Solar Multi-Use Water Systems (SolarMUS)

Using the sun and gravity to access easy, affordable, and reliable water in communities


What is a SolarMUS?

Pronounced ‘solar moose’, this simple system is known for its solar-powered water pumping abilities. The SolarMUS uses energy from the sun to pump water from a distant source to storage tanks strategically placed above a community. These tanks allow a community to collect large amounts of water. This ensures a reliable supply of water year-round. Once in the storage tanks, the system cleverly lets gravity do the rest. This is a big reason it is so efficient – only half of the power normally needed to distribute the water is used. With the simple turn of a spout below, water is distributed to households, farms, and businesses on-demand. It is called a multi-use system (MUS) for this very reason. The water can be used for many purposes such as drinking, cooking, sanitation, irrigation, and more.

Where is the SolarMUS appropriate?

The SolarMUS is best used in mountainous regions where communities live far above their nearest water source. They can also be useful for communities who live in flat areas but are simply a long distance away from a dependable supply of water. Because it relies on solar energy, this system is also best for regions that experience many days of sunshine.

Unlike our Hydram systems (which require a high volume of water), this system can be used in areas where the water source is low in quantity, such as a naturally occurring spring. This unique feature, paired with system lifespans of 20 years, make this technology a highly versatile and practical solution.


Fun fact, these systems have the potential to lift water over 200 vertical metres – this is extremely helpful when working in mountainous terrain like Nepal! Speaking of, did we mention that we have already delivered 29 SolarMUS systems in Nepal? Well, we have, and these systems are currently lifting an incredible 436,843 litres of water per day (enough for 7,000 showers) to a total of 8,475 people. Read more about these current systems and our future plans in Nepal.


How does the SolarMUS really work?

A diagram of the Solar Multiple Use Water System (Solar MUS)

Diagram Description

A solar photovoltaic (PV) array generates electricity as Direct Current (DC) from the sun’s light. This electricity drives a motor in a connected pump and brings the pump into operation. The pump lifts water, from the source(s), up to a storage tank or reservoir located above the community. A gravity fed system then distributes the water down to individual tap stands, outside homes and within easy reach of fields.

  • A collection tank is constructed near the water sources to collect the water from different sources.
  • The pump is submerged under the water in the collection tank (if the pump is a submersible type) or near the collection tank (if it is a surface mounted type). Solar panels are erected close to the collection chamber, ensuring that the solar array gets as many hours of sunshine as possible. The solar PV array generates the electricity as DC.
  • The electricity generated from the solar PV array passes through the cable to drive the motor, and the motor operates the pump. If an Alternative Current (AC) pump is used, an inverter is required to convert the DC to AC.
  • The pump draws water from the collection tank and delivers it to the storage tank through a delivery pipe. The storage tank is constructed at the top of the village and the size of the tank is designed to allow at least 3 days of autonomy (i.e. it will be made large enough to hold 3 day’s worth of water). This means that even if there are 3 consecutive days of cloudy weather when the pump is not in operation, there is still sufficient water for distribution.
  • 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.

Here is a link to a video that explains SolarMUS in Nepal.


We believe SolarMUS technology is a promising renewable energy solution. However, it wouldn’t be sustainable or profitable without the direct involvement, training, and cooperation of communities. This is why we put communities at the centre of our work – working with them from day one to create a long-term vision and management plan. Read how we work alongside communities as hand-in-hand partners.


Should you have questions about SolarMUS our highly experienced field team would be happy to answer them. Contact us here.

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