Paint all the roofs of the world in whiteIn

Electricity from the Sun of the Sahara

The Germans are convinced. To the extent that the Commerzbank, second Bank of the country, has just announced that it joined the Desertec project, which studied the construction of solar power plants in the Sahara to supply electricity to the two shores of the Mediterranean, including Germany. Researchers of the Club of Rome, the origin of Desertec, 15 of EU electricity needs could be provided from here to 2050 by a network of solar power plants in concentration. In this technology, parabolic mirrors reflect light from the Sun to heat fluid filled giant towers, which heated, turning steam turbines and produce electricity. The Desertec Foundation, supported by the reinsurer Munich Re, Deutsche Bank, Siemens, E.ON, RWE and other calculated, with the Aviation Centre and German Aerospace (DLR), would cover 0.3 of the deserts of North Africa to produce enough electricity for the region and Europe! In six hours, the desert regions of the world receive more energy that humanity did consumes in a year, she says. To electrify the Maghreb and décarboner old Europe, Desertec encrypted investment to EUR 400 billion over 40 years. A sum that seems crazy, but Siemens does not show that the dream did not price The German group disbursed 418 million to acquire specialist Israeli solar thermal, the company Solel, whose financial performance (38 million of turnover and 17 million loss in 2008) does not explain this sudden interest. But the German Mastodon on a gain of several years in his research on solar thermal collectors.

Within the official framework of the Union for the Mediterranean, a Mediterranean solar plan was launched, with the key construction in the South with a capacity of 20 gigawatts of solar energy, the equivalent of 15 to 16 nuclear reactors of the latest generation!

Take place in solar planes

If the price of kerosene and per ton of CO2 climbs over time, as is likely, in view of the future shortage of oil, the aircraft could well become unaffordable for the mortals. A Paris-New York, it is 0.5 tonne of carbon, the equivalent of 750 litres of fuel per passenger, or 5,000 km in the city in a small car. Aviation industry ardently seeks ways to reduce its energy needs through its weight relief, an overhaul of its aerodynamics and the discovery of a "green kerosene. November 23, a Boeing 747 of KLM company thus conducted a flight with a mixture of oil and biofuel produced oil cameline, technology developed by UOP LLC, subsidiary of Honeywell.

But the most exciting adventure was launched by Switzerland Bertrand Piccard, who dreams of a solar airplane since that made the round the world nonstop by balloon in 1999. November 6, "solar Impulse", the solar-powered aircraft, whose scope is equivalent to that of an Airbus A340 (63,40 metres), but whose weight does not exceed that of a car (1,600 kilos), made his first tours of wheels on the military airfield in Dübendorf near Zurich. Six years of work, calculations and simulations were needed to develop this ultralight aircraft, the wing is covered with thousands of photovoltaic cells, which must supply renewable four electric motors equipped with lithium-polymer batteries. They will have to store the energy to fly at night. "We have built an aeroplane with the field of flight is not explored to date, compared to its weight and size, it is ten times lighter than the most powerful of the gliders", explained André Borschberg, the co-founder of the project. With the support of Deutsche Bank, Solvay, Omega, Dassault Aviation, and others (the budget reached 70 million), Bertrand Piccard wants to write the next pages of the history of aviation, making a tour of the world with solar energy. "solar Impulse" is not just a technological challenge: "this scientific adventure is also philosophical by his desire to educate society and bring everyone to save energy resources of our planet," he says.

Capture the energy elsewhere on Earth

Research in space and the sea is relaunched! At sea, all is now good to: swell, tides, currents and even differences in temperature between the surface and bottom. Long live the TRA (renewable marine energies)! With the Grenelle sea, pilot projects restart again in France, with aims to obtain a power of 6,000 megawatts in 2020 on the oceans. An unexpected player positions in the race: the Group DCNS, French specialist of the naval military (12,000 employees and net sales EUR 2.5 billion). DCNS is the installation off the coast of the island of the meeting of the first demonstrator of thermal energy in the seas, using the difference in temperature between the surface of the Sea (hot) and deep (cold) water to power a turbine. Its competitor in this technology The aircraft manufacturer military us Lockheed Martin, supported by the U.S. Government! The TRA interested members! DCSN also grows its pawns in the research of floating offshore wind turbines, that men could Moor where they like.

In space, the most daring draw solar power plants placed in orbit, and the more players wind kites! In California, Makani society founded by Australian inventor Saul Griffith imagine these kites, able to take advantage of the stronger and more regular winds circulating at high altitude. With the support of a community of sweet crazy of Stanford, Berkeley and MIT. A small kite could generate enough electricity to five houses, but huge and strange birds would have a capacity of 6 megawatts!

Cool world

It is called the "geo-engineering". A world of science fiction: it is to see how "tampering" atmosphere or oceans to combat an excess of CO2 in complete skid of climate... Plan B, the panic! "Even if we decrease our emissions, we already have far too much CO2 in the air and as we do not know in advance what will be the climate response, should therefore study the emergency tools which could develop to cool the planet", says Ronn Prinn, Director of the MIT Energy Initiative. Two routes are being considered: the first is to increase albedo, i.e. the reflection of solar radiation into space. To do this, everything is possible: put in space orbit of reflective mirrors, cover the deserts of films or disseminate tons of sulphur in the upper atmosphere particles to form a sort of giant parasol reducing the intensity of solar radiation, the image of volcanic eruptions. The second way is to remove CO2 from the atmosphere, for example seeding oceans with iron particles to promote the production of phytoplankton, which will boost the capacity of the sea to capture atmospheric CO2. Assuming some effectiveness to cool the planet, the side effects... remain unknown. And the cost! Rosy! But this has not prevented the venerable Royal Academy of Sciences of Great Britain in a very serious report on climate engineering: "there are major doubts about its effectiveness, its cost and environmental consequences, but it could be useful."

Paint all the roofs of the world in white

In. The two men seized rolls to... paint the white roof. In dreaming of the white houses of Greece, the Americans have become fans of the "cool roofs". In his laboratory at the University of Berkeley, Ronnen Levinson researcher working for years on these "cool roofs, which are intended to be the opposite of our paved or with Brown tiled roofs which function as heat sinks. In a climate such as California, considers possible to reduce consumption of air conditioning of buildings and repainted, white for the albedo effect to better reflect the solar energy by 10 to 20. The inhabitants of greater note every day, the temperature is higher in the heart of urban, concrete and asphalt, areas that capture heat. A white roof of 100 square metres would help avoid to emit 10 tons of CO2 over the duration of its operations. And if the 100 largest cities in the world covering clear paint, they could save 44 billion tonnes of CO2, have calculated the Berkeley researchers, who are working with the manufacturers of tiles and coatings on of new pigments capable to remove heat.