Benedetto Cotrugli et son traité De navigatione (1464-1465)

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Electric vehicle charging network in Europe: An accessibility and deployment trends analysis

If coupled with a low-carbon electricity mix, electric vehicles (EVs) can represent an important technology for transport decarbonization and local pollutants abatement. Yet, to ensure large-scale EVs adoption, an adequate charging stations network must be developed. This paper provides the first comprehensive bottom-up analysis of the EV charging network in Europe. Combining a crowd-sourced database of charging stations with accessibility data and algorithms, we produce maps of the travel time to the most accessible EV charging station across Europe, we evaluate the charging points density and the number of active operators in different areas. We find that although recent years have witnessed a notable expansion of the EV charging network, stark inequalities persist across and within countries, both in terms of accessibility and of the charging points available to users. Our results allow for a better understanding of some of the key challenges ahead for ensuring mass EVs adoption throughout Europe and thus potentially reducing the environmental impact of the transport sector

Dynamic Simulation of the Operation of a Molten Salt Parabolic Trough Plant, Comprising Draining Procedures☆

Abstract The dynamic simulation of a molten salt operated parabolic trough plant is presented. The simulated plant is a typical 9 MWe CSP unit comprising 10 loops with 8 collectors in series (in turn this can be a "module" of a larger CSP solar field) a Two Tanks TES and a molten salt Steam Generator. This type of plant represents a challenge due to the large extension and relative complication of piping network operating with molten salt, in comparison to e.g. a molten salt Tower. The simulation model, implemented in Isaac Dynamics environment, is able to represent the normal operation of the plant with circulating HTF at variable mass flow depending on input DNI, and night circulation at reduced mass flow. In addition, in molten salt operated CSP plants draining operations are of prominent importance, given that these operations should be operated within a due time (depending on boundary conditions) avoiding the possible freezing of the salt mixture. Moreover also emergency draining (e.g. as a consequence of faults in the pump and/or in heat trace equipment) should be analyzed. At this purpose, the model has been modified and utilized to represent also circuit draining, involving flow reversal, that normally requires use of specialized thermo-hydraulic codes like Relap (Reactor Loss of coolant Analysis Program). In conclusion, the paper shows how the simulation environment is able to represent most of the dynamics that affect the operation of a molten salt parabolic trough plant

Mosquitoes and Potatoes: How Local Climatic Conditions Impede Development

The historical diffusion of the potato in the Old World serves as an example of the contribution of technological innovations to socio-economic growth and development (Nunn and Qian in Q J Econ 126(2):593–650, 2011). Climate-related diseases, on the other hand, might offset some of these benefits. Here we examine the long-term impact of malaria on the potato-driven growth of the population and urbanization in the Old World during the 18th and 19th centuries. We exploit local variations in environmental suitability both for potato and for malaria transmission to estimate and compare the impact of potato cultivation on population and urbanization in highly endemic to non-endemic areas at a high level of spatial disaggregation. We show that local climate conditions ideal for malaria transmission counteracted the potential benefits of introducing the potato to the Old World, which are conversely found to be strong and positive in non-endemic regions. These results highlight the interplay between technological change, public health, and development outcomes

Representative meat consumption pathways for sub-Saharan Africa and their local and global energy and environmental implications

In sub-Saharan Africa (SSA) most people live on plant-dominated diets, with significantly lower levels of per-capita meat consumption than in any other region. Yet, economic development has nearly everywhere spurred a shift to dietary regimes with a greater consumption of meat, albeit with regional heterogeneity for meat-type and magnitude. A growing regional economy, changing cultural attitudes, and a steeply increasing population could thus push the regional demand upward in the coming decades, with significant depletion of regional and global natural resources and environmental repercussions. We study the historical association of the four main meat types with demand drivers in recently developed countries via seemingly unrelated regression (SUR) equation systems. Using the calibrated coefficients, trajectories of meat consumption in SSA to 2050 are projected relying on the SSP scenarios over GDP and population growth. Then, using a Leontiefian environmentally extended input-output (EEIO) framework exploiting the EXIOBASE3 database, we estimate the related energy, land, and water requirements, and the implied greenhouse gas (CO2, CH4, N2O) emissions. We calculate that if production to meet those consumption levels takes place in the continent – compared to the current situation – global greenhouse gas (GHG) emissions would grow by 230 Mt CO2e (4.4% of today’s global agriculture-related emissions), the land required for cropping and grazing would require additional 4.2 · 10^6 km2 (more than half of the total arable land in SSA), total blue water consumption would rise by 10,300 Mm3 (0.89% of the global total), and additional 1.2 EJ of energy (6% of today’s total primary energy demand in the region) would be required. Alternative scenarios where SSA is a net importer of final meat products are reported for comparison. The local policy and attitudes towards farming practices and dietary choices will have significant impact on both the regional environment and global GHG emissions

Better Sound Rural or Criminal? Data from a Case Study: The City Of Temara, Morocco

This paper moves from the following issue: is there a homogeneous variety of spoken Arabic in expansion in Morocco? An ongoing research project on language practices in the Moroccan town of Temara, a sort of “new-town” that has been growing dramatically in the last four decades by the effect of internal immigration, seeks to partially answer this question by analysing language in an urban context, which by its very nature demands a “delocalisation” of speech from its dwellers. After stating why the focus is placed on the social interpretation of single linguistic features rather than on the definition of a “variety”, the paper goes on to motivate the choice of comparing the data collected on the field with the use of spoken Moroccan Arabic in fiction as a technique to acquire more information on the sociolinguistic connotation of linguistic traits in the community. Finally, a brief sketch of the linguistic features selected and the first results of the analysis are provided

Monitoring hydropower reliability in Malawi with satellite data and machine learning

Hydro-climatic extremes can affect the reliability of electricity supply, in par-ticular in countries that depend greatly on hydropower or cooling water andhave a limited adaptive capacity. Assessments of the vulnerability of the powersector and of the impact of extreme events are thus crucial for decision-makers,and yet often they are severely constrained by data scarcity. Here, we intro-duce and validate an energy-climate-water framework linking remotely-senseddata from multiple satellite missions and instruments (TOPEX/POSEIDON.OSTM/Jason, VIIRS, MODIS, TMPA, AMSR-E) and field observations. Theplatform exploits random forests regression algorithms to mitigate data scarcityand predict river discharge variability when ungauged. The validated predic-tions are used to assess the impact of hydroclimatic extremes on hydropowerreliability and on the final use of electricity in urban areas proxied by night-time light radiance variation. We apply the framework to the case of Malawifor the periods 2000-2018 and 2012-2018 for hydrology and power, respectively.Our results highlight the significant impact of hydro-climatic variability anddry extremes on both the supply of electricity and its final use. We thus showthat a modelling framework based on open-access data from satellites, machinelearning algorithms, and regression analysis can mitigate data scarcity and im-prove the understanding of vulnerabilities. The proposed approach can supportlong-term infrastructure development monitoring and identify vulnerable pop-ulations, in particular under a changing climate

Essays on Energy and Development in sub-Saharan Africa: Energy access, climate change, and the Nexus

La seguente Tesi di Dottorato si articola in cinque saggi che esaminano alcuni importanti aspetti legati all'energia in Africa subsahariana, e in particolare all'interazione tra lo sviluppo socio-economico e le sue implicazioni per l'ambiente a livello regionale e globale. I saggi sono introdotti da un capitolo di avvicinamento generale ai temi trattati. Questo capitolo prepara il lettore offrendo un riassunto delle principali sfide legate all'energia nel contesto subsariano e formulando le domande di ricerca e gli strumenti sui quali si basa la tesi stessa. Le principali implicazioni di ciascuno dei saggi, sia per la ricerca che per i decisori politici, vengono poi presentate in un capitolo di discussione finale. Il primo saggio esamina la problematica dell’accesso all'energia, e in particolare all'elettricità. Viene illustrato il ruolo dei dati satellitari e dell'analisi statistica dei dati geospaziali nel migliorare la comprensione della situazione dell'accesso all'elettricità in Africa subsahariana. Il saggio include un'analisi delle disuguaglianze che caratterizzano la qualità dell'accesso all'elettricità nella regione. Il risultato principale è che, dopo decenni, la disuguaglianza nell'accesso all'energia sta iniziando a diminuire. Essa rimane però prominente, in particolare per quanto riguarda la quantità di energia consumata. Viene stimato che gli sforzi di elettrificazione tra il 2020 e il 2030 debbano triplicare il loro passo per raggiungere l'obiettivo di sviluppo sostenibile SDG 7.1.1. Il secondo saggio consiste di una piattaforma di valutazione della domanda energetica bottom-up spazialmente esplicita per stimare il fabbisogno energetico tra le comunità in cui l'accesso all'elettricità è attualmente carente, come identificato con la metodologia introdotta nel primo saggio. La valutazione non si limita al fabbisogno energetico residenziale, ma include un resoconto dettagliato, basato sugli usi finali, del fabbisogno energetico di scuole, strutture sanitarie, pompaggio dell'acqua per l'irrigazione, lavorazione delle colture e microimprese, i principali motori dello sviluppo rurale. Viene condotto uno studio nazionale per il Kenya per dimostrare l'importanza di considerare molteplici fonti di domanda oltre al residenziale quando l'obiettivo è sviluppare una strategia di elettrificazione che supperisca veramente alla povertà energetica. Si dimostra poi che esiste un notevole potenziale di crescita della produttività e della redditività rurale grazie all'apporto di energia elettrica. In molte aree, questi profitti locali potrebbero ripagare gli investimenti nelle infrastrutture di elettrificazione in pochi anni. Il terzo saggio analizza un aspetto specifico dell'interazione tra pianificazione dell'accesso all'elettricità, domanda di energia residenziale e adattamento ai cambiamenti climatici. Vengono combinati dati e scenari climatici, satellitari e demografici per produrre una stima globale spazialmente esplicita della domanda di circolazione e condizionamento dell’aria non soddisfatta a causa della mancanza di accesso all'elettricità. Sulla base di modelli integrati di elettrificazione climatica-energetica e geospaziale, risulta che in Africa sub-sahariana, l'hotspot globale della povertà energetica, tenere conto del fabbisogno di circolazione e condizionamento dell’aria locale stimato (in aggiunta agli obiettivi di consumo residenziale di base) determini una riduzione sostanziale della quota di sistemi standalone come l'opzione di elettrificazione meno costosa entro il 2030, e un importante aumento della capacità di generazione di elettricità e dei requisiti di investimento. Tali risultati suggeriscono la necessità di una maggiore considerazione delle esigenze di adattamento climatico nella pianificazione dei sistemi energetici dei paesi in via di sviluppo e nella valutazione del trade-off tra l'espansione della rete elettrica centrale e sistemi decentralizzati per raggiungere un’elettrificazione universale. La pianificazione dell'elettrificazione deve essere tecnicamente efficiente, ma deve anche considerare l'ambiente politico-economico in cui gli investimenti vengono canalizzati. Il quarto saggio valuta il ruolo della governance e della qualità regolatoria nel quadro di modellazione dell'accesso all'energia elettrica. In particolare, si introduce un indice di governance dell'accesso all'elettricità basato su più indicatori che viene poi implementato nel modello di elettrificazione IMAGE-TIMER. L’effetto dell’indice viene modellato attraverso il suo effetto modificatore sui tassi di sconto privati (una misura del rischio e della disponibilità ad accettare costi futuri rispetto ai costi attuali). I risultati mostrano che la governance e la qualità regolatoria nell'accesso all'elettricità hanno un impatto significativo sul mix tecnologico ottimale e sui flussi di investimenti privati per raggiungere l'elettrificazione universale in Africa subsahariana. In particolare, un ambiente rischioso scoraggia l’investimento da parte dei fornitori privati di soluzioni di accesso decentralizzato all'energia, con il rischio di lasciare molti senza elettricità anche oltre il 2030. Il quinto e ultimo saggio analizza il settore energetico africano da un punto di vista ‘Nexus’. Il saggio valuta l'affidabilità del sistema energetico nei sistemi energetici dominati dall'energia idroelettrica (come in molti paesi dell'Africa centrale e orientale) e del ruolo che i cambiamenti climatici e gli eventi estremi possono esercitare su di esso. Il lavoro combina analisi qualitative e quantitative per (i) proporre un solido framework per evidenziare le interdipendenze tra energia idroelettrica, disponibilità di acqua e cambiamento climatico, (ii) analizzare sistematicamente lo stato dell'arte sugli impatti previsti dei cambiamenti climatici su l'energia idroelettrica nell'Africa subsahariana e (iii) fornire evidenza empirica sui trend passati e sulle traiettorie di sviluppo futuro del settore. I risultati suggeriscono che il cambiamento climatico influenzerà l'affidabilità e la sicurezza della fornitura elettrica attraverso diversi canali. Ad esempio, molti dei principali bacini idrologici sono stati caratterizzati da una diminuzione del livello idrico nel corso del ventesimo secolo. Si evidenzia come tuttavia una diversificazione del mix di generazione elettrico sia finora stata promossa solo in un numero limitato di paesi. Si suggerisce infine che l'integrazione delle fonti rinnovabili variabili con l'energia idroelettrica possa aumentare la resilienza del sistema.This dissertation is a collection of five essays examining some important energy-related aspects at the interplay of sub-Saharan Africa (SSA)’s development and its interactions with the regional and global environment. The essays are introduced by a general overview chapter – highlighting the core energy-related challenges of SSA and the scope of this work. The main implications of the essays, both for research and for policymakers, are then considered in the final discussion chapter. The first essay focuses on access to modern energy, and chiefly on electricity. I illustrate the role of satellite data and the statistical analysis of geospatial data in improving the understanding of the electricity access situation in sub-Saharan Africa. The essay includes an analysis of inequality characterising the electricity access quality in the region. The main finding is that after decades, energy access inequality is beginning to decline but it remains prominent in particular as far as the quantity consumed is concerned. I find that electrification efforts between 2020 and 2030 must triplicate their pace to meet Sustainable Development Goal 7.1.1. The second essay develops a spatially-explicit bottom-up energy demand assessment platform to estimate the energy needs among communities where access to electricity is currently lacking, as identified with the methodology introduced in the first essay. The assessment is not restricted to residential energy needs, but it includes a detailed, appliance-based account of power needs for schools, healthcare facilities, water pumping for irrigation, crop processing, and micro enterprises, the key drivers of rural development. I carry out a country-study for Kenya to show the importance of considering multiple demand sources beyond residential when the aim is developing an electrification strategy which truly overcomes energy poverty. I also show that there is considerable potential for rural productivity and profitability growth thanks to the input of electric energy. In many areas, these local profits might pay back the electrification infrastructure investment in only few years. The third essay analyses a specific aspect at the interplay between electricity access planning, household energy demand and climate change adaptation. I combine climate, satellite, and demographic data and scenarios to produce a global spatially-explicit estimate of unmet ACC demand due to the lack of electricity access. Based on integrated climate-energy and geospatial electrification modelling, I find that in sub-Saharan Africa, the global hotspot of energy poverty, accounting for the estimated local ACC needs on top of baseline residential consumption targets determines a substantial reduction in the share of decentralised systems as the least-cost electrification option by 2030, and a major ramp-up in the power generation capacity and investment requirements. My results call for a greater consideration of climate adaptation needs in the planning of energy systems of developing countries and in evaluating the trade-off between the central power grid expansion and decentralised systems to achieve universal electrification. Electrification planning must be techno-economically efficient, but it must also consider the political-economic environment where investment needs to be channelled. The fourth essay evaluates the role of governance and regulatory quality in the electricity access modelling framework. In particular, I introduce an Electricity Access Governance Index based on multiple indicators implement it into the PBL’s IMAGE-TIMER electrification model through its modifier effect on private discount rates (a measure of risk and willingness to accept future costs vis-à-vis present costs). The results show that governance and regulatory quality in electricity access have a significant impact on the optimal technological mix and the private investment flows for reaching universal electrification in sub-Saharan Africa. In particular, risky environment crowd out private providers of decentralised energy access solutions with the risk of leaving many without electricity even after 2030. The fifth and final essay takes a nexus perspective in the analysis of the African power sector. It deals with the reliability of the energy system in hydropower-dominated power systems (such as in many countries in Central and East Africa) and the role that climate change and extreme events can exert on it. The essay combines qualitative and quantitative analysis to (i) propose a robust framework to highlight the interdependencies between hydropower, water availability, and climate change, (ii) systematically review the state-of-the art literature on the projected impacts of climate change on hydropower in sub-Saharan Africa, and (iii) provide supporting evidence on past trends and current pathways of power mix diversification, drought incidence, and climate change projections. I find that climate change can affect supply reliability and security in multiple ways. For instance, several major river basins have been drying throughout the twentieth century. Nonetheless, I highlight that diversification has hitherto only been promoted in a limited number of countries. I suggest how integrating variable renewables and hydropower can increase system resilience

Benedetto Cotrugli et son traité De navigatione (1464-1465)

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Energy access investment, agricultural profitability, and rural development: time for an integrated approach

In rural sub-Saharan Africa, the global poverty hotspot, smallholder farmers account for 80% of agricultural production, with 90% of cropland being exclusively rainfed. A key obstacle to rural development and poverty elimination is the lack of electricity access: less than one in three dwellers have electricity at home. The main barrier to rural electrification is the capital-intensiveness of energy supply infrastructure among sparse communities with low demand density and insecurity of payment. While public governments have largely been unable to channel the required resources, private players are often unwilling to pursue risky and unprofitable household electrification programs. In this context, this perspective argues that the paradigm of rural electrification should be centred around an integrated approach aiming at increasing agricultural productivity and profitability. These bear the necessary potential to enable local income generation and thus also provide an incentive for private energy investment, including in the residential sector. A framework for the integrated approach is proposed and the crucial synergetic role of data modelling and business and policy research to pursue this paradigm is discussed