Bringing power and progress to Africa in a financially and environmentally sustainable manner

EXECUTIVE SUMMARY: The future of electricity supply and delivery on the continent of Africa represents one of the thorniest challenges facing professionals in the global energy, economics, finance, environmental, and philanthropic communities. Roughly 600 million people in Africa lack any access to electricity. If this deficiency is not solved, extreme poverty for many Africans is virtually assured for the foreseeable future, as it is widely recognized that economic advancement cannot be achieved in the 21st Century without good electricity supply. Yet, if Africa were to electrify in the same manner pursued in developed economies around the world during the 20th Century, the planet’s global carbon budget would be vastly exceeded, greatly exacerbating the worldwide damages from climate change. Moreover, due to low purchasing power in most African economies and fiscal insolvency of most African utilities, it is unclear exactly how the necessary infrastructure investments can be deployed to bring ample quantities of power – especially zero-carbon power – to all Africans, both those who currently are unconnected to any grid as well as those who are now served by expensive, high-emitting, limited and unreliable electricity supply. With the current population of 1.3 billion people expected to double by 2050, the above-noted challenges associated with the African electricity sector may well get substantially worse than they already are – unless new approaches to infrastructure planning, development, finance and operation can be mobilized and propagated across the continent. This paper presents a summary of the present state and possible futures for the African electricity sector. A synthesis of an ever-growing body of research on electricity in Africa, this paper aims to provide the reader a thorough and balanced context as well as general conclusions and recommendations to better inform and guide decision-making and action. [TRUNCATED]This paper was developed as part of a broader initiative undertaken by the Institute for Sustainable Energy (ISE) at Boston University to explore the future of the global electricity industry. This ISE initiative – a collaboration with the Global Energy Interconnection and Development Cooperation Organization (GEIDCO) of China and the Center for Global Energy Policy within the School of International and Public Affairs at Columbia University – was generously enabled by a grant from Bloomberg Philanthropies. The authors gratefully acknowledge the support and contributions of the above funders and partners in this research

Simulations of Collisional Effects in an Inner-Shell Solid-Density Mg X-Ray Laser

Inner-shell K$\alpha$ x-ray lasers have been created by pumping gaseous, solid, and liquid targets with the intense x-ray output of free-electron-lasers (FELs). For gaseous targets lasing relies on the creation of K-shell core-holes on a time-scale short compared with filling via Auger decay. In the case of solid and liquid density systems, collisional effects will also be important, affecting not only populations, but also line-widths, both of which impact the degree of overall gain, and its duration. However, to date such collisional effects have not been extensively studied. We present here initial simulations using the CCFLY code of inner-shell lasing in solid density Mg, where we self-consistently treat the effects of the incoming FEL radiation and the atomic kinetics of the Mg system, including radiative, Auger, and collisional effects. We find that the combination of collisional population of the lower states of the lasing transitions and broadening of the lines precludes lasing on all but the K$\alpha$ of the initially cold system. Even assuming instantaneous turning on of the FEL pump, we find the duration of the gain in the solid system to be sub-femtosecond.Comment: This paper has been submitted to Philosophical Transactions

Species reintroduction and community-level consequences in dynamically simulated ecosystems

Global biodiversity, and its associated ecosystem services, are threatened due to species extinctions. Reintroducing locally extinct species may be a partial solution to this problem. However, the success and possible consequences of any artificial reintroduction will depend on its ecological community, and the reaction of that community to the species' extinction and reintroduction. Mathematical models can offer useful insights by identifying the key features of communities and reintroduced species most likely to result in successful reintroductions. Here we simulated extinctions and reintroductions for a range of theoretical food webs generated using an established bioenergetics model. This allows the probability of successful reintroductions to be quantified as a function of two important ecological factors: the connectance of the food web, and of the time between extinctions and reintroductions. Reintroduction success is measured across an ensemble of 1796 simulated communities, with connnectances of 0.05, 0.15 and 0.3, using three criteria: presence of the reintroduced species in the final community, unchanged species richness in the final community compared to the pre-extinction persistent community and the complete restoration of the community (including both species richness and equilibrium biomass distributions). Although only 12 reintroduced species fail to re-establish according to minimal criteria, the process of extinction and reintroduction frequently has a large effect on the community composition. Increasing time to reintroduction increases both the probability of species loss, and equilibrium biomass change in the community. Proportionally, these community-level impacts occur more frequently when the reintroduced species is a primary producer or top predator. These results indicate that ignoring broader measures of reintroduction success could seriously underestimate the impact of reintroductions on the ecological community. These quantitative results can be compared to empirical literature and may help reveal which factors are most important to the success of reintroductions

Social networks : the future for health care delivery

With the rapid growth of online social networking for health, health care systems are experiencing an inescapable increase in complexity. This is not necessarily a drawback; self-organising, adaptive networks could become central to future health care delivery. This paper considers whether social networks composed of patients and their social circles can compete with, or complement, professional networks in assembling health-related information of value for improving health and health care. Using the framework of analysis of a two-sided network – patients and providers – with multiple platforms for interaction, we argue that the structure and dynamics of such a network has implications for future health care. Patients are using social networking to access and contribute health information. Among those living with chronic illness and disability and engaging with social networks, there is considerable expertise in assessing, combining and exploiting information. Social networking is providing a new landscape for patients to assemble health information, relatively free from the constraints of traditional health care. However, health information from social networks currently complements traditional sources rather than substituting for them. Networking among health care provider organisations is enabling greater exploitation of health information for health care planning. The platforms of interaction are also changing. Patient-doctor encounters are now more permeable to influence from social networks and professional networks. Diffuse and temporary platforms of interaction enable discourse between patients and professionals, and include platforms controlled by patients. We argue that social networking has the potential to change patterns of health inequalities and access to health care, alter the stability of health care provision and lead to a reformulation of the role of health professionals. Further research is needed to understand how network structure combined with its dynamics will affect the flow of information and potentially the allocation of health care resources

An Empirical Analysis of Forecast Sharing in the Semiconductor Equipment Supply Chain

We study the demand forecast-sharing process between a buyer of customized production equipment and a set of equipment suppliers. Based on a large data collection we undertook in the semiconductor equipment supply chain, we empirically investigate the relationship between the buyer\u27s forecasting behavior and the supplier\u27s delivery performance. The buyer\u27s forecasting behavior is characterized by the frequency and magnitude of forecast revisions it requests (forecast volatility) as well as by the fraction of orders that were forecasted but never actually purchased (forecast inflation). The supplier\u27s delivery performance is measured by its ability to meet delivery dates requested by the customers. Based on a duration analysis, we are able to show that suppliers penalize buyers for unreliable forecasts by providing lower service levels. Vice versa, we also show that buyers penalize suppliers that have a history of poor service by providing them with overly inflated forecasts

On the Friedmann Equation in Brane-World Scenarios

The Friedmann law on the brane generically depends quadratically on the brane energy density and involves a ``dark radiation'' term due to the bulk Weyl tensor. Despite its unfamiliar form, we show how it can be derived from a standard four-dimensional Brans-Dicke theory at low energy. In particular, the dark radiation term is found to depend linearly on the brane energy densities. For any equation of state on the branes, the radion evolves such as to generate radiation-dominated cosmology. The radiation-dominated era is conventional and consistent with nucleosynthesis.Comment: 4 pages. v2,v3: discussion on BBN extended, minor correction

The Critical Role of Public Charging Infrastructure

Editors: Peter Fox-Penner, PhD, Z. Justin Ren, PhD, David O. JermainA decade after the launch of the contemporary global electric vehicle (EV) market, most cities face a major challenge preparing for rising EV demand. Some cities, and the leaders who shape them, are meeting and even leading demand for EV infrastructure. This book aggregates deep, groundbreaking research in the areas of urban EV deployment for city managers, private developers, urban planners, and utilities who want to understand and lead change