The way in which Dubai removes salt from seawater to create drinking water is set to change radically in the years ahead as the emirate implements its Clean Energy Strategy 2050, which aims to reduce Dubai’s carbon footprint to the smallest in the world.
Dubai’s existing desalination facilities run off thermal energy provided by fossil fuel-fed power stations, but the next generation of plants will use reverse osmosis, a membrane technology, which is approximately one order of magnitude 90 per cent more efficient in terms of energy use.
Earlier this year, Dubai Electricity & Water Authority (DEWA) awarded the construction contract for its first large reverse osmosis plant, which will meet water demand from 2020 and beyond, and a second, larger project is now being tendered.
A further advantage of this type of desalination technology is that it does not use thermal energy. Thermal desalination plants release hot brine into coastal waters, which increases seawater temperature in addition to salinity. So the move towards reverse osmosis technology is better for the marine environment. It also means the plants do not need to be coupled to power stations and can instead be run from the grid using in principle renewable energy.
With Dubai targeting solar and other clean energy to provide 75 per cent of its electricity needs by 2050, the move towards reverse osmosis is part of a wholesale reform of Dubai’s power and water sector. Dubai is aiming for reverse osmosis technology to produce 41 per cent of its daily water needs by 2030, saving 43 tonnes of carbon emissions in the process. And it wants all of its desalinated water to be produced using a mix of clean energy and waste heat by that date.
Desalination technology is evolving all the time; a new process called forward osmosis was recently piloted in the UAE by Abu Dhabi’s Masdar, along with renewable-powered desalination.
The reforms that are now getting under way constitute a massive shake-up in the water industry for Dubai, the likes of which I have not seen before in my 30 years working in the UAE as a water consultant. But the targets are ultimately achievable as many of the desalination plants built in Dubai since the 1980s are now coming up for retirement. DEWA has the chance to plan a managed transition and set Dubai up with a much more sustainable water supply.
Of course, addressing the supply side is only half of the equation: a sustainable water strategy must also tackle wasteful usage of this precious resource. This is especially important because, despite being one of the most water-starved countries on the planet, the UAE has one of the highest per capita water consumption rates in the world.
Residential consumers account for the majority of water used in Dubai, at 61 per cent, followed by commercial users at 27 per cent.
Educating people to do simple things like turning off the tap while brushing their teeth, or taking slightly shorter showers can reap huge benefits for a utility provider, not just in terms of the volume of water saved, but also the energy needed to desalinate that water.
DEWA has developed a demand-side management strategy that aims to reduce water and electricity usage by 30 per cent by 2030. It has been conducting audits of buildings to encourage the installation of more efficient technologies and to promote behavioural change to curb electricity and water consumption.
There are many steps that can be taken to lower the amount of water used by a building, from installing water-limiting devices in bathrooms, to encouraging facilities management staff to be more mindful of the quantities of water they use for cleaning and irrigation. When replicated across an entire city this can have a significant impact on daily water demand.
The tourism industry is an important and fast-growing segment of Dubai’s economy, but hotels are known for being heavy water users – for guest rooms, pools, landscaping, laundry and so on. Studies have also shown people tend to shower more often and for longer when on holiday, something we can all probably admit to.
To address this, Dubai has drawn up a sustainable tourism strategy, which includes advice for hotels on how they can cut their water consumption. The recommendations range from installing lower flow rate showers, toilets and washbasins, to using drip irrigation systems controlled by timers in the grounds of the hotel.
The hospitality industry has a strong commercial incentive to reduce water usage and the payback from retrofitting water-saving equipment can be seen very quickly. Leading hotel operators are growing wise to this and many now publish annual sustainability reports on their properties, which help to attract the more environmentally conscious traveller.
One area in which the hotel industry in Dubai is doing particularly well is in using treated sewage effluent for irrigation. Dubai has been successful in encouraging hotels and golf resorts to switch from higher cost potable water to lower cost recycled water and, in this way, it is able to make its resources go further. Dubai currently reuses about three quarters of its treated wastewater, the highest reclamation level among all the emirates. However, the remainder is ejected into the sea, which still represents a loss of value that should be captured.
When we talk about sustainable living, we must not forget about food and agriculture. The UAE currently imports more than 80 per cent of its food requirements, which obviously carries a huge carbon footprint. The most sustainable way to make food is to produce it close to the area of consumption.
But how do you manage fresh food production in a desert climate without using massive volumes of water and with very limited nutrients? With the technology available today, amazing things are possible.
Earlier this year, the region’s first hi-tech vertical farm opened in Dubai and it is now supplying microgreens to restaurants and hotels on the same day that they are picked. The produce travels less than 30 kilometres from farm to fork, compared with the thousands of kilometres travelled by imported food.
Badia Farms, the company behind the venture, is hoping to revolutionise farming in the UAE through the use of hydroponic technology. This innovative process sees the plants grow in nutrient-rich water rather than soil and take in light energy from LEDs instead of from the sun. The water is recoverable and so this method of farming uses 90 per cent less water than open field growing.
Hydroponics is a really exciting development for this part of the world. And the environmental benefits are not just limited to the lower water requirements. As the plants are grown in a controlled indoor environment, there is also no need for pesticides or other chemicals. For now, the range of produce grown in this way is very small, but this is definitely an area that will expand in the years ahead.
When we see all the water around us, the fountains, the swimming pools, the sea and the marinas, it is easy to forget we are living and working in a desert. But as we go about our daily lives it is important to remember the immense challenge the authorities face to produce more and more water, with a lower and lower environmental impact. Total water demand increased by 3 per cent last year in Dubai according to DEWA, and the emirate’s population is expected to treble again in the not-too-distant future. Every one of us can make their work a little bit easier, just by using a little less water.