The economics of renewable energy expansion in rural Sub-Saharan Africa

Accelerating development in Sub-Saharan Africa will require massive expansion of access to electricity -- currently reaching only about one-third of households. This paper explores how essential economic development might be reconciled with the need to keep carbon emissions in check. The authors develop a geographically explicit framework and use spatial modeling and cost estimates from recent engineering studies to determine where stand-alone renewable energy generation is a cost effective alternative to centralized grid supply. The results suggest that decentralized renewable energy will likely play an important role in expanding rural energy access. But it will be the lowest cost option for a minority of households in Africa, even when likely cost reductions over the next 20 years are considered. Decentralized renewables are competitive mostly in remote and rural areas, while grid connected supply dominates denser areas where the majority of households reside. These findings underscore the need to de-carbonize the fuel mix for centralized power generation as it expands in Africa.Energy Production and Transportation,Climate Change Mitigation and Green House Gases,Transport Economics Policy&Planning,Power&Energy Conversion,Carbon Policy and Trading

Optimizing operation of a campus energy system for economic and environmental considerations

The objective of this thesis is to determine effective costs of campus utilities, optimal operation of energy conversion and production subsystems through minimization of economic and environmental costs, and to evaluate how changing electrical grid costs and sources will affect future optimal operations at a campus. Characteristic days were developed to typify campus activities and their impact on energy consumption. At current grid electricity and natural gas prices, utilization of a cogeneration unit, a form of combined heat and power plant, is less expensive than purchasing equivalent amounts of electric and gas to produce steam, as long as there is sufficient campus demand for the electricity and steam produced. Carbon dioxide emissions during cogeneration unit operation was nearly the same as purchasing equivalent amounts of electric and gas to produce steam. Simulation of economic and environmental performance of the cogeneration plant, found minor differences between least expensive and greenest operations. Analyses suggested that grid emissions will not become clean enough to merit decommissioning of cogeneration plant early. Operation of the cogeneration plant is favorable for economical and environmental considerations

Feasibility Study of a Satellite Solar Power Station

A feasibility study of a satellite solar power station (SSPS) was conducted to: (1) explore how an SSPS could be flown and controlled in orbit; (2) determine the techniques needed to avoid radio frequency interference (RFI); and (3) determine the key environmental, technological, and economic issues involved. Structural and dynamic analyses of the SSPS structure were performed, and deflections and internal member loads were determined. Desirable material characteristics were assessed and technology developments identified. Flight control performance of the SSPS baseline design was evaluated and parametric sizing studies were performed. The study of RFI avoidance techniques covered (1) optimization of the microwave transmission system; (2) device design and expected RFI; and (3) SSPS RFI effects. The identification of key issues involved (1) microwave generation, transmissions, and rectification and solar energy conversion; (2) environmental-ecological impact and biological effects; and (3) economic issues, i.e., costs and benefits associated with the SSPS. The feasibility of the SSPS based on the parameters of the study was established

Power Quality Enhancement in Electricity Grids with Wind Energy Using Multicell Converters and Energy Storage

In recent years, the wind power industry is experiencing a rapid growth and more wind farms with larger size wind turbines are being connected to the power system. While this contributes to the overall security of electricity supply, large-scale deployment of wind energy into the grid also presents many technical challenges. Most of these challenges are one way or another, related to the variability and intermittent nature of wind and affect the power quality of the distribution grid. Power quality relates to factors that cause variations in the voltage level and frequency as well as distortion in the voltage and current waveforms due to wind variability which produces both harmonics and inter-harmonics. The main motivation behind work is to propose a new topology of the static AC/DC/AC multicell converter to improve the power quality in grid-connected wind energy conversion systems. Serial switching cells have the ability to achieve a high power with lower-size components and improve the voltage waveforms at the input and output of the converter by increasing the number of cells. Furthermore, a battery energy storage system is included and a power management strategy is designed to ensure the continuity of power supply and consequently the autonomy of the proposed system. The simulation results are presented for a 149.2 kW wind turbine induction generator system and the results obtained demonstrate the reduced harmonics, improved transient response, and reference tracking of the voltage output of the wind energy conversion system.Peer reviewedFinal Accepted Versio

Pyroelectric conversion in space: A conceptual design study

Pyroelectric conversion is potentially a very lightweight means of providing electrical power generation in space. Two conceptualized systems approaches for the direct conversion of heat (from sunlight) into electrical energy using the pyroelectric effect of a new class of polar polymers were evaluated. Both of the approaches involved large area thin sheets of plastic which are thermally cycled by radiative input and output of thermal energy. The systems studied are expected to eventually achieve efficiencies of the order of 8% and may deliver as much as one half kilowatt per kilogram. In addition to potentially very high specific power, the pyroelectric conversion approaches outlined appear to offer low cost per watt in the form of an easily deployed, flexible, strong, electrically ""self-healing'', and high voltage sheet. This study assessed several potential problems such as plasma interactions and radiation degradation and suggests approaches to overcome them. The fundamental technological issues for space pyroelectric conversion are: (1) demonstration of the conversion cycle with the proposed class of polymers, (2) achievement of improved dielectric strength of the material, (3) demonstration of acceptable plasma power losses for low altitude, and (4) establishment of reasonable lifetime for the pyroelectric material in the space environment. Recommendations include an experimental demonstration of the pyroelectric conversion cycle followed by studies to improve the dielectric strength of the polymer and basic studies to discover additional pyroelectric materials

Dynamic modeling and simulations of solid oxide fuel cells for grid-tied applications

As energy consumption rises, one must find suitable alternative means of generation to supplement conventional existing generation facilities. In this regard, distributed generation (DG) will continue to play a critical role in the energy supply-demand realm. The common technologies available as DG are micro-turbines, solar photovoltaic systems, fuel cells stack and wind energy systems. In this thesis, a dynamic model of solid oxide fuel cell (SOFC) is presented. Fuel cells operate at low voltages and hence need to be boosted and inverted in order to be connected to the utility grid. The interconnection of the SOFC with a DC-DC converter and a DC-AC inverter for interfacing with the grid is presented in this thesis --Abstract, page iii

Space power distribution system technology. Volume 2: Autonomous power management

Electrical power subsystem requirements, power management system functional requirements, algorithms, power management subsystem, hardware development, and trade studies and analyses are discussed

SIMULATION STUDIES OF A PV SYSTEM FOR RESIDENTIAL SECTOR

The aim of this project is to carryout simulation studies on a photovoltaic based system, to be used in residential sector. Photovoltaic is a semiconductor device that generates electrical power, from solar radiation. Sunlight received by the solar cell, and will be used to generate direct current. Sunlight is necessary for PV to generate electricity, and in order to ensure continuous supplyof powerstorage is required. A properanalysis of a PV based system is necessary, as the sunlight that is received at the surface of earth is transient in nature. On the average, Malaysia receives between 6-9 sunshine hours. Due to this, the system identification process is rather critical and the main specification is related to the PVarray sizing. Since sunlight is mandatory; then the next important aspect is the battery array sizing. A typical house model was used to do load calculation, and this is an important process to assist in the planning of the number of PV panels and batteries required. To safely ensure sustainable power supply, storage is vital. Experiments were carried out by using a standard 80W PV array, subjected to local weather condition at UTP. Results obtained clearly indicated that a system simulation, based on precise mathematical model is very important. Visual Basic Software was used as a programming tool for simulation of the project. A simulation of a project is simple and user-friendly to design PV system for the house such as sizing PV array, sizing battery and load calculation. The objective of the; project has been accomplished. The result has been successfully achieved andproject working effectively