What the increasing use of desalination means for the world


August 25th, 2015

Hundreds of new desalination plants are cropping up across the globe to meet the growing needs for water – estimated to be increasing by an astonishing 640bn liters per year. But as the world looks towards technology to solve the growing crisis of fresh water access, what does this mean for people and our planet?

Access Issues

Only 2% of the world’s water is drinkable or useful for farming and sanitation. The vast majority of this unique life-giving resource is saltwater, unsuitable for drinking and most modern applications of water. Climate change is driving the icreasing severity and number of droughts in many of the worlds most populous areas, threatening both so-called ‘developed’ and ‘developing’ nations. Equally, many of the most remote and marginalised communities globally are facing pressures to access sufficient volumes of water to survive, let alone power a modern economy. Water is often seen as an endless and bountiful supply, with limited debate over the preservation of existing freshwater supplies when compared with other finite resources, such as fossil fuels. Equally, little attention is given to the environmental impacts of rapidly increasing water consumption and use.

Access to water is unfairly distributed. Partly this is due to geography – remote communities in arid and semi-arid areas often have fewer local freshwater sources, and infrastructure to carry water is technically complex and expensive. But it is mostly about inequality and injustice – millions of urban slum dewelers remain excluded from accessing clean, safe and affordable water supplies, as investments in service upgrading are targeted at serving higher-income city residents and businesses; and thousands of smallholder farmers are denied access to water sources which are diverted for irrigating enormous commercial agriculture plots.

Impacts of Desalination

As a result of the access constraints, many countries, cities and companies are turning to desalination technologies to alleviate their thirst for water. The possibility of turning the trillions of liters of saltwater abundant in the world appears as an enticing option when faced with severely limited freshwater supplies. Israel expects more than half of its water supply to come from desalination sources by next year.

desalination-plant-Oman

Water desalination plant in Oman

But while technologies such as those used in Israel are becoming increasingly efficient, they still have enormous energy requirements, making them unsuitable for many developing countries which struggle to provide sufficient and stable energy supplies, even in urban areas. It makes such technologies even less suitable in remote areas where energy supplies are still critically lacking.

Moreover, desalination has an appalling ecological impact – the highly concentrated brine discharged from the plants causes ocean acidification and has myriad impacts on marine life, the full consequences of which are still being investigated. The salty sludge from desalination plants is a multi-component waste (including chlorine, heavy metals, and cleaning agents), with multiple effects on water, sediment and marine organisms. It therefore degrades the quality of the very resource it depends on.

Emerging Technologies

There are some promising innovative technologies in development to help alleviate some of the negative impacts of desalination. Aston University are developing a process to harness the power of solar energy to hydrolyse brine to create an alkaline, which also helps remove carbon dioxide from the atmosphere – a true win-win solution.

A team from MIT, who won the Desal prive for innovative desalination technology, created a hotovoltaic-powered electrodialysis reversal system that desalinates water by using electricity to pull charged particles out of the water and further disinfect the potable water using ultraviolet rays. MIT and Jain Irrigation Systems specifically designed their system for low energy consumption, adapting traditional electrodialysis to limit costs, especially in off-grid areas.

Missing the point

While these advancements in desalination technology are greatly welcomed, to reduce the impact of existing desalination treatment plants globally, the world is missing the point. Access to existing freshwater supplies remains uneven, unfair and unjust. According to the WHO GLAAS Report 2014, which looks at finance in water and sanitation services, only 23% of developing countries apply financial measures to reduce disparities in access to drinking water for the poor, and only 21% of international aid is directed at meeting basic services, including safe water.

Sticking with the status quo of water access and unsustainable use by industrial farming systems, fossil-fueled power plants, and inefficient personal use by high-income users, and turning to technology to save the day, will only increase the technology injustice of water access for the poor globally. Safe and efficient desalination technology can play its part in alleviating water needs in times of critical shortages; but the efforts of the global community need to be focused on addressing existing inequalities to freshwater access, and the sustainable use of this most vital of earth’s resources.

Innovating for Access

barsha-punp

Barsha pump installed in Kankai, Nepal. An accessible no-power technology used by Practical Action to increase access to freshwater

Practical Action have worked with local technology developers in Nepal to pioneer the Barsha pump (pictured above) It is essentially a modern waterwheel designed to be tethered in a river and lifts water up to 20 metres into a storage pond, from which it can be sent by pipe to sprinklers or drip irrigation systems for high value vegetables and winter crops.

To achieve a state of Technology Justice, where people can access and utilise the technologies they need to live safe and prosperous lives, we need to ensure considerations of affordable access and sustainable use of technologies are at the centre of development efforts. In this way, we can ensure that efforts to achieve the Sustainable Development Goals truly do leave no-one behind.

Read more about Practical Action’s work on Urban Water and Sanitation issues on our new Policy & Practice website.

2 responses to “What the increasing use of desalination means for the world”

  1. Patrick Davey Says:

    Tha Barsha pump appears to be a great innovation although the ram pump does much the same job. In each case moving water is required and fresh water is being moved,not created so no use where the water resource is a lake or well.

    I wonder how much reparation would be possible using re-afforestaton to restore rainfall as described by Willie Smits in his TED talk; it is known that nucleation for tropical rainfall is different from temperate regions.

    There are low energy desalination systems, which if I remember correctly have a higher flow rate and hence produce effluent with lower concentrations. Generally speaking the energy requirements increase as the concentration of the feed increases.

    Developing a much wider use of the concept of virtual water, especially for food supplies imported into Europe could make a significant difference in the medium term.

  2. Ahmed Says:

    / Great article Jeff. My only qusetion is whether we should be asking then to pay, or if we should be considering whether to continue allowing them access to our aquifers. As obesity soars and aquifers are drained are the momentary pleasures of sugary drinks worth their negative impacts to the common good?

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