Tag Archives: Science

UAE consider to build man-made mountain to increase rain fall

After the extraordinary success of the cloud seeding operations that saw a significant increment of the quantity of rain fell over the United Arab Emirates, it seems that the government is seriously considering the opportunity to build a man made mountain in a bit to improve rainfall.

The United Arab Emirates invested a significant amount of 558,000 USD in the 2015 alone within the Rain Enhancement Program initiative activated by the UAE Ministry of Presidential Affairs (MOPA) and run by the National Center of Meteorology & Seismology (NCMS). As reported by a local newspaper, the  Program provides grants to up to five innovative research and technology proposal over a three year period that are trying to find new ways to enhance rainfall in the Country.

“What we are looking at is basically evaluating the effects on weather through the type of mountain, how high it should be and how the slopes should be. We will have a report of the first phase this summer as an initial step”

Said  National Center for Atmospheric Research (NCAR) scientist and lead researcher Roelof Bruintjes to ArabianBusiness.

He further clarified that the NCAR received funds to provide a detailed modelling study evaluating the effects of building a mountain on the weather.

For those not really specialized in climatology and how the rain process works, humid and warm air moving towards the mountains will be forced by them to raise. While raising the air temperature drops (almost 6.5 Celsius per km for humid air) causing the condensation of the humidity and the creation of rain drops.

In order to do so, the mountain shall intercept the predominant air currents forcing them to release their water content before passing through.

“Building a mountain is not a simple thing. We are still busy finalizing assimilation, so we are doing a spread of all kinds of heights, widths and locations as we simultaneously look at the local climatology. If the project is too expensive, logically the project won’t go through, but this gives them (the Government) an idea of what kind of alternatives there are for the long-term future” Bruintjes said.

“If it goes through, the second phase would be to go to an engineering company and decide whether it is possible or not.”

 We have no other option but to wait the preliminary results.

Record rain in the UAE achieved thanks to clouds seeding

If you are wondering why it rained so much this winter in the UAE, the answer might be more surprising of what you can possibly think. According to updates from the National Center of Meteorology & Seismology (NCMS)’s meteorologist and cloud seeding expert Sufian Farrah, as reported by The National, cloud seeding operations might have played a decisive role in this extraordinarily wet winter.

Annual rainfall in the UAE rarely exceeds 120 millimeters whereas the last 9 March 2016 alone we have witnessed a rainfall of 287 millimeters as reported by ArabianBusiness.

dubai_climate_chart

Average weather statistics for Dubai. – Photo credit climateandweather.com

The aim of the 77 cloud seeding missions performed during the first three months of the year was to increase the chance of rain (even though the cloud seeding operation doesn’t necessarily makes it rain) and the quantity of rain falling on the UAE.

This is very important to replenish the water reserves both above ground (dams and channels) and underground,, sustaining the agriculture sector and reducing the overall need of producing sweet water from the sea for daily use.

Basically the clouds are “injected” with salt crystals by mall planes which fly above the clouds. Not all the clouds are targeted since the NCMS cloud seeding programme focuses on mature clouds that have the right configuration to generate rain.

“We covered most of the available clouds in the country, so the rainfall increased. Even if we didn’t carry out any operations it would rain, but the objective of cloud seeding is rain enhancement, and most of the clouds that are subject to seeding will generate rain,” he is quoted saying.

National Center of Meteorology & Seismology regularly publishes interesting videos and photos like the following.

 

UAE to be Solar Thermodynamic Energy’s World Leader by using sand to generate electricity

Concentrated Solar Power (CSP) uses mirrors to reflect heat from the sun to one point, most typically the tow of a tower filler with a fluid (usually molten salt) capable of storing heat for prolonged periods then used to produce electricity.

Thermodynamic Solar Plant with Central Tower

Traditional Thermodynamic Solar Plant that concentrates sun light in the tow of the tower – photo from http://www.fotovoltaicosulweb.it

An alternative to the central tower is represented by curved mirrors concentrating the sun light in a suitable pipe that runs all the way from/to the storage accumulating heat while running in the plant.

Thermodynamic Solar Plant

An alternative to the central concentration tower – photo from http://www.strettoweb.com

In both cases, the molted salts are heated up to 600 degree Celsius and transferred in a hot storage.

The fluid so heated is used to produce high temperature/high pressure steam that is used to generate electricity by evolving in a steam turbine.

The main benefit of this technology is that energy is easily stored and can be used at night when the source of heat (the sun) is absent. However, the popular photovoltaic modules are currently more cost effective and therefore preferred over the concentrated solar power plants.

But now the situation can drastically change.

Masdar Institute of Science and Technology’s scientists, indeed, have published a breakthrough research into more efficient solar power plants by using sand as vector fluid to transport and store energy.

Named “Sandstock”, the research published at the Solar Power and Chemical Energy Systems Conference in South Africa in December 2015, showed sand can withstand temperatures of up to 1,000°C and the higher you can push the temperature, the more efficient the plant will be in generating electricity.

The approach chosen by the researchers at Masdar Institute completely eliminates the most expensive components of the traditional CSP, the molten fluid and the pump system, by substituting it with sand and gravity. The design concept, which is inspired by a traditional sand hourglass, features a ‘cold tank,’ where sand is initially stored – before flowing into a ‘hot tank,’ located directly underneath. The cold tank will take the form of a hollow cylinder, designed to allow the concentrated solar flux to penetrate an empty central cylinder part.

Sandstock diagram

Schematic concept of the Sandstock  design – photo from social.csptoday

 

“Sand is really always a drawback in this country but in this project we wanted to use it as an advantage because it can withstand very high temperature, and of course it is very cheap here,” said Dr Nicolas Calvet, assistant professor of mechanical and materials engineering, and guide for the research project, as also reported by The National.

“Photovoltaic is more popular because of more than 40 years of research, and the Chinese entering the market and driving prices down,” Dr Calvet said.

“If you want to make CSP more competitive you must significantly reduce the cost.”

The main costs for CSP are the reflective material, and whatever is used for heat transfer and storage. Dr Calvet and his students are using sand for the last two steps at almost no cost.

“When you build a CSP plant you need to import usually several thousand tonnes of molten salts from Chile,” he said.

“With this concept you can just build your plant in the desert and you don’t have to bring any other material, you have it on site.”

Dr Behjat Al Yousuf, interim provost at the Masdar Institute of Science and Technology, said: “The research success of the Sandstock project illustrates the strength of our research and its local relevance.