Abstract

In order to reduce the consumption of fossil fuels, solar energy is a promising alternative. However, solar potential depends on several atmospheric parameters. In the absence of clouds, aerosols are the primary source of solar radiation attenuation. This study aims to examine the impact of aerosol optical depth on the attenuation of solar irradiance under clear sky conditions. For this purpose, aerosol data from satellite database and irradiance data from high-performance meteorological stations installed in two sites in Morocco were exploited. Under clear sky conditions, the results showed a decrease in global horizontal irradiance relative to the global irradiance at the top of the atmosphere of 24% for aerosol optical depth values of 0.02 and exceeding 53% for 0.6. Aerosols have a more significant impact on the direct normal irradiance under clear sky conditions; over the test data, a decrease of 66% was observed for the direct normal irradiance according to the extraterrestrial irradiance for aerosol optical depth of 0.2 and reaching 92% for 0.6.

Abstract

The accelerating pace of urbanization sharpens the contradictions between the needs of cities residents and the quality of environment. Due to growing intensity of materials and energy flows between urban spaces and environment the “urban metabolism” concept can be considered as a basic need to study cities’ ecosystems resilience and sustainable development. A comprehensive assessment of the resource intensity of large cities in this paper was based on calculating the Sustainable Development of Energy, Water, and Environment Systems Index that benchmarks cities by 7 dimensions and 35 main indicators. The index is calculated for the first time taking into account the capital city of the Republic of Kazakhstan, Nur-Sultan, which has recently joined to the Race to Zero to achieve net zero carbon emissions by 2050. Positions of Nur-Sultan city in the sustainability rating were analyzed in comparison with 21 cities of the world. The results showed that Nur-Sultan belongs to the group with the lowest index values “Challenged Cities”, which determines the key directions of future development. The results are useful for the city's integration into the race to net-zero targets achievement, focusing on energy and CO₂-saving measures, rising renewable energy potential and water and environment quality, and development of research, innovations and sustainability policy.

Abstract

This work investigates bioethanol production from wastepaper via acid and enzymatic hydrolysis with the aim to attain the highest possible yield, including an evaluation of energy consumption of the production processes and costs involved. A mathematical model was designed using MATLAB software, in which pre-calculated chronological stages have been specified with the parameters that significantly affect the bioethanol yield, including type and number of consumables, reaction temperature and residence time. The independent variables have been decided based on recommended values found in the literature and are provided as suggestions to the user, who is also given the choice to manually input the values. Mass and energy balance are carried out for each process stage of bioethanol production in order to calculate the energy consumption of the chemical reactions. The model also calculates the bioethanol yield per 100 g of lignocellulosic biomass and the related costs. A comparison between enzymatic and acid hydrolysis bioethanol is presented by a line chart on the software interface, helping the understanding of the effects of the independent variable parameters. As a result, the most optimal conditions to produce the highest yield of bioethanol and therefore increasing the efficiency of a process is obtained. The model is expected to aid in the reduction of laboratory-based experiments being conducted, saving time, human errors, costly microorganisms and other consumables.

Abstract

Small scale biomass-based cogeneration has the potential to contribute significantly to a clean, flexible, secure, and cost-efficient energy system. It provides flexibility to future energy systems by balancing variable intermittent renewable energy sources. To exploit its flexibility, a smart control unit is needed. To enable smart control of a cogeneration unit, and to determine its optimal working points, a dynamic system model is required. The purpose of this study is to develop, parameterize and tune a dynamic model of a cogeneration plant fuelled with fast pyrolysis bio-oil. The system is a hybrid diesel generator/flue gas boiler plant for electricity generation and water/space heating. The plant has two unique features: (i) pyrolysis bio-oil is a new fuel for both engine and boiler, and as such it influences their operation and emissions, (ii) power and heat generation are partially decoupled hence non-linearly correlated. The paper presents the integration of the components’ dynamic models into a system model. The model is parameterized and partially validated using measurements from a turbocharged four-cylinder diesel engine and a swirl burner both running on FPBO. Preliminary controls are designed and evaluated. Results show applicability and usefulness of the model for cogeneration system analysis and control design evaluation.

Abstract

Power generation from the natural temperature difference between the soil surface and soil depth was examined by comparing four different thermoelectric generator scenarios using ANSYS software. A 40-cm stainless steel heat pipe filled with water was used to transmit heat from the soil depth to the surface to run eight thermoelectric generator modules. 30 cm of the heat pipe was buried in the soil while the remaining 10 cm was kept above the earth’s surface to which the modules were attached. In the first scenario, no fins were added. In the second, aluminium fins were attached to the cold side of the modules and copper fins were attached to the lower end of the heat pipe. The third scenario differed from the second in that the surface area of the aluminium fins was increased ten times. The fourth scenario differed from the third in that the material of the heat pipe was copper. Results showed that the generated power in the first scenario was 169.68 microwatts which were increased 2.17, 4.7, and 5.85 times in the second, third, and fourth scenarios respectively. The findings suggest that such modules can be used in indoor and outdoor low-power applications.

Abstract

This paper evaluates the energy operational performance of a system to produce domestic hot water, from the use of waste heat in a centralized air conditioning system in a hotel in Cuba. The hotel facility has two different chillers capacities, where the system recovers the condensed heat, through a heat exchanger at the compression process outlet. These schemes allow the simultaneous production of air conditioning and Domestic Hot Water, also those considering thermal storage tanks. The system modelling starts analyzing its components and their processes, based on the traditional thermodynamics and heat transfer equations and ends with a validation process. This model estimates a wide range of operating conditions, such as thermal demands of the cooling load, the chiller water temperature, the electricity consumed by chillers, and the climatological variables involved. The system is evaluated in the highest tourism season in Cuba during a year under partial load. Results were validated in a hotel as a study case, which allowed us to estimate the thermal potential available in the plant to meet the thermal demand of the hot water required, as well as showing that variations in the chiller operation affect the temperature stability in the hot water system.

Abstract

Global climate mitigation requires a renewable energy transition. Due to interactions between energy demand and material use, improvements in material efficiency promise to contribute to climate mitigation. To analyse such potentials, system dynamics modelling was applied to test four different scenarios towards a 100% renewable energy world. The model findings show that a 100% renewable energy world with zero greenhouse gas emissions seems feasible. However, the chosen pathway matters. While material efficiency reduces emissions and increases availability of secondary raw materials for renewable energy generation, only absolute reductions in energy demand through sufficiency-oriented lifestyles and sustainable choices in food, housing, and mobility seem able to achieve emission reductions needed to stay within 1.5-degree warming. Here, international policies are needed to create globally equitable opportunities for decent lifestyles in a safe and just planetary space.

Abstract

The transport sector accounts for around 30 % of Europe’s final energy consumption. To meet the EU’s decarbonization goals by 2050, it is important to quantify the energy savings potential in technology, infrastructure, and planning. This study analyses the European transport sector in the context of traditional and energy-efficient urban development. The latter demonstrates a scenario where accessibility is provided through enhanced proximity to a destination rather than through increased mobility, where mobility is shifted from roads and aviation towards rail. This development is ensured by, among other things, investing heavily in urban and inter-urban transport systems and abstaining from building new freeways and airports. The results indicate that it is not only desirable but economically beneficial to shift towards an energy-efficient transport system. The development of the European transport sector in the proposed trajectory significantly reduces annual final energy demand, and the investment made in new infrastructure for rail, bikes, and walkable urban areas are paid back by the reduced cost from road transport.

Abstract

In most developing countries, renewable energy still cannot compete with fossil-based electricity generation costs. Compared to various measures to support renewable energy deployment, fiscal instruments can be considered the most promising tool in emerging economies. Fiscal instrument effectiveness in renewable energy development in developing countries is still underemphasized in the literature.  Using the case of Indonesia, this study aims to simulate how different fiscal incentives can affect the economic price of renewable energy by employing six types of fiscal incentive scenarios, namely tax reduction including the tax holiday, tax allowance, value-added tax reduction and subsidy policy consisting of the cost of debt subsidy (soft loan), exemption of land acquisition costs, and project development facility. Using a typical financial model for 66 projects of solar photovoltaic and wind technology provided in Indonesia’s ten years national electricity plan, the findings generate two major outcomes. First, compared to other incentive policies, tax holiday and tax allowance are the most significant policies that would reduce the electricity price of renewables in Indonesia. Second, solar photovoltaic is relatively more sensitive in response to fiscal intervention compared to wind technology. The findings would be of high value to support specific strategies toward energy transition in developing countries.

Abstract

Many cities have set goals for reducing greenhouse gas emissions. Mobility is a major target sector as it is still widely fossil fuel-dependent and largely car-oriented. In this paper, a new methodological approach for modelling the impact of different policies on mobility, energy demand and resulting flow and embedded greenhouse gas emissions from vehicles is derived up to 2050. Finally, this approach is applied to the case of the City of Vienna. Three scenarios are developed with different policy targets focusing on battery electric vehicles and public transport. Each scenario was calculated with an average mix of electricity and a mix of renewable energy sources to be reached by 2030. The major conclusions are: (i) The impact of policies is of tremendous importance; (ii) Travel activity must be reduced and (iii) Public transport must be supported (iv) The electricity mix has to be switched to renewable energy sources.

Abstract

In this paper, the analysis of the diffusion of photovoltaic systems is performed using the Bass model. The historical data of installed rooftop photovoltaic is not enough for the model, as the installation of photovoltaic was almost non-existent, hence data of solar water heaters is utilized to calculate the parameters for the model. The trajectory of growth for solar water heaters in the market presents a congruence for the growth of solar photovoltaic due to inherent similarities in the technologies and its application. India was used as a case study of the application of this borrowing approach in a market where photovoltaic is also used to provide electricity to local communities. Data from solar water heater market in India were used and they indicate innovator parameters of 0.00105 and imitator parameters of 0.12219. The study is significant as it forecasts the diffusion of photovoltaic in the market, which is essential for achieving India's Intended Nationally Determined Contributions goals and Renewable Energy targets. The results indicate that residential rooftop photovoltaic diffusion will tend to present a slower pace in India than in other markets if no additional policies are implemented to foster this market.

Abstract

Limited water accessibility threatens the development of communities, especially where agriculture is the main income source.  The implementation of decentralized Energy-Water-Food systems is a promising approach to improve the situation in these communities, creating synergies and improving the profitability of the system. The model urbs optimizes Energy-Water-Food systems to generate the highest revenues, considering the local conditions and sustainability limits. This work improves the hydrogeological part of urbs in order to model the water potential of a given community, establishing interrelations of the water sector with the energy and food sectors, and maximizing the long-term benefits within the sustainability limits. The proposed method was applied to the rural community of St. Rupert Mayer in Zimbabwe. In order to analyse the impact of data uncertainty on the model results, the sensitivity of the main input parameters is analysed. The results indicate that it is important to implement reliable input data for dimensioning the proper system configuration, as otherwise the whole system would not be sustainable. 

Abstract

Hospitals are among the most energy-intensive buildings in the service industry. The development of energy management strategies could lead to important energy savings, and it must pass through detailed analyses of each specific activity energy requirement. The present study aims to find the main energy drivers of a healthcare facility and to develop an offline monitoring method appliable to future healthcare energy requirements. A Multiple Linear Regression model has been realized to define the standard energy consumption based on the year 2019, allowing to realize a Cumulative Sum of differences control chart including the 2020 energy consumption data. The proposed method allows to find variations between actual and standard building energy demands, being a useful tool to monitor the effectiveness of energy system control strategies.

Abstract

Common problem in the operation of breastshot water wheel in Indonesia is discontinuity operation of the wheel due to very low stream velocity in the channel during dry season. In order to minimize the problem, it is important to study the method of maintaining the continuity operation of the wheel during dry season. Thus, the installation of water-jumper at upstream of the wheel is proposed in the present work. The laboratory models of the water channel and breastshot water wheel were fabricated. The water jumper is attached at the upstream whose slope angle can be adjusted. The present work investigates the effect of water-jumper slope on the performance of the breastshot wheel. The slope angles are set at 5°, 10°, 15°, 20°, 25°, 30°, 35°, and 40°and the upstream velocities are 1.1, 1.2, 1.3, 1.4, 1.5, and 1.6 m/s. The result reveals that the use of water-jumper can increase the gross head and hydraulic power of very low stream, and hence the torque and the output power of the breastshot wheel are enhanced. The highest efficiency is achieved at the slope angle of 10º for stream velocity of 1.3 m/s. The water-jumper gives significant effect at stream velocity lower than 1.3 m/s. The hydraulic power is influenced by both discharge and gross head where they increase at increasing slope angle of the water-jumper. However, higher momentum losses occurs at the wheel for stream velocity higher than 1.3 m/s, thus output power and efficiency of the breastshot decreases even though hydraulic power increases. The water-jumper can keep continuous operation of the breastshot wheel in the irrigation channel during dry season.

Abstract

The Passive House building concept has been widely-researched in relation to its performance, especially the aspects of energy consumption and thermal properties. Nevertheless, the design stages still do not present a dynamic thermal comfort predictive process that aids investigating the design performance. This research focuses on a methodology that calculates summer months peak conditions in a pilot Passive House dwelling in the United Kingdom, based on the natural ventilation plan effectiveness in maintaining sufficient airflows, while the mechanical ventilation-heat recovery summer bypass mode is on. The methodology’s technical aspect involves EnergyPlus dynamic simulations, Ansys computational fluid dynamics simulations, and the Centre for the Built Environment Thermal Comfort Tool. The results presented showed a  spectrum of predicted percentages of people dissatisfied ranging between 13.3-99.2% for different airspeeds. The majority were of uncomfortable levels at summer peak days. Results also presents the ranges of thermal comfort parameters simultaneously. The findings produced by the methodology may add a more comprehensive description to the thermal comfort status during design stages, employing the integrated software combination.

Abstract

The number of Life Cycle Assessment studies in urban public transportation focusing on modals that aim to reduce global warming impacts are increasing significantly in the last few years. These studies suggest that the insertion of green modals on local public transportation systems could be a solution to reach sustainable development. However, the impact of this insertion in developing countries is not clear yet. Then, our main objective is to evaluate the environmental impact of an emerging city’s public transportation system, considering different public policies. Consequently, we conducted a Life Cycle Assessment study considering the transitions from diesel to biodiesel buses and electric buses from 2020 to 2030. Three scenarios were performed, with the following criteria: battery changes, the increase of biodiesel percentage used in the fuel mix and buses’ expected average lifespan transitioning to electric vehicles. The results show a decrease in impact by 2030 in analysed scenarios and may support policymakers to decide whether to focus on a short-term or long-term transport policy to reduce the fleet sustainable impact. Particularly, electric buses emerge as an option to reduce environmental impacts in the public transportation system in Porto Alegre, Brazil.

Abstract

Circular economy in Architecture, Engineering, and Construction requires consideration in the design, deconstruction-planning, and waste management. This paper aims to develop a Framework to evaluate the material sustainability of buildings by comparing the proportionality of costs to environmental impacts of construction waste flows. Therefore, an extensive literature review was conducted to find parameters needed, such as building certification, life cycle assessment, or material passports. Next, a distillation process was conducted to reduce the large number of parameters found to be manageable. Following the applicable legislation, procedures to be carried out at different stages, from dismantling to recycling or treatment, were defined. Practical applications were derived, such as support for deconstruction management, resource management, and conclusions for planning. The final parameters were assigned to these processes. Due to a lack of data, data collection and public data provision are essential for applicability.

Abstract

Water-energy nexus approach analyses water and energy interactions to provide sustainable usage of resources. This study incorporates a comprehensive bottom-up optimization model to assess the combination of technologies based on the water-energy nexus (watergy) optimal point. To achieve this goal, the watergy reference system is introduced according to six principles of watergy system. In this study, a new method is developed by adding an integration layer to the optimizing model with the objective function of the minimum total cost. In this layer, the demands for water and energy, for supplying the water and energy services, are calculated endogenously. A sensitivity analysis is performed by presenting six scenarios for greenhouse case study. Results indicate that the drainage recycling, combined heat and power, and photovoltaic were chosen at the watergy optimal point. Compared to the base case scenario, the maximum achievable reduction in the total cost of production is 31% in the most cost-effective scenario (Scenario B). Also, among the modelled scenarios, the optimal combination of technologies could result in reducing the use of water, electricity, and fertilizer by 18%, 31%, and 25% respectively.

Abstract

Rapid population growth requires more intense production of food industry, with two major consequences: significant amount of food processing residues and more sewage sludge originating from biological wastewater treatment plant. Sludge is a big concern for the disposal for wastewater treatment plant. The European Union makes an effort regarding the reduction of organic fractions disposed at a landfill. Composting is a cost-effective and ecological-friendly alternative for managing biodegradable organic fractions. Experiments of co-composting of sewage sludge, green waste and food waste, at carbon/nitrogen ratios 8.75, 18.00 and 24.90, were performed during three months by monitoring of temperature, pH, moisture, carbon and nitrogen proportion, carbon/nitrogen ratio, and germination index. The results showed that co-composting of sewage sludge, green waste and food waste is effective and results in the production of quality compost

Abstract

The Journal of Sustainable Development of Energy, Water and Environment Systems (JSDEWES) is an international journal dedicated to the improvement and dissemination of knowledge on methods, policies and technologies for increasing the sustainability of development by de-coupling growth from natural resources and replacing them with knowledge based economy, taking into account its economic, environmental and social pillars, as well as methods for assessing and measuring sustainability of development, regarding energy, transport, water, environment and food production systems and their many combinations.

In total 49 manuscripts were published in Volume IX, all of them reviewed by at least two reviewers. The Journal of Sustainable Development of Energy, Water and Environment Systems would like to thank reviewers for their contribution to the quality of the published manuscripts.