Pub Date : 2019-07-01DOI: 10.1109/OSES.2019.8867217
A. Koen, Pau Farres Antunez, A. White
Electricity storage is widely regarded as critical to a sustainable energy future, and currently deployed technologies such as pumped hydroelectric storage have drawbacks which limit the scale to which they can be implemented. Pumped thermal energy storage (PTES) has recently started to attract interest as an alternative. This article focuses on transcritical cycles and aims to identify the best working fluids, in a configuration with a single hot store and no cold store. Three different storage media were considered for the hot store: water, Therminol D12, and Therminol 66. For the transcritical cycle, 176 different working fluids were screened for thermodynamic, environmental and safety suitability, and the resulting list of 8 fluids was tested with cycles at a range of storage temperatures. The optimal round-trip efficiency is a trade-off between heat exchanger losses and turbomachinery losses. Pareto fronts were used to rank the fluids for efficiency, power density, and heat to work ratio. The most promising fluid was found to be trifluoroiodomethane (R13I1) with a peak round-trip efficiency of 57.6%.
{"title":"A study of working fluids for transcritical pumped thermal energy storage cycles","authors":"A. Koen, Pau Farres Antunez, A. White","doi":"10.1109/OSES.2019.8867217","DOIUrl":"https://doi.org/10.1109/OSES.2019.8867217","url":null,"abstract":"Electricity storage is widely regarded as critical to a sustainable energy future, and currently deployed technologies such as pumped hydroelectric storage have drawbacks which limit the scale to which they can be implemented. Pumped thermal energy storage (PTES) has recently started to attract interest as an alternative. This article focuses on transcritical cycles and aims to identify the best working fluids, in a configuration with a single hot store and no cold store. Three different storage media were considered for the hot store: water, Therminol D12, and Therminol 66. For the transcritical cycle, 176 different working fluids were screened for thermodynamic, environmental and safety suitability, and the resulting list of 8 fluids was tested with cycles at a range of storage temperatures. The optimal round-trip efficiency is a trade-off between heat exchanger losses and turbomachinery losses. Pareto fronts were used to rank the fluids for efficiency, power density, and heat to work ratio. The most promising fluid was found to be trifluoroiodomethane (R13I1) with a peak round-trip efficiency of 57.6%.","PeriodicalId":416860,"journal":{"name":"2019 Offshore Energy and Storage Summit (OSES)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115623082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/OSES.2019.8867324
M. Trabelsi, J. Charpentier, F. Scuiller, Christopher Franquet, E. Nicolas
To smooth the power fluctuations induced by marine current speed and to satisfy standard grid constraints, the tidal current turbine system should be combined with an energy storage unit (ESU). However, adding ESU into the existing system results in a complex structure of the entire electromechanical conversion chain that needs appropriate tools for system modeling and control development. For that purpose, this paper focuses on the use of a graphical tool based on energetic macroscopic representation (EMR) in order to model the system and design control schemes of a grid-connected tidal current turbine system including a supercapacitor-based energy storage. The transcription of EMR to Matlab/Simulink environment through the available EMR library allows a simple development of overall system control using the inversion-based rules. Simulation results, obtained from the developed simulator, are shown and discussed.
{"title":"Energetic Macroscopic Representation and Inversion-Based Control of a Grid-Connected MCT Power Generation System with Super-Capacitor Based Energy Storage Unit in Ushant Island","authors":"M. Trabelsi, J. Charpentier, F. Scuiller, Christopher Franquet, E. Nicolas","doi":"10.1109/OSES.2019.8867324","DOIUrl":"https://doi.org/10.1109/OSES.2019.8867324","url":null,"abstract":"To smooth the power fluctuations induced by marine current speed and to satisfy standard grid constraints, the tidal current turbine system should be combined with an energy storage unit (ESU). However, adding ESU into the existing system results in a complex structure of the entire electromechanical conversion chain that needs appropriate tools for system modeling and control development. For that purpose, this paper focuses on the use of a graphical tool based on energetic macroscopic representation (EMR) in order to model the system and design control schemes of a grid-connected tidal current turbine system including a supercapacitor-based energy storage. The transcription of EMR to Matlab/Simulink environment through the available EMR library allows a simple development of overall system control using the inversion-based rules. Simulation results, obtained from the developed simulator, are shown and discussed.","PeriodicalId":416860,"journal":{"name":"2019 Offshore Energy and Storage Summit (OSES)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115192181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/OSES.2019.8867078
R. Loisel, Corentin Simon, M. Woznicki, Mathias Guérineau, Laurent Baranger, L. Lemiale, E. Schaeffer, G. Le Solliec
The French strategy on hydrogen deployment shows good perspectives at 2050, yet at short term, the economics of clean hydrogen remains ambiguous, and locally inhibits investments. This study evaluates wind-hydrogen project applications at different milestones, following a roadmap of hydrogen industry maturity built over the entire supply chain. Simple linear interpolations are assumed to draw the path of deployment and pave the way for the H2 ecosystem. Hydrogen is here obtained from a dedicated far-offshore wind farm and targets primarily the use in transportation, following policy agenda priorities of maritime transport which could also trigger the H2 demand in industry, gas and power sector. By means of an optimization algorithm, the operation of hybrid wind-hydrogen is simulated to set the size of the necessary infrastructure, under the constraint of H2 delivery timeline (daily or weekly). For instance, the harbor of Saint-Nazaire will distribute at least 4 t H2 per day in 2050 for maritime and road transport, needing the installation of 60 MW of wind energy capacity. Residually it could supply 1,880 t H2 for industry and energy sector, yet, the sectors' coupling hinders business ecosystem building that remains essential to economies of scale and industry establishment. These orders of magnitudes are crucial for the hydrogen industry planning and highly needed by policy makers to set commitments and build regional hydrogen roadmaps for next decades.
{"title":"Green hydrogen multi-market optimisation: real complementarities or temporary transaction costs?","authors":"R. Loisel, Corentin Simon, M. Woznicki, Mathias Guérineau, Laurent Baranger, L. Lemiale, E. Schaeffer, G. Le Solliec","doi":"10.1109/OSES.2019.8867078","DOIUrl":"https://doi.org/10.1109/OSES.2019.8867078","url":null,"abstract":"The French strategy on hydrogen deployment shows good perspectives at 2050, yet at short term, the economics of clean hydrogen remains ambiguous, and locally inhibits investments. This study evaluates wind-hydrogen project applications at different milestones, following a roadmap of hydrogen industry maturity built over the entire supply chain. Simple linear interpolations are assumed to draw the path of deployment and pave the way for the H2 ecosystem. Hydrogen is here obtained from a dedicated far-offshore wind farm and targets primarily the use in transportation, following policy agenda priorities of maritime transport which could also trigger the H2 demand in industry, gas and power sector. By means of an optimization algorithm, the operation of hybrid wind-hydrogen is simulated to set the size of the necessary infrastructure, under the constraint of H2 delivery timeline (daily or weekly). For instance, the harbor of Saint-Nazaire will distribute at least 4 t H2 per day in 2050 for maritime and road transport, needing the installation of 60 MW of wind energy capacity. Residually it could supply 1,880 t H2 for industry and energy sector, yet, the sectors' coupling hinders business ecosystem building that remains essential to economies of scale and industry establishment. These orders of magnitudes are crucial for the hydrogen industry planning and highly needed by policy makers to set commitments and build regional hydrogen roadmaps for next decades.","PeriodicalId":416860,"journal":{"name":"2019 Offshore Energy and Storage Summit (OSES)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116242192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/OSES.2019.8867356
G. Qiao, X. She, Tongtong Zhang, L. Cong, Yi-chung Chen, Yulong Ding
Molten salts have been widely used for thermal energy storage in the field of solar plants and waste heat recovery. It is reported that adding nanoparticles could enhance the specific heat capacity of molten salts. One explanation is that there is a solid-like structure formed in the molten salts which leads to the enhancement. However, the underlying mechanism from molecular scale is still not clear. In this paper, KCl is chosen as the molten salt since K and Cl ions have the same charges and also the very close molar mass. SiO2 is selected as the nanoparticles. The intermolecular potential is modified in three different patterns to study the relationship between the force fields and the enhancement of specific heat capacity. A distinctive structural arrangement of K+ and Cl-ions is observed around the nanoparticles. The structure characteristics are analyzed using cross correlation covariance. It is found that, with the cross correlation covariance less than −0.041, specific heat capacity is significantly enhanced, which indicates that a separation of K+ and Cl-ions happens around nanoparticles. This finding proves from molecular scale that the enhancement of specific heat capacity is contributed by a solid-like layer around the nanoparticles. This paper provides a new approach to study the mechanism of specific heat capacity enhancement of molten salts based nanofluids.
{"title":"Mechanism of Specific Heat Capacity Enhancement of Molten Salts Based Nanofluids for Thermal Energy Storage - A Molecular Study","authors":"G. Qiao, X. She, Tongtong Zhang, L. Cong, Yi-chung Chen, Yulong Ding","doi":"10.1109/OSES.2019.8867356","DOIUrl":"https://doi.org/10.1109/OSES.2019.8867356","url":null,"abstract":"Molten salts have been widely used for thermal energy storage in the field of solar plants and waste heat recovery. It is reported that adding nanoparticles could enhance the specific heat capacity of molten salts. One explanation is that there is a solid-like structure formed in the molten salts which leads to the enhancement. However, the underlying mechanism from molecular scale is still not clear. In this paper, KCl is chosen as the molten salt since K and Cl ions have the same charges and also the very close molar mass. SiO2 is selected as the nanoparticles. The intermolecular potential is modified in three different patterns to study the relationship between the force fields and the enhancement of specific heat capacity. A distinctive structural arrangement of K+ and Cl-ions is observed around the nanoparticles. The structure characteristics are analyzed using cross correlation covariance. It is found that, with the cross correlation covariance less than −0.041, specific heat capacity is significantly enhanced, which indicates that a separation of K+ and Cl-ions happens around nanoparticles. This finding proves from molecular scale that the enhancement of specific heat capacity is contributed by a solid-like layer around the nanoparticles. This paper provides a new approach to study the mechanism of specific heat capacity enhancement of molten salts based nanofluids.","PeriodicalId":416860,"journal":{"name":"2019 Offshore Energy and Storage Summit (OSES)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116559464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/OSES.2019.8867358
M. Budt, Markus Hadam, Eva Schischke
Compressed air energy storage is a promising storage technology to face the challenges of high shares of renewable energies in an energy system by storing electric energy for periods of several hours up to weeks. The particularly advantageous adiabatic CAES concepts, which are not dependent on fossil fuels, are technical feasible, but still not widespread. Low-temperature adiabatic CAES concepts address some of the existing barriers by limiting process temperatures for higher flexibility and use of market available components to lower CAPEX. On the other hand, these advantages are achieved at the expense of roundtrip efficiency losses. Therefore, a suitable plant layout is highly dependent on the specific application. The new KompEx LTA-CAES® design presented in this paper reduces CAPEX even further by using a combination of reversibly operable turbo- and piston machinery. Doing so, these modules can be combined with any compressed air storage volume and thus not only salt caverns, but also decentralized storage units such as pipe storage or LRC can be used. As a case study for decentralized application, the use of a KompEx LTA-CAES® module to support the integration of renewable generation from PV on an island without interconnection to the mainland electricity grid is evaluated.
{"title":"Low-temperature Adiabatic Compressed Air Energy Storage for Island Applications","authors":"M. Budt, Markus Hadam, Eva Schischke","doi":"10.1109/OSES.2019.8867358","DOIUrl":"https://doi.org/10.1109/OSES.2019.8867358","url":null,"abstract":"Compressed air energy storage is a promising storage technology to face the challenges of high shares of renewable energies in an energy system by storing electric energy for periods of several hours up to weeks. The particularly advantageous adiabatic CAES concepts, which are not dependent on fossil fuels, are technical feasible, but still not widespread. Low-temperature adiabatic CAES concepts address some of the existing barriers by limiting process temperatures for higher flexibility and use of market available components to lower CAPEX. On the other hand, these advantages are achieved at the expense of roundtrip efficiency losses. Therefore, a suitable plant layout is highly dependent on the specific application. The new KompEx LTA-CAES® design presented in this paper reduces CAPEX even further by using a combination of reversibly operable turbo- and piston machinery. Doing so, these modules can be combined with any compressed air storage volume and thus not only salt caverns, but also decentralized storage units such as pipe storage or LRC can be used. As a case study for decentralized application, the use of a KompEx LTA-CAES® module to support the integration of renewable generation from PV on an island without interconnection to the mainland electricity grid is evaluated.","PeriodicalId":416860,"journal":{"name":"2019 Offshore Energy and Storage Summit (OSES)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132445007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/OSES.2019.8867162
J. Rouse, S. Garvey, B. Cárdenas, A. Hoskin, W. Xu
Compressed air is an attractive energy storage solution that can address many of the problems associated with operating large electricity grids with high levels of renewable penetration. The mature nature of the technology makes compressed air a robust and cheap alternative to batteries that is particularly applicable to offshore generation. Storage tanks (pressure vessels) must be utilised if geological alternatives, such as solution mined salt caverns, are not available or cannot be excavated in a particular deployment. Tanks are typically expensive, however it is possible to realise significant improvements (over 50%) in cost per unit exergy stored if “real gas effects” of air are exploited. Economic benefits resulting from realistic air property dependencies rely on storing air at low temperatures, circa −40°C. In this temperature range concerns are raised over the integrity of common pressure vessel materials; a transition from ductile to brittle failure modes is observed in many BCC (body centred cubic) steels that limits the size of “safe” (non-propagating) flaws in the vessel and increases the potential for fast fracture/catastrophic failure. Autofrettage is a manufacturing process in which a beneficial compressive stress state at the internal wall of a pressure vessel is induced by over pressurising the cylinder during manufacture. Autofretteage allows larger flaws or defects (such as cracks) to be safely accommodated in a design, compared to an identical vessel that has not undergone autofrettage. In this work autofrettage is investigated as a method which can allow cold compressed air energy storage to be realised. Safe operating pressures and temperatures are determined for vessels that have undergone autofrettage. These are then compared to similar calculations for more “simple” vessel designs (i.e. without autofrettage) and economic arguments are developed for the adoption of cold compressed air storage. Costings (cost per unit exergy stored) are not significantly sensitive to the additional effort required to autofrettage a vessel (due to the pressure levels involved).
{"title":"Enabling Cold Compressed Air Energy Storage through Pressure Vessel Manufacture with Autofrettage","authors":"J. Rouse, S. Garvey, B. Cárdenas, A. Hoskin, W. Xu","doi":"10.1109/OSES.2019.8867162","DOIUrl":"https://doi.org/10.1109/OSES.2019.8867162","url":null,"abstract":"Compressed air is an attractive energy storage solution that can address many of the problems associated with operating large electricity grids with high levels of renewable penetration. The mature nature of the technology makes compressed air a robust and cheap alternative to batteries that is particularly applicable to offshore generation. Storage tanks (pressure vessels) must be utilised if geological alternatives, such as solution mined salt caverns, are not available or cannot be excavated in a particular deployment. Tanks are typically expensive, however it is possible to realise significant improvements (over 50%) in cost per unit exergy stored if “real gas effects” of air are exploited. Economic benefits resulting from realistic air property dependencies rely on storing air at low temperatures, circa −40°C. In this temperature range concerns are raised over the integrity of common pressure vessel materials; a transition from ductile to brittle failure modes is observed in many BCC (body centred cubic) steels that limits the size of “safe” (non-propagating) flaws in the vessel and increases the potential for fast fracture/catastrophic failure. Autofrettage is a manufacturing process in which a beneficial compressive stress state at the internal wall of a pressure vessel is induced by over pressurising the cylinder during manufacture. Autofretteage allows larger flaws or defects (such as cracks) to be safely accommodated in a design, compared to an identical vessel that has not undergone autofrettage. In this work autofrettage is investigated as a method which can allow cold compressed air energy storage to be realised. Safe operating pressures and temperatures are determined for vessels that have undergone autofrettage. These are then compared to similar calculations for more “simple” vessel designs (i.e. without autofrettage) and economic arguments are developed for the adoption of cold compressed air storage. Costings (cost per unit exergy stored) are not significantly sensitive to the additional effort required to autofrettage a vessel (due to the pressure levels involved).","PeriodicalId":416860,"journal":{"name":"2019 Offshore Energy and Storage Summit (OSES)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131349594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/OSES.2019.8867355
Sophie Molina, E. Nicolas, M. Trabelsi, F. Scuiller, J. Charpentier, Christopher Franquet
This paper presents research and development of an industrial project which aims to propose a realistic solution to smooth short time power fluctuations for marine renewable energy sources. This project, funded by the European Community and Brittany Region (FEDER funding), associates SABELLA and Entech Smart Energies with the French Naval Academy research laboratory. The main objective is to design and test a preindustrial prototype of a controlled Energy Storage System (ESS) based on a supercapacitor bench, which can be associated with marine energy devices. The project includes realistic scale (several hundred kW rated power) design and test of this prototype in a dedicated emulation test bench. This paper details the project context, the test bench and prototype design and configuration.
{"title":"A Real Scale Prototype to Smooth Short-Time Power Fluctuations of Marine Renewable Energy Sources -Uliss.EMR Project-","authors":"Sophie Molina, E. Nicolas, M. Trabelsi, F. Scuiller, J. Charpentier, Christopher Franquet","doi":"10.1109/OSES.2019.8867355","DOIUrl":"https://doi.org/10.1109/OSES.2019.8867355","url":null,"abstract":"This paper presents research and development of an industrial project which aims to propose a realistic solution to smooth short time power fluctuations for marine renewable energy sources. This project, funded by the European Community and Brittany Region (FEDER funding), associates SABELLA and Entech Smart Energies with the French Naval Academy research laboratory. The main objective is to design and test a preindustrial prototype of a controlled Energy Storage System (ESS) based on a supercapacitor bench, which can be associated with marine energy devices. The project includes realistic scale (several hundred kW rated power) design and test of this prototype in a dedicated emulation test bench. This paper details the project context, the test bench and prototype design and configuration.","PeriodicalId":416860,"journal":{"name":"2019 Offshore Energy and Storage Summit (OSES)","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133046594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/OSES.2019.8867351
L. Lemiale, R. Loisel, S. Bourguet, A. Roy, M. Machmoun
Islands have traditionally experienced great dependency on external energy supply and many of them opted for diesel as fuel for power generation. This study tests scenarios of different levels of renewable penetration on the French Atlantic island Ouessant, facing the general problems of the energy planning such as grid reliability, the lack of economies of scale and reduced investor profitability. A complex model is built combining long-term investment routines with short-term hourly plant dispatching, following a parametric procedure. The energy mix is composed of wind - PV - tidal power plants and distributed battery storage. Their sizes adapt to the peaking loads, leading to an oversized infrastructure and to low usage rates due to loss of market opportunities during low demand hours. New evaluation criteria are necessary to policy makers in the selection of the energy mix, based on the performance of each plant and storage device, the cost of each power facility and the total system cost. From the investor perspective, the key indicator is the loss of energy generated, therefore storage will support the integration of intermittent renewables by avoiding the power curtailed and accurately sizing the generation mix. The final trade-off is between the reasonable rates of energy in excess to be curtailed, the cost of additional storage and the loss of load probability, which are socially and economically admitted by the regulator and by energy operators, having each conflicting interests and objectives.
{"title":"Building sustainable power mix in small island grids: a multi-criteria analysis","authors":"L. Lemiale, R. Loisel, S. Bourguet, A. Roy, M. Machmoun","doi":"10.1109/OSES.2019.8867351","DOIUrl":"https://doi.org/10.1109/OSES.2019.8867351","url":null,"abstract":"Islands have traditionally experienced great dependency on external energy supply and many of them opted for diesel as fuel for power generation. This study tests scenarios of different levels of renewable penetration on the French Atlantic island Ouessant, facing the general problems of the energy planning such as grid reliability, the lack of economies of scale and reduced investor profitability. A complex model is built combining long-term investment routines with short-term hourly plant dispatching, following a parametric procedure. The energy mix is composed of wind - PV - tidal power plants and distributed battery storage. Their sizes adapt to the peaking loads, leading to an oversized infrastructure and to low usage rates due to loss of market opportunities during low demand hours. New evaluation criteria are necessary to policy makers in the selection of the energy mix, based on the performance of each plant and storage device, the cost of each power facility and the total system cost. From the investor perspective, the key indicator is the loss of energy generated, therefore storage will support the integration of intermittent renewables by avoiding the power curtailed and accurately sizing the generation mix. The final trade-off is between the reasonable rates of energy in excess to be curtailed, the cost of additional storage and the loss of load probability, which are socially and economically admitted by the regulator and by energy operators, having each conflicting interests and objectives.","PeriodicalId":416860,"journal":{"name":"2019 Offshore Energy and Storage Summit (OSES)","volume":"183 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115074359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/OSES.2019.8867145
J. Aquilina, R. Farrugia, T. Sant
Offshore wind energy is being seen as a major energy player as the quest for clean renewable energy solutions intensifies. Wind turbines operating at sea are subjected to a harsh and unforgiving marine environment that calls for timely inspections and maintenance in order to maintain high levels of availability. Inspections at height and especially at sea are inherently time-consuming, expensive and fraught with risks, so the automation of such procedures will benefit the industry at all levels. Unmanned Aerial Vehicles (UAVs) are finding niche applications as a remote sensing tool in various sectors, one of which is wind turbine inspection. This paper investigates the onboard energy requirements and operational flight duration of a drone used for offshore wind turbine inspections subject to aspects such as wind turbine size and site wind conditions. The energy requirements of the UAV are numerically modelled using a single-wind turbine blade inspection routine as a basis. Flight path distance is inherently linked to wind turbine blade length and, based on the need for four passes per blade during an inspection, this property featured prominently on the UAV's performance. The research then moved on to investigate UAV energy requirements for multiple-wind turbine arrays with factors such as wind speed and direction, inter-turbine spacing and array layout and rotor wakes being considered. This part of the study utilised the numerical model mentioned earlier and the WindPRO software package. The undisturbed wind speed was declared as that characteristic having the highest influence on energy consumption and flight duration. Wind direction, wind turbine rotor wake and inter-turbine downwind spacing were the other forcing factors considered, with the significance of their impacts in the same order respectively. The results of this study identify the effects of the various parameters on UAV energy requirements and inspection flight duration as a means of enabling better planning and optimisation of offshore wind turbine blade inspection using drones.
{"title":"On the Energy Requirements of UAVs Used for Blade Inspection in Offshore Wind Farms","authors":"J. Aquilina, R. Farrugia, T. Sant","doi":"10.1109/OSES.2019.8867145","DOIUrl":"https://doi.org/10.1109/OSES.2019.8867145","url":null,"abstract":"Offshore wind energy is being seen as a major energy player as the quest for clean renewable energy solutions intensifies. Wind turbines operating at sea are subjected to a harsh and unforgiving marine environment that calls for timely inspections and maintenance in order to maintain high levels of availability. Inspections at height and especially at sea are inherently time-consuming, expensive and fraught with risks, so the automation of such procedures will benefit the industry at all levels. Unmanned Aerial Vehicles (UAVs) are finding niche applications as a remote sensing tool in various sectors, one of which is wind turbine inspection. This paper investigates the onboard energy requirements and operational flight duration of a drone used for offshore wind turbine inspections subject to aspects such as wind turbine size and site wind conditions. The energy requirements of the UAV are numerically modelled using a single-wind turbine blade inspection routine as a basis. Flight path distance is inherently linked to wind turbine blade length and, based on the need for four passes per blade during an inspection, this property featured prominently on the UAV's performance. The research then moved on to investigate UAV energy requirements for multiple-wind turbine arrays with factors such as wind speed and direction, inter-turbine spacing and array layout and rotor wakes being considered. This part of the study utilised the numerical model mentioned earlier and the WindPRO software package. The undisturbed wind speed was declared as that characteristic having the highest influence on energy consumption and flight duration. Wind direction, wind turbine rotor wake and inter-turbine downwind spacing were the other forcing factors considered, with the significance of their impacts in the same order respectively. The results of this study identify the effects of the various parameters on UAV energy requirements and inspection flight duration as a means of enabling better planning and optimisation of offshore wind turbine blade inspection using drones.","PeriodicalId":416860,"journal":{"name":"2019 Offshore Energy and Storage Summit (OSES)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125622198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1109/OSES.2019.8867329
G. Malara, C. Ruzzo, F. Arena
This article proposes the numerical modeling of a plant composed by an array of U-Oscillating Water Columns (U-OWC). The U-OWCs are wave energy converters, commonly embodied in vertical breakwaters, belonging to the family of Oscillating Water Columns. Their particular feature is that they utilize a small vertical duct for connecting the water column to the open wave field. Calculating the system response of these system requires the solution of a system of integro-differential equations involving the determination of the plant hydrodynamic parameters. The article describes the implementation of a numerical model in the ANSYS AQWA® environment. Such a model is used for estimating the radiation damping of the system and its added mass. The numerical results are compared against data based on a semi-analytical approach. It is shown that numerical and analytical models provide similar results, although discrepancies are observed in case of U-OWC with small transversal widths of the openings, due to the different distribution of the pressure field on the U-OWC inlets. However, these differences do not affect significantly the power output estimates.
{"title":"Three-dimensional numerical modelling of a U-Oscillating Water Column array","authors":"G. Malara, C. Ruzzo, F. Arena","doi":"10.1109/OSES.2019.8867329","DOIUrl":"https://doi.org/10.1109/OSES.2019.8867329","url":null,"abstract":"This article proposes the numerical modeling of a plant composed by an array of U-Oscillating Water Columns (U-OWC). The U-OWCs are wave energy converters, commonly embodied in vertical breakwaters, belonging to the family of Oscillating Water Columns. Their particular feature is that they utilize a small vertical duct for connecting the water column to the open wave field. Calculating the system response of these system requires the solution of a system of integro-differential equations involving the determination of the plant hydrodynamic parameters. The article describes the implementation of a numerical model in the ANSYS AQWA® environment. Such a model is used for estimating the radiation damping of the system and its added mass. The numerical results are compared against data based on a semi-analytical approach. It is shown that numerical and analytical models provide similar results, although discrepancies are observed in case of U-OWC with small transversal widths of the openings, due to the different distribution of the pressure field on the U-OWC inlets. However, these differences do not affect significantly the power output estimates.","PeriodicalId":416860,"journal":{"name":"2019 Offshore Energy and Storage Summit (OSES)","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134002782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：