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The design of a geothermal heat pump system and geothermal heat exchangers to replace conventional cold and heat production systems in a winery on the island of Lanzarote (Canary Islands, Spain), taking into account its active volcanic geological peculiarities, is presented in this work. Firstly, a study was carried out to estimate the cold and heat needs of the winery during its operation. A calculation program was implemented in Matlab software framework to estimate the influences of the winemaker’s decisions on the cold and heat consumption of the winery. Once the needs were determined, a commercial geothermal heat pump (GHP) was selected, using exhaust heat to produce hot and cold water at the same time. After assessing hot and cold-water consumption along with heat pump requirements, a field of closed-loop borehole heat exchangers (BHE) was designed using a finite element heat transport numerical model. The existing geological profile, characterized by alternating basalt lava flows and pyroclasts, was carefully considered. The high porosity of the pyroclastic layers resulted in a 20.1% reduction in BHE performance compared to the initial expectations. Consequently, the depth of the 12 BHE was increased 21.9 additional meters from the original design. Thus, it was concluded that the alternation of basaltic lava flows and pyroclasts is prevalent in volcanic islands, emphasizing the need to attentively account for these pyroclastic layers in such environments.

Geothermal energy comes in many different forms depending on the specific conditions of the resource. For example, in volcanic areas (such as the Canary Islands) or with subduction of tectonic plates, deposits of water/steam of very high energy and temperatures (150°–350 °C) are sometimes produced, known as high enthalpy resources. Due to their high quality, these can be used for electricity production in binary cycles. The design of a geothermal heat pump system to replace conventional cæold and heat production systems in a winery on the island of Lanzarote (Canary Islands, Spain) is presented. First, a calculation system based on the Matlab program was designed to review the influences of the winemaker’s decisions on the cold and heat consumption of the winery. After calculating hot and cold water consumption and heat pump requirements, a field of geothermal probes was designed using available software. Subsequently, the dimensions of the liquid impulsion equipment were estimated, and an electrical installation was created for the whole system. The data considered are related to winery logistics, must properties, environment, tank dimensions, and energy needs (cooling and heating). Finally, it was decided to use a reversible heat pump with exhaust heat recovery. This system allows heat extracted by the cooling system to be partly used to produce hot water instead of all of it being discharged to the ground. The cooling system will be operated for 18 h daily as a design criterion. The pump selected for the final project installed has an exhaust heat recovery system that allows domestic hot water to be produced in cooling mode. Hot water generation, when the heat pump is cooling, is 15 kW, and the temperature provided is 60 °C, which is adequate to meet the hot water needs of the winery. In addition, the heat pump’s heat sink is in the ground, which remains in practically constant conditions throughout the year, so the effect of outside temperature is minimized. In

La isla de El Hierro es la más pequeña y más joven del archipiélago de Canarias. En el año 2000 fue declarada Reserva de la Biosfera y, a partir del año 2014 cuenta con el proyecto denominado la Gorona del Viento, que se trata de una Central Hidroeólica que pretende abastecer de energía 100% renovable a toda la isla. Con respecto a la demanda hídrica de la isla, según los datos del Plan Hidrológico de la isla de El Hierro esta se cifra en 1,57 hm3 /año de demanda urbana y 1,72 hm3 /año de demanda por parte del sector agropecuario. Esta necesidad hídrica se cubre con las aguas subterráneas y la desalación, que aporta 1,37 hm3 /año. Por lo tanto, debido a las características de la isla, ha sido seleccionada como lugar de interés para formar parte del caso de estudio de las Islas Canarias, dentro del Proyecto Europeo Arsinoe. A través de este proyecto se tratará de modelizar el acuífero y obtener un mejor conocimiento del mismo, para ser capaces de establecer valores más certeros de recarga natural, así como de proponer medidas de mejora en su manejo, al tener en cuenta escenarios futuros de cambio climático.

[EN] Managed aquifer recharge (MAR) and, in particular, recharge by direct injection into the aquifer through wells or boreholes allows for a series of very interesting solutions to solve various technical and environmental problems related to management of the urban water cycle. These problems include the overexploitation of water resources, marine intrusion or contamination of groundwater by irrigation returns. The island of Gran Canaria presents several of these problems; thus, the feasibility of implementing a recharge system has been studied to provide a solution to some of them, using a resource of great potential such as reclaimed water. A detailed characterization of groundwater quality in the study area was carried out, complemented by a field campaign with water sampling from the surrounding catchments, in situ analysis and subsequent laboratory analysis. Specifically, an MBR treatment with disinfection is proposed, where the final conclusions indicate that this is a technically and economically viable project, innovative in its application on islands, a priori with an acceptable productive recharge capacity, possibly scalable after the experimental phase and extrapolable to other locations with similar conditions. In addition, it presents a set of important environmental benefits with respect to conservation of and improvement of the state of the groundwater bodies in the studied area, as well contributing to knowledge of and research into water management in volcanic lands and islands.

[EN] Carbon dioxide emissions linked to the transport sector are particularly relevant to islands. The Canary Islands have high level of tourism, with tourists who generally travel in rented vehicles on arrival in the archipelago. In addition, mobility of the local population in the islands is also always growing. Thus, transport is one of the sectors that emits the greatest amount of greenhouse gases. In this sense, the net carbon balance becomes a pioneering study in the framework of management of high-capacity road transport routes and will help plan new strategies, which pursue the neutrality and climate resilience of the road network. It will therefore be possible to design different future scenarios, according to traffic intensities detected, to mitigate their local effects by increasing green areas, which will contribute to greater absorption. This study calculated the carbon footprint linked to vehicles on the three high-capacity roads on the island of Tenerife, as well as the carbon footprint of the public lighting attached to these roads. The absorption of carbon by vegetation planted by the Road Service and the soil located on the margins of the road have also been calculated to explore the possibility of modifying the vegetation, using other types of local shrubs and trees that have a higher absorption factor. The results demonstrate that conifers have the highest absorption factor, the Canary Island pine being the best option in this case. However, it is not always possible to place trees on the roadside, and it is necessary to resort to smaller species. This study concludes that better mobility planning, an increase in electric vehicles, improved energy production from renewable sources, and the promotion and enhancement of absorption capacity of carbon sinks are key in the face of climate change. Integr Environ Assess Manag 2023;19:1023-1030. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on b

[EN] Solar photovoltaic energy is increasingly positioned as an excellent renewable energy source to be implemented in energy communities. However, studies on photovoltaic potential are still required in order to enhance the clean energy transition in energy dependent systems, such as oceanic islands. This work is a study of photovoltaic potential of public building roofs in the World Heritage city of San Cristóbal de La Laguna in Tenerife (Canary Islands). The buildings selected for the study are sports centres, educational centres and civic centres, considering optimum and maximum production scenarios. The results showed the electricity generation capacity of each building, with 8811 and 861 MWh capacity for the maximum and optimum scenarios, respectively. In the optimal scenario, 56% of energy would be generated, of which 31% would be consumed on site, and the remaining 25% would be sent to the grid. The main difference is that in the case of optimal photovoltaic systems, economic profitability criteria take precedence, while in the case of maximum photovoltaic systems, the environmental benefits in terms of CO2 emissions into the atmosphere increase considerably. In the latter case, CO2 emissions are reduced by 771%, compared to 75% in the case of optimal photovoltaic systems.

[EN] The integral urban water cycle of the Balearic Islands (Spain) is composed of desalination plants, extraction wells, water distribution networks, treatment plants and sewerage systems. This article presents the results of the carbon and water footprint of each of the islands that form the Balearic archipelago, finding differences between those islands with a greater contribution of groundwater, such as Mallorca, and those that are fed exclusively with desalinated water, such as Formentera. Water consumption on these islands is highly seasonal, which results in peaks in demand, which are mainly supplied by desalination. This article aims to be the starting point for assessing the water and energy status of the facilities related to drinking water consumption in the archipelago to be able to take measures aimed at ecological transition in this sector. The results obtained show that seawater desalination plants have the largest carbon footprint, mainly due to their high electricity consumption.