Power for the people: Overview
Energy beyond the grid

Most of the electric power needs of people living in remote rural areas of the developing world are small. But these people are dispersed and they exist in large numbers - which is precisely why they are so difficult to satisfy.

As research shows, most of these energy needs can be met with power sources yielding 1kW or less, and it is rare to find stationary applications demanding as much as 5kW, let alone ten.

Unfortunately, the infrastructure for distributing conventional centralised mains electricity does not lend itself to serve dispersed populations with small energy needs economically.

By contrast, renewable energy technologies have the advantage of using resources that are readily available at the point of use, namely sun, wind, biomass or flowing water. They need little in the way of infrastructural and support costs.

It is true that a renewable energy system may produce energy at a relatively high cost compared with a large centralised power station, but this should be more than compensated for by savings on cables and connection costs.

Moreover, most of the lifecycle costs for a reliable renewable energy system is the capital investment. Running costs will generally be low as there is little need for consumables and no need for fuel supplies (other than those locally available in the case of biomass).

In some cases it may be possible to adopt conventional systems by extending the grid or using generating sets, run on petrol or diesel. But renewables could and should have a major future role to play if we are to have a reasonably uniformly civilised world.

Of these, solar energy is the least site specific being technically available over most of the land area of the Earth. But it does require a back up energy supply if energy demand is to be satisfied at any time of day or night. At present, batteries to store the energy have a shorter life and higher costs than is compatible with a good primary energy source.

Solar panels carried through the desert
� Madanjeet Singh

Nevertheless, photovoltaic systems can improve lighting and provide access to radio and television at costs which are beginning to bear comparison with traditional sources of energy such as kerosene lamps, hurricane lanterns, candles or car batteries. World Bank research has shown that households often spend as much as $10 a month on such inefficient energy sources.

Wind is dependent on both local climatic conditions and terrain. Again, back up power supplies are generally essential, though in the case of wind pumps, water can be stored to provide a supply at times of little or no wind.

UK-designed Marlec wind turbine provides nomads with lighting and power to run their radio in their yurt, Mongolia.

Biomass in all its various forms (solid, liquid and gaseous fuels) clearly has tremendous potential for more efficient use, including traction in internal combustion engines or improved externally-heated engines.

Hydro power is perhaps the most developed, reliable and practical renewable energy resource for delivering high levels of continuous power in rural areas, but it also the most site specific, which will limit its otherwise vast untapped potential.

Overall, although renewable energy technologies are mainly at a relatively immature stage of development and deployment, the examples reported in this magazine are sufficient to show their scope. To recycle a well known advertising slogan, renewables will reach the parts that other technologies cannot reach.

Peter Fraenkel is Technical Director of IT Power Ltd (UK), a research and development company covering the whole field of renewable energy technology. An expert in design and implementation of small-scale energy systems for use in remote regions, he has worked in this field for more than 20 years.

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