The ecological buildings with positive energy
Copenhagen is the capital of Denmark, but it is also the capital of green building. A United Nations building in the city has 1400 solar panels and an air conditioning system that uses seawater. Energy performance of this type of building, have nothing to do with what was there just 20 years.
In the European Union, the building sector is among the most energy intensive sectors. It represents 40% of total energy consumption, while exceeding two transport sectors and industry. Therefore, the needs to achieve energy savings in the building are a major economic and environmental issue. Houses based consumption, called passive, are already thousands in northern Europe, Germany, Denmark, the Netherlands, Sweden… and have already proven that technical solutions exist.This achieves a very low consumption in these buildings, approximately 50 KWh/m2 a year, or eight times less (450 KWh/m2) than a classic average building dating of 1970s. A positive energy building is still better, it is a building that produces more energy than it consumes for its operation.This is possible thanks to a local energy production with means of abstraction or productions like photo voltaic collectors, solar heat, wind turbines, heat popes buried in the ground …
The positive energy buildings are becoming more innovative and more numerous, though still too rare. It is mainly offices, a third of individual houses and the rest of the collective housing.
The intelligent buildings bloom everywhere in Europe. New standards of construction are indeed imperative so that the new buildings consume less and less energy.The goal for 2020 is much more ambitious, generalized positive energy buildings, that is, those that produce more energy than they consume. To get there, we must use good insulation, good air circulation, a mastery of sunshine and also all electrical appliances without forgetting the energy in the building.That is easy to say, but far more difficult to put into practice.
This is the case of the Green Office at Meudon; this smart building is a model of its kind and among the best examples of demonstration. An area of 23 000 m2, it houses the offices of 1250 employees, all the engineering of the building is facing and develop sustainable production of green energy. After three years of service, he can already see a very positive energy balance. It is capable of producing annually 80 000 kWh/m2, while he consumes only nine-tenths.
Eric MAZOYER, chief operating officer Bouygues constructions, behind the project, has thought of everything to reduce energy losses. The first stake for Eric MAZOYER, the air conditioning, the building is endowed with an intelligent system of ventilation, 54000 temperature sensors are scattered as a whole and when the offices exceed 21°, they regulate themselves through a system of natural and automated air traffic. The second challenge for Eric MAZOYER was to limit the consumption of energy bound (connected) to the multiple lamps in offices.He made the choice to focus maximum natural light, 50% of which are glazed surfaces compared to 50% of facade surfaces that are full.
In addition to a design promoting the daylight, the building is able to calibrate the artificial lighting needed. Detectors connected to lamps movements, allow the light to automatically turn off when an employee is no longer in his office.The building therefore is fully controlled by a nerve center that fits all situations to avoid unnecessary energy expenditure, but the green office goes further in chasing energy through a high-performance software uses regularly responsible for the building environment. This software measures related to each consumer uses, unlike other conventional buildings where there is a comprehensive bill that suffers in general and which are not absolutely measurement details.With this software for any purpose studied as heating, elevator, office, lighting … we’re able to tell month by month what is the consumption of each of these uses, enabling informed cause of action on the consumption and savings.So, it is possible to detect certain problems, such as the lighted without reason computers.
In a typical building, there is nothing to detect anomalies or to save money on this or that position. In this case, employees will be encouraged to turn off their computers at night and on weekends.Result of all these efforts, the green office consumes three times less than a traditional office building, but it is not enough to be a positive energy building, it is also massively producing its electricity.In this building, photovoltaic panels are everywhere, on the facades of the building, the roofs of parking and of course the roof. Their orientation is an essential element for electricity production.
Photovoltaic panels are a centerpiece of green office room. By themselves, they can meet half of its energy needs, but it is not enough. The rest of its resources come from the basement, through a new type of boiler that not only heat the building, but also produce excess electricity.
One of the major technical innovations of green office, it is this set consists of cogeneration boilers that operate with vegetable oil (rapeseed oil). One burning rapeseed oil, he released two things boilers: steam that can heat the building and at the same time, she will turn an electric turbine which produces electricity that is consumed by the building.
Energy production is increasingly green thanks to the combination of cogeneration and photovoltaic panels. This allows generating an abundant and especially excess energy. Finally, the green office produces 10% more than it consumes. Today in France, there are about 200 positive energy buildings, but the phenomenon is growing as 20-30 new buildings spring up every year.
The France of tomorrow will be positive.
Etudiant en Master 2 Commerce électronique à l’Université de Strasbourg, je suis passionné par le domaine du numérique, les innovations technologiques et le droit de l’internet.