Solar Powered Water Pumping (SolarMUS)
‘We are very happy water is coming. We already feel relieved’ – Villager in Kavre District, Nepal.
What is SolarMUS?
This is a system where a solar powered water pump lifts water from the source to a reservoir above a community. The water is then distributed to tap-stands near households in the community through a gravity powered system. The MUS refers to the Multiple Use Water System meaning that the water system is designed to be used for multiple purposes such as domestic use (drinking and cooking), sanitation, and agricultural and productive end uses.
Where is it appropriate?
We use a SolarMUS system in the mountainous regions of Nepal, where communities often live far above their nearest water source. Unlike hydram, SolarMUS can be used in areas where the water source is low in quantity but high in quality, such as a naturally occurring spring, as it is able to cap the source and lift all the available water up to the community.
Why is SolarMUS innovative?
- It uses solar radiation, a freely available resource.
- The water can be released and shut off on demand by the community members, meaning each household can take what they need, when they need it.
- The time women save on water collection can be used to improve their position. They can start their own businesses, grow more crops and pursue education. It will help women to play a larger role in the household decision-making process because of their increase income.
- Greater quantities of water mean that crops can be grown outside of the normal growing season, when they will fetch a better price.
- The MUS infrastructures are constructed with local materials and labours, and this simple technology integrated with solar system provides the water for domestic and micro-irrigation.
Where have we used it?
We have installed Solar MUS systems in Nepal’s Central and Western Development Regions: We are expanding the program in Mid and Far Western Regions of Nepal Typically a tap has been shared between 3-4 households. Communities are using the pumped water for domestic as well productive end uses. It is benefitting community in different ways, such as: drastically reduced the time and drudgery required to collect water, increased girls and children’s regular attendance in school, increased in income by selling vegetables, improve in health and nutritional status etc.
Interviewer: ‘What will you do with the time saved from water carrying?’
Kavre District Villager: ‘I’ll spend more time on my children. I’d like to train for a skilled job, motivate the community, and grow vegetables to earn a little income.’
In Kavre District Nepal, newly installed Solar MUS systems provide safe, accessible water for drinking and irrigation. This frees women and children from the burden of water collection and allows crops to be grown out of season.
Working with these communities has also given us the opportunity to work with marginalised local households. We help them to claim their full financial entitlements from the government, including solar pumping subsidies.
How does it work?
In Solar Photovoltaic Water Pumping for Multiple Use System (Solar MUS), Solar PV array generates electricity as DC from the sun’s light. This electricity drives the motor in the pump and brings the pump in operation. Pump lifts the water up to a community storage tank high above its source. A gravity fed system then distributes the water to individual community members and institutions.
- A collection tank is constructed nearby the water sources to collect the water from different sources.
- The pump is submersed under the water in collection tank (if the pump is submersible type) or nearby collection tank (if it is surface mounted type). Solar panels are erected near to the collection chamber, ensuring that the solar array get the longest sunshine hours. Solar PV array generates the electricity as DC.
- Electricity generated from Solar PV array passes through the cable to drive the motor. The motor operates the pump. If AC pump is used, Inverter is required to convert the DC to AC.
- The pump draws the water from collection tank and delivers to storage tank through delivery pipe. The storage tank is constructed at the top of the village. The size of the storage tank is designed considering at least 3 days of autonomy so that it can accommodate enough water sufficient for 3 days to distribute, even there is cloudy days for consecutive 3 days and pump is not in operation.
- A distribution pipe carries the water from the storage tank to a series of taps and outlets at various locations in the community.
- Water can be released on demand by community members.
Our Solar MUS programme is proudly supported by The Big Lottery Fund
McLoughlin, Fintan, Duffy, Aidan and Conlon, Michael. 2013. Solar Photovaltaic Pumping for Multiple Use Water Systems (MUS) in Nepal [pdf] Dublin Institute of Technology. Available here [Accessed 2nd December 2014]