I’m singing in the rain…

By Sériane Kenema

The first time, I heard about “man-made rain” I thought it was a joke. I was told by a friend in Beijing that the artificial rain was used to reduce the air pollution. Suspicious I decided to do my own research.


I quickly discovered that “man-made rain” is nothing new.  Discovered in July 1946 through a series of serendipitous events by two researchers from General Electric.

How it works?

Man-made rain is a weather modification process called “cloud-seeding”. In the ancient times, during periods of severe drought witches could be seen performing rain dances to bring back the rain. Today in the technology era, the new witches are the geo-engineers.


The most common chemicals used for cloud seeding include: silver iodide, potassium iodide, dry ice (solid carbon dioxide) and in some cases liquid propane, which expands into a gas, has also been used.


Cloud seeding can be done by ground generators, plane, or rocjet

 The effects from cloud seeding are almost instantaneous, it takes only minutes to see a visible increase in cloud size and precipitation levels.

China : World leader in cloud seeding

Through our courses we have learned about the success of Emperor Yu. As far back as 2150 BC he was made famous by his ability to control the Yellow River and stop the flood. Today China’s rulers face the opposite problem; water scarcity is threatening farms and industries.

In 1958, the cloud seeding technology was brought to the Middle Kingdom of China via Russia. In 2011, China spent $150 million on a single regional artificial rain program, for comparison the United State spends around $15 million per year. According to Reuters China’s Ministry of Finance aims to use the technology to create more than 60 billion cubic meters of additional rainfall annually by 2020.

With its horrendous air pollution and acute water shortage, China is a natural contender to be the world’s leading cloud seeder.

Global cloud seeding

China may have the most advanced technology when it comes to cloud-seeding, but it is far from the only nation with a water modification program. The World Meteorological Organization, lists over 52 countries who are trying to address large-scale shifts in temperature and precipitation brought about by climate change through similar programs, including 10 countries which started programs less than five years ago.

People across the globe are becoming increasingly more aware of the constraints that arid environments have on resources.

Apart from the environmental benefits associated with increased rainfall, there are economic opportunities for companies as well. In recent years, several commercial companies have grown offering weather modification services centered on cloud seeding. While some government operated, projects exist the most popular type of project involves coordination between the government and a private company, such as farms or hydropower stations. The largest such company, Weather Modification Incorporated, has operations worldwide and it claims prominently that its technology works.


  • Use in water scarce areas and those suffering from severe drought


 Due to the increase in rainfall conditions such as famine can be avoided. Many countries which are experiencing severe drought can utilize this technology to alleviate their problems. Last year, the drought-stricken Indian state of Maharashtra spent $4.5 million on cloud-seeding.

  • Economic improvement for Agriculture

In some cases, this technology has been effectively used to suppress undesirable forms of precipitation, such as hail storms, which can cause damage to crops and urban areas. Given better weather conditions farmers would have the ability to grow and sell more crops. This would result in an overall improved economy for the region.

  • Economic improvement for Tourism

Aside from agriculture, dry and arid places which were previously considered as inhospitable could be transformed into new desirable vacation spots.

Additionally, as part of the 2008 Summer Olympics opening ceremony in Beijing to keep the stadium dry, cloud seeding was used. The rockets were launched into the sky prior to the cumulus nimbus reached the Olympic City, preventing the disruption of the events. Cloud-seeding is also occasionally used by major ski resorts to induce snowfall.


  • Negative weather impacts

Cloud seeding is feared to ultimately change climate patterns even though it is also believed to regulate the weather. Some people argue that it would have rained anyway but in another location, the process leads to depriving other areas of precipitation.

  • Flooding

 It is doubtful in regions experiencing chronic water shortage that there is a system in place to deal with flooding. Hail and excessive snowfall are another risk to consider. During the winter of 2009, ice rockets were launched into the sky to induce rainfall during a four-month long drought, Beijing’s longest in 38 years. However, the temperatures dropped sharply and the precipitation fell as snow. The snowfall was heavier than expected leading to the closure of 12 main roads around Beijing.

  •  Health and Environmental impacts

Compared to other geo-engineering technologies, cloud-seeding is considered as a relatively environment friendly method. Still there is some concern about the uptake of elemental silver iodide in highly sensitive ecological conditions. Current research is showing that the silver generated by cloud seeding is fairly minimum (less 1%) of industry emissions into the atmosphere in many parts of the world, or even individual exposure from tooth fillings.

The long-term effects due to accumulation on the health of plants, animals (including humans), and the environment are not yet known. There are other processes, which require further research on their impacts and are worth investigating, such as shooting salt-and-mineral-filled bullets into the atmosphere.

Enhancing cloud seeding with biomimetics

Naturally occurring cloud seeding is called bioprecipitation. Bacteria present in some clouds have evolved to use rainfall as a means of dispersing themselves. The cloud forming and the rain are a key element of their bacterial life cycle. The most known bacterium species are the Pseudomonas syringae, which have proteins on their surface allowing water to freeze at temperatures around the melting point of ice (0 °C).

 So far, those bacteria have been used most frequently by ski resorts. Ski resorts dose their snowmaking machines with the bacteria, Pseudomonas syringae, which have been found to outperform artificial cloud-seeding chemicals, suggesting it might be able to be used as a rain-maker, one day in the not too distant future. However there is still much research that needs to be done to better understand the protein composition of these bacteria before we can expect to see them used to trigger rain.

Renewable energy in Scotland

By Joshua Wilkie

When I think back to what Scotland was like in my childhood, even before I started my undergrad in 2006, the change in the country is fascinating. When I was younger I was aware of a few hydroelectric dams and our two nuclear power stations, but other than that I – as most people do – had no clue where exactly my electricity was coming from. Since then both nuclear power stations have been decommissioned and strong opposition to any more being constructed, a carbon capture pilot at the country’s only coal fired power station was not renewed and no plans for any new large hydro-power schemes. How on earth do we manage to turn on the lights and keep our houses warm during our cold, dark winters?

I was driving home from England in the winter of 2012 – a journey I had made countless times in the past. I had recently bought my first car and it was the first time I had made the journey during daylight hours. As I admired the mountain scenery, I suddenly realised that, my country now had an abundance of wind turbines rising over the forested hillsides. Much of the hillsides within the central belt of the country – where most of Scotland’s 6 million people reside – are now a dynamic landscape of farmland, forestry and gleaming turbines.

Renewable energy now accounts for over 57.7% of Scotland’s electricity annually. The country is a green superpower: on top of the incessant winds, the country’s coastline (which is longer than that of Spain) possesses 25% of EU tidal reserves, and 10% of EU wave reserves. Our renewable projects are also not just restricted to large scale projects either; there are widespread small generation projects now underway such as micro-hydro installations in remote locations, wind-to-heat, and reclaiming heat and biomass from the world-famous whisky industry. So vast are these combined green energy reserves that their potential capacity (60GW or higher) almost exceeds Scotland’s current electricity production from all sources by a factor of six. The country has repeatedly exceeded the Scottish Government’s renewable energy targets – even the current ambitious goal of 100% of electricity from renewable sources by 2020 does not seem beyond reach. In fact, one very windy day this summer the country joined only a small handful of countries which have ever achieved 100%! Who would have thought our bad weather would be a blessing in disguise!


Scotland’s iconic coastline also offers extensive opportunities for thedeployment of wind, wave and tidal power

Of course, it isn’t as simple as throwing up a few thousand wind turbines – there are still environmental and ecological impacts to consider. Scotland also had to translate it’s success decarbonising it’s electricity supply into other areas such as transportation and heating systems (although such technical challenges are not beyond one of the most ingenious societies in human history). It’s also a country with a small population spread out over a relatively large area – would the same achievements be possible elsewhere? The greatest concern is the increasing conflict in energy policy between the Scottish Government in Edinburgh and the climate-sceptic British Government in London, as subsidies for renewables are being cut severely to promote nuclear power and shale gas fracking in England (both of which the Scottish parliament block using its control over planning permission within Scotland). This division is likely become increasingly profound in the new uncertainty of Britain’s relationship with the EU, which could impact UK environment legislation and renewable energy targets, which Scotland has no control over.

As a young person it is really encouraging to see that your government, society and culture values your future – as well as the futures of people beyond your borders. It is also positive to be included in making that future a reality; many students have opportunities to research and work towards achieving a sustainable future – I spent my Master’s year researching redox flow batteries which are a technology that could one day be used to store renewable electricity for those rare days when it is perhaps not so windy as we would like. It’s interesting to see the change too from 10 years agwhen most of my classmates aspired to work in the North Sea oil industry, when today many students look forward to working in renewable energy and sustainable development.

Yes, there is a still a long way to go, and many challenges along the way, but I’m still optimistic. The massive strides in progress Scotland has made towards a sustainable energy future is exciting and speaks volumes about how much our societies can achieve if we have the collective will and determination to address our problems.

A fieldtrip week in China: from Beijing to Henan

Par Karim Thibault & Vincent Mougammadoussane

fieldtrip-1For the first two days of our fieldtrip week, we travelled to Henan province to visit several industries in the region, and to discover another side of China’s development. Our train stopped in Xinxiang, which is a prefecture-level city nicknamed -not without humour- New-York by Chinese people themselves (as Xin 新, actually stands for New in Chinese). Xinxiang, though experiencing a rapid growth, remains a middle-sized Chinese prefectural city with its 5,707,801 inhabitants and an area of 8,629 km².


There, we were warmly welcome by local government officials from the bureau of environmental protection, who accompany us to Weihui City where we were to visit the Chunjiang cement factory (春江水泥有限公司). The Chunjiang group was created in September 2006, and first established there, by a PRC representative of the People’s congress who invested 30 million RMB to start this company, which has then become the biggest in Henan. Nowadays, it covers a wide range of activities ranging from cement production to financial services.


After an instructive introduction on the background of the group, we were invited to visit the cement factory to discover the process of production from the initial raw material to the final output. The cement is initially made from inorganic material such as limestone, bauxite or magnesium. These are blended into appropriate proportion and further grinded before entering the preheater tower. The heated mixture of raw materials then enters a rotary kiln, where it is partially melted to form a new material known as clinker. Finally, the clinker is cooled down and further grinded to give the end product. Each of these steps is monitored carefully in the control room.

In an effort to protect the environment and the health of their fellow citizens, the company also implemented specific measures. The dust emissions are limited by covering the coal storage, and also by installing a dust collector at each end of the rotary kiln. Moreover, fly ash issued from coal burning is added to the clinker to alter the quality of the cement. Finally, the heat recovered from the cooling process is recirculated into the rotary kiln in order to save energy.


After the visit at Chunjiang, we were given a presentation by the delegate from the local government who introduced us to the city, its history and its environmental background. The geographic situation of the city is particularly challenging as the neighbouring Yellow River is higher, in terms of elevation, than the city, and the average wind direction is perpendicular to the river’s bed.  It leads to high water risk and a potentially high pollution. In order to deal with this peculiar situation, the local environmental policy is based on five pillars:

  • Improve control on coal burning
  • Promote an adjustment of the local industry structure
  • Save energy
  • Develop circular economy
  • Improve technologies in the sense of carbon efficiency

The economy of the Henan province has been mainly based on the mining exploitation and heavy industries, it is the fourth producer of coal in China. In the afternoon of our first day in the Henan province, we had the opportunity to visit the sub-critical coal power plant operated by the Huadian Qudong Power Generation Company in the Xinxiang city.

The Xinxiang coal power plant has an installed capacity of 1,320 MW with two generating units of 660 MW, the main goal of the visit was to get an overview of the general process to produce electricity from coal:

1/ The coal is crashed into powder by the pulveriser grinds before being mixed with hot air, it is then moves to the firebox of the boiler for an optimal combustion.

2/ The coal and hot air mixture heats the water of the boiler which turns into steam reaching 500 degrees at a pressure of 165 kg/cm2.

3/The steam is then released to power a turbine turning the heat from the steam into mechanical energy which is used to spin the turbine engine.

4/ The spinning turbine is linked to a generator: magnets spin within copper coils to produce electricity.

5/ The steam moving through the turbine is cooled by a condenser. in this step, a nearby water source is used to pump cool water through a tubes network. As the steam is cooled, it turns back to water which is reused in the process by returning in the boiler.


The company running the coal power plant also underlines some effort made to reduce the environmental impact of the coal power plant process: dust collection, by electrostatic precipitators, NOX (nitrogen oxides) control by non-catalytic reduction system, SO2 (sulphur dioxide)  reduction in the preparation of coal.

To bring that first day to a close, we went back to our hotel where we had a taste of the local food, before returning to our respective rooms for a night of sleep.



The next morning, we appreciated a hearty Chinese breakfast providing us an energetic start for our last day in the Henan province. Our environmental friendly group then headed in the direction of the Henan Xinlianxin Fertilizer company located at the ancient riverbed of the Yellow River in the Xinxiang Economic Development Zone.

With more than 6,000 employees and 45 years of experience, the Henan Xinlianxin Fertilizer co. has evolved from a small nitrogen fertilizer plant to one of the major actor in the fertilizer sector in China. The company produces and sells urea, compound fertilizers, alcohol, methanol, melamine products for a total asset of nearly 1.6 billion yuan?. After a cordial greeting from the company team, we had an introduction of the enterprise background and environmental policy. It was first established in 1969 and has changed from a private to a state-owned company in 2003. Xinlianxin fertilizer company owns four production branches of urea and other chemicals in its two factories in the Xinxiang, Henan province and Xinjiang province producing more than 4 million tons of products.


The company has made considerable efforts to reduce its environmental impact, thus it has been awarded « the national petrochemical industry leader of energy efficiency benchmarking enterprises » by the Chinese Ministry of Industry and Information Technology thanks to the optimisation of its process. Research and Development at Xinlianxin Fertilizer Co. is organized in 5 scientific research centres working on various subjects such as: smart greenhouse, waste energy, reused water process in partnership with the Chinese Academy of Sciences and Zhengzhou University. The company has built a strong environment management system and invest more than 500 million yuans to develop circular economy in the manufacturing process of fertilizers.


After the presentation of the background company and its environmental strategy, we had the opportunity to have a tour of the manufacturing site and the different solutions developed to improve the environmental impact of the process. Xinlianxin Fertilizer has gone beyond China’s environmental standard concerning the emission of SO2, NOX, and dust by developing technological solutions to capture NOX in the process by catalyst and conversion to nitrogen. Although, other improvement of the manufacturing process has been implemented to recycle the carbon dioxide : 60 % is reinjected in the process and 20 % is addressed to other companies using carbon dioxide for their own products process.


To conclude the fieldtrip in the Henan province, the afternoon was dedicated to the visit the Xinxiang museum which is one of the largest collection including ceramics, jade, paintings, porcelain art, and calligraphy. After visiting the museum, we then moved towards the train station on our way back home  to Beijing…


Back to Beijing, we went to visit a plant for wastewater treatment and reuse of Beijing Beikong (北京北控). This plant is located north of the Shahe Reservoir and south of the Changping county, and is composed of two treatment units. The construction of the first unit was initiated in December 2011 and completed two years later and it currently treats 30,000 tons of municipal wastewater per day. This capacity will increase up to 90,000 tons a day, upon completion of the second unit.

There, we were welcome by the staff, who later toured us through the facility where we discovered the different steps of the water treatment process. It starts with a screening step that aims at removing the large solids from the wastewater. The water is then taken to a pre-anaerobic tank to release the nitrogen and phosphate from recycled water/sludge mix, after which an anaerobic tank is used to reduce the phosphate salinity. The next step is the anoxic tank where nitrates are reduced into nitrogen gas and the oxidation comes at last to lower the microorganism content. After, the water is retained in a sedimentation tank for 4 hours and at the end of this step the sludge is collected, dewatered and the residual water is sent back into the system, to the pre-anaerobic tank. Finally, the water flows to the last step of the process which is ultrafiltration.


The effluent obtained exceeds first grade A of national standard and can be either reused or sent back into nature. At the time of our visit, the Sha river was experiencing some serious drought issues, thus, the treated effluent was integrally discharged into that river.


For the last day of our field trip week we were to visit the headquarters of the Sound Group (桑德集团), an international group covering a wide range of activities linked to environmental engineering, management and consulting over a variety of specific fields such as municipal solid waste treatment, wastewater treatment, water supply, hazard waste treatment and clean energy. The group, founded in 1993, was the first of its kind in China and, nowadays, its expertise is exported to foreign countries such as Saudi Arabia or Bangladesh. They operate all along the business chain from investment, to design, construction, operation & management and production.


After a brief presentation of the group, we were invited to visit the museum of the company located next to the headquarter. It was impressive to see that the group was not only importing cutting-edge environmental technology onto the Chinese market but also innovating decisively. They notably introduced us to two of their patented technologies: the electro-osmotic dehydrator/dry sludge incinerator and their own garbage cleaning treatment technology.

The end of this visit also marked the end of this fieldtrip week; a week rich in discovery, and which demonstrated how, in the field, the companies, in a common effort with the Chinese government, are tackling the environmental challenges that currently undermine China’s development.

Life on Tsinghua University’s campus

by Joseph Lemoine

When we first arrived at Tsinghua University, we were all amazed by this huge American-style campus: 400 hectares for tens of thousands of students, teachers, administrative staff and so on. First thing to do: buy (and of course bargain for) a bike, then the adventure on the campus could begin.

A few words of history: Tsinghua University (in Chinese: 清华大学 – Qīnghuá Dàxué) was established in Beijing in 1911 after some American politician made an important investment in China. Tsinghua served at first as a preparatory school for students to be sent by the government to study in the United States. In the late 1980’s, under the « Four Modernizations » movement introduced by Deng Xiaoping, it transformed from an institution dedicated to engineering sciences into a multidisciplinary university with the incorporation of several schools: School of Sciences, School of Economics and Management, and later, School of Environment! Today, there are as many as 14 faculties surrounded by dozens of research facilities and laboratories.

Three months are far from enough to discover the whole campus. While riding your bike for a campus tour you can observe the Tsinghua Garden, which was preserved for centuries, the Auditorium, mixing Greek and Roman architecture, Shui Mu Tsinghua, that is often compared to the Garden of Harmonious Interest in the famous summer palace, the Palace of the Ancient Moon, built for the emperor Dao Guang, and many more. In terms of services, you could live your life on the university campus without taking a step into the outer world of Beijing. There are widely available banks, post offices, super-markets, book stores, barbershops, laundries, sport facilities… And if you are hungry, you may choose from nearly ten canteens where you can enjoy an incredible variety of meals.

All the students are welcome to participate in various extracurricular activities. There are approximately 200 student associations covering pretty much everything imaginable. Some of us have already joined some groups: football, wall-climbing, calligraphy… Chinese student are always welcoming and well receiving their international classmates, and they will be very happy to talk to new foreign students.

Concerning the on-campus dorms, international students are well accommodated. The rooms, single or double, are clean and comfortable. Unfortunately there was a problem when we arrived the first night, the rooms had not been reserved… Ultimately they managed to find some place for us but we could not be together in the same building. No big deal though, compared to one really unpleasant surprise: the heating system in the rooms does not work! September was fine, but it got quite cold in the end of October. And actually, there is no heating in the whole campus: the reason for that is Beijing waiting for mid-November to switch the power on, probably for some energy-savings. Hopefully the next few weeks will be warmer!

What about the night life then? There are no places on the campus where you can have a drink at night. However, it will only take a 15-minute ride by cycle to get to Wudaoku, the nearest metro station, where you may find several bars. Many students meet there with their friends so the atmosphere is very friendly. And if it is still not enough, you can still take the subway to go downtown and find some other places!


We just realised that we have reached the halfway point already; time goes by so fast! But this experience will not stop in one month and a half since we will all meet again in January, this time in Paris and Fontainebleau. It will be the chance for our Chinese classmates to discover the French campus as we did here, although it should be quite different. Until then, we are sure there are still plenty of surprises waiting for us that we are eager to appreciate!