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Following the Paris Agreement in 2015, the worldwide focus on global warming countermeasures has intensified. The Japanese government has declared its aim at achieving carbon neutrality by 2050. The concept of zero-energy buildings (ZEBs) is based on measures to reduce energy consumption in buildings, the prospects of which are gradually increasing. This study investigated the annual primary energy consumption; as well as evaluated, renewed, and renovated buildings that had a solar power generation system, and utilized solar and geothermal heat. It further examines the prospects of hydrogen production from on-site surplus electricity and the use of hydrogen fuel cells. A considerable difference was observed between the actual energy consumption (213 MJ/m2), and the energy consumption estimated using an energy simulation program (386 MJ/m2). Considerable savings of energy were achieved when evaluated based on the actual annual primary energy consumption of a building. The building attained a near net zero-energy consumption considering the power generated from the photovoltaic system. The study showed potential energy savings in the building by producing hydrogen, using surplus electricity from on-site power generation, and introducing hydrogen fuel cells. It is projected that a building’s energy consumption will be lowered by employing the electricity generated by the hydrogen fuel cell for standby power, water heating, and regenerating heat from the desiccant system.

The selection of the peak power of a photovoltaic system to meet the energy demand of a building is a key task in the energy transformation. This article presents an algorithm for assessing the correctness of the selection of a photovoltaic system with a peak power of 50 kWp for the needs of a university administration building. This is made possible due to the use of an advanced photovoltaic inverter, which is a device of the Internet of Things and the smart metering system. At the beginning of the review, the authors employed the naked eye measurement data of the time series related to the power production by the photovoltaic system and its consumption by the university building. Then, traditional statistical analyses were performed, characterizing the generated power divided into self-consumption power and that fed into the power grid. The analysis of the total consumed power was performed with the division into the power produced by the photovoltaic system and that taken from the power grid. The analyses conducted were subjected to expert validation aimed at explaining the nature of the behavior of the power generation and consumption systems. The main goal of this article is to determine the signatures of the power generated by the photovoltaic system and consumed by the administration building. As a result of unsupervised clustering, the power generation and consumption space were divided into states. These were then termed based on their nature and their usefulness in managing the power produced and consumed. Presentation of clustering results in the form of heatmaps allows for localization of specific states at specific times of the day. This leads to their better understanding and quantification. The signatures of power generated by the photovoltaic system and consumed by the university building confirmed the possibility of using an energy storage system. The presented computational algorithm is the basis for determining the correctness of the photovoltaic system selection for the current energy needs of the building. It can be the basis for further analysis related to the prediction of both the power generated by Renewable Energy Sources and the energy consumed by diverse types of buildings.

This study is a product of the Africa Infrastructure Country Diagnostic (AICD), a project designed to expand the world's knowledge of physical infrastructure in Africa. The AICD provides a baseline against which future improvements in infrastructure services can be measured, making it possible to monitor the results achieved from donor support. It also offers a more solid empirical foundation for prioritizing investments and designing policy reforms in the infrastructure sectors in Africa. The book draws upon a number of background papers that were prepared by World Bank staff and consultants, under the auspices of the AICD. The main findings were synthesized in a flagship report titled Africa's infrastructure: A time for transformation, published in November 2009. Meant for policy makers, that report necessarily focused on the high-level conclusions. It attracted widespread media coverage feeding directly into discussions at the 2009 African union commission heads of state summit on infrastructure.

Because of the increasing challenges raised by climate change, power generation from renewable energy sources is steadily increasing to reduce greenhouse gas emissions, especially CO2. However, this has escalated concerns about the instability of the power grid and surplus power generated because of the intermittent power output of renewable energy. To resolve these issues, this study investigates two technical options that integrate a power-to-gas (PtG) process using surplus wind power and the gas turbine combined cycle (GTCC). In the first option, hydrogen produced using a power-to-hydrogen (PtH) process is directly used as fuel for the GTCC. In the second, hydrogen from the PtH process is converted into synthetic natural gas by capturing carbon dioxide from the GTCC exhaust, which is used as fuel for the GTCC. An annual operational analysis of a 420-MW-class GTCC was conducted, which shows that the CO2 emissions of the GTCC-PtH and GTCC-PtM plants could be reduced by 95.5% and 89.7%, respectively, in comparison to a conventional GTCC plant. An economic analysis was performed to evaluate the economic feasibility of the two plants using the projected cost data for the year 2030, which showed that the GTCC-PtH would be a more viable option.

An investigation into the effectiveness of surrogate measures for the hydraulic reliability and/or redundancy of water distribution systems is presented. The measures considered are statistical flow entropy, resilience index, network resilience and surplus power factor. Looped network designs that are maximally noncommittal to the surrogate reliability measures were considered. In other words, the networks were designed by multi-objective evolutionary optimization free of any influence from the surrogate measures. The designs were then assessed using each surrogate measure and two accurate but computationally intensive measures namely hydraulic reliability and pipe-failure tolerance. The results indicate that by utilising statistical flow entropy, the reliability of the network can be reasonably approximated, with substantial savings in computational effort. The results for the other surrogate measures were often inconsistent. Two networks in the literature were considered. One example involved a range of alternative network topologies. In the other example, based on whole-life cost accounting, alternative design and upgrading schemes for a 20-year design horizon were considered. Pressure-dependent hydraulic modelling was used to simulate pipe failures for the reliability calculations.

It is necessary to evaluate the reliability of the water supply network, when the water supply network is damaged by an earthquake. Therefore, this paper researched the feasibility and characteristics of the surplus power entropy as the reliability index of the water supply network, and established a scheme framework for optimizing and improving the reliability of the water supply network. This paper developed a reliability evaluation model for the water supply network after an earthquake. Combined with the Monte Carlo stochastic simulation hydraulic analysis, this model is also based on the pressure-driven nodes water demand model. In the case study, the surplus power entropy method was applied to test the reliability of the model. The statistical curves of the surplus power entropy of nodes and pipe networks, the distribution of the surplus power entropy with different intensities in pipe networks, and the comparison results of three reliability improvement schemes, before and after, were obtained. The influence factors of the surplus power entropy were obtained from the data analysis. The high consistency between the surplus power entropy and flow entropy verifies the feasibility of the surplus power entropy as a reliability index. The three schemes show that the surplus power entropy index can be used as a beneficial supplement to the reliability evaluation index of the pipe network.

The paper discusses a supply and demand scenario using renewable energy sources for the city El Gouna in Egypt as an example for a self-supplying community. All calculations are based on measured meteorological data and real power demand during the year 2013. The modeled energy system consists of a concentrating solar tower plant with thermal storage and low-temperature seawater desalination unit as well as an integrated photovoltaic plant and a wind turbine. The low-temperature desalination unit has been newly developed in order to enable the utilization of waste heat from power conversion processes by improved thermal efficiency. In the study, special attention is given to the surplus power handling generated by the photovoltaic and wind power plant. Surplus power is converted into heat and stored in the thermal storage system of the solar power plant in order to increase the capacity factor. A brief estimation of investment costs have been conducted as well in order to outline the economic performance of the modeled energy and water supply system.

To solve the problem of residual wind power in offshore wind farms, a hydrogen production system with a reasonable capacity was configured to enhance the local load of wind farms and promote the local consumption of residual wind power. By studying the mathematical model of wind power output and calculating surplus wind power, as well as considering the hydrogen production/storage characteristics of the electrolyzer and hydrogen storage tank, an innovative capacity optimization allocation model was established. The objective of the model was to achieve the lowest total net present value over the entire life cycle. The model took into account the cost-benefit breakdown of equipment end-of-life cost, replacement cost, residual value gain, wind abandonment penalty, hydrogen transportation, and environmental value. The MATLAB-based platform invoked the CPLEX commercial solver to solve the model. Combined with the analysis of the annual average wind speed data from an offshore wind farm in Guangdong Province, the optimal capacity configuration results and the actual operation of the hydrogen production system were obtained. Under the calculation scenario, this hydrogen production system could consume 3,800 MWh of residual electricity from offshore wind power each year. It could achieve complete consumption of residual electricity from wind power without incurring the penalty cost of wind power. Additionally, it could produce 66,500 kg of green hydrogen from wind power, resulting in hydrogen sales revenue of 3.63 million RMB. It would also reduce pollutant emissions from coal-based hydrogen production by 1.5 tons and realize an environmental value of 4.83 million RMB. The annual net operating income exceeded 6 million RMB and the whole life cycle NPV income exceeded 50 million RMB. These results verified the feasibility and rationality of the established capacity optimization allocation model. The model could help advance power system planning and operation research and assist offshore wind farm operators in improving economic and environmental benefits.

Information and communication technologies (ICTs) have been a remarkable success in Africa. Across the continent, the availability and quality of service have gone up and the cost has gone down. In just 10 years dating from the end of the 1990s mobile network coverage rose from 16 percent to 90 percent of the urban population; by 2009, rural coverage stood at just under 50 percent of the population. Although the performance of Africa's mobile networks over the past decade has been remarkable, the telecommunications sector in the rest of the world has also evolved rapidly. Many countries now regard broadband Internet as central to their long-term economic development strategies, and many companies realize that the use of ICT is the key to maintaining profitability. This book is about that challenge and others. Chapters two and three describe the recent history of the telecommunications market in Africa; they cover such issues as prices, access, the performance of the networks, and the regulatory reforms that have triggered much of the investment. This part of the book compares network performance across the region and tries to explain why some countries have moved so much more quickly than others in providing affordable telecommunications services. Chapter four explores the financial side of the telecommunications revolution in Africa and details how the massive investments have been financed and which companies have most influenced the sector. Chapter five deals with the future of the sector. The final chapter synthesizes the main chapters of the book and presents policy recommendations intended to drive the sector forward.

Hydraulic power capacity of the water distribution network (WDN) is analyzed, and energetically maximum flows in pipes and networks are determined. The concept of hydraulic power for the analysis of WDN characteristics is presented. Hydraulic power capacity characterizes the WDN capacity to meet pressure and flow demands. A capacity reliability indicator called the surplus power factor is introduced for individual transmission pipes and for distribution networks. The surplus power factor s that characterizes the reliability of the hydraulic system can be used along with other measures developed to quantify the hydraulic reliability of water networks. The coefficient of the hydraulic efficiency ηn of the network is defined. A water distribution system in service is analyzed to demonstrate the s and ηn values in the water network in service under different demand conditions. In order to calculate the s factor for WDNs, a network resistance coefficient C was determined. The coefficient C characterizes overall head losses in water pipelines and is a basis for the s factor calculation. This paper presents a theoretical approach to determine the coefficient C through matrix equations.