Micro-hydro power

Using water power to fight poverty

Micro-hydro power is the small-scale harnessing of energy from falling water, such as steep mountain rivers. Using this renewable, indigenous, non-polluting resource, micro-hydro plants can generate power for homes, hospitals, schools and workshops.

Practical Action promotes small-scale hydro schemes that generate up to 500 kilowatts of power. The micro-hydro power station, which converts the energy of flowing water into electricity, provides poor communities in rural areas with an affordable, easy to maintain and long-term solution to their energy needs.

We have developed micro-hydro systems with communities in Peru, Zimbabwe, Sri Lanka, Nepal and Kenya. These systems, which are designed to operate for a minimum of 20 years, are usually 'run-of-the-river' systems.

Micro-hydro: the basics

"Run of the river" systems do not require a dam or storage facility to be constructed. Instead they divert water from the stream or river, channel it in to a valley and drop it in to a turbine via a pipeline called a penstock.

The turbine drives a generator that provides the electricity to the local community. By not requiring an expensive dam for water storage, run-of-the-river systems are a low-cost way to produce power. They also avoid the damaging environmental and social effects that larger hydroelectric schemes cause, including a risk of flooding.

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’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 power has a positive effect on the local environment.

The power to recharge communities

Micro-hydro power can also be supplied to villages via portable rechargeable batteries. People can use these convenient sources of electricity to fuel anything from workshop machines to domestic lighting – and there are no expensive connection costs. The batteries are charged at a station in the village, thus providing the local community with a clean, renewable source of power.

For industrial use, the output from the turbine shaft can be used directly as mechanical power, as opposed to converting it into electricity via a generator or batteries. This is suitable for agro-processing activities such as milling, oil extraction and carpentry.

Micro-hydro schemes are owned and operated by the communities they serve, with any maintenance carried out by skilled members of that community. So they provide employment in themselves, as well as providing the power to re-energise entire communities.

Micro-hydro projects on video

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.

Micro-hydro power systems like these are designed to operate for a minimum of twenty years if they are properly looked after. That’s why we train local people to build and maintain their own system. 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.

Find out how energy from micro hydro tranformed the life of Rosa from Mount Kenya:

Tungu-Kabri micro-hydro power project in Kenya

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.

This project was the first of its kind in Kenya. Funded by the United Nations Development Programme and developed by Practical Action East Africa and the Kenyan Ministry of Energy, the project benefits 200 households (around 1,000 people) in the Mbuiru village river community. The project is a cheap, sustainable and small-scale technology that harnesses the energy of falling water to make electricity. It also alleviates the environmental problems associated with using wood and dung for cooking, diesel for milling and kerosene for lighting - and keeps on working, even in the face of drought.

The problem

Life is hard for the women and men in rural Kenya and the need for access to modern, ‘clean’ energy is acute. 96 per cent off Kenyans live without access to grid electricity. In rural homes, families spend at least a third of their income on kerosene for lighting and diesel for the milling of grain. Kenyan women also devote a huge amount of time collecting, processing and using wood and dung for cooking - time which could be spent on child care, education or income generation.

And according to the UN, in a country where nearly 80 percent of the population rely on farming for a living, poor farmers face declining yields and incomes in the traditional coffee and tea growing areas which pushes them into even more biting poverty. Just to survive, they will be forced to clear forests in higher, cooler, areas. This can only add to environmental damage, which in turn can lead to increased poverty, hunger and ill health.

Putting the power in people’s hands

Mbuiru village - 200 kilometres north of Nairobi - is a typical rural village in Kenya. It is very poor, with few opportunities for change. However, villagers in Mbuiru had the will to help themselves to generate the power to beat drought and poverty.

Step 1 The project site is assessed. Many rivers do keep flowing, however bad the drought. Practical Action looked at flow records going back 40 years, to ensure the water power project will work. The River Tubgu, near Mbuiru is perfect.

Step 2 Practical Action explains its intentions at a village meeting. The villagers have many questions - the only hydro-power people know about means big dams. Practical Action explains how a small scheme could help them, how it works and how it would belong to all the villagers. Everyone is eager.

Step 3 Villagers hold back the river and start to build an intake weir and canal, giving up every Thursday to labour for months. Families work together, digging, shifting stones and laying concrete. The canal alone takes many weeks to build.

Step 4 Groups of villagers toil to make bays to clean dirt out of the water, and build a tank to hold the water before it goes through ‘penstock’ pipes into a turbine. People learn to mend as they build, so they can do repairs themselves.

Step 5 Two years later, power! The powerhouse goes up, in goes the machinery. Now the river can be released. The villagers hold their breath. It works and all that effort seems worthwhile.

Impact on the future

"This power is wonderful’, says villager Mrs Kaburu. ‘All of us will feel the benefit for many years to come’.

The project generates an estimated 18 kilowatts of electrical energy. This amount can light 90 homes and Practical Action estimates that the power the system generates will benefit about 200 households.

In the months ahead, the villagers will be able to light their homes, save time and run small enterprises with this power. This will bring them a little vital money, to help buy clothes, food, and even schooling for their children. Also, water power also means less wood is used - so the environment benefits.

Water-powered computers in Sri Lanka

For a school facing an energy crisis a small ‘pico’ hydro scheme installed with help from Practical Action has come to the rescue. Pico hydro manages to produce energy from the smallest of river streams - typically a pico hydro scheme can produce upto 5Kw of energy.

The Batuwangala Maha Vidyalaya school in Galle Sri Lanka has transformed the lives of its pupils and villagers by introducing the internet and providing online access to the modern world. A computer centre with 23 desktop computers has been funded through the Secondary Education Modernisation Project (SEMP).

But there remained a problem. The SEMP grant only covered the cost of the equipment and the monthly internet bill. It did not stretch to paying for the electricity. As most of the students came from poor families, they were unable to contribute to the cost of powering the centre that had had such a positive impact on their lives. With a rising electricity bill, the school faced being cut-off from their link to an online world of knowledge and resources.

The school’s plight was brought to the attention of Practical Action’s Enhancing Renewable Energy Options (EREO) project. The team set to work to secure an alternative power source. A visit to the school revealed lots of natural nearby water sources and the plan for a ‘pico’ hydro energy scheme was hatched. Pico hydro can produce up to 5KW of energy from the smallest of streams.

A power house was built by students of the local Open University of Sri Lanka and materials were sourced from a pico hydro machine manufacturer. On completion, the power centre could produce 650-watts of electricity - a small amount but just enough to power the computer lab and save the school.

The Batuwangala Maha Vidyalaya school is now considered a sustainable energy pioneer. No longer does it rely on the main Sri Lanka grid. The pico hydro system can power four computers and all the light-bulbs in the school at the same time. The school’s overall electricity bill has been halved as a result. The students have gained not only a sustainable source of electricity, but also learnt how they can produce their own energy. They’ve now set up a maintenance committee which takes turns in making sure the pico hydro system is working properly.

If you want to see the impact the computer centre has had visit the blog set up by the school.

"You have brought us something great. We can only call it a miracle."

Electricity is the miracle that Francis Mwai, a resident of Kathamba, Kenya, described to Practical Action visitors.

Kathamba, 130 kilometres north of the capital Nairobi, and Thima are villages involved in a pilot scheme bringing electricity to remote areas where national grid connection is costly and difficult.

Thanks to Practical Action, Nottingham Trent University and members of Kathamba Self Help Group 2000, a pico-hydro power unit is now providing electricity for 30-plus homes with another 35 awaiting connection. Thima’s scheme already covers 66 homes with more connections planned.

This scheme aims to highlight how these smaller versions of micro-hydro systems can generate electricity from very small streams. The Kenyan Energy Ministry’s Department of Renewable Energy, dubbed it "wonderful".

No more travelling to buy or recharge batteries for lighting, radios or televisions. No more buying fuel for lighting homes. Kathamba villager Sebastian Wakone previously used kerosene for lighting, but now pico-hydro power means that savings on fuel can go towards other essential family budget areas, particularly his children’s education.

"No longer will our children fail to study due to lack of ten bob for purchasing paraffin," said Kathamba Self Help Group 2000 chairman, James Muchira.While Practical Action helped provide power generation equipment, technical knowledge and support, the local people contributed the hard physical work. "It has really helped us as a community," according to Thima resident Polly Murimi.

Practical Answers

You can download  technical briefs and manuals on Micro Hydro at Practical Answers, the technical information service of Practical Action, or you can submit an enquiry to the Practical Action staff via the online form


Policy and practice

Other Practical Action resources on hydro power:

Up-scaling micro hydro: a success story?

It is over a decade since Practical Action first embarked on micro hydro in Sri Lanka. This report attempts to capture some of the highlights in the development process and assess the path of up scaling micro hydro beyond the initial goal of Practical Action South Asia in the present context.

Social impact evaluation project 'Fund for the promotion of Micro Hydro Power Stations (MHSP)'

This paper presents the social impact evaluation of the Project “Fund for the Promotion of Micro Hydro Power Stations (MHSP)”, which was carried out by Practical Action (then ITDG).

Small-scale hydro power

Practical Action's position on small-scale hydropower

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MEGA Malawi

The Mulanje Electricity Generation Authority micro-hydro project in Malawi is a sustainable and ambitious social enterprise - aiming to tackle the dual challenges of sustainability and scale.

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