• Energy Research

The aim of this paper is to present options to make low-carbon footprint large-scale desalination a reality on arid islands with weak electrical grids. Through these options, the goal is to reconfigure on-grid wind energy/ desalination systems for large- and medium-scale water production. In this context, it is proposed to use lithium- ion batteries for stationary energy storage together with management strategies aimed at avoiding the wind energy/desalination systems having to consume energy from the conventional grid they are connected to. The control strategy is based on ensuring that the power provided by the wind farm and batteries remains in synchrony with the power demand of the desalination plant throughout the system’s useful life. The interannual variation of wind energy is considered when sizing the renewable energy system and processes for its estimation are proposed. The case study is centred on the Canary Archipelago, a region that is especially vulnerable to the impacts of climate change, but which enjoys exceptional characteristics for the exploitation of wind energy. The results obtained show the optimal wind farm and energy storage system capacities of the analysed configurations. The approach presented allows a low-carbon operational footprint. If the control strategy were to be put into practice today, the current grid restrictions and a life cycle assessment of the system carried out in a societal context that continues to be fossil fuel dependent indicate a potential reduction of 77.4% of the footprint. However, the remaining 22.6% could be eliminated in the future when the manufacturing processes of wind turbines, batteries and desalination plants receive the benefits of carbon-neutral societies. 25 2,907 11,2 Q1 Q1 SCIE 11,0

En este trabajo se presenta y se analiza una primera aproximación de un algoritmo cuyo objetivo final es optimizar técnica y económicamente la gestión de los excedentes energéticos de una instalación de autoconsumo renovable. Para ello, y como variables adicionales de control, se han considerado el coste de la energía comprada al sistema por la instalación, así como el precio del pool energético en la venta de los excedentes. El algoritmo se ha implementado en LabVIEW y simulado en MATLAB, lo que ha permitido obtener unos resultados preliminares que facilitan la tarea de mejora del algoritmo para futuros trabajos y versiones de este.

Water scarcity is a global problem that particularly affects islands located in arid regions or regions with limited water resources. This issue has prompted the development of non-conventional water sources such as fossil fuel-powered desalination systems. Concern about the high energy and environmental costs associated with this type of facility has created the ideal framework for the proliferation of desalination projects powered by renewable energies, especially wind energy due to the multiple advantages it offers. This article provides a bibliometric analysis to identify the advances made in wind-powered desalination on islands. While many studies explore wind-powered desalination, none compile references specific to islands. This paper analyses islands’ desalination needs and showcases wind-powered systems, exploring their types and uses. Firstly, the most relevant international scientific journals are identified to allow the subsequent selection and quantitative and qualitative analysis of articles directly dealing with wind-powered desalination systems. A total of 2344 articles obtained from the Scopus database were analyzed, of which 144 including 181 case studies were selected. Among the results of this study, an increasing year-on-year trend is observed in the number of published studies tackling wind-powered desalination. Finally, this paper presents a series of maps showing the most relevant facilities, projects, and data in this field, and provides an overview of the lessons learned in the decarbonization of desalination.

This paper presents a new method based on the Smart Energy System concept to link the water infrastructure and the energy system of an island. The principal aim of this study is to determine whether this new method can increase the contribution of renewables (wind power and photovoltaic) to the primary energy supply of the island. The method considers water production and treatment systems as flexible loads and explores a wide range of possible water supply infrastructures and PV/wind power combinations in the search for an optimal energy-water configuration. The final optimal solution is based on a balance between energy fuel needs and energy excesses, CO2 emissions, oil consumption, minimization of total annual costs and maximization of the renewable contribution. The proposed method increased the contribution of renewables from 5.14% to 24.6%. This corresponds to, on average, over 35% of the hourly electricity demand throughout 2018 being covered by renewables, against the current 6.6%. The study reveals that wind technology integration is of fundamental importance for renewable exploitation in insular water-energy systems, with wind energy contributing more than 70% of the renewable participation in this case study. 19 2,743 9,709 Q1 Q1 SCIE

This study analyzes the potential of cross-border electricity cooperation as an effective way to reduce the costs of renewable energy deployment in the South Asian region using a novel cooperation mechanism among countries. This paper studies the case of India, Bhutan, and Nepal. From the analysis, Bhutan and Nepal have a large under-exploited hydropower potential that presents a great opportunity for India’s energy supply by developing cross-border electricity trading infrastructure and associated markets. For this, developing the infrastructure for power transmission and hydropower plants in each country is necessary to reduce investment in flexibility solutions, power system costs, and CO2 emissions. According to a previous analysis, in Nepal’s case, the Cross-Border Electricity Market (CBEM) development would increase Nepal’s Gross Domestic Product (GDP) by up to 39%. India would also benefit from this mechanism. Using this energy trade mechanism, India’s power generation needs would be reduced by 2% and CO2 emissions would be reduced by 5.60% by 2045. The most important conclusions to highlight are that (i) there is an important opportunity to simultaneously enhance the economy sector in some undeveloped countries in the region when, at the same time, reducing carbon intensity in India; (ii) at the same time, there is a large barrier, as the analysis shows that despite these associated benefits there is a major risk in the lack of policy harmonization among all countries involved; and (iii) that one of the most important key aspects for success is the development of a coordinated regulation strategy. These results show the potential of CBEM systems in the region but also encourage researchers and policymakers worldwide to explore this mechanism as an effective way to enhance the decarbonization of power systems.

In this paper, two studies are carried out related to the performance simulation and analysis of a wind-powered seawater reverse osmosis (SWRO) desalination plant prototype installed on the island of Gran Canaria (Spain). Three machine learning techniques (artificial neural networks, support vector machines and random forests) were implemented to predict the performance (pressure, feed flow rate and permeate flow rate, and permeate conductivity) of the SWRO desalination plant. Subsequently, plant operation was analysed in two different operating modes: a) constant pressure and flow rate through connection with a wind-battery microgrid, b) variable pressure and flow rate as a function of the power supplied by a stand-alone wind microgrid without energy storage. The paper supports two main outcomes. First, support vector machines and random forests are significantly (5% significance level) better predictors of the plant's performances than neural networks. Second, over one year, the operating mode that considers variable pressure and flow rate operates more continuously (higher operating frequencies and lower stop/start frequencies) than the constant pressure and flow rate alternative; however 1.2 times less permeate with 1.08 higher conductivity is produced on an annual basis. 1,689 6,035 Q1 Q1 SCIE

This article discusses the integration of renewable energy sources in islanded energy systems, focusing on electrification of the transport sector and highlighting the challenges that are faced. The proposed method comprises different steps. First, the energy system is analyzed using the Smart Energy Systems concept to identify high renewable energy scenarios. Then, the power system is evaluated to ensure compliance with security and stability requirements. The method innovatively combines an overall energy system analysis, from an energy planning perspective, with more detailed power system analyses, where the power balance at each instant is the main item of interest rather than the energy balance. The study, applied to Gran Canaria (Canary Islands, Spain), demonstrates that 100% electrification of passenger cars with renewable energy sources is the optimal scenario, resulting in reductions of 45.86% and 45.1% in oil consumption and CO2 emissions, respectively, compared to the reference scenario. In addition, in these optimal conditions, there would be a 29.9% reduction in the total annual costs of the energy system and a 13.81% reduction in the total energy required to supply it. The stability analysis that was undertaken confirms that the system can handle a significant electric vehicle load and high renewable energy production without excessive load shedding. 19 2,514 10,4 Q1 Q1 SCIE 11,0