What is a Micro Hydro Turbine Electric Generator.


The Southern African Alternative Energy Association is doing research in to Micro Hydro Turbine Electric Generators for use in our region and require some knowledgeable input and advice.

Running water has power. A micro hydro turbine can turn a stream’s potential energy into electricity, satisfying people’s need for power in remote areas. If you can find a steam/river nearby you can benefit from it.
Micro hydro power is generally identified as a system by which power is under 100kw. Micro hydro could supply power solutions for the remote mountain residents/national park/rural village/school/military camp/outdoor camp/etc which possess micro hydro resources. 0.1kw power could satisfy lighting, TV, charging and other basic needs; higher power could make the house or village use different electrical household appliances, meanwhile it could supply power for small plants for manufacturing.

You can benefit from the power of nature using clean, renewable and sustainable, micro hydro turbines.
The lack of energy supplies in rural areas is a chronic problem. In many developing countries less than 10% of the rural population has access to electricity. Rural electrification through conventional means such as grid connection or diesel generators is very costly. Fortunately, abundant water resources for energy production are available in some poor countries.
Micro hydro is perhaps the most mature of the modern small-scale decentralised energy supply technologies used in developing countries. There are thought to be tens of thousands of plants in the “micro” range operating successfully in China, and significant numbers are operated in wide ranging countries such as Nepal, Sri Lanka, Pakistan, Vietnam and Peru. This experience shows that in certain circumstances micro hydro can be profitable in financial terms, while at others, even unprofitable plant can exhibit such strong positive impacts on the lives of poor people. The advantage of using micro hydro turbine power systems:
1. Stable costs: Comparing with gas or oil power generation, the running cost is nearly free and stable compared to fluctuant prices of oil and gas. Even the electricity price charged by the power companies is rising all the time.
2. Short transmission lines. The micro hydro power system do not need long lines because its users are nearby. Generally 800m is long enough.
3. Long running life. Generally a micro hydro system could run for over 20 years, longer than other power generation systems. In some places, using micro hydro power can also get public finance support.

Although we can sort micro hydro turbines by its type, we think it is better to sort them by usage.
We sort them into 3 kinds: home use, village use and factory use.
Special turbines could be tailored by sending us the parameters of the local stream.
Home use
This category covers turbines under 800w, single-phase.
Water head: 4-18m
Flow rate: 0.003-0.05m3/s
Village use
This category covers turbines over 800w, single-phase.
Water head: 4-35m
Flow rate: 0.08-0.165m3/s
Industrial use

With micro hydro, you can generate power for household use, such as lights, washers, TV,
refrigerator, etc.
Some of the African buyers buy micro turbines to refrigerate the beer. In their words, they “can bear no light, but they could not bear having no cold beer”

By using electricity generated by micro hydro turbine sets, the local people can develop loca industry which could not be done before due to outages of the grid.

How does it work?
Water from the river is channelled through a settling basin, which helps to remove sediment that could harm the turbine. The water then flows into the Forebay Tank where it is directed downhill through a pipe called a penstock. When the water reaches the bottom, it drives a specially designed turbine to produce the electricity.
What does it cost?
Costs vary depending upon the particular project, but as a rough guide, these projects cost just over $1200 per kilowatt of power generated. So a system with a capacity of six kilowatts – enough to drive a mill and provide electric light to a community of 20 families – would cost about $8000 (This cost depends on local area economy).
Once the system is in operation, local people pay a small charge to use the electricity. This covers maintenance and the eventual cost of replacement.
Why is it needed?
Of course, every community’s particular needs are different. But in general, access to energy is a vital stage in the development of remote villages like these.
It can lead to swift and significant improvements in education, sanitation, healthcare and the overall standard of living. These benefits are achieved both directly – as in the provision of light – and indirectly – as the time and money that people save is redirected into other projects.
How long will it last?
Micro-hydro systems like these are designed to operate for a minimum of twenty years if they are properly looked after. And by making a small charge for use, communities can accumulate enough money to pay for the replacement of the unit at the end of its useful life.
Once schemes are set up, they should continue to function indefinitely without any more external funding.
What’s the environmental impact?
Unlike traditional power stations that use fossil fuels, micro-hydro generators have practically no effect on the environment. And because they don’t depend on dams to store and direct water, they’re also better for the environment than large-scale hydro-electric stations.
In fact, by reducing the need to cut down trees for firewood and increasing farming efficiency, micro-hydro has a positive effect on the local environment.
What can we do if we don’t have enough flow?
You can build a reservoir to store the water and generate power when needed.
For example, there is a micro water source near the resident. During the dry season it only have a 0.0006 m3/s flow, and the water head is 14 meter. How to design a micro hydro system to solve the problem?
Calculation as below:
Each day we can storage water: 0.6X3600X24=51840kg=52 cubic meters.
1. Choose 300w type micro hydro turbine set. It consume 3 kg waters per second.
2. Water consumption per hour: 3X3600=10.8 cubic meters.
3. Power period= 52/10.8=4.8hours.
4. Generator output=14X3X5=210w
Thus we can satisfy the basic lighting needs for a family.
According the above calculation, we need to build a 30CMS pond ( 52 – 5*0.6*3600).