Page 301 - Applied Photovoltaics

F.3 DRAUGHT ANIMALS
Advantages:
x readily available
x medium investment costs
x convenient power output for small-scale irrigation
x can be flexibly deployed.

Disadvantages:
x high feeding costs involving extra food production
x feed required even when no power can usefully be employed.

F.4 PETROL- OR DIESEL-FUELLED SMALL ENGINES

Advantages:
x widely available technology
x high outputs possible on demand
x portable
x low initial capital investment per unit of output
x easy to use.

Disadvantages:
x fuel costs dominate and are increasing in real terms
x fuel shortages are common in many developing countries
x spare parts are often hard to obtain in remote areas
x good maintenance difficult to obtain in remote areas of developing countries
x relatively short useful life
x breakdown common
x high imported element involving scarce foreign currency in most developing
countries.

F.5 CENTRALISED RURAL ELECTRIFICATION

Advantages:
x low marginal investment cost for prime mover (electric pump) if transmission
lines installed
x pump sets are reliable provided supply is guaranteed
x can be low cost depending on power source and system.
Disadvantages:
x electricity supply often unreliable in developing countries owing to peaky
demand, low load factors and sparse consumer population
x very high system investment cost and high generating and distribution costs
x extended power failures could cause widespread crop loss
x limited to uses less than about 1 km from the nearest grid.

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