| 1. |
- Agar, David, et al.
(författare)
-
The CO2 cutting cost of biogas from humanure and livestock manure
- 2022
-
Ingår i: Sustainable energy technologies and assessments. - : Elsevier BV. - 2213-1388 .- 2213-1396. ; 53
-
Tidskriftsartikel (refereegranskat)abstract
- The European Union is accelerating its rollout of sustainable energy production and promotion of a circular economy. Electricity from biogas has synergy with energy-policy and rural-development goals yet its economic value is often convoluted. This study assessed the economic potential of biogas electricity using a representative rural case and quantified the cost and level of state support required for viability. The cost of CO2-equivalent emission reductions was determined using the recast Renewable Energy Directive (RED II). The results showed that a feed-in tariff of 0.33 € kWh−1 for green electricity was required for economic feasibility. This yielded a CO2 cutting cost of 251 € t−1. The methane energy potential was 78 467 kWh a−1 from 31 498 kg (dry mass) of substrates, 80% livestock manure and humanure and 20% plant-based. Circular use of the digestate from anaerobic digestion, enabled a nitrogen recovery potential of 1 575 kg a−1. The conclusions reached are that the economic value of the avoided emissions, through the RED II framework, is significant but it does not substantially improve the cost-effectiveness of biogas as an emission-mitigation technology. For biogas plant capacities less than 500 kW, current EU feed-in tariffs do not support economic viability.
|
|
| 2. |
- Akel Hasan, A., et al.
(författare)
-
A review of solar thermal cooling technologies in selected Middle East and North African countries
- 2022
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier Ltd. - 2213-1388 .- 2213-1396. ; 54
-
Tidskriftsartikel (refereegranskat)abstract
- Cooling loads are a substantial part of the total electricity demands of countries in the Middle East and North Africa (MENA). Fortunately, because of its warm and sunny climate, the MENA region is naturally suited to solar cooling technologies. This article summarizes the most recent research and developments in solar thermal cooling technologies. The working principles and a general literature survey of solar thermal cooling technologies including absorption, adsorption, and desiccant is presented. This is followed by a summary of the literature specific to the MENA region, along with a survey of the prototypes and commercial installation of solar cooling across the MENA region. Based on this review, pilot solar cooling projects in the region are around 1180 kWc, which are split between space conditioning and industrial refrigeration applications. Most of the pilot projects are of absorption cooling type using an ammonia–water binary cycle and parabolic trough solar collectors. However, a few adsorption cooling systems are employed with a water–silica working pair and flat plate collectors. Finally, desiccant cooling systems are still in their infancy, as research and experimental systems in educational institutes.
|
|
| 3. |
- Atabaki, Mohammad Saeid, 1986-, et al.
(författare)
-
Exploring the role of electrification and modal shift in decarbonizing the road passenger transport in British Columbia
- 2023
-
Ingår i: Sustainable Energy Technologies and Assessments. - Amsterdam : Elsevier. - 2213-1388 .- 2213-1396. ; 56
-
Tidskriftsartikel (refereegranskat)abstract
- The possibility of the modal shift to public transport and active mobility while considering transport electrification and fuel efficiency improvement has yet to be adequately investigated. This paper explores transition pathways toward an environmentally sustainable road passenger transportation system in the province of British Columbia (BC), Canada. MESSAGE, as a bottom-up energy systems optimization model, is used to find the cost-optimal fuel and technology mix in the transport and power sector. Multiple scenarios mainly assess the influence of modal shift and electric vehicle (EV) diffusion on greenhouse gas emissions by 2050. Besides, the effects of scenarios on the power sector configuration are examined. The results show that BC would not achieve the 80% emissions reduction target in the Climate Change Accountability Act unless by a radical expansion of transport electrification. The target could be met by a minimum diffusion of 70% EVs in the total car stock as well as 35% public transport contribution in total passenger kilometers. The findings also indicate that fully electrified light-duty vehicles coupled with active transport would lead to almost a zero-emission level. Nevertheless, 100% electrification would impose an extra 5.6 TWh burden on the power supply system relative to the business-as-usual scenario. © 2023 The Authors. Published by Elsevier Ltd
|
|
| 4. |
- Barney, Andrew, et al.
(författare)
-
Decarbonisation of islands : A multi-criteria decision analysis platform and application
- 2022
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier. - 2213-1388 .- 2213-1396. ; 52:Part B
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper the REACT-DECARB energy planning platform, designed to assist with the assessment of decarbonisation scenarios for islands’ electricity grids, is fully presented and applied to eight (8) EU islands. The scenarios were developed in the context of a Horizon 2020 EU project employing a renewable energy production forecasting and an optimisation mixed-integer linear programming model. The platform employs energy and economic modules, life-cycle assessment and multi-criteria decision analysis to facilitate the integrated evaluation of scenarios and enables decision makers to fully grasp the technical, environmental, economic and social aspects of energy systems’ decarbonisation. Results indicate that island electrical autonomy should be considered with caution and can be a valid option only if cost criteria are not prioritised. Further, it was determined that seeking autonomy in countries with low carbon costs for electricity production may be not be environmentally beneficial. A number of inter-island comparisons have been made and have shown that the REACT-DECARB platform can assist planners and decision-makers to identify the best available scenarios, define the sensitivity issues with respect to the criteria weights and, together with local communities, come to a common ground in order to establish a roadmap for the transition towards a decarbonised energy future for islands.
|
|
| 5. |
- Barney, Andrew, et al.
(författare)
-
Transition towards decarbonisation for islands : Development of an integrated energy planning platform and application
- 2021
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier BV. - 2213-1388 .- 2213-1396. ; 47
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents REACT-DECARB, an energy planning decarbonisation platform employing renewable energy sources coupled with storage for islands. The paper implements the energy scenario creation and economic evaluation steps of the platform on eight geographic islands in seven countries within the EU. Twenty-one technologically feasible energy scenarios, applicable to the specific conditions of each island, are specified and their economic assessment via a levelized cost of energy (LCOE) calculation is then performed. The main aim of this application is to verify the noted steps of the platform as well as to test its flexibility across geographically, socially and dimensionally disparate islands with various scenario generation methods. The results of the economic analysis show a wide variation of LCOE depending primarily on whether full island autonomy is assumed. In some cases the islands’ scenarios’ costs approach current market prices but are never below them; some scenarios are, however, below the current price of the island’s thermal generation. The sensitivity and uncertainty of the economic performance results’ and the variables used to calculate them are evaluated and discussed for two of the islands. The overall analysis and application has shown that the REACT-DECARB platform is suitable for different islands, regardless of location and size and can be useful for island energy planners.
|
|
| 6. |
- Björnsson, Lovisa, et al.
(författare)
-
Integrating bio-oil production from wood fuels to an existing heat and power plant - evaluation of energy and greenhouse gas performance in a Swedish case study
- 2021
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier. - 2213-1388 .- 2213-1396. ; 48
-
Tidskriftsartikel (refereegranskat)abstract
- Combined heat and power (CHP) production in combination with a district heating (DH) grid gives an energy efficient use of wood fuels. The heat demand in the DH grid will, however, decline in the coming decades, and operators are seeking additional heat sinks. In this case study, the integration of a pyrolysis unit into an existing CHP plant was investigated as a possible solution. The retrofitted pyrolysis unit makes use of excess heat and yields a liquid bio-oil. Pyrolysis integrated with CHP production was shown to give a net energy yield of at least 80%, and to decrease the net heat output to the DH grid. The carbon footprint of the delivered heat was very low at maximum 1.6 g CO(2)eq/MJ. Prolonging the operation of the pyrolysis unit to periods without heat delivery to the DH grid would increase the use of existing installations, but at the cost of energy yields decreasing to 63-70%. Up to 2.8 PJ(LHV)/yr crude bio-oil could be produced at the investigated CHP plant. The bio-oil was shown to have a low carbon footprint, 1.7-4.0 g CO(2)eq/MJ(LHV), which makes it attractive for the rapidly expanding transport biofuel market.
|
|
| 7. |
- Canales, Fausto A., et al.
(författare)
-
Cost-reliability analysis of hybrid pumped-battery storage for solar and wind energy integration in an island community
- 2021
-
Ingår i: Sustainable Energy Technologies and Assessments. - : ELSEVIER. - 2213-1388 .- 2213-1396. ; 44
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a mathematical model for estimating the optimal sizing and assessing a standalone hybrid power system's performance entirely based on variable renewable energy sources and coupled with a hybrid energy storage system. This study evaluates how different levels of the main components' capital cost and the loss of power supply probability would affect the cost of energy and the power system's optimal sizing. The case study selected for this study was Ometepe Island in Nicaragua, where the crater lake of an extinct volcano was considered a feasible upper reservoir of a pumped storage hydropower plant, reducing the investments associated with this component. The mathematical formulation considers energy storage losses and gains, and the Pareto efficient solutions of the multi-objective optimization model simultaneously increase reliability, reduce the cost of energy, and minimize curtailment energy. By employing time-series with an hourly resolution, the model allows assessing the impact of the interannual variability of renewable energy sources on the system's performance. As for the case study, the cost of energy obtained from the model results ranges between (sic)0.047/kWh and (sic)0.095/kWh, based on international reference values, and these values match the information available in the literature and other databases.
|
|
| 8. |
- Chowdhury, Mohammed Gofran, et al.
(författare)
-
Experimentally validated CFD simulations predicting wind effects on photovoltaic modules mounted on inclined surfaces
- 2018
-
Ingår i: Sustainable Energy Technologies and Assessments. - : ELSEVIER SCIENCE BV. - 2213-1388 .- 2213-1396. ; 30, s. 201-208
-
Tidskriftsartikel (refereegranskat)abstract
- Computational Fluid Dynamics (CFD) and wind tunnel experiments were used to study wind flow over PV modules attached to inclined surfaces. Wind velocities were investigated at various positions on a WA module, for five wind speeds varying from 1 to 5 m s(-1). After validation the CFD model was used to study the effects air gaps and wall cavities under the module have on the airflow over the module. Data were measured for two air gaps, 3.5 cm and 5.5 cm thick, and for three cavity depths ranging from 0 cm to 9 cm. The 3.5 cm air gap resulted in lower near-surface wind speeds over the PV module. This will result in less wind-generated cooling of the module, and consequently, in a lower electrical performance. The wall cavities did not affect the magnitude of the wind speed over the module but generated an increased deflection of the wind towards the lateral sides of the module. They also created clockwise and anti-clockwise eddies next to the PV setup and in the cavity itself. The study shows that in CFD simulations for PV applications, even small irregularities in the PV setup should be included in the model to predict reliable results.
|
|
| 9. |
- Fu, Y., et al.
(författare)
-
Effects of uncertainties on the capacity and operation of an integrated energy system
- 2021
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier Ltd. - 2213-1388 .- 2213-1396. ; 48
-
Tidskriftsartikel (refereegranskat)abstract
- Uncertainty is a common and critical problem for planning the capacity and operation of integrated energy systems (IESs). This study evaluates the effects of uncertainties on the capacity and operation of an IES. To this aim, system planning and operation with uncertainties are optimized by a two-stage stochastic programming model and compared with a referencing deterministic case. Specifically, the uncertainties of photovoltaic (PV) generation and energy demand are investigated. Regarding system capacity, a larger energy storage capacity is needed to accommodate a higher uncertainty. The superimposed uncertainties have a higher effect on system capacity than the sum of the effect of each uncertainty. The uncertainty of energy demand has a higher impact than the uncertainty of PV generation. Regarding system operation, the increase in operation cost is smaller than the increase in investment cost and total cost. In addition, the average flexibility provided by the energy storage increases with uncertainty and uncertainties affect the change rate for power charging/discharging of the electric energy storage. Regarding the effect on the grid, the uncertainties increase not only the magnitude of ramping-rate, but also the frequency of power-dispatch.
|
|
| 10. |
- Fu, Zuhang, et al.
(författare)
-
Fuel cell and hydrogen in maritime application : A review on aspects of technology, cost and regulations
- 2023
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier BV. - 2213-1388 .- 2213-1396. ; 57
-
Tidskriftsartikel (refereegranskat)abstract
- Currently, fuel cell and hydrogen technology are attracting more and more attention as a kind of green and clean energy technology in the context of the increasingly stringent carbon emission requirements of the shipping industry. However, there are still many obstacles to their maritime application due to high costs and a lack of infrastructure. This paper conducts a literature survey of fuel cell maritime applications from four aspects: key technologies of fuel cell and hydrogen maritime applications, cost and standards. It can be concluded that ships powered by hydrogen fuel cells will have a broad application prospect with the maturity of the hydrogen industry chain and the improvement of standards and regulations. Two main contributions of this paper are to fully understand a whole-process perspective of hydrogen and fuel cell maritime application, and to provide the problems and future direction in this field, which can help relevant research institutions and scholars evaluate the development status of the industrial chain and find new valuable research topics.
|
|
| 11. |
|
|
| 12. |
- Goding, Louise Charlotte, et al.
(författare)
-
Preferences for bio jet fuel in Sweden: The case of business travel from a city airport
- 2018
-
Ingår i: Sustainable energy technologies and assessments. - : Elsevier BV. - 2213-1388 .- 2213-1396. ; 29, s. 60-69
-
Tidskriftsartikel (refereegranskat)abstract
- A viable green alternative to petroleum-based jet fuel is urgently needed in order for the aviation industry to meet its environmental targets. This study elicited Swedish business organisations' willingness to pay (WTP) a price premium for flights using bio-fuel blends using a contingent valuation approach. It also examined whether certain company characteristics had an effect on the stated WTP. It was found that the overall mean price premium amounted to 11.9 percent of the base price of flights, which is not high enough to cover the actual costs to airlines of using a 50/50 fuel blend. Only one-third of the respondents reported sufficiently high WTP to cover the associated costs of using bio jet fuel at current price levels. Furthermore, organisations that encouraged employees to choose the least expensive ticket at all times had lower WTP than organisations with no explicit travel policy. Accordingly, use of least-cost travel policies would prevent commercialisation of bio jet fuel. Moreover, voluntary actions by organisations in the form of price premiums on green flights could not create Swedish market demand for bio jet fuel. Development of other policy instruments is therefore vital to establish long-term market predictability and demand.
|
|
| 13. |
- Harrucksteiner, Alexander, et al.
(författare)
-
A geospatial assessment of the techno-economic wind and solar potential of Mongolia
- 2023
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier BV. - 2213-1388 .- 2213-1396. ; 55, s. 102889-
-
Tidskriftsartikel (refereegranskat)abstract
- Even though the country's geographic and climatic characteristics are favourable for renewable energy tech-nology, Mongolia's power infrastructure has a large carbon footprint. Therefore, it is crucial to determine Mongolia???s economic potential for solar and wind energy. The technological and financial potential of solar and wind energy in Mongolia is determined in a two-step approach while considering the geographical feasibility. In order to include physical-geographical limits such as slope and socio-geographical constraints such as protected areas in the assessment of renewable energy potential, a GIS-based technique for assessing the appropriateness of possible renewable energy sites is first created. This is followed by an energy potential tool which calculates the technical and economic potential. The combined technical wind and solar potential is estimated to be 7.25 TW capacity and 12.17 PWh/year of electricity. The results indicate an economic wind potential capacity of 0 to 73.36 GW (0 to 123.10 TWh/year). The economic potential of ground-mounted PV is 5.12 TW (9.57 PWh/year) and rooftop PV is 1.11 GW (1.92 TWh/year). In addition, the estimated area suitable for wind power plants is 325 431 km(2), ground-mounted PV is 118 484 km(2) and rooftop PV is about 27 km(2).
|
|
| 14. |
- Hesaraki, Arefeh, PhD, 1987-, et al.
(författare)
-
A comparative review on the application of radiant low-temperature heating and high-temperature cooling for energy, thermal comfort, indoor air quality, design and control
- 2022
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier BV. - 2213-1388 .- 2213-1396. ; 49
-
Tidskriftsartikel (refereegranskat)abstract
- Radiant low-temperature heating (LTH) and high-temperature cooling (HTC) has become popular due to their high energy efficiency, thermal comfort, and improving indoor air quality. This system has been investigated in many studies from theory to practical applications. In this review article, LTH/HTC systems based on their results on energy usage, thermal comfort, indoor air quality, design and control are analysed and discussed. Furthermore, the radiant system with all-air systems are compared and the application of a hybrid system in different climate conditions is also presented. The outcome of this study revealed that in many studies radiant LTH/HTC systems can save between 10 and 30% energy and provide better thermal comfort compared to the all-air system. Moreover, combining a radiant system with a small-sized air system has a positive impact on indoor air quality and thermal comfort as required ventilation air is introduced and the latent load is removed. Overall, more studies are needed to monitor long-term performance of the building in use with radiant LTH/HTC to optimize the overall system performance and system design, and to extend its application in different climates and wide ranges of building types.
|
|
| 15. |
- Hultman, Erik, et al.
(författare)
-
A robotized 6-DOF dry test rig for wave power
- 2023
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier. - 2213-1388 .- 2213-1396. ; 59
-
Tidskriftsartikel (refereegranskat)abstract
- Wave power has the potential to contribute significantly to sustainability by reducing our global dependence on fossil fuels. Due to harsh conditions and high costs associated with offshore testing, lab experiments are favourable for resource-efficient validation and optimization in developing Wave Energy Converter (WEC) technologies. The limited scale and availability of existing wave tanks, and the limited flexibility of existing dry test rigs does however put significant restraints on such experiments. In this paper we introduce an alternative novel robotized dry test rig concept for wave power, evaluate its performance and discuss its potential. A full-scale robotized dry test rig demonstrator is constructed and used for experiments with a WEC prototype device. High motion flexibility and accuracy is thereby validated, also for repeating recorded wave and buoy motions. Compared to other dry test rigs, no special components were used and the motion trajectories were defined in full 6-Degrees-Of-Freedom. Two real-time hydrodynamic motion response methods are also demonstrated in the test rig, enabling emulation of actual offshore operation as well as development of advanced WEC control strategies. With a larger industrial robot manipulator, the introduced test rig concept could achieve realistic scaled force and power experiments with most point absorber WECs.
|
|
| 16. |
- Jaradat, M., et al.
(författare)
-
Liquid desiccant systems for cooling applications in broilers farms in humid subtropical climates
- 2022
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier Ltd. - 2213-1388 .- 2213-1396. ; 51
-
Tidskriftsartikel (refereegranskat)abstract
- This paper intends to numerically analyse the performance of liquid desiccant systems on the supply air conditions for closed poultry barns. A commercially available evaporative cooler for poultry barns was modified into a desiccant dehumidifier by circulating desiccant solutions of LiCl-H2O and CaCl2-H2O instead of water. Ambient air conditions for one of humid and subtropical climates were simulated based on an ∊-NTU effectiveness model for an externally cooled liquid desiccant dehumidifier. Also, a distinctive temperature-humidity index (THI) was implemented to study the environmental thermal conditions that the poultry were subjected to. Concerning the thermal comfort for broilers, the results show that conventional direct evaporative cooling systems are not feasible when the ambient air is near saturation. The THI values for ambient and direct evaporative cooler were positioned mainly in the severe heat stress region, with THI value in the range of 80 to 82, and most air outlet conditions were near saturation. The numerical results for the liquid desiccant systems show a consistent reduction in humidity ratio and air dry-bulb temperature. The assessment of air outlet temperature and humidity in terms of THI values was shifted out of the emergency and danger zone with a preference for LiCl solution.
|
|
| 17. |
- Jurasz, Jakub, et al.
(författare)
-
Component degradation in small-scale off-grid PV-battery systems operation in terms of reliability, environmental impact and economic performance
- 2020
-
Ingår i: Sustainable Energy Technologies and Assessments. - : ELSEVIER. - 2213-1388 .- 2213-1396. ; 38
-
Tidskriftsartikel (refereegranskat)abstract
- Photovoltaic systems supported by energy storage are commonly applied solutions for supplying power in off-grid locations. Properly designed systems can ensure reliability at a level comparable to conventional diesel generators. In addition, renewables-based systems not only have lower cost of maintenance (its operation is not fuel supply dependent) but also a significantly smaller environmental footprint. In this paper, a PV-battery system is designed to supply four different loads in a remote location. The cost of reliability as well as related emissions are estimated and compared with a diesel generator. In contrast to the previous approach, PV-battery system reliability of is determined in a long-term horizon. The performance of the PV-battery is influenced not only by the variability of irradiation and temperature but also the degradation of PV system efficiency and a drop in battery capacity. In the available literature these three aspects are frequently neglected but even if considered, then never simultaneously. Based on the conducted analysis the following conclusions are drawn: PV-battery system has a significantly lower environmental impact than a diesel generator but it is not close to zero as the system tends to be oversized and the utilization of PV generation is relatively low; the solar energy system supplies variable loads at a cost comparable to a diesel generator (0.68 (sic)/kWh) but for constant loads it is more expensive by over 0.3 (Sic).
|
|
| 18. |
- Kerkvliet, Hans, et al.
(författare)
-
Offshore wind farms’ decommissioning : a semi quantitativeMulti-Criteria Decision Aid framework
- 2016
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier BV. - 2213-1388 .- 2213-1396. ; 18, s. 69-79
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper a framework for identifying an appropriate decommissioning method for offshore windfarms is developed and applied. The whole approach is based on Multi-Criteria Decision Aid techniquesthat perform an integrated evaluation of three available wind farms’ decommissioning methods. A numberof evaluation criteria are established and assessed on a semi quantitative basis. The preference of adiverse audience of pertinent stakeholders can be also incorporated in the overall analysis. The frameworkis applied in a case-study in the Netherlands. Even though the stakeholders included were hypotheticaland their preferences only assumed the proposed overall approach, methodology andapplication could be useful for practitioners in the field.
|
|
| 19. |
- Khan, Ershad Ullah, et al.
(författare)
-
Techno-economic analysis of small scale biogas based polygeneration systems : Bangladesh case study
- 2014
-
Ingår i: Sustainable Energy Technologies and Assessments. - Amsterdam : Elsevier. - 2213-1388 .- 2213-1396. ; 7, s. 68-78
-
Tidskriftsartikel (refereegranskat)abstract
- Access to electricity, clean energy, and safe drinking water services are genuine needs of the rural poor for their welfare. These needs can be addressed either individually or in an integrated approach. Biogas digesters are promising in the rural setting and integration of biogas production with power generation and water purification is an innovative concept that could be applied in remote areas of Bangladesh. This paper presents a new concept for integrated biogas based polygeneration and analyzes the techno-economic performance of the scheme for meeting the demand of electricity, cooking energy and safe drinking water of 30 households in a rural village of Bangladesh. The specific technologies chosen for the key energy conversion steps are as follows: plug-flow digester; internal combustion engine; and air-gap membrane distillation. Mass flows and energy balance, levelized cost of producing electricity, cooking gas and safe drinking water as well as the payback period of such a polygeneration system were analyzed. The results indicate that this polygeneration system is much more competitive and promising (in terms of levelized cost) than other available technologies when attempting to solve the energy and arsenic-related problems in Bangladesh. The payback period of such system is between 2.6 and 4 years.
|
|
| 20. |
- Khullar, Subodh, et al.
(författare)
-
Influence of runner cone profile and axial water jet injection in a low head Francis turbine at part load
- 2022
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier. - 2213-1388 .- 2213-1396. ; 50
-
Tidskriftsartikel (refereegranskat)abstract
- Development of rotating vortex rope (RVR) at part load (PL) operation is a source of pressure fluctuations in draft tube and power swings, which may lead to runner failure under extreme conditions. Fluid injection methodologies like air and water injection may be employed to mitigate the RVR and the pressure pulsations associated with it. A small turbine test rig is being developed at IIT Roorkee (India) to study the effect of the fluid injection measures (air/ water) in the Francis turbine. The present work summarizes a preliminary numerical investigation of the runner cone design and water jet injection to be used in the test rig. The runner cone is modified to incorporate provisions for axial water jet injection. Two different runner cone designs have been compared based on power output, efficiency, pressure recovery, and pressure pulsations in the draft tube for four different jet discharges. The water jet affects both the magnitude and the frequency of the pressure pulsations associated with RVR, and improves the overall efficiency. The results also indicate that the water jet injection may not always be effective and may increase pressure fluctuations in some cases.
|
|
| 21. |
- Ma, Shengyuan, et al.
(författare)
-
Indoor thermal environment in a rural dwelling heated by air-source heat pump air-conditioner
- 2022
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier BV. - 2213-1388 .- 2213-1396. ; 51
-
Tidskriftsartikel (refereegranskat)abstract
- Air-source heat pumps (ASHP) are increasingly used to improve space heating. However, few relevant studies have focused on the rural residential buildings that use ASHP air-conditioners for heating conditions. Therefore, this paper presents experiments and numerical simulations to analyse the impact of ASHP air-conditioners on the indoor thermal environment of a rural dwelling during heating seasons. In this study, the influences of different air-supply parameters (temperature, angle and velocity of air supply) and the position of the ASHP airconditioner on the local thermal comfort were evaluated. The influence weights of both the above factors and their interaction were obtained. The simulation results showed that the temperature differences between the head and foot region (Delta Th-f) in most cases exceeded 3.0celcius, demonstrating the thermal comfort in the rural dwelling was more unacceptable than the urban buildings. Moreover, the results of orthogonal design indicated that air-supply velocity had the most significant impact on the Delta Th-f values, followed by the air-supply temperature, air-supply angle and installation height. Reducing any air-supply parameter or enhancing the installation height might improve the thermal comfort performance. This research can provide practical strategies for improving the indoor thermal environment of rural dwellings, and guide the design of ASHP air-conditioning systems.
|
|
| 22. |
- Martinez-Manuel, Leopoldo, et al.
(författare)
-
Optimization of the radiative flux uniformity of a modular solar simulator to improve solar technology qualification testing
- 2021
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier BV. - 2213-1388 .- 2213-1396. ; 47
-
Tidskriftsartikel (refereegranskat)abstract
- Solar simulators are key facilities for conducting solar research and certification tests under a well-controlled environment. This study presents the optical design optimization of a modular low flux solar simulator to improve solar technology qualification testing. The optical system was designed as a multi-lamp array of 26 subunits. Each subunit consists of a 575 We metal halide lamp and a parabolic reflector. The Monte Carlo ray tracing technique was used for analyzing the optical performances of the proposed design. Reflector design parameters were analyzed in detail for optimizing the uniformity of the flux distribution on the target. Results show that an average flux of 1198 W/m(2) over a target area of 2000 mm x 1000 mm, with a conversion efficiency of 25.7% and a sustained non-uniformity of only 1.4% was numerically achieved, predicting a Class A solar simulator for large target areas. A shutter curtain was modeled and introduced between the light source and the target for flux regulation, achieving average flux levels ranging from 1162 to 105 W/m(2) with a resolution of approximately 100 W/m(2). The modular nature of this design has the great advantage that it could be easily scaled according to the test requirements of potential solar systems.
|
|
| 23. |
- Olsson, Andreas, 1990-, et al.
(författare)
-
Strategic development of environmental impact assessment decision support tool for offshore energy enables decreased costs, increased utilization, and quality
- 2023
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier. - 2213-1388 .- 2213-1396. ; 60
-
Tidskriftsartikel (refereegranskat)abstract
- In the transition to a sustainable energy system, there is an urgent need for expansion of offshore renewable energy installations. To ensure sustainable development also with respect to the marine environment, a variety of decision support tools (DSTs) are currently under development, aiming at potentially increased quality and efficiency for environmental risk assessment (EIA) of planned offshore energy installations. However, the savings potential of a DSTs is to a large extent governed by the timing of the DST development, which in turn is directly dependent on the investment rate over time. A set of development scenarios were evaluated, simulating different degrees of strategic implementation and successful utilization of the DST for offshore energy. Using the situation in Sweden as a case study, we demonstrate that a planned investment can lead to considerably lower total costs for the EIA at a national level, at the same time allowing for improved quality of the EIA in line with the ambitions in both marine spatial planning and existing goals within marine environmental management. © 2023 The Author(s)
|
|
| 24. |
- Pandya, Sharnil, Researcher, 1984-, et al.
(författare)
-
Federated learning for smart cities : A comprehensive survey
- 2023
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier. - 2213-1388 .- 2213-1396. ; 55
-
Tidskriftsartikel (refereegranskat)abstract
- With the advent of new technologies such as the Artificial Intelligence of Things (AIoT), big data, fog computing, and edge computing, smart city applications have suffered from issues, such as leakage of confidential and sensitive information. To envision smart cities, it will be necessary to integrate federated learning (FL) with smart city applications. FL integration with smart city applications can provide privacy preservation and sensitive information protection. In this paper, we present a comprehensive overview of the current and future developments of FL for smart cities. Furthermore, we highlight the societal, industrial, and technological trends driving FL for smart cities. Then, we discuss the concept of FL for smart cities, and numerous FL integrated smart city applications, including smart transportation systems, smart healthcare, smart grid, smart governance, smart disaster management, smart industries, and UAVs for smart city monitoring, as well as alternative solutions and research enhancements for the future. Finally, we outline and analyze various research challenges and prospects for the development of FL for smart cities.
|
|
| 25. |
- Persson, Tomas, et al.
(författare)
-
Low temperature heating system for greenhouses based on enclosed water curtain and liquid foam insulation
- 2022
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier BV. - 2213-1388 .- 2213-1396. ; 53:Part A
-
Tidskriftsartikel (refereegranskat)abstract
- A greenhouse water curtain heating system allows heating of the greenhouse by low-temperature water, which can be obtained from residual waste heat sources. The water curtain can be applied on the outside of the greenhouse roof or enclosed between two foils. But also enclosed water curtains suffer from high heat losses, which limits the integration of low temperature waste heat sources. An effective way of reducing the heat losses is to combine the water curtain system with retractable liquid foam enclosed between two foils. But until now, a systematic evaluation of the thermal performance of such system combination is still lacking. Thus, this study aims to fill in this research gap by evaluating the heat transfer characteristics of a double-foil greenhouse roof section installed with a combined water curtain and liquid foam system. Experimental tests have been conducted under a wide range of temperature scenarios in a climate chamber where the heat loss and heat gains from the water curtain is measured. The results have been compared with the data in the existing studies. This study revealed that combining the water curtain system with liquid foam, reduces the heat losses by half compared to using just the water curtain: the heat loss coefficient was reduced from 4.4 W·m−2·K−1 down to 2.0 W·m−2·K−1. The heat losses through the roof using the combined system are also lower than the heat losses from a double foil greenhouse with other heating systems. An average water curtain temperature of 5.1 °C above the inside greenhouse temperature can compensate for the heat losses through the roof at an outdoor temperature of −19 °C. Based on the study results, recommendations for market implantation of this technology are provided. This study confirms energetic benefit of combining water curtains and the liquid foam technology.
|
|
| 26. |
- Prasshanth, C.V., et al.
(författare)
-
Enhancing photovoltaic module fault diagnosis: Leveraging unmanned aerial vehicles and autoencoders in machine learning
- 2024
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier. - 2213-1388 .- 2213-1396. ; 64
-
Tidskriftsartikel (refereegranskat)abstract
- Photovoltaic (PV) modules play a pivotal role in renewable energy systems, underscoring the critical need for their fault diagnosis to ensure sustained energy production. This study introduces a novel approach that combines the power of deep neural networks and machine learning for comprehensive PV module fault diagnosis. Specifically, a fusion methodology that incorporates autoencoders (a deep neural network architecture) and support vector machines (SVM) (a machine learning algorithm) is proposed in the present study. To generate high-quality image datasets for training, unmanned aerial vehicles (UAVs) equipped with RGB cameras were employed to capture detailed images of PV modules. Burn marks, snail trails, discoloration, delamination, glass breakage and good panel were the conditions considered in the study. The experimental results demonstrate remarkable accuracy of 98.57% in diagnosing faults, marking a significant advancement in enhancing the reliability and performance of PV modules. This research contributes to the sustainability and efficiency of renewable energy systems, underlining its importance in the quest for a cleaner, greener future.
|
|
| 27. |
- Venkatesh, Naveen, et al.
(författare)
-
A comparative study on bayes classifier for detecting photovoltaic module visual faults using deep learning features
- 2024
-
Ingår i: Sustainable Energy Technologies and Assessments. - 2213-1388 .- 2213-1396. ; 64
-
Tidskriftsartikel (refereegranskat)abstract
- Renewable energy is found to be an effective alternative in the field of power production owing to the recent energy crises. Among the available renewable energy sources, solar energy is considered the front runner due to its ability to deliver clean energy, free availability and reduced cost. Photovoltaic (PV) modules are placed over large geographical regions for efficient solar energy harvesting, making it difficult to carry out maintenance and restoration works. Thermal stresses inherited by photovoltaic modules (PVM) under varying environmental conditions can lead to failure of internal components. Such failures when left undetected impart a number of complications in the system that will lead to unsafe operation and seizure. To avoid the aforementioned uncertainties, frequent monitoring of PVM is found necessary. The fault identification in PVM using essential features taken from aerial images is presented in this study. The feature extraction procedure was carried out using convolutional neural networks (CNN), while the feature selection process was carried out by the J48 decision tree method. Six test conditions were considered such as delamination, glass breakage, discoloration, burn marks, snail trail, and good panel. Bayes Net (BN) and Naïve Bayes (NB) classifiers were utilized as primary classifiers for all the test conditions. Results obtained from the classifiers were compared and the best classifier for fault detection in PVM is suggested.
|
|
| 28. |
- Villarroel-Schneider, Johnny, et al.
(författare)
-
Biogas based polygeneration plant options utilizing dairy farms waste : A Bolivian case
- 2020
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier. - 2213-1388 .- 2213-1396. ; 37
-
Tidskriftsartikel (refereegranskat)abstract
- This study presents a comparative techno-economic feasibility analysis for two polygeneration plant solutions, applied to low-income dairy farms in Bolivia. The first option considers an internally fired microturbine (IFMT) and, the second, an internal combustion engine (ICE). They are integrated with an absorption refrigeration system and a fertilizer dryer. Biogas, produced with farms waste, fuels these power generators. The levelized costs of biogas for cooking, electricity, cooling and fertilizers were determined. The cost of biogas, for both options, was found to be 0.020 USD/kWh, which is lower than the subsidized price of LPG. The most competitive cost of electricity was determined for the ICE plant option; it was found to be 0.082 USD/kWh and is lower than the subsidized cost of fossil fuel-based electricity. The cost of cooling was found to be around 0.082 USD/kWh, which is slightly higher than the cost of cooling supplied by using grid electricity. In a realistic scenario, the shorter payback period was found to be 4.4 years for the ICE plant option. From this, the ICE-based plant was found as the most feasible option. Additionally, if no subsidies are applied to the fossil fuel-based services, the proposed polygeneration systems are a highly competitive alternative.
|
|
| 29. |
- Wallin, Jörgen, 1972-, et al.
(författare)
-
Analyzing the efficiency of a heat pump assisted drain water heat recovery system that uses a vertical inline heat exchanger
- 2014
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier BV. - 2213-1388 .- 2213-1396. ; 8, s. 109-119
-
Tidskriftsartikel (refereegranskat)abstract
- The purpose of the present study is to accumulate knowledge on how a drain water heat recovery system using a vertical inline heat exchanger and a heat pump performs under different drain water flow profile scenarios. Investigating how the intermittent behavior of the drain water influences the performance for this type of system is important because it gives insight on how the system will perform in a real life situation. The scenarios investigated are two 24. h drain water flow rate schedules and one shorter schedule representing a three minute shower.The results from the present paper add to the knowledge on how this type of heat recovery system performs in a setting similar to a multi-family building and how sizing influences the performance. The investigation shows that a heat recovery system of this type has the possibility to recover a large portion of the available heat if it has been sized to match the drain water profile. Sizing of the heat pump is important for the system performance; sizing of the storage tank is also important but not as critical.
|
|
| 30. |
- Wang, F., et al.
(författare)
-
Do ‘green’ data centres really have zero CO2 emissions?
- 2022
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier Ltd. - 2213-1388 .- 2213-1396. ; 53
-
Tidskriftsartikel (refereegranskat)abstract
- The claim of a green data centre is generally made based on a net-zero CO2 emission through a ‘balance-sheet’ approach, which considers renewable electricity through on-site installation or purchase agreement as abatement measures against the use of fossil electricity from the electric grid on an annual basis. However, when the hourly dynamic fuel mix is accounted for in the assessment, the annual net-zero energy approach does not lead to a true carbon neutral data centre. In response, two approaches based on net-zero energy and net-zero CO2 emission respectively are proposed and investigated regarding the goal of net-zero CO2 emission. A data centre in Singapore with typical load profiles is used as a case study, different scenarios considering climate change and projected future energy are defined to examine the impacts of dynamic energy mix on the net CO2 emission of the data centre. The net-zero energy approach is found to result in significant amount of annual CO2 emissions. In comparison, the net-zero CO2 emission approach can assure a true net-zero CO2 emission, but this approach will require an increase of PV capacity by 20% and 60% as compared to the net-zero energy approach based on assessment for the year 2030 and 2050, respectively.
|
|
| 31. |
- Yang, S., et al.
(författare)
-
Economic feasibility of using fuel cells as backup power supply in data centers
- 2024
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier Ltd. - 2213-1388 .- 2213-1396. ; 69
-
Tidskriftsartikel (refereegranskat)abstract
- The backup power system (BPS) is essential to data centers (DCs) in case of grid outage. Currently, the diesel generator (DG) is the most commonly used solution. However, due to the need of decarbonization, fuel cells (FCs) are emerging as a promising alternative. This paper conducts a holistic economic analysis to investigate the benefit from using FCs to replace DGs, which takes into account more key impact factors. Different requirements by different Tiers of DCs, such as on the BPS runtime and the BPS test time, are considered. Under the benchmark condition, i.e. 800 USD/kW for the FC capital cost, 4.8 USD/kg, 1.25 USD/L and 90 USD/ton for hydrogen, diesel, and CO2 prices, the payback period is 13.4 years and 13.1 years when using FCs to replace DGs for Tier 1–2 DCs and Tier 3 DCs. Since Tier 4 DCs require more units, FCs can be economically feasible if the FC capital cost reduces by 20.3 %, the diesel price increases by 19.7 %, or the green hydrogen price decreases by 35.5 %, compared to the benchmark conditions. Among the factors, the FC capital cost, the diesel price, and the hydrogen price are found to affect the payback period mostly.
|
|
| 32. |
- Yu, H., et al.
(författare)
-
Improved triangle splitting based bi-objective optimization for community integrated energy systems with correlated uncertainties
- 2022
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier Ltd. - 2213-1388 .- 2213-1396. ; 49
-
Tidskriftsartikel (refereegranskat)abstract
- Economic and environmental benefits are the most important in the operation of community integrated energy systems (CIES), modeled as a bi-objective optimization problem. In the case of the uncertainties from loads and renewable energy generators, the effectiveness of the operation strategies may be degraded in the practical applications of CIES. In this paper, an improved triangle splitting based bi-objective optimization method is proposed to search for the Pareto optimal solution of the CIES operation. The general preference of decision-makers in practical applications is utilized in the search process to reduce the detailed search interval and consequently improve the optimization efficiency. In addition, a bi-objective uncertain optimization framework is established for the economic-environmental operation of the CIES under uncertainties. The correlation between uncertainties is considered to generate the operation scenarios, in which the solution probability function is employed to determine the final operation strategy with robustness. A comprehensive case study is conducted based on a practical CIES in China, proving the feasibility and effectiveness of the proposed methods.
|
|
| 33. |
- Zhao, Ruikai, et al.
(författare)
-
Comparative study on energy efficiency of moving-bed adsorption for carbon dioxide capture by two evaluation methods
- 2021
-
Ingår i: Sustainable Energy Technologies and Assessments. - : ELSEVIER. - 2213-1388 .- 2213-1396. ; 44
-
Tidskriftsartikel (refereegranskat)abstract
- Because of the fast heat transfer and the low pressure drop, the technology of moving-bed adsorption for carbon dioxide capture is gathering the momentum in the last decade. The primary aim of this paper is to investigate the influence of various parameters on the energy-efficiency performance of moving-bed adsorption for CO2 capture. The relevant parameters involve desorption temperature, desorption pressure, CO2 capture rate and CO(2 )mole fraction of flue gas. The energy efficiency assessment of moving bed is performed and compared in the light of the minimum separation work and the second-law efficiency. Moreover, two evaluation approaches, which are the thermodynamic carbon pump model and regeneration separation model, are employed and compared as well. Results indicate that the values of minimum separation work for CO(2 )capture by moving bed, which are calculated by regeneration separation model, are about 15% higher than those of thermodynamic carbon pump model under the same conditions. Furthermore, the second-law efficiencies of both models are approximately 10% under the given conditions. It is also found that the regeneration separation model is closer to real status owing to the additional consideration of the adsorption isotherm equilibrium data.
|
|
| 34. |
|
|
| 35. |
- Stolfo, Davide, et al.
(författare)
-
Sex-Based Differences in Heart Failure Across the Ejection Fraction Spectrum Phenotyping, and Prognostic and Therapeutic Implications
- 2019
-
Ingår i: JACC. Heart failure. - : ELSEVIER SCI LTD. - 2213-1779 .- 2213-1787. ; 21, s. 505-505
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES This study assessed sex-related differences in a large cohort of unselected patients with heart failure (HF) across the ejection fraction (EF) spectrum. BACKGROUND Females are under-represented in randomized clinical trials. Potential sex-related differences in HF may question the generalizability of trials. METHODS In the Swedish Heart Failure Registry population multivariate Cox and logistic regression models were fitted to investigate differences in prognosis, prognostic predictors, and treatments across mates and females. RESULTS Of 42,987 patients, 37% were females (55% with HF with preserved EF [HFpEF], 39% with HF with mid-range EF [HFmrEF], and 29% with HF with reduced EF [HFrEF]). Females were older and more symptomatic and more likely to have hypertension and kidney disease but less likely to have diabetes and ischemic heart disease. After adjustments, females were more likely to use beta-blockers and digoxin but less likely to receive HF device therapy. Crude mortality/HF hospitalization rates for HFpEF (hazard ratio [HR]: 1.16) and HFmrEF (HR: 1.14) were significantly higher in females but lower in females with HFrEF (HR: 0.95). After adjustments, the risk was significantly tower in females regardless of EF (HR: 0.80 in HFrEF, HR: 0.91 in HFmrEF, and HR: 0.93 in HFpEF). The main sex-related differences in prognostic predictors concerned diabetes in HFrEF and anemia in HFmrEF. CONCLUSIONS Mates and females with HF showed different characteristics across the EF spectrum. Mates reported a lower crude risk of mortality/morbidity in HFpEF and HFmrEF but higher risk of HFrEF, although after adjustments, prognosis was better in females regardless of EF. The observed sex-related differences highlight the need for an adequate representation of females in HF randomized controlled trials to improve generatizabitity.
|
|
| 36. |
- Taylor, Peter N, et al.
(författare)
-
C-peptide and metabolic outcomes in trials of disease modifying therapy in new-onset type 1 diabetes: an individual participant meta-analysis
- 2023
-
Ingår i: The Lancet Diabetes and Endocrinology. - : Elsevier. - 2213-8587 .- 2213-8595. ; 11:12, s. 915-925
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Metabolic outcomes in type 1 diabetes remain suboptimal. Disease modifying therapy to prevent β-cell loss presents an alternative treatment framework but the effect on metabolic outcomes is unclear. We, therefore, aimed to define the relationship between insulin C-peptide as a marker of β-cell function and metabolic outcomes in new-onset type 1 diabetes.Methods: 21 trials of disease-modifying interventions within 100 days of type 1 diabetes diagnosis comprising 1315 adults (ie, those 18 years and older) and 1396 children (ie, those younger than 18 years) were combined. Endpoints assessed were stimulated area under the curve C-peptide, HbA1c, insulin use, hypoglycaemic events, and composite scores (such as insulin dose adjusted A1c, total daily insulin, U/kg per day, and BETA-2 score). Positive studies were defined as those meeting their primary endpoint. Differences in outcomes between active and control groups were assessed using the Wilcoxon rank test.Findings: 6 months after treatment, a 24·8% greater C-peptide preservation in positive studies was associated with a 0·55% lower HbA1c (p<0·0001), with differences being detectable as early as 3 months. Cross-sectional analysis, combining positive and negative studies, was consistent with this proportionality: a 55% improvement in C-peptide preservation was associated with 0·64% lower HbA1c (p<0·0001). Higher initial C-peptide levels and greater preservation were associated with greater improvement in HbA1c. For HbA1c, IDAAC, and BETA-2 score, sample size predictions indicated that 2-3 times as many participants per group would be required to show a difference at 6 months as compared with C-peptide. Detecting a reduction in hypoglycaemia was affected by reporting methods.Interpretation: Interventions that preserve β-cell function are effective at improving metabolic outcomes in new-onset type 1 diabetes, confirming their potential as adjuncts to insulin. We have shown that improvements in HbA1c are directly proportional to the degree of C-peptide preservation, quantifying this relationship, and supporting the use of C-peptides as a surrogate endpoint in clinical trials.
|
|
| 37. |
- Kumar, Amit, et al.
(författare)
-
Anticipating the impact of glaciers, landslides and extreme weather events on vulnerable hydropower projects and the development of an integrated multi-hazard warning system (IMWS)
- 2024
-
Ingår i: Sustainable Energy Technologies and Assessments. - 2213-1388. ; 65
-
Tidskriftsartikel (refereegranskat)abstract
- The Himalayan river basins offer great potential for hydropower development, but they are also vulnerable to various hazards such as debris flows, landslides, flash floods, glacial lake outburst floods (GLOFs), and landslide lake outburst floods (LLOFs). Despite the regional and global significance of these hazards, there is a lack of information and data on different aspects, including meteorology, hydrology, geology, and seismology. Many hazards often go unnoticed or receive little attention until they start affecting humans and their activities like damage to buildings, infrastructure, and other human-made structures. It is important to recognize that hazards can have severe and long-lasting impacts on society, even when they do not directly affect humans. For example, flash floods can disrupt ecosystems, destroy habitats, and threaten biodiversity and the complexity of climatic influences on both regional and local scales cannot be overlooked. Therefore, we highlight the importance of basin-wise and basin-wide continuous long-term monitoring in the Himalaya. It is also recommended that the highest hydropower projects in the basins should have their network of hydro-meteorological observatories at different altitudes with a provision of real-time data transmission and deployment of a multi-hazard warning system (IMWS) for flash floods.
|
|
| 38. |
- Larsson, Mårten, et al.
(författare)
-
Bio-methane upgrading of pyrolysis gas from charcoal production
- 2013
-
Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 3, s. 66-73
-
Tidskriftsartikel (refereegranskat)abstract
- This article presents a novel route for bio-methane synthesis utilizing pyrolysis gas from charcoal production. It is a retrofit option that may increase overall process efficiency in charcoal production while adding a valuable product. The pyrolysis gas from charcoal production can be used for bio-methane production instead of burning, while the required heat for the charcoal production is supplied by additional biomass. The aim is to evaluate the energy efficiency of bio-methane upgrading from two types of charcoal plants, with and without recovery of liquid by-products (bio-oil). Aspen simulations and calculations of the energy and mass balances are used to analyse the system. The yield of bio-methane compared to the import of additional biomass is estimated to be 81% and 85% (biomass to bio-methane yield) for the syngas case and the pyrolysis vapour case, respectively. When the biomass necessary to produce the needed electricity (assuming ηel = 33%) is included, the yields amount to 65% and 73%. The results show that the suggested process is a competitive production route for methane from lignocellulosic biomass.
|
|
| 39. |
- Lindroos, Tomi J., et al.
(författare)
-
Robust decision making analysis of BECCS (bio-CLC) in a district heating and cooling grid
- 2019
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier BV. - 2213-1388. ; 34, s. 157-172
-
Tidskriftsartikel (refereegranskat)abstract
- Additional investments to negative emission technologies, such as reforestation or bioenergy with carbon capture and storage (BECCS), are required to achieve Paris Agreement targets. Chemical-looping combustion of biomass (Bio-CLC)is an under-the-development combustion technology that could provide relatively low cost negative CO2 emissions. We modelled Bio-CLC units as a part of a city-level district heating and cooling (DHC)grid based on literature and our experimental work with Bio-CLC pilot plants. We applied robust decision-making (RDM)to identify preconditions that favour Bio-CLC over certain competing investment options. In the selected case study, a Bio-CLC unit had a 50% chance to be profitable (10% Internal rate of return or better)around the level of 10 €/tCO2 net income from captured bio-CO2. If the net income from captured bio-CO2 was below 10 €/tCO2, as currently, large heat pumps with COP of 3.5 were the most robust of the studied investment options. Traditional bio-CHP performed better than large heat pumps only when electricity market price was above 50 €/MWh and biomass price below 20 €/MWh. Performed RDM analysis provides a systemic background for both technology developers and DHC operators when considering the competitiveness of the technology in an uncertain future.
|
|
| 40. |
- Lohani, Sunil Prasad, et al.
(författare)
-
Small-scale biogas technology and clean cooking fuel: Assessing the potential and links with SDGs in low-income countries – A case study of Nepal
- 2021
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier BV. - 2213-1388. ; 46:101301
-
Tidskriftsartikel (refereegranskat)abstract
- Small-scale biogas technology has been instrumental in providing clean cooking fuel in several low-income countries. This study investigates the role of domestic biogas technologies in meeting the Sustainable Development Goal (SDG) 7.1, i.e., the share of the population using modern cooking solutions, considering a case study in Nepal. The country has an over 60 years’ successful history in the development of household biogas technologies with more than 431,000 biogas plants installation in close co-operation with different stakeholders including government, international development agencies, and private companies. There has not been an appreciable technological development over several decades of biogas promotion in Nepal, nonetheless, there is a need for indigenous technologies that can cope with multi-feedstock and fluctuating ambient temperature. Household bio-digester is one of viable options for simultaneously producing clean energy source (i.e. biogas) and nutrient-rich digestate (i.e. bio-fertilizer). In Nepal, less than one percent of the total biogas potential has been harnessed despite the government’s support and financing schemes. The total potential of biogas production from livestock manure is estimated to be about 3043.58 million m3/year when the full potential will be utilized. The corresponding avoided emissions would be 4.35 million tonnes CO2eq/year. Clean cooking fuel from domestic biogas technology could help in achieving SDGs in low-income countries when plans and policies for promoting robust small-scale biogas technology are in place. This study also explores the complementarity and synergies of biogas development and their interlinkages with other SDGs.
|
|
| 41. |
- Salomon Popa, Marianne, 1976-, et al.
(författare)
-
Technical polygeneration potential in palm oil mills in Colombia : A case study
- 2013
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier. - 2213-1388. ; 3, s. 40-52
-
Tidskriftsartikel (refereegranskat)abstract
- Agricultural residues offer the possibility of reducing fossil fuel consumption, increasing energy security, and lowering greenhouse gas emissions. However, certain residues, like palm oil residues, either represent a disposal problem for the processing industries or they are not used and thus, there is a considerable potential for improvement. These factors represent a strong driving force for the development of innovative polygeneration plants based on solid residues. This paper considers an energy analysis of a Palm Oil Mill (POM) in Colombia processing 30 ton of Fresh Fruit Bunch per hour (FFB/h). Different heat and power generation options were considered with solid residues as feedstock. These configurations included steam cycles using backpressure or condensing-extraction turbines. The possibilities to produce pellets from the residues and biodiesel from palm oil were also analyzed. The steam cycle base operational parameters were 20 bar and 350 °C. More advanced steam conditions (40 bar) were also considered. The results show that it is possible to cover the demand of the POM and the required energy demand for residues preparation including possible pelletization and also biodiesel production. It is possible to obtain an excess of electricity between 0.4 and 3 MW if only residues are used.
|
|
| 42. |
- Xiong, Qingang, et al.
(författare)
-
A comprehensive review on the application of hybrid nanofluids in solar energy collectors
- 2021
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier BV. - 2213-1388. ; 47
-
Tidskriftsartikel (refereegranskat)abstract
- Over the years, nanofluids have proved to be beneficial in various heat transfer applications, particularly in solar energy collectors. Hybrid nanofluids have also shown promise in such applications due to their enhanced thermal conductivity relative to mono-nanofluids and to pure fluids. The aim of this review paper is to scrutinize recent research in this topic in order to identify the key advantages and disadvantages of hybrid nanofluids as heat transfer agents in solar energy collectors. First, the various types of non-concentrating and concentrating solar collectors are described. Then, recent research on hybrid nanofluids is summarized and discussed. Most studies have reported significant enhancements in the thermal and optical performance of solar thermal energy devices operating on hybrid nanofluids. The thermal efficiency was found to be proportionally dependent on the nanoparticles' fraction in regular fluids with reasonable values. Finally, the limitations of the presented studies, relating to considerations such as stability and pumping power requirements, as well as recommendations for future investigation are addressed.
|
|
