passive solar products to vulnerable communities as part of food security and
livelihood programmes.
2.3. Water energy technologies
2.3.1. Hydro-power
Water power can be harnessed
in many ways; the most common
way is to use a turbine which is
turned by water moving in a
controlled manner.19 The output
from the turbine can be can be
used directly as mechanical
power or connected to an
electrical generator to produce
electricity. Mechanical power is
suitable for some productive
livelihood activities including
food processing such as milling Figure 3: Layout of a typical micro-hydro
or oil extraction, sawmill,
scheme: Practical Action
carpentry workshop, small scale
mining equipment, etc. Electricity can be supplied to homes directly through an
electrical distribution system or by means of batteries that are periodically
recharged at the point of generation.
Systems are categorized by their power output; pico-hydro (less than 10kW) and
micro-hydro (10kW up to 300kW) are suitable for supplying power to a household
or community. The power is dependent on the volume of water and the available
head of falling water.
Small systems can provide energy without requiring large and expensive dams.
The best geographical areas for exploiting small-scale hydro power are those
where there are steep rivers flowing all year round, for example, the hill areas of
countries with high year-round rainfall, or mountain ranges and their foothills. Hydro
power can be the most cost effective of decentralized RETs; the installed cost of
electricity ranges from US$0.20 – 0.60 per kWh.3
Hydro power projects require careful assessment and design by an experienced
technical person. Local caretakers are usually trained in the technical operation
and maintenance of a system and are linked to other service providers including
suppliers of spare parts etc. For community systems a local organization is
required for management of the system – and the development of leadership and
management capacity is an important requirement for success. Finance of
community projects is a key consideration given the high capital cost of a system.
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