources and growing environmental concerns, it is expected that solar energy i.e. a renewable energy source is going to play a very significant role in the future. Over the last three decades, a significant research on photovoltaic (PV) solar cells and modules has been carried out. Today, the electricity conversion efficiency of a silicon solar module available under standard test condition (I(t)=1000 W/m2& T a = 25 °C) for commercial application is about 12 %. More than 75% of the incoming solar energy is either reflected or converted into heat energy. The abundant solar energy obtained from solar radiation can be utilized in the form of either thermal energy or electrical energy (DC) using photovoltaic (PV) modules. The efficiency of the PV system is more sensitive to the operating temperature. The higher the operating temperature, lower is the electrical efficiency and vice-versa. The operating temperature of PV systems can be lowered by withdrawing/utilizing the thermal energy associated with it. The thermal energy associated with the PV module can be carried away by flowing air below it. This type of system is known as hybrid photovoltaic thermal (PVT) system. The hybrid PVT system allows the enhancement of the electrical performance of PV by removing thermal energy and subsequently decreasing the operating temperature. Standalone Photo voltaic (SPV) systems has less electrical efficiency hence long payback period is observed. The parameter performance ratio is usually employed for performance of SPV systems. This paper illustrates that both types of energy are generated and by utilizing both types of energy, payback period can be reduced hence performance is improved. SPV system is mounted on roof of administrative building of University. It has been observed improvement in average electrical efficiency is 7.02%.

The objective was to determine how solar radiation affects the electric power generation in Huancayo city, using an electric power generation system based on a Stirling engine. The solar energy characteristics described in these coordinates of the center of Peru and the solar radiation conversion characteristics into electrical energy. The research has an experimental design, an electric power generation system based on a solar collector cylinder design was implemented, which applies thermal energy to a Stirling engine to generate electric energy, each stage of these processes were analyzed; performance tests and thermal power generation, mechanical and electrical energy with the experiments were performed. As a result it was possible to implement an electric power generation module having solar energy as a source; it was possible to obtain experimental results from the solar radiation entry, the temperature in concentration focus, mechanical energy generation which generates an electrical output potential according to the generator and the Stirling engine characteristics, and according conditions to the solar radiation of the geographical area. In conclusion, the electrical generation implementation of the Stirling system allows to have an integrated system with its analyzed processes, which allowed to evaluate the electrical potential values that solar energy provides us in experimental conditions in this studied geographic region.

Separating the Heat from the Gap

The development of simple and high-throughput approaches to yield solid-state nanopores on large surface membranes may facilitate the prevalence of nanopore analysis technology and in-vitro diagnosis using portable devices. However, solid-state nanopores are typically realized by complex and high-end nanofabrication equipments. Here, we present a method to achieve nanopores on polymer membranes using silver nanoparticles (AgNPs) as templates and intense pulsed light (IPL) as a heating source. The density and size of nanopores are controllable by adjusting the spin coating rate, the concentration of nanoparticle suspension, and the size of nanoparticles (NPs). The temperature of the AgNPs can rapidly reach 1132 K under instant heating of photothermal effect through light irradiation in 2 ms, resulting in localized melting and decomposition of an underneath polycarbonate (PC) membrane to yield nanopores with sizes ranging from 10 to 270 nm. After removing the nanoparticle residues, the flexible membrane with nanopores can be integrated into a flow cell to achieve a nanopore sensor that has been used to measure the translocation behaviors of bovine serum albumin (BSA). The results have demonstrated the capability of the sensor in protein denaturation identification. This low-cost and high-throughput technique to fabricate solid-state nanopores on flexible polymeric membranes may facilitate the development of more nanopore-based flexible sensors that can be integrated with other flexible components for wearable diagnosis.