x Abu Dhabi, UAETuesday 25 July 2017

How to get water from the sun

Researchers at Abu Dhabi's Masdar Institute believe solar energy is a key to unlocking the world's water reserves.

As recently as 40 years ago obtaining fresh water was a day-to-day challenge for many people living in the region.
As recently as 40 years ago obtaining fresh water was a day-to-day challenge for many people living in the region.

As populations grow and the effects of climate change become increasingly evident, the world must face up to a shortage of water. More than one billion people do not have access to safe drinking water, according to recent figures from the International Atomic Energy Agency. More than 25 countries have reached the per capita water-poverty level, as defined by the UN, including the UAE, GCC and the surrounding countries in the Middle East and North African region.

For the UAE and other countries in a similar position, the challenge is as much about energy as it is about water. Among the critical areas of research at Masdar Institute of Science and Technology in Abu Dhabi are how to tackle this water shortage and how to do so in an energy-efficient way. As recently as 40 years ago obtaining fresh water was a day-to-day challenge for many people living in the region. Yet through the introduction of desalination and water management, the UAE gained a viable and cost-effective alternative to the daily chore of securing fresh water. For many years, water was no longer in short supply.

Today, proven desalination technologies are used to help meet the needs and sustain the lives of people in over 120 countries. Worldwide, desalination plants produce more than 59.9 million cubic metres of fresh water per day. The UAE alone produces a massive 14 per cent of this. In simple terms, the popularity of desalination in countries such as the UAE and throughout the Middle East lies in the fact that it is actually cheaper and more secure to desalinate seawater than transport treated water to highly populated areas thousands of kilometres away from natural water resources.

Despite its many obvious benefits, desalination is not without its problems. It can be a very costly process in terms of energy usage and brine deposits, which contribute significantly to each UAE citizen's carbon footprint and add to the environmental concerns of the region. In response, the Masdar Institute of Science and Technology is committed to finding ways to help the people of Abu Dhabi and the world live more sustainably, tackling the inextricably linked issues of water supply and energy consumption.

As a research priority, desalination is high on the agenda for a number of postgraduate students and their faculty staff, including myself. It is our belief that solar energy is one of the keys to unlocking the water reserves of the world and ensuring supply meets the ever-growing demand, especially in Abu Dhabi. By harnessing the power of the sun, we are researching new processes in desalination which are cost-effective and limit the impact on the environment by reducing carbon-dioxide emissions. Such processes have obvious advantages for the sun-blessed UAE.

The abundance of potential energy through solar radiation in the Emirates provides the opportunity to couple desalination plants with solar-energy systems, supplying water in a more sustainable manner both economically and environmentally. By reducing our reliance on fossil fuel for desalination, hydrocarbons - an increasingly valuable resource - can be used for only the most essential products and as a valuable export, maintaining Abu Dhabi's position as a leading energy producer.

At Masdar Institute, our students are researching solar technologies from around the world and, by taking the best of each, are hoping to improve the efficiency of existing solar desalination plants by up to 50 per cent. Plants to benefit will include the first solar desalination plant in Abu Dhabi, an existing gas-fired plant located on Umm al Nar Island, about 20 kilometres to the east of Abu Dhabi city.

In addition to carbon-dioxide emissions, desalination produces large volumes of brine which can be highly damaging to the local environment. A key challenge is finding a way to use this brine. Part of my work involves supporting students in their research of methods to distil the brine and recover its salts and minerals for use in industry, to lessen the environmental and financial costs of the entire desalination process.

As an island, Abu Dhabi city has access to plenty of seawater, but inland in the emirate and in landlocked countries it is often necessary to rely on underground water reserves. In the UAE, these are often at least twice as salinated as seawater, meaning the desalination process can be almost impossible and highly energy-intensive. By using a combination of cutting-edge solar-energy technologies to maximise heat generation, trials are taking place in Masdar City on new and more economical ways of making hyper-saline water potable. It is critical research which could be replicated in many countries beyond the UAE.

On a smaller, domestic scale, simple solar stills and membrane-distillation techniques will be put on trial, in association with local and international companies, to allow remote households to desalinate their own water. In these ways, demands on the desalination plants in cities can be reduced, citizens can take the issue of water usage into their own hands and even the problems of urban migration, which are prevalent worldwide, may be stemmed.

For Emirati industry, these innovations could deliver huge savings and technology to develop new and diverse revenue streams, ensuring that the staff and students at Masdar Institute are contributing not just to the intellectual world of science but also driving business and industry in the Emirates. As part of my research, a patent has already been disclosed to improve existing desalination technologies and develop a new generation of giant desalination plants, ensuring that Abu Dhabi and cities of the future can continue to provide enough water for their growing populations without increasing the volume of fossil fuel required. Other patents are pending, and as they look for the next challenge beyond solar, several students are looking at ways to exploit even more of the renewable sources of energy in the region, such as geothermal.

The UAE has a vast depth of energy resources beyond oil and gas, and eventually beyond even solar. By bringing together the world's top scientists and the brightest students from the UAE and beyond, the Masdar Institute aims to become the world leader in the long-term fight to deliver clean water to the world through innovative and indigenous desalination technologies using solar energy.
Dr Hassan Fath is a leader of the R&D programme at Masdar Institute. He is an expert in desalination and energy technology.