Energy Options: An introduction to small-scale renewable energy technologies - Softcover

Softcover

ISBN 10: 1853390828 ISBN 13: 9781853390821

Verlag: Practical Action Publishing, 1991

Inhaltsangabe

Renewable energy can present a baffling array of options to aid agency managers, government officials, and advisers. This publication contrasts the relative merits of biomass, solar, hydro, and wind power, as well as detailing some direct applications.

Über diesen Titel

Über die Autorin bzw. den Autor

At the time of writing, Drummond Hislop was a development economist and director of Biomass Energy Services and Technology.

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Energy Options

An Introduction to Small-Scale Renewable Energy Technologies

By Drummond Hislop

Practical Action Publishing Ltd

Copyright © 1992 Intermediate Technology Publications Ltd
All rights reserved.

ISBN: 978-1-85339-082-1

Contents

Preface, vii, 
1 INTRODUCTION, 1, 
2 POWER FROM SOLAR ENERGY, 11, 
3 HEAT FROM SOLAR ENERGY, 33, 
4 POWER FROM THE WIND, 48, 
5 WATER POWER, 58, 
6 BIOMASS, 77, 
ANNEXE I FURTHER INFORMATION, 98, 
ANNEXE II EQUIPMENT SUPPLIERS AND MANUFACTURERS, 102, 
ANNEXE III GLOSSARY, 108, 

CHAPTER 1

Introduction

For most developing countries, interest in renewable energy technologies was originally a response to the energy shortages and price increases of the early and late 1970s. But by mid-1990, international oil prices were back to levels as low, in real terms, as they were in the late 1960s. In this context, it is instructive to reflect on why there is still interest in renewable energy technologies, what the contribution of renewable energies to developing countries has so far been, and what is likely to be their future contribution.

The increasing demand for energy

In almost all developing countries the demand for energy is growing as populations increase and as economic development takes place; a process which is often conventionally associated with increasing per capita consumption of energy.

But in most of these countries, it is all too clear that there are limits on the ability of existing energy resources and delivery systems to meet this increasing energy demand, especially in the energy forms needed by low-income groups and at prices they can afford. The situation varies both between and within countries, but some broadly valid observations on why this happens can still be made. In doing so it is useful to distinguish between two categories of energy resource and delivery systems – the traditional and the modern/conventional.

Traditional energy systems

The traditional energy resource base in developing countries is biomass (over 80 of total energy use in some of the poorest countries) in the form of wood, wood and crop residues, and animal residues. This biomass provides mainly heat for domestic cooking, space heating, and commercial and industrial heat processes, especially for processing agricultural and forestry products. Direct solar energy provides further heat for drying crops and animal products.

Energy in the form of draught power is also provided by biomass, although indirectly, in the form of food and fodder for animals and humans. Biomass as a source of power is also often supplemented by traditional water and wind technologies.

Over the past few decades, many developing countries have suffered rapid reductions in the capacity of traditional energy systems to supply the energy needs of their growing populations at existing levels of per capita consumption, let alone those associated with economic growth. There are many reasons for this, often inter-related, and combinations of the following are usually important:

* Land clearances for agriculture, large-scale cash-cropping and monocultures, urban and industrial developments, hydro-electric, drainage and other infrastructural development, and the wind and water erosion and salination that so often follow them, can and often do reduce the biomass available as a direct energy resource.

* Rapid urbanization, population increases and overgrazing all increase demand on biomass resources. In many cases demand goes beyond the capacity of the land to replace the biomass removed, leading to reductions in biomass stocks and production.

* Armed conflict can have the same effect by forcing populations to move to areas unable to sustain them.

* Restricted access to or ownership of land forces poor people to exploit biomass resources on what land to which they do have access to, unsustainably.

* Some experts argue that climatic change also contributes to reductions in biomass cover in some parts of the world, especially in areas vulnerable to the expansion of existing deserts.

Conventional modern energy systems

For many years, the modern/conventional sector has gradually supplemented and replaced traditional energy resources. Liquid fossil fuels are used for static power (e.g. irrigation pumping, milling) and mobile power (e.g. for tractors and related machinery, and for transport); kerosene is used for lighting and for domestic cooking, and oil or gas for process heat. Finally, rural electrification, usually from fossil fuels or large scale hydro, has brought electricity for power, lighting, entertainment and refrigeration.

However, the ability of the conventional modern sector to meet all the energy demands of both increasing populations and increasing economic activity, especially in the rural areas, is also limited. In the case of domestic heat energy, although kerosene is usually available in urban areas, and often in rural areas, supplies are frequently interrupted. In rural areas, its costs are usually high relative to those of biomass fuels, so although it is used for lighting by most people, its use as a cooking fuel tends to be restricted to high-income groups. Cooking by liquid petroleum gas (LPG) or electricity is, in most rural areas, confined to very small minorities.

The purchasing power of industry allows it to overcome biomass fuel shortages more readily than households. Even so, in many countries rural and even urban industries who had switched to oil for heat have then been forced back onto wood because of rising fossil fuel costs.

In the case of power, diesel generators, engines and pumps are very common. But again, supplies of low-cost fuels are not necessarily secure, while operating costs can be very high. Many rural villages are electrified in the sense that the grid has reached them. But the proportion of households within the village which is actually connected is, in many areas, very low. This is largely because of connection costs; but it is also because low-income levels, and the lack of industrial customers mean that load factors on rural electrification schemes are very low, and tariffs are, unless subsidized, too high to be afforded by poor people.

Meanwhile, the costs of providing further rural electrification schemes increase, while the ability of many developing countries to afford the necessary foreign exchange is also limited. Large hydro-electric schemes run into increasing opposition on the grounds of population removal, deforestation and environmental considerations. Environmental and cost pressures also work against fossil and nuclear installations, and are likely to do so even more in the future.

In this context it is likely that scarce capital resources and foreign exchange will tend to be devoted to large-scale conventional schemes which serve urban areas and major industrial plant. Although conventional rural electrification in the form of grid extensions will continue, it is unlikely to meet more than a small fraction of the unmet power demand of many rural populations, especially those in isolated and/or mountainous areas.

The role of renewables

It is clear that there is a gap, both now and in the future, between the energy needs of economic development, especially in rural areas, and the ability of both the traditional and the conventional modern energy sectors to meet this need. In seeking means of bridging this gap, consumers, rural energy planners and...

Details zur Ausgabe

• Verlag: Practical Action Publishing
• Erscheinungsdatum: 1991
• Sprache: Englisch
• ISBN 10: 1853390828
• ISBN 13: 9781853390821
• Einband: Taschenbuch
• Anzahl der Seiten: 118
• Herausgeber: Hislop Drummond
• Kontakt zum Hersteller: Nicht verfügbar
• Verantwortliche Person: preigu; mail@preigu.de; ; Lengericher Landstr. 19; Osnabrück; 49078; Deutschland