14 september 2015
Energy-efficient pilot project with Masdar
Henri Casalis is SIDEM’s Project Manager at Masdar. We asked him about the project, the progress made and the future steps.
Located 30 kilometers from Abu Dhabi in the midst of an inhospitable desert, Masdar City aims to be the world’s first sustainable “smart city”, with no carbon footprint. Construction in the United Arab Emirates began in 2008 and is scheduled for completion in 2025. Solar energy and smart buildings will be used to meet Masdar City’s goal of “zero waste, zero carbon.”
Masdar has selected Veolia, through its desalination specialist SIDEM, as an industry partner to collaborate on the ambitious Renewable Energy Water Desalination Program launched early 2013. The pilot program aims to test and develop advanced, energy-efficient seawater desalination technologies suitable to be powered by renewable energy sources. The long-term goal of the program is to implement renewable energy-powered desalination plants in the UAE.
As technology partners, Veolia and Masdar are sharing the costs to build and operate a pilot plant - the first step of this partnership - that will have the same characteristics as future large scale innovative and low energy consumption desalination plants.Can you briefly outline the background behind the SIDEM-Veolia project in Abu Dhabi as part of the Masdar Renewable Energy Seawater Desalination Program?
Veolia has always been very active in developing new technologies in all disciplines of water treatment. As a major player in desalination for past several decades, using various processes, Veolia is very involved in the coming challenges of desalination which are linked to environmental protection and energy savings. These are two major components that still have to be improved for the ever-growing desalination demand in water-scarce regions.
Our commitment to ”Resourcing the World” drives our innovations so when we found out about Masdar’s bid for the development of new desalination technologies, we applied without hesitation as we were eager to implement ongoing developments on several process parts.
The project is a so-called pilot plant, which is in fact the exact replica of a large-scale plant, able to produce potable water with the same operation constraints as a large plant. This means that we have to build a small desalination plant that we will operate for more than one year to test its reliability and availability and also to further test the reactions of the plant at its operation limits; the aim being to test the plant beyond the expected operation parameters we are confident with today. It is therefore an ambitious request from Masdar, who expects this program to lead to the discovery of new technologies, pushing them to their operation limits. What energy-efficient or renewable-energy based desalination technology is being developed and used as part of the project?
Desalination requires a lot of energy but thankfully, we have come a long way since the early days of desalination and today, around 95% of this energy can be recovered. Various recovery technologies currently coexist, and we will implement a new one that has a better efficiency as it combines advantages of the existing ones.
Renewable energy will not be implemented on this program but it can easily be done in the future. It has to be kept in mind that the use of renewable energy doesn’t necessarily have to be by means of a dedicated power plant combined with a desalination plant: in the future it is more likely to be one or several renewable energy power plants, with production capacities in proportion with the energy demand, connected on the general power grid.
The obvious drawback of solar and wind power is that they cannot feed the plant on a continuous basis, requiring an extra-feeding form the grid, which is why these renewable power plants have to be connected to the grid and not directly to the desalination plant’s substation.
Another challenge for solar panel plants will be to figure out how to avoid dust affecting the capacity of the panels, as unfortunately dust goes with dry and sunny areas. Dust is mainly removed manually today, which requires manpower; low energy and automatic dust removal systems are still to be developed for panels. Wind farms do not have this drawback but do represent a noise nuisance even when installed few kilometers away from houses, which implies wind farms can only be built in remote areas, compared to solar panel.In your view, what are the main advantages of the technology you are testing?
The technologies we will implement are new but not experimental, in the sense that we know they will work with a high level of reliability and will not require an additional 5 to 10 years to have them implemented on large-scale plants. We consider they can almost be implemented on large-scale plants today.
These technologies all converge to better power efficiency and at the same time, to extended lifetime of the plant.
Desalination membranes are sensitive to water quality and their clogging is not as easy to handle as many want to believe, especially in regions where the sea water is warm and rich in organic matters. We refuse to fall into the trend of believing that pretreatment membranes solve any problem just because their filtering mesh is very small. Treating water is not just about removing particles: the clogging of RO membranes is linked to organic matters and bacteria that pass through the pretreatment membranes and develop colonies downstream. Classical technologies do not have this drawback even if perceived as less sophisticated; sophistication does not always go with improvement. What progress have you made on the project so far? And, what is next?
The first components were delivered to the site in February and assembly time was quite short thanks to a modular design. Construction was completed at the end of April and after pretreatment commissioning, the plant was started-up at the end of June. Today, the plant is producing potable water!
We are currently undertaking a reliability and optimization period prior to starting the Operations phase of the project which will take place over the next 9 months. We will demonstrate on the Pilot Plant scale what a large plant could achieve in terms of availability and main performances.
The pretreatment filtration is maintaining a good Silt Density Index at all times to protect our Reverse Osmosis membranes while the intervals between filter backwashes are kept very large.
Following the Operations phase will be a Research and Development period during which we will use all the opportunities given by our design to push the limits of our system and try to reach the very best energy consumption and plant recovery possible, and learn from it. Looking ahead, what do you think are the prospects for the use of energy-efficient and renewable energy-based desalination technology across the Middle East?
The Gulf countries have long understood the necessary use of renewable energy, especially that from the sun which is a major resource for them. They are actually very proactive in this field and are pushing the industry to develop better, larger and more reliable units. So our natural prospects for renewable energies are first in the Gulf and also in other areas of the world where water scarcity is combined with a lot of sun and/or wind.
As far as our new technologies are concerned we are ready to implement them on all our desalination plants.