• Energy Research
• Closed Access close
• 13. Climate action close
• 12. Responsible consumption close
• 8. Economic growth close

Abstract Compared with other traditional energy sources, renewable energy, which results the less pollution and has numerous resources, is a significant factor in addressing the current issues of the serious environmental pollution and the resource depletion. Large-scale renewable energy integrated to the grid could bring change in both morphological structure and operation modes of energy transmission. Therefore, it is necessary to research the evolution mechanism of the future transmission network with a high proportion of the renewable energy. In this paper, an evolution framework of power system with high proportion of renewable energy is proposed. Firstly, a network equivalence and simplification based on power transfer distribution factors (PTDFs) is proposed, which can effectively simplify the decision-making process of evolution of large-scale power system. Then, an annual production simulation (8760 h) which takes into account renewable energy and load fluctuations is used to find out the bottleneck of the power grid. Based on the above methods, evolution strategy of power system with high proportion of renewable energy is studied for finding out optimal expansion strategy. A real power system of Zhejiang province is used as a test system. Test results demonstrate the feasibility of the proposed evolution framework.

Abstract Canada has numerous climatic and geographical regions and the Canadian housing stock (CHS) is diversified in terms of vintage, geometry, construction materials, envelope, occupancy, energy sources and heating, ventilation and air conditioning system and equipment. Therefore, strategies to achieve net zero energy (NZE) status with the current stock of houses need to be devised considering the unique characteristics of the housing stock, the economic conditions and energy mix available in each region. Identifying and assessing pathways for converting existing houses to NZE buildings at the housing stock level is a complex and multifaceted problem and requires extensive analysis on the impact of energy efficiency and renewable/alternative energy technology retrofits on the energy use and GHG emissions of households. A techno-economic analysis of retrofitting renewable/alternative energy technologies in the CHS to reduce energy consumption and GHG emissions was conducted to develop strategies to achieve or approach NZE status for Canadian houses. The results indicate that substantial energy savings and GHG emission reductions are techno-economically feasible for the CHS through careful selection of retrofit options. While achieving large scale conversion of existing houses to NZEB is not feasible, approaching NZE status is a realistic goal for a large percentage of Canadian houses.

Abstract The increasing energy demand in developing countries has jeopardised energy security, necessitating the employment of solar energy to augment conventional energy sources. It is important to assess the annual performance parameters of solar power plants to understand its place in energy generation. This study analyses the performance and economic viability of a large-scale solar power park located in India. A 50 MWp Solar Photovoltaic Power Park (SPPP) located at Sakunala, in the State of Andhra Pradesh, is one of the largest solar power park in India, and the site receives an average solar radiation of 5.5–6.0 kWh/m2/day. The design, performance analysis, economic feasibility, and greenhouse gas mitigation of the 50 MWp SPPP is presented. The energy yields, performance ratio (PR), capacity utilization factor (CUF), and losses are assessed based on the IEC 61724 standards for two consecutive years (2018–2019 and 2019–2020). The performance results obtained are compared with the PVsyst simulation results. The PR, CUF, and energy yields are estimated as 0.779, 0.24, and 107,326.4 MWh in 2018–2019 and 0.691, 0.22, and 96,707.336 MWh in the year 2019–2020, respectively. The PVsyst simulator evaluates the PR, CUF, and energy yields as 0.80, 0.24, and 106,022 MWh, respectively. Further, the effect of power curtailment policies on solar PV projects is also discussed and the effect of curtailment policy on the economy of the solar power park in terms of payback period and emissions are analysed. The performance of the SPPP is also compared with those of other PV plants installed all over the world.

Microbial fuel cell (MFC) is a sustainable and energy efficient technology, which uses graphite as cathode for hydrogen peroxide (H2O2) production often with simultaneous power production. Nevertheless, slow kinetics of oxygen reduction reaction (ORR) at the surface of graphite often results in poor performance of MFC. In an attempt to improve the performance of MFC for in‐situ H2O2 production, a treatment of graphite cathode using nitric acid was performed. The treatment was conducted in three steps (i) heat treatment at 450°C for 2 h; (ii) acid treatment with concentrated nitric acid for 5 h; and (iii) drying at 120°C for 2 h. After the treatment, four times increase in surface area of treated cathode (GR‐HA) was observed. Energy‐dispersive X‐ray spectroscopy (EDX) and Fourier transform infrared (FTIR) analysis revealed the presence of nitrogen and quinone based functional groups on the surface of GR‐HA. Cyclic voltammetric (CV) analysis of GR‐HA cathode further confirmed the production of H2O2 at the peak current value of −3.7 mA and on‐set potential of −0.1 V. Following CV analysis, H2O2 production experiments were performed in a dual chamber MFC using GR‐HA as cathode. Maximum 150 mg/L of H2O2 was produced with simultaneous power production of 36.438 mW/m2. Approximately, 25% increase in both H2O2 and power production was observed in the case of G cathode. Subsequently, Fenton oxidation experiments were performed (with GR‐HA and GR‐CA cathodes) to determine the efficacy of in‐situ produced H2O2. This resulted in an increase of 8.28%, 11.04%, and 31.32% in decolorization, chemical oxygen demand (COD), and Total Organic Carbon (TOC) removal efficiency, respectively. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 382–393, 2017

Abstract To alleviate the shortage of natural gas resource and ease carbon emissions, a novel solar-driven combined cooling, heating and power (CCHP) system is designed and optimized using the genetic algorithm in the work. Different from the process of direct combustion in a conventional CCHP system, natural gas is firstly converted into syngas by a solar-driven natural gas reforming step, which is consumed in an efficient tri-generation system. Energy, economic and environmental evaluations on five office buildings in different climate zones in China are implemented to validate the advantages of the proposed system. Results show that the annual maximum primary energy saving, total cost saving, and CO2 emission reduction are 69.76%, 49.80%, and 71.55%, respectively. The system located in severe cold zones, where solar energy is abundant and building requires more heat load in whole year, achieves the highest benefits in comparison with separate systems. Furthermore, the sensitivities on the price fluctuations of electricity, natural gas and solar field to the system profits are investigated, which indicates that the influence of electricity price on the system performance is the most significant. Thus, a promising method for reducing the natural gas consumption and improving the utilization efficiency of solar energy is provided.

The aim of this study was to investigate the effectiveness of cultivating Parachlorella kessleri and Acutodesmus obliquus, in anaerobic digestion effluent (ADE) derived from the co-digestion of end-of-life dairy products with mixtures of agro-industrial wastes. To this end, their performance under sterile and non-sterile conditions and different ADE loadings was evaluated, in terms of biomass and lipid production, nutrient removal efficiency and vitality of the photosynthetic apparatus. 10% (v/v) ADE loading inhibited growth over 9-12days of cultivation, however biomass yields of 1.1 and 1gL-1, 22.7% and 19.5% (w/w) fatty acids concentration, as well as NH3-N assimilation of 49.7mgL-1 and 32.3mgL-1 and TP removal of 84.2% and 84% were recorded for P. kessleri and A. obliquus, respectively. Among all the ADE-based treatments tested, P. kessleri outperformed A. obliquus, with no differences observed between sterilized and non-sterilized ADE.

Bioplastics are alternatives of conventional petroleum-based plastics. Bioplastics are polymers processed from renewable sources and are biodegradable. This study aims at conducting an environmental impact assessment of the bioprocessing of agricultural wastes into bioplastics compared to petro-plastics using an LCA approach. Bioplastics were produced from potato peels in laboratory. In a biochemical reaction under heating, starch was extracted from peels and glycerin, vinegar and water were added with a range of different ratios, which resulted in producing different samples of bio-based plastics. Nevertheless, the environmental impact of the bioplastics production process was evaluated and compared to petro-plastics. A life cycle analysis of bioplastics produced in laboratory and petro-plastics was conducted. The results are presented in the form of global warming potential, and other environmental impacts including acidification potential, eutrophication potential, freshwater ecotoxicity potential, human toxicity potential, and ozone layer depletion of producing bioplastics are compared to petro-plastics. The results show that the greenhouse gases (GHG) emissions, through the different experiments to produce bioplastics, range between 0.354 and 0.623 kg CO2 eq. per kg bioplastic compared to 2.37 kg CO2 eq. per kg polypropylene as a petro-plastic. The results also showed that there are no significant potential effects for the bioplastics produced from potato peels on different environmental impacts in comparison with poly-β-hydroxybutyric acid and polypropylene. Thus, the bioplastics produced from agricultural wastes can be manufactured in industrial scale to reduce the dependence on petroleum-based plastics. This in turn will mitigate GHG emissions and reduce the negative environmental impacts on climate change.

Abstract In hot and humid climate such as in Japan and south east Asia, dehumidification in summer is really important for air conditioning. Temperature and humidity independent control (THIC) of air conditioning system can handle sensible heat and latent heat separately, and provide good indoor environment and achieve energy conservation. Desiccant air handling unit is one of the major solution for THIC of air conditioning system. It needs hot water to regenerate sorbent which absorbs moist in the air. Combined heat and power can supply hot water at almost constant temperature for desiccant air handling system and also contribute to the business continuity plan of commercial buildings. However, there are still uncertainties about the factors which affect energy performance of desiccant air handling unit and the optimum design and operations in hot and humid climate. The objectives of this paper are to prove factors which affect energy performance of desiccant air handling unit by measurement analysis and show optimum condition of the desiccant air handling unit under various room conditions by simulation. Measurement analysis shows that energy performance of desiccant air handling unit depends not only on the inlet air condition to dehumidification wheel but also on designed supply air humidity. Furthermore, simulation results show the optimum inlet air condition entering dehumidification wheel under various supply air absolute humidity which is determined by design room conditions. These results provide useful information of desiccant air handling unit during design and operation phase of buildings in hot and humid climate.

Abstract To further improve the cycle efficiency with the heat transfer curves between higher than 350 °C heat resource and the evaporating working medium of the Kalina cycle and to reduce the exhaust temperature of heat resource, the dual-pressure vaporization Kalina cycle for cascade utilization of high-to-mid grade heat resource is proposed. The optimization was conducted for parameters in this modified Kalina cycle such as concentrations of work solution and basic solution, evaporation dew point temperature. Under the conditions of inlet temperatures of heat resource and cooling water of respectively 400 °C and 25 °C and the constraints of proper heat transfer pinch point temperature differences, the maximum evaporation pressure not exceeds 20 MPa, the vapour quality at the turbine outlet is greater than 0.85 and the exhaust temperature of heat resource is not lower than 90 °C, the optimum parameters are obtained that the work and basic concentrations are 0.45 and 0.272 respectively, the dew point temperature of evaporation is 300 °C, and the corresponding power recovery efficiency of the dual-pressure vaporization Kalina cycle reaches 27%, which is 17% higher than that of the Kalina cycle with optimum parameters.