scholarly journals Integrating field, textural, and geochemical monitoring to track eruption triggers and dynamics: a case study from Piton de la Fournaise

Solid Earth ◽  
2018 ◽  
Vol 9 (2) ◽  
pp. 431-455 ◽  
Author(s):  
Lucia Gurioli ◽  
Andrea Di Muro ◽  
Ivan Vlastélic ◽  
Séverine Moune ◽  
Simon Thivet ◽  
...  

Abstract. The 2014 eruption at Piton de la Fournaise (PdF), La Réunion, which occurred after 41 months of quiescence, began with surprisingly little precursory activity and was one of the smallest so far observed at PdF in terms of duration (less than 2 days) and volume (less than 0.4  ×  106 m3). The pyroclastic material was composed of golden basaltic pumice along with fluidal, spiny iridescent and spiny opaque basaltic scoria. Density analyses performed on 200 lapilli reveal that while the spiny opaque clasts are the densest (1600 kg m−3) and most crystalline (55 vol. %), the golden pumices are the least dense (400 kg m−3) and crystalline (8 vol. %). The connectivity data indicate that the fluidal and golden (Hawaiian-like) clasts have more isolated vesicles (up to 40 vol. %) than the spiny (Strombolian-like) clasts (0–5 vol. %). These textural variations are linked to primary pre-eruptive magma storage conditions. The golden and fluidal fragments track the hotter portion of the melt, in contrast to the spiny fragments and lava that mirror the cooler portion of the shallow reservoir. Exponential decay of the magma ascent and output rates through time revealed depressurization of the source during which a stratified storage system was progressively tapped. Increasing syn-eruptive degassing and melt–gas decoupling led to a decrease in the explosive intensity from early fountaining to Strombolian activity. The geochemical results confirm the absence of new input of hot magma into the 2014 reservoir and confirm the emission of a single shallow, differentiated magma source, possibly related to residual magma from the November 2009 eruption. Fast volatile exsolution and crystal–melt separation (second boiling) were triggered by deep pre-eruptive magma transfer and stress field change. Our study highlights the possibility that shallow magma pockets can be quickly reactivated by deep processes without mass or energy (heat) transfer and produce hazardous eruptions with only short-term elusive precursors.

2017 ◽  
Author(s):  
Lucia Gurioli ◽  
Andrea Di Muro ◽  
Ivan Vlastélic ◽  
Séverine Moune ◽  
Nicolas Villeneuve ◽  
...  

Abstract. The 2014 eruption at Piton de La Fournaise (PdF), la Reunion, which occurred after 41 months of quiescence, began with surprisingly little precursory activity, and was one of the smallest so far observed at PdF in terms of duration (less than 2 days) and volume (less than 0.4 Mm3). The pyroclastic material was composed of spiny-opaque, spiny-iridescent, and fluidal scoria along with golden pumice. Density analyses performed on 200 lapilli reveal that the spiny-opaque clasts are the densest (1600 kg/m3) and richest in crystals (54 vol%), and the golden pumices are the lightest (400 kg/m3) and poorest in crystals (14 vol%). The connectivity data indicate that the fluidal and golden (Hawaiian-like) clasts have more isolated vesicles (up to 40 %) than the spiny (Strombolian-like) clasts (0–5 %). These textural variations are linked to primary pre-eruptive magma storage conditions. The golden and fluidal fragments track the hotter portion of the melt, in contrast to the spiny fragments which mirror the cooler portion of the shallow reservoir. Progressive tapping of these distinct portions leads to a decrease in the explosive intensity from early fountaining to Strombolian activity. The geochemical results confirm the absence of new hot input of magma and confirm the involvement of a single, shallow, differentiated magma source, possibly related to residual magma from the November 2009 eruption. We found that the eruption was triggered by water exsolution, favoured by the shallow depth of the reservoir, rather than cooling and chemical evolution of the stored magma.


2021 ◽  
Vol 13 (8) ◽  
pp. 4549
Author(s):  
Sara Salamone ◽  
Basilio Lenzo ◽  
Giovanni Lutzemberger ◽  
Francesco Bucchi ◽  
Luca Sani

In electric vehicles with multiple motors, the torque at each wheel can be controlled independently, offering significant opportunities for enhancing vehicle dynamics behaviour and system efficiency. This paper investigates energy efficient torque distribution strategies for improving the operational efficiency of electric vehicles with multiple motors. The proposed strategies are based on the minimisation of power losses, considering the powertrain efficiency characteristics, and are easily implementable in real-time. A longitudinal dynamics vehicle model is developed in Simulink/Simscape environment, including energy models for the electrical machines, the converter, and the energy storage system. The energy efficient torque distribution strategies are compared with simple distribution schemes under different standardised driving cycles. The effect of the different strategies on the powertrain elements, such as the electric machine and the energy storage system, are analysed. Simulation results show that the optimal torque distribution strategies provide a reduction in energy consumption of up to 5.5% for the case-study vehicle compared to simple distribution strategies, also benefiting the battery state of charge.


Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2048 ◽  
Author(s):  
Rodrigo Martins ◽  
Holger Hesse ◽  
Johanna Jungbauer ◽  
Thomas Vorbuchner ◽  
Petr Musilek

Recent attention to industrial peak shaving applications sparked an increased interest in battery energy storage. Batteries provide a fast and high power capability, making them an ideal solution for this task. This work proposes a general framework for sizing of battery energy storage system (BESS) in peak shaving applications. A cost-optimal sizing of the battery and power electronics is derived using linear programming based on local demand and billing scheme. A case study conducted with real-world industrial profiles shows the applicability of the approach as well as the return on investment dependence on the load profile. At the same time, the power flow optimization reveals the best storage operation patterns considering a trade-off between energy purchase, peak-power tariff, and battery aging. This underlines the need for a general mathematical optimization approach to efficiently tackle the challenge of peak shaving using an energy storage system. The case study also compares the applicability of yearly and monthly billing schemes, where the highest load of the year/month is the base for the price per kW. The results demonstrate that batteries in peak shaving applications can shorten the payback period when used for large industrial loads. They also show the impacts of peak shaving variation on the return of investment and battery aging of the system.


Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 431
Author(s):  
Nur Najihah Abu Bakar ◽  
Josep M. Guerrero ◽  
Juan C. Vasquez ◽  
Najmeh Bazmohammadi ◽  
Muzaidi Othman ◽  
...  

Microgrids are among the promising green transition technologies that will provide enormous benefits to the seaports to manage major concerns over energy crises, environmental challenges, and economic issues. However, creating a good design for the seaport microgrid is a challenging task, considering different objectives, constraints, and uncertainties involved. To ensure the optimal operation of the system, determining the right microgrid configuration and component size at minimum cost is a vital decision at the design stage. This paper aims to design a hybrid system for a seaport microgrid with optimally sized components. The selected case study is the Port of Aalborg, Denmark. The proposed grid-connected structure consists of renewable energy sources (photovoltaic system and wind turbines), an energy storage system, and cold ironing facilities. The seaport architecture is then optimized by utilizing HOMER to meet the maximum load demand by considering important parameters such as solar global horizontal irradiance, temperature, and wind resources. Finally, the best configuration is analyzed in terms of economic feasibility, energy reliability, and environmental impacts.


2021 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Chris Ogwumike ◽  
Huda Dawood ◽  
Tariq Ahmed ◽  
Bjarnhedinn Gudlaugsson ◽  
Nashwan Dawood

This paper presents an assessment of the impacts of the different tools implemented within the inteGRIDy project through the analysis of key performance indicators (KPIs) that appropriately reflect the technical and economic domains of the inteGRIDy thematic pillars, comprising demand response and battery storage systems. The evaluation is based on improvements brought about by individual components of the inteGRIDy-enabled smart solution across the Isle of Wight (IOW) pilot site. The analyses and the interpretation of findings for the pilot use case evaluation are presented. The results indicate that the smart solution implementation across the IOW pilot site resulted in achieving the inteGRIDy set objectives. Overall, a 93% reduction in energy consumption, equivalent to 643 kWh was achieved, via the M7 energy storage system and heat pumps developed as part of inteGRIDy solution. Additionally, the grid efficiency and demand flexibility contribution to the distribution network operator (DNO)-triggered DR services, based on a 10% increase/decrease in demand, resulted in stabilizing the grid efficiency.


2021 ◽  
Vol 3 ◽  
Author(s):  
Chidera O. Iloejesi ◽  
Lauren E. Beckingham

Subsurface porous aquifers are being considered for use as reservoirs for compressed energy storage of renewable energy. In these systems, a gas is injected during times in which production exceeds demand and extracted for energy generation during periods of peak demand or scarcity in production. Current operational subsurface energy facilities use salt caverns for storage and air as the working gas. CO2 is potentially a more favorable choice of working gas where under storage conditions CO2 has high compressibility which can improve operational efficiency. However, the interaction of CO2 and brine at the boundary of the storage zone can produce a chemically active fluid which can result in mineral dissolution and precipitation reactions and alter the properties of the storage zone. This study seeks to understand the geochemical implications of utilization of CO2 as a working gas during injection, storage and extraction flow cycles. Here, reactive transport simulations are developed based on 7 h of injection, 11 h of withdrawal and 6 h of reservoir closure, corresponding to the schedule of the Pittsfield field test, for 15 years of operational life span to assess the geochemical evolution of the reservoir. The evolution in the storage system is compared to a continuously cyclic system of 12 h injection and extraction. The result of the study on operational schedule show that mineral reactivity occurs at the inlet of the domain. Furthermore, the porosity of the inner domain is preserved during the cycling of CO2 acidified brine for both systems.


2011 ◽  
Vol 403-408 ◽  
pp. 3758-3762
Author(s):  
Subhajit Patra ◽  
Prabirkumar Saha

In this paper, two efficient control algorithms are discussed viz., Linear Quadratic Regulator (LQR) and Dynamic Matrix Controller (DMC) and their applicability has been demonstrated through case study with a complex interacting process viz., a laboratory based four tank liquid storage system. The process has Two Input Two Output (TITO) structure and is available for experimental study. A mathematical model of the process has been developed using first principles. Model parameters have been estimated through the experimentation results. The performance of the controllers (LQR and DMC) has been compared to that of industrially more accepted PID controller.


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