Water has been the main driving force for human settlements throughout human history; and we as a human race have become more aware of the important role water plays in our daily lives. In many drier parts of Africa, the main concern of the population is limited or inaccessible water resources and as water is fundamentally the essence of life, the pressing question is how to supply water to people living in rural off-grid areas in an economic, social, and environmentally sustainable way.
These rural off-grid areas refer to those with no immediate or limited freshwater and electrical supply. And the settlements can be rural communities or luxurious resorts far away from civilization and ranging geographically from mountainous landscapes to coastal shores. Various solutions are available to provide water to these areas including water transportation, groundwater extraction, atmospheric water extraction, rainwater harvesting and desalination, which we’ll cover below together with the integration of solar power where possible. In addition, although mini-grid solar electrical supply has been around for quite some time, it is becoming increasingly more economical with each passing year.
Sufficient sunlight over a 6-7 hour period is all that is required to generate and potentially store electricity. However, with water, there are additional constraints.
What if the settlement is not close to any visible open water source bodies such as rivers, lakes, springs, and oceans? What if the area is experiencing a period of severe drought?
Enter : The Water mini-grid
Water mini-grid solutions offer the possibility for isolated communities and businesses to have access to water. They consist of decentralised water infrastructures powered by renewable energy and provide an integrated approach to sustainable water management, including water custodianship. There are various mini-grid permutations, but the most fitting would be that which is contextually relevant and serves the need of the particular community on an economic, environmental and social level.
Rural off-grid areas usually also lack the proper water reticulation infrastructure to distribute the water from the mini-grid system or water source to the end-user. This contrasts with that of luxurious resorts where these water reticulation infrastructures are already in place. The lack of proper infrastructure in rural communities adds an additional cost to these mini water grid systems and should be weighed up against the use of water kiosks or water ATMs, with the latter ideally centrally located for ease of access, as well as safety, especially that of women, who have borne the brunt of water collection in many rural communities. These water collection points can also be an area where conflict within a community can arise and thus the appointment a water management committee, that would be responsible for ensuring the equitable distribution of water resources, is key for conflict mediation and local custodianship, in conjunction with digital monitoring platforms.
Trucking it in
One of the most used and best-known water solutions to provide potable water to very remote off-grid areas is through bottle transportation. This method is usually utilised as an emergency response to offer some drought relief for rural communities. However, the reality is that it cannot provide the area with long-term water security or potential socio-economic development opportunities, as well as being expensive and polluting. Delays and breakdowns are regular occurrences in various parts of the world, not to mention the carbon emissions emitted through transportation, especially over long distances. These long distances in turn could result in water deterioration as well.
Water below the Surface
If no open water body is present, the other potential solution is investigating possible groundwater resources. This solution is viable and can be sustainable in the long term if the area sits comfortably on an interconnected vein of aquifers. Borehole exploration and drilling will then follow with the addition of solar energy for a more sustainable and resilient off-grid solution. If the available groundwater is contaminated, this solution can be integrated with other water treatment technologies such as reverse osmosis (RO), UV treatment, or chlorination treatment (to name a few), which is dependent on the severity of the contaminated groundwater, as well as its level of salinity. Solar-powered borehole schemes are affordable, and cost would be influenced by the number of boreholes that should be drilled as well as the depth of boreholes. This solution is sustainable in the long term if a proper hydrogeological study of the area is conducted and in compliance with the appropriate water legislation.
Water in the ocean
Areas with arid to semi-arid climates, near the ocean, with limited annual rainfall, can implement desalination technologies such as seawater reverse osmosis (RO). Desalination is a great alternative water supply system and can be integrated with solar power, reducing the operating costs and carbon emissions significantly. Some environmental limitations do exist with RO when it comes to the discharge of the brine effluent, but proper due diligence of environmental good practice and mitigation measures (as stipulated in an environmental management plan) will avoid any negative impacts the brine discharge will have on the marine ecosystem.
Water in the atmosphere
Other mini-grid systems that are low cost also exist, such as rainwater harvesting and atmospheric water generators. However, rainwater harvesting naturally requires sufficient rainfall and due to underdeveloped infrastructure within rural communities, can be a health and safety risk if the water is not stored under the right conditions. Atmospheric water generators (AWGs) are also limited to favourable environmental conditions, such as the humidity level, and the energy consumption can be high to obtain enough water. AWGs are also generally only used for lower water consumption applications.
It is important to note that all the above-mentioned water provision solutions can be combined and integrated to achieve optimal water production that meets the need of the particular application, in conjunction with solar power integration, as well as digital metering and remote monitoring. These platforms allow the water user to have custodianship of the water resources, a key element for long-term sustainability, as well as full water autonomy in a decentralized context.
Proper water infrastructure within rural communities creates water security that in turn allows development opportunities to arise. Examples include construction water for housing and other infrastructure, as well as agricultural and agribusiness development. These developments in turn can alleviate other social ills, thus having a broader impact than just water provision alone. Time is also freed up that used to be used for water collection, allowing more time for educational activities.
With the proliferation of different innovative technologies in the water and energy sector, together with decreasing costs, water-energy mini-grids are becoming more economically, environmentally, and socially viable and will play a key role in providing rural areas with sustainable, long-term and resilient water and energy services.
Emke Hartnick and Rudolph Retief