Difference between revisions of "Water Portal / Rainwater Harvesting / Surface water / Micro hydropower"

Revision as of 06:41, 5 September 2012

The Tungu-Kabiri community hydro project. The Tungu-Kabri micro-hydro power project in Kenya is a cheap, sustainable and small-scale technology that harnesses the energy of falling water to make electricity. Photo: microhydropower.net.

Micro hydroelectric power is different from typical hydroelectric power because it doesn't attempt to significantly interfere with the flow of the river. Typically rated at a maximum capacity of 300 kW hours, the micro hydro systems don't dam rivers, but instead divert a stream of water that flows downhill through a pipeline dropping into the turbine. The turbine then generates electricity which can be stored in batteries and transported to where villagers may need it most.

Suitable conditions

Costs

In the examples examined in the five countries, the capital cost13 of micro hydro plants, limited to shaft power, ranged from US$714 (Nepal, Zimbabwe) to US$1,233 (Mozambique). The average cost is US$965 per installed kW which is in line with the figures quoted in some studies. The installed costs for electricity generation schemes are much higher. The installed cost per kW ranged from US$1,136 (Pucará, Peru) to US$5,630 (Pedro Ruiz, Peru) with an average installed cost of US$3,085.

An important observation is that the cost per installed kilowatt is higher than the figures usually cited in literature. This is partly due to the difficulty analysts have in establishing full costs on a genuinely comparative basis. A significant part of micro hydro costs can be met with difficult to value labour provided by the local community as ‘sweat equity’. Meaningful dollar values for local costs are difficult to establish when they are inflating and rapidly depreciating relative to hard currencies. In addition, there is little consistency in the definition of boundaries of the systems being compared, for instance, how much of the distribution cost, or house wiring, is included, how much of the cost of the civil works contribute to water management and irrigation, and so forth.

Field experiences

• There are approximately 130 MHP plants66 currently in operation in Sri Lanka. Most are less than 100 kW in capacity.
• The Tungu-Kabiri community hydro project.

Reference manuals, videos, and links

• The Rise of Micro-Hydro Projects in Africa.
• Video: Micro Hydro Turbines: The Expert.
• Small Scale Hydro: Here are some good references for planning, designing, and building a micro-hydro system. The first step is to carefully determine if you have a hydro resource that is worth developing -- some of the references cover how to do this in detail.

Acknowledgements

Smail Khennas and Andrew Barnett, BEST PRACTICES FOR SUSTAINABLE DEVELOPMENT OF MICRO HYDRO POWER IN DEVELOPING COUNTRIES, Department for International Development, UK. March 2000.