L.M. Alves

Potential of Kyoto Protocol Clean Development Mechanism in transfer of clean energy technologies to Small Island Developing States: case study of Cape Verde

The developed countries committed to greenhouse gases reductions under the aegis of the Kyoto Protocol of the United Nations Framework Convention on Climate Change will, in order to reduce the cost of meeting their commitments, depend on cheaper reductions elsewhere. The reductions will be materialised through several mechanisms of the Kyoto Protocol: the Emission Trade, Joint Implementation and Clean Development Mechanisms. The Mechanisms will carry a strong financial incentive for the dissemination of clean energy technologies, including renewable energy technologies and especially technologies that increase the efficiency of energy transformation and consume. This paper concentrates on the case typical of more than 30 Small Island Developing States, that all have a common situation of relatively low carbon intensity and high price of fossil fuel based economies, and on how the Clean Development Mechanism is expected to influence the transfer of clean energy technologies under the aegis of the Kyoto Protocol. The paper shows, by assessing a case of a small island, that although the emission reduction on global scale is small, there is great potential for establishing a strong market presence of renewable energy technologies in developing countries. A typical small island electricity generation is heavily dependent on Diesel engines, expensive and polluting, but still the most appropriate on such a small scale. This paper studies implications of different scenaria of development of electrical energy system on the island of Santiago, Cape Verde. An estimate of electricity demand for the period until 2030 is given. Baseline scenarium based on Diesel capacity is compared to a renewable energy scenario envisaging 30% of the electricity generated by the wind power, and the other supply side efficiency scenario replacing Diesel capacity with combined cycle. The declining price of clean energy technologies is taken into account. The possible influence of the Clean Development Mechanism is assessed. The potential for financing the technology transfer is quantified and its influence on different electricity system planning scenarios estimated.

Analysis of potential for market penetration of renewable energy technologies in peripheral islands

Cape Verde Islands have important energy and water problems that limit their social and economic development. A field study will be performed focused on Cape Verde Islands to describe the present and future regional power market and to give a clear indication of the best strategies for the optimization of the power energy supply mix in Cape Verde Islands. The study will take into consideration renewable energy technologies and the concerned social, economic and environmental aspects of a given set of possible strategies. One case study will be considered in detail: the situation of the Santo Antao Island. Different energy technologies will be considered: solar, wind, geothermal and biomass. The present structure of the energy sector (capacity, distribution); energy demand, supply and trend; generating plants and infrastructures of Santo Antao will be described.

Energy Storage in Islands - Modelling Porto Santo’ s Hydrogen System

Most islands depend mainly on the importation of fossil fuels for energy production. This causes economic and environmental problems. But generally, islands present a considerable potential in renewable energies. Islands that have energy sources such as hydro or geothermal energy, can easily integrate them into the power system, but those with mainly intermittent renewable energy sources (wind, solar) have to tackle the need of energy storage. In these cases, advanced energy planning should be used, The present paper intends to demonstrate the urging need of planning energy storage systems for small islands and the results of a case-study carried out in a Portuguese island. The need to store intermittent energy is an important issue in the island of Porto Santo, since it is a small and isolated network. H2RES was used to model the energy storage scenarios for this island. One scenario was chosen to evaluate the potential of hydrogen as an energy storage vector and a pilot system of two 5kW fuel cells, one electrolyser of 13 kW, and a 55 m3 storage tank was built. The main objective of this system is to produce hydrogen from electricity from wind mills that otherwise would be wasted, and to use this hydrogen for electricity during peak time.

Injection Forging Of Solid Asymmetric Branched Components

Injection forging allows producing near-net or net-shape asymmetric branched components with geometries that are difficult or impossible to fabricate by means of conventional impression die forging. On the contrary to previous research work in the field that was mainly focused on proposing methodologies for shape classification, systematization of forming defects, definition of workability ranges and evaluation of the overall performance of finite element predictions against experiments, the aims and scope of this article are centred in material flow and forging load requirements that result from double-acting tool concepts with closing spring elements. The presentation includes details on the active tool parts that were utilized for producing solid branched components with different numbers of radial straight legs, on the mechanical characterization of the material and on the numerical simulation and experiments that were performed with selected test cases. Results and observations confirm that double-acting tool concept with closing spring elements is a flexible and efficient manufacturing process for producing injection forged components because it can eliminate the formability problems and defects that are commonly found in single-acting tool concepts and can avoid the need for employing multi-acting presses with counteracting punches.

KYOTO PROTOCOL OBJECTIVES BY PROMOTING THE TECHNOLOGY TRANSFER TO SMALL ISLAND DEVELOPING COUNTRIES: SANTO ANTAO, CAPE VERDE

Cape Verde is an example of a state that consists of several islands, with its particular energy situation. The electrical energy system is split into nine islands, and some of the islands, as well as Santo Antao, are further split into several independent electrical energy systems, which makes it hard for modern energy planning. The electricity generation is heavily dependent on Diesel engines of various powers, while on some islands there are some wind capacities installed, particularly on Sao Vicente. Diesel power is expensive and polluting, but still the most appropriate for such small scale electricity generation. This paper studies implications of different scenarios of development of electrical energy system on the island of Santo Antao, one of the most undeveloped and hard to electrify because of geography and lack of resources. An estimate of electricity demand for the period until 2030 is given. Business as usual scenario based on Diesel capacity is compared to two renewable energy scenarios, one envisaging 30% of the electricity generated by the wind power, and the other combining 25% of wind power with 5% of photovoltaic power. Further scenarios were generated and compared to the previous by the assumption of declining prices of renewable energy technologies. The scenarios were compared from the point of view of electricity generation prices, but also from the point of view of greenhouse gases (GHG) emissions. The possible influence of Clean Development Mechanism as a part of satisfying the United Nations Framework Convention on Climate Change objectives were assessed. A certain potential for financing the technology transfer was quantified and its influence on different electricity system planning scenarios estimated.

Elastomer-assisted compression beading of tubes

This article proposes a new tube forming process designated as ‘elastomer-assisted compression beading’ that is made from a combination of tube bulging produced by elastomer forming and conventional pressworking compression beading. The presentation includes independent determination of the mechanical properties of the tubes, analytical modelling, finite element simulation and experimentation under laboratory conditions with the aims and objectives of identifying the key operating parameters, understanding plastic flow and failure and establishing the formability limits of the elastomer-assisted compression beading process. Results and observations show that the elastomer-assisted compression beading process is capable of producing sound, large-width, compression beads in a broader range of operating parameters than those currently being achieved by means of conventional compression beading. Applications of the proposed elastomer-assisted compression beading process span a wide range of industrial uses involving attachment of tubes to sheets and damping vibrations in air-pressure lines, liquid systems or exhaust tubes.

Understanding Invert Forming of Thin-Walled Polyvinyl Chloride Tubes Using a Die Based on a Mechanical Flow Formulation

The design of sound metallic double-walled tubular parts by internal and external inversion using a die is presently well established. Major operating parameters are identified and the typical modes of deformation that can occur during the process are fully characterized. In contrast to metals, there are no practical design rules and no published research work in the specialized literature concerning the manufacture of double-walled polymer tubes by inversion. This article is concerned with the abovementioned lack of knowledge and is a contribution towards the application of existing metallic tube inversion technologies to polymers. The experimental research work makes use of Polyvinyl Chloride (PVC) and the overall findings are interpreted in the light of an innovative extension of the flow formulation that is capable of modeling cold plastic deformation of pressure-sensitive materials under a non-associated flow rule. Emphasis is placed on the deformation mechanics of tube inversion applied to PVC and on the influence of the major operating parameters on the overall formability limits of the process. Results show that invert-forming of thin-walled PVC tubes using a die can be successfully utilized for producing custom and specific shapes at the tube ends.

Pressure-assisted forming of non-concentric tubular cross sections with solid medium

Pressure-assisted forming of tubes allows producing a wide variety of tubular components that are difficult or impossible to fabricate by means of conventional tube forming. In contrast to previous investigations in the field that were almost exclusively focused on the utilization of fluids (tube hydroforming) or elastomers (tube rubber forming) as pressuring medium, the subject matter of this article is centred in the utilization of low melting point, recyclable, metallic alloys as solid pressurizing medium. The aims and scope of the article are centred on the feasibility of forming straight carbon steel tubes into complex gooseneck geometries with non-concentric cross sections using lead as a solid pressuring medium and employing a double-action cam-driven tool system. The presentation is focused on the tool system, on its adequacy to produce customized tubular components, on the required forming forces and on the typical modes of deformation that result from the different movements provided by the vertical and horizontal actuators of the double-action tool system. Results and observations confirm that the utilization of a double-action tool system with a solid pressurizing medium to assist plastic deformation and prevent collapse can be successfully and effectively employed to fabricate non-concentric tubular cross sections for prototypes and small batches of lightweight components.

Open die forging of large shafts with porosity defects – physical and numerical modelling

The aim and scope of this paper is centered to analyze the influence of the geometry of V-shaped dies on the closure of internal centerline porosity defects in ingots during multistep open-die forging. The investigation is performed with small scale physical models made from lead using V-shaped dies with 90º and 120º and a reference pair of flat parallel platens. Holes drilled through the center of these preforms are produced to mimic centerline porosity in full scale cast ingots and intermediate rotation of the preforms replicate a multi-stage forging sequence under laboratory testing conditions. The presentation is supported by finite element modelling using an in-house developed computer program and the overall investigation shows that better results in closure of centerline defects are obtained with a V-shaped die with 120º die angle.

Cold End Forming Of Welded Steel Tubes

The production of custom and specific tube end shapes by cold end forming using a die is generally limited to seamless tubular parts. Current research work in the field follows the same trend as that of industry and, therefore, there is no accumulated experience, no practical design rules, and no information available in the specialized literature concerning the utilization of tube end forming for shaping the end of thin-walled welded tubes. This paper is concerned with the lack of knowledge and is a contribution towards the understanding of the mechanics of deformation of tube end forming applied to welded tubes. The presentation addresses the influence of major operating parameters on the formability limits of the process with the purpose of understanding feasibility and establishing design rules for the benefit of those who design tubular parts in daily practice. The authors effectively contribute to transferable technological knowledge opening new market opportunities that stimulate innovations among carbon and stainless steel tubular products.