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Solar energy’s most promising application is in water heating, followed by other solar thermal applications. In this investigation, a novel method of incorporating a phase-change material (PCM) between the annulus space of an evacuated tube and an aluminum finned heat pipe is employed. During day time, the PCM stores the excess amount of heat and releases it in order to heat the flowing water during high-demand/insufficient solar radiation. This study aims to evaluate the detailed heat transfer assessment and energetic and exergetic efficiencies of the developed PCM-integrated solar water heater in both clear and cloudy weather conditions at 20 LPH. The outcomes of the study found that the maximum useful amounts of energy collected daily for the clear and cloudy days were 10.65 MJ and 8.52 MJ, respectively, whereas temperatures of the stored water were found to be 45.2 °C and 41.4 °C on the next day at 6:00 a.m. for the corresponding days. The daily energetic and exergetic outputs of the designed system were 76.57% and 79.64%, and 2.37% and 1.38%, respectively, at fixed mass flow rate for the clear and cloudy day conditions. The overall heat transfer coefficients (UL) for both days were 0.75 and 0.72 W/m2 K, respectively. The findings show that the proposed system overcomes the issue of overheated heat pipes and can provide hot water even in cloudy/low-sunshine conditions.

Due to the rapid increase in energy demand and associated environmental effects, renewable energy especially solar energy is being prioritized and promoted as the best choice for meeting energy demands and mitigating environmental issues. Solar energy is effectively utilized in the distributed generation (DG). The main component of the solar photovoltaic system used for converting produced DC power into AC power is the solar inverter. The solar inverter can supply both active and reactive power. However, conventional solar inverters are configured for producing only active power. Demand for reactive power is served by grid only. Therefore, the solar inverters can be upgraded to utilize their reactive power capability also. Which will decrease the reactive power requirement from the grid, resulting in the mitigation of various power quality issues. Reactive power compensation by a smart solar inverter does not require much additional cost or system resources. This article reviews various reactive power support and control techniques provided by the solar inverter.

Due to the intermittent nature of solar energy, researchers and scientists are working to develop thermal energy storage (TES) systems for effective utilization of solar energy. Phase change materials (PCMs) are considered to be promising materials for TES. In this study, organic paraffin RT50 and graphene silver (Gr:Ag) nanopowder are adopted as TES material and thermal property enhancers. Microstructure and morphological behavior as well as chemical, optical, and thermal stability of the prepared composite PCM are visually investigated using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy, thermal conductivity analyzer, differential scanning calorimeter (DSC). and thermogravimetric analyzer (TGA). Furthermore, based on the outstanding thermal performance of the composite, an extended investigation on the thermal and chemical properties are evaluated for 500 thermal cycles to ensure their reliability. Results show the thermal conductivity of RT50 improved by 53.85% when Gr:Ag nanopowder is dispersed at a weight percent of 0.8 (RT50-0.8Gr:Ag). The change in latent heat value of the composite sample is less than 3%, which is significant for effective thermal energy storage. The thermal decomposition of RT50 is slightly improved from 300 °C to 330 °C. To ensure a reliable and passive technique for thermal energy storage within solar thermal application devices, such as solar air heaters and solar photovoltaic thermal systems, using nanoparticle enhanced PCMs at the range of a 50 °C melting point are a current research hotspot.

In India, flowers are widely used as an offering to Deities at religious places. Flower waste (FW) is rich in several nutrients and organic matter, therefore, can be utilized for the production of organic compost. This study investigated the potential of temple FW along with cow dung (CD) for the production of compost through aerobic valorization (AV) for 60 days. The FW was collected from the Mahan Shiv Parvati temple of Jammu, India. For this, laboratory-scale AV was done using a 1:3 mixture of FW and CD in a 20 kg capacity bin facilitated with aeration. The result showed that there was a significant increase (P 0.8805), respectively. This study showed that the AV process of FW and CD mixture gave compost of good quality which presents a sustainable waste management approach.

Pollution-free rivers give indication of a healthy ecosystem. The stretch of Tawi river particularly in the Jammu city is experiencing pollution load and the quality is degraded. The present study highlights the impact of COVID-19 lockdown on the water quality of Tawi river in Jammu, J&K Union Territory. Water quality data based upon the real-time water monitoring for four locations (Below Tawi Bridge, Bhagwati Nagar, Belicharana and Surajpur) have been obtained from the web link of Jammu and Kashmir Pollution Control Board. The important parameters used in the present study include pH, alkalinity, hardness, conductivity, BOD and COD. The river was designated fit for bathing in all the monitoring locations except Bhagwati Nagar which recorded a BOD value >5 mg/L because of domestic sewage and municipal waste dumping. The overall water quality in the river during lockdown was good and falls in Class B with pH (7.0-8.5), alkalinity (23.25-185.0 mg/L), hardness (84.25-177.5 mg/L), conductivity (117-268 ms/cm). The improved water quality obtained during lockdown is never long-lasting as evident from the BOD and COD values observed during Unlock 1.0 due to accelerated anthropogenic activities in response to overcoming the economic loss, bringing the river water quality back to the degraded state. The statistical analysis known as cluster analysis has also been performed to evaluate the homogeneity of various monitoring sites based on the physicochemical variables. The need of the hour is to address the gaps of rejuvenation strategies and work over them for effective river resiliency and for sustainable river basin management.

Solar water heating is the most promising way to effectively use solar energy among all other solar energy applications. In this study, an innovative way of incorporatingphase change material (PCM) between the annulusspace of the heat pipe and the evacuated tubes for solar water heaters (SWHs) is used. The proposed system can deliver hot water when demand is high/solar radiation is insufficient by using palmitic acid as PCM. The energetic and exergetic analysis of the developed systemintegrated with PCM is studied on both clear and cloudy days. The results revealed that the maximum daily collected useful energyfor the clear and cloudy days was10.65 MJ & 8.52MJ respectively, whereas the maximum storage tank temperature was found to be 46.2°C and 41.4°C for the corresponding days. The daily average energetic and exergetic efficiencies of the proposed system were found to be 76.57% and 79.64%, and 2.37% and 1.38%, respectively at a fixed mass flow ratefor clear and cloudy days conditions.The results reveal that the designed system eliminates the problem of overheating heat pipes and can supply hot water even under cloudy conditions.

The phytoremediation of wastewater has certain advantages, but the interactions of soil and crop properties have not been systematically studied. This study aimed to analyze how different concentrations of textile dyeing industry wastewater (25%, 50%, 75%, and 100%) affected soil qualities, growth, and yield attributes (Vigna radiata). In reaction to dyeing effluent at varying concentrations, the seed germination percentage, growth metrics such as tolerance index, phytotoxicity percentage, relative toxicity, extreme and plumule length were calculated. With increasing effluent concentrations, a gradual decrease in the germination of seed and seedling growth was observed. The maximal relative toxicity and percentage of phytotoxicity was 100%. Interaction of biometric growth profile relative seed germination, relative root growth, relative shoot growth, growth index, and seedling vigor index of V. radiata and physicochemical parameter of textile dyeing industry wastewater were also investigated by using the Pearson correlation co-efficient. Principal component analysis (PCA) is helped to obtain and recognize the factors/sources accountability of different concentrations of textile dyeing industry wastewater. The results of the PCA revealed that four components (PC1 to PC4) out of total principal components retained PC1, PC2, with values of 69.25% and 28.85%, respectively.

Sustainable development goals not only contributes towards a clean environment but also towards better climatic conditions. Within Asia next to China and India, the Association of Southeast Asian Nations (ASEAN) are the actively developing countries in terms of economy and technologies. On the verge of achieving development, the ASEAN countries highly depend on fossil fuels for their energy needs. The ASEAN countries have taken visionary steps towards increasing the renewable energy mix with the conventional grid without hampering the ongoing development; this study presents the solar energy utilization policies, potential, progresses, and challenges adopted in ASEAN countries; furthermore, in these nations there is a huge potential of solar energy being located near the equator, therefore, they should focus on both solar to electrical and solar to thermal energy applications; however, in order to meet the peak demand and ensure the reliability of renewable energy like solar power, the development of advanced energy storage systems could be the key areas, and concrete efforts are required. Therefore, this article is a spotlight on government policies and goals focusing on energy potential, major progress in terms of energy storage and challenges in implementation of renewable energy systems in ASEAN countries; furthermore the recommended highlights on policies to accelerate the exploitation of renewable energy usage among the people are also discussed in detail, besides, the insights on reduction of carbon footprints over the next decade through incorporation of advanced energy storage systems. The issues discussed in this article will be helpful for exploring the desired energy storage systems and energy policies to be followed, which will eventually attract the stakeholders for small and medium-scale entrepreneurs for the development of renewable energy business in the region, if implemented on the ground.

Energy is the primary driver of current economic. Drastic increasing population and their improved living standards are augmenting the demand of energy. This increasing demand of energy is ...

Decline in the availability of potable water due to introduction of enormous contaminants including heavy metals and dyes paves way for the introduction of new and advanced water treatment technologies that ensures suitability of water for drinking purpose and at the same time eliminate pollutants or contaminants present in water. Adsorption based on nanoadsorbents is promising because of cost effectiveness and ease of operation. Therefore, this chapter intends to provide comprehensive detail about the adsorption process which is considered as the best method for heavy metal and dye removal along with the factors affecting the adsorption process. Different types of nanoadsorbents showing greater efficiencies in terms of heavy metal and dye removal are also discussed in detail. Much consideration is being given to conducting polymers. An insight about the synthesis of certain conducting polymer based nanoadsorbents is provided. The excellent properties of conducting polymers have enabled them to be used in remediation of toxic contaminants. Recommendations for future research in the area of conducting polymer based nanoadsorbents for improving the heavy metal and dye removal potentials are also put forth.

The current study focused on the pollution remediation of textile industry wastewater by using Chlorella pyrenoidosa in two different physical forms: free algal biomass and immobilized algal biomass. The hypothesis behind the present study was to analyze the pollution reduction efficiency of immobilized algal biomass and free algal biomass on comparative scale on the basis of the adsorption process which is directly proportional with the surface area of the adsorbate. So, in this context the immobilized form of algae could enhance the pollution reduction efficiency due to availability of more surface area. So, the textile industry wastewater was treated by both free algal biomass and immobilized algal biomass and the major wastewater contributors like nitrate, phosphate, Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) were assessed before and after the treatment process. To conclude the optimum comparative results, the pH of wastewater was maintained constant, as it can capitalize or moderate the adsorption process (initial pH of was 8.2 ± 0.1, but it was maintained to 8). The contamination remediation was found to be effective with immobilized algal biomass (46.7% of nitrate, 59.4% of phosphate, 83.1% BOD and 83.0% of COD) than free algal biomass (43.2% of nitrate, 56.7% of phosphate, 71.4% of BOD and 78.0% COD).

A microbial fuel cell (MFC) is an advance device to contend with three-dimensional problems of fossil fuel-based energy production with high-cost and pollution-generating units. It is an emerging t...

The integration of membrane-less microbial fuel cell (ML-MFC) with wastewater treatment provides an opportunity to produce energy as well as treat wastewater without membranes. Countries are making efforts to obtain a sustainable solution against energy crisis and pollution. Renewable energy such as solar energy, waste-to-energy, wind energy, bio-energy, and small hydro energy are being adopted widely as a sustainable tool. The process involves oxidation of organic matter by microorganisms, while resulting electrons from their metabolism are transferred to an electrode. The MFC device treats organic pollutants present in wastewater with the help of microbial communities and reduces up to 90% of the chemical oxygen demand and biochemical oxygen demand of wastewater. Microorganisms are the main driver of power production and degradation of organic substances; hence microbial inoculums are one of the major requirements for MFC system. New researches have proved that fuel cell will be the promising technology for upcoming future having the possibility of new dimension of research.

Wastewater discharged from domestic, agricultural, and commercial industries potentially release significant amounts of toxic and pathogenic contaminants into the environment. Wastewater treatment via bioprocess techniques has received a wide attention due to the benefits of end use, i.e., biochemical compounds with sustainable/eco-friendly bioenergy and bioproduct options. Biological treatment of wastewater is beneficial over physical and chemical treatment technology, as it provides biomass in bulk, which can be used for various purposes. The use of reclaimed water (after biological treatment) is significant in terms of environmental, economic, and social aspects, as it does not harm the ecosystem and produces biomass-based products that generate revenue to maintain economic sustainability and provide job opportunities to maintain social integrity. A central goal of these efforts is identifying the means for closing the loop in production systems that take into account legacy management, waste from fossil fuel industries, and integrated design for advanced renewable energy production systems (biogas from biowaste, bioenergy from crassulacean acid metabolism (CAM) plants) that value five aspects of governance: property rights, policy design, financing, and scale as tools to assist enhanced institutional design for integrative management, technology innovation, and public development. The produced biomass on wastewater can further be used to produce bioenergy (biohydrogen, biogas, bioethanol, and biodiesel) and biobased products that have high market value.

Energy and environment are the opposite sides of the same coin. Increasing energy production depends on the fossil fuel availability and is the main cause of the environmental degradation by emission of greenhouse gases. To overcome the environmental degradation problem, the whole world is moving towards the renewable energy technologies. The sun is the main direct source of all forms of energy present on the earth. The solar energy can prove to be the sustainable future for maintaining energy demand. Solar energy is the utmost auspicious technology because it can be used for heating as well as electricity production. This technology is the most mature technology and can be used at large or small scale as cleanest source of energy. This chapter deals with the different solar energy technologies mainly working towards the environmental sustainability and cleaning.

Solar energy is an abundant source of renewable energy which can able to support the expansion of energy demand. This review paper represents a complete literature review on recent developments in the phase change material (PCM) based solar collectors for air heating applications such as building heating, greenhouse heating, etc. In this paper thermal efficiency of various types of storage based collector and their performance for air heating (SAH) applications have been discussed. Based on the literature, it has been found that compared to basic solar air heating (SAH) systems, the collector-storage based air heating systems are able to provide higher efficiency with their capacity to recover and utilize the stored heat at night or cold weather conditions. These storage based collectors can be efficiently utilized for applications requiring medium operating temperature range during daytime as well as night times.

Sustainable Development Goal and Paris Agreement are guidelines provided by the global community for a better future. One of the ways is through the utilization of solar energy. But solar energy is plagued by unpredictable energy delivery, which can be solved through latent heat energy storage system. In this study, a phase change material (A70) composite with 0.1% wt Al2O3 is prepared using probe sonication. The composite is characterized through Differential Scanning Colorimetry (DSC), Thermogravimetric Analyzer (TGA) and UV-VIS-NIR spectrometer. The DSC showed a 5.02% decrease in the value of latent heat while the composite was thermally stable for the temperature range 30 °C to 200 °C where majority of domestic solar application lies. The composite and pure A70 may be useful for thermal system application where indirect heat absorption like heat exchangers, heat sinks, photovoltaic thermal and concentrated photovoltaic thermal system.

Among the various energy plant species, Jatropha curcus is found to be best oil-bearing plant species with a wide range of applications and having enormous economic potentials for its seed, which can be converted into biodiesel via transesterification which is an alternative to petrodiesel. In this present study, the effect of three factors, Time (1-4 hour), temperature (60-120°C) and quenching agents (NaCl, KCl, and ZrCl2) and dose of quenching agent(0.5-2gm) use for the extraction of oil from 10grm of jatropha seed. Using the Box-Benken Design (BBD) approach of Response Surface Methodology (RSM), 17 experimental runs were generated. n-Hexane was used as solvent for each experiment carried out in the 100 ml soxhlet extraction apparatus. Results obtained from the experiments were modeled and analyzed by choosing a quadratic model. From the analysis of modeled found temperature extraction time and dose of quenching agent revealed the good agreement of value (R2=0.98) between observed and predicted value of the experiment and were to be p>0.05 that was based on 95% confidence interval. By the use of RSM-BBD an optimizing experiment 60°C temperature 3h time and 2gm ZrCl2 quenching agent give best extraction of oil yield 41.41%.

Solar collector is an important technology for the effective utilisation of solar energy that the earth is blessed with. Flat plate solar collectors present a simple and easy to maintain design and thus are widely used for low and medium temperature applications. But being less efficient than alternatives, justifying the initial investment of flat plate solar collectors becomes difficult in the long run. This paper presents the efforts of researchers in the past some years to improve the efficiency of flat plate solar collectors through the improvement and optimization of the existing design. The range of research work covered gives a general idea of the variety of techniques being developed, analysed and tested to increase the efficiency of flat plate solar collector through means such as new absorber design, design of absorber tubes, new coatings on glass cover, and other means to reduce heat transfer losses, increase heat transfer from absorber to working fluid and absorbing and retaining direct as well as diffuse radiation. Design and efficiency improvement for better adoption of flat plate collectors in building facades has also been discussed. This paper will be beneficial for exploring the range of research avenues in the field of optimization and efficiency improvement of flat plate solar collectors.

One of the major drawbacks of solar water heating systems is unable to supply hot water during night time or off sunshine hours. The integration of phase change material with solar water heating systems is cost effective and efficient solution to overcome this major problem associated with solar water heating systems. The phase change material integrated with solar water heating system stores thermal energy during sun shine hours and this stored energy can be recovered during off shine hours or night time to produce hot water. The phase change material can be integrated with water tank of collector, evacuated tubes, external water tank for solar collector and flat plate collector by adding layers at the bottom of absorber plate. The integration of phase change material with SWH system not only overcome the drawbacks of SWH system but also enhance the efficiency of conventional SWH system. Many investigations for the application of TES materials integrated SWH system have been carried out and found a significant enhancement in the performance. This paper presents a comprehensive review of recent advances in the applications of PCM with SWH system for TES.

The global annual milk powder trade was estimated to be of 851.84 Million Metric Tons whereas; its Indian counterpart was recorded as 196.18 Million Metric Tons in the year 2019. The world’s annual milk powder production has registered a growth of 50% in the last three decades. In view of high thermal and electrical energy consumption; the present work focus upon energy, exergy and enviroeconomic assessments for comprehensive powder production wherein, the value of exergy efficiency, specific exergy destruction and specific exergy improvement potential. The exergetic performances of triple effect evaporator and single stage spray dryer unit were computed as 56.62% and 66.11% respectively. Additionally, involvement of economic approach with total saving in uniform yearly cost through electricity from PV panels will be approximately calculated as 979,006 $ and 874,319 $ at an interest rates of 4.5% and 7.5% respectively. Similarly, the investment on PV panels will be recovered after 8 and 11 years of operation for the respective rates of interests. On the basis environmental evaluation, it was found that adoption of clean energy solution (PV panels); could assist in mitigation of approximately 17,670 Tonnes of CO2 during its lifetime with securing a revenue of 256,215 $/lifetime.

Wild strains of algal biomass, a major contributor for eutrophication in freshwater bodies, can be used as a potential substrate in association with other nutrient-rich biowaste materials like animal excreta and industrial wastewater, for biogas production. This novel concept was experimentally evaluated and analyzed by the modified Gompertz equation for maximum biogas production (μ m), lag phase (λ), and biogas yield (P). The value of correlation coefficient (R 2) was 0.99 at varying temperature ranges (30, 40, and 50 °C). Thermodynamic functions like enthalpy (∆H), entropy (∆S), and Gibb’s free energy (∆G) were evaluated for the chemical oxygen demand removal efficiency. Thermodynamic functions such as ∆G (−), ∆H (+), and ∆S (+) showed the spontaneous and endothermic nature of substrate degradation and biogas production was found to be increased with increasing temperature. So, this novel co-digestion approach using nutrient-rich biowaste materials provides a new insight into biogas production with the aim of waste-to-energy generation.