Solar thermal, still a luxury but no longer a utopia THE WORLD | 14.02.04 | 14h09
"Solar, it could replace marble in the hall." Never running out of images, Alain Maugard, president of the Scientific and Technical Center for Building (CSTB), is convinced that this renewable energy can become an outward sign of wealth. Undoubtedly more rewarding, for the one who exhibits it, than an energy-consuming sedan.
"We have come out of the era of the pioneers", wants to believe Michèle Pappalardo, president of the Agency for the environment and energy management (Ademe). The two organizations, which signed a new agreement on Thursday February 5 to strengthen their cooperation, inaugurated the same day solar laboratories on the CSTB site, in Sophia-Antipolis (University of Nice). Solar thermal energy - that which produces hot water, not electricity - is it no longer quite a utopia? Anyone who has left a garden hose in the sun on a summer day knows the temperature of the water coming out of the tap. But, between this rustic form of solar thermal heating and the reliable and economical production of hot water, there is a step which few have yet taken.
According to Ademe, the price of a solar water heater, equipped with 4 m2 of collectors and a 200 to 300 liter tank (three or four people), is between 3 € and 000 €, installation included. Aid and subsidies can cover up to 5% of this cost. But the amortization of the installation should not be expected for around twenty years. The purchase of such equipment is still a matter of conviction.
In France, the 2006 Ademe Sun plan favored the installation in metropolitan France of some 86 m400 of sensors between 2 and 2000. According to the White Paper on Energy from the Ministry of Industry, it is a million square meters of sensors that will have to be installed every year after 2003 if France wants to comply with a European directive imposing to reach 2010% of renewable energies by this deadline ...
At the end of 2002, France had 670 m000 of collectors, while Germany - where subsidies are high - totaled 2 million, far ahead of Greece (4,7 million) and Austria (2,8 million), out of a total of 2,5 million square meters in Europe.
ADEME offers explanatory sheets and estimates of the cost of installations and foreseeable energy savings to encourage individuals to get equipped. There are several types of solar water heaters depending on the needs of the home or community and the existing heating methods.
Difficult to choose, given the profusion of models. With its test laboratory in Sophia-Antipolis, CSTB hopes to provide, within two years, assessments similar to those which accompany household appliances and make it possible to estimate, on a scale from A to G, their merits in terms of reduction in energy consumption. Tested for one year continuously, to simulate ten years of aging, the equipment is subjected to severe tests - including winds of 200 km / h.
"We should not look for the feat, but for robust solutions", comments Alain Maugard, who dreams of positive energy buildings, capable of producing more calories and frigories than it consumes. But, he warns, "housing cannot be a field of experimentation, except at the risk of disqualifying a technology for a long time". Thus studies have shown that solar thermal has sometimes disappointed, for questions of upkeep and maintenance.
All the ingredients seem to be in place for a take-off of this energy: in addition to financial incentives, the public authorities have planned a certification policy for equipment and installers: there are almost as many heating engineers adhering to the "Qualisol" charter (4177) as 'there were sensors installed in 2003 (5)! Until EDF and GDF, which, as the opening of the energy market approaches, include solar in their offers to make them more attractive.
Hervé Morin
The Ademe website offers information on solar water heaters and other renewable energies.
Toll free number: 0800-310-311.
Blow the cold thanks to the hot
During the heatwave of summer 2003, the 250 m2 of offices of the CSTB laboratory in Sophia-Antipolis were cooled with solar energy. "While it was 34 degrees outside, we were holding 28 degrees inside", indicates Dominique Cacavelli, director of the laboratory. It is the sun, via a Japanese-designed lithium bromide-water absorption machine, and 63 m2 of vacuum collectors, which allowed this performance: the water, heated between 75 and 95 degrees, provides energy that produces cold (between 7 and 12 degrees).
The equipment is similar to that installed several years ago in a cellar in Banyuls. It represents an investment of € 150, a prohibitive cost given the current level of that of fossil fuels and electricity. But this technology could be a solution for the future to make it easier for the electricity network to absorb peaks in electricity consumption linked to the increasing air conditioning of buildings, we told CSTB.