Part of the Paris Climate Energy Plan, which aims to reduce 75% of greenhouse gas emissions by 2050, « 2050 PARIS SMART CITY » is an R& D project to build high-rise, positive energy buildings, capable of producing energy for their surrounding areas. The study presents 8 prototype designs for mixed towers to combat the urban “heat island” phenomenon and to help develop the city in a sustainable way. These towers bring nature back into the heart of the city. They incorporate bioclimate regulations and renewable, short-loop recyclable energy sources in their innovative systems. The main aim of these social innovations is to invent new, eco-responsible ways of living, combining quality of life for city dwellers and respect of the environment.
This study was carried out for the Mairie de Paris by «Vincent Callebaut Architectures » in collaboration with «Setec Bâtiment » engineers. Here are 5 of the 8 prototype towers that were presented:
75001 – Rue du Rivoli
Paris has always been rebuilt on its former self. But does a lack of political ambition and vision for the future mean the city must be doomed to gentrification or to becoming a museum? Such is the question raised by the « Mountain Towers » on the rue de Rivoli.
With its severe elegance and impressive Neoclassical rigour, the rue de Rivoli, also known as the «wall», crosses the heart of Paris and stretches from east to west for almost 3 km on the right bank of the river Seine. Its buildings were all subjected to the same alignment and size constraints, giving the street its massive appearance with strict lines and surprising perspectives. This suited Napoleon who wanted to build a prestigious street dedicated to luxury.
This «eternal stretching » as Victor Hugo, used to call it, was created in the 18th century to resolve traffic and hygiene problems in the overcrowded old districts. It also helped to control uprisings in the capital. The model of the rue de Rivoli was then extended to all new Parisian streets, a standardization which artists of the time considered a «stifling monotony».
The « Mountain Towers » project aims to control smog and to “re-naturalise” hyper energy and space consuming urbanism by building bioclimatic mountains with renewable energy sources on the roofs and in the heart of the tower blocks. These positive energy «Mountain Towers» will triple housing vertically in each Parisian housing block, distributing the structural loads through the old, disused chimney ducts.
Three types of renewable energies will be available in each tower: During the day, two huge solar photovoltaic and thermal shields, inspired by the fine structure of dragonfly wings, will produce electricity and hot water. At night, a reversible pump-turbine, hydro-electrical storage station will supply a cascade of water from the top of the tower to two rainwater retention tanks located at different levels, so that no batteries will be needed to store the electricity produced by the solar dragonfly wings.
Garden balconies will surround the inhabited levels of the towers to filter water used by the inhabitants using phyto-purification and bio-composting techniques.
75014 Petite Ceinture
The ‘Petite Ceinture’ is an old double railway line of 32 kilometers that went around Paris inside the Maréchaux boulevards. Its interest was twofold: to link the radial lines emanating fom the main Parisian railway stations enabling freight exchanges between the different networks, and it also, strategically, served the Paris fortifications from within.
Competition from the métro lead Parisians to desert this line, and most of its length has been closed to the traffic since 23rd July 1934. Currently 60% of the line is in open air. The remaining 40% is underground.
There are 61 bridges: 36 are « rail » type (railway line on top of road) and 25 are « street » type (road on top of railway line). Urban policy is to transform this space into a green corridor by preserving the railway heritage and the tripling the use of the site with the railway, cycle paths, and walkways. Fallow land, trees and meadow plantations will help vegetation reclaim its rights on urban minerality.
The « Antismog Towers » will re-naturalize the railway lines by integrating community food gardens cultivated by the residents. Cycle paths and urban vegetable gardens built vertically around cyclonic towers, will purify the ground by hydroponic phyto-purification and filter
atmospheric smog with their photocatalytic titanium dioxide structure.
These purifying towers will provide ecological urban housing with minimal need for ground space due to their splayed architecture. They will be built at geographical crossing points between the radial Parisian boulevards and the Petite Ceinture and in existing ecosystems such as the Buttes Chaumont, the Monsouris Park, the André Citroên Park, etc.
The towers will produce electricity using integrated axial wind turbines in their strengthened facade, and a flexible photovoltaic textile which catches rainwater and dew on the roof. The temperature differential with the tunnels of the Petite Ceinture will be used to create geothermal cooling/heating wells to provide passive, bio air-conditioning inside the towers. These tunnels will be illuminated by piezoelectrical promenades.
75015 Montparnasse Tower
The foundations of the Montparnasse Tower were laid in 1970, on the site of the former Montparnasse railway station. The project was supported by André Malraux, then Minister of Culture, and Georges Pompidou, French President at that time. Built as an extension of the axis running from the Palais de Chaillot, the Trocadéro, the Eiffel Tower, the Champ-de-Mars and the Ecole Militaire, the often denigrated Montparnasse Tower was the highest tower in Europe for over twenty years until 1990.
In 1975 the municipality decided to forbid the construction of any buildings comprising more than seven floors. The « Photosynthesis Towers » project aims to improve the aesthetic and energy-consuming impact of the Montparnasse Tower by transforming it into a vertical Central Park for the public, and by covering the new suspended gardens with positive energy green algae bioreactors.
In 2050, the Montparnasse Tower will be a carbon-neutral ecosystem (no fossil fuels), built as a multi-storey vertical public park with overhanging gardens. Banisters will encompass the reinforced structure offering helical piezoelectrical promenades in the Paris sky around the 58 floors.
Public elevators in triangular openings at both extremities of the tower, will function on renewable energy, and will be separated from those of the office staff working in the tower. The slab-roof of the shopping mall will be transformed into a phyto-purification lagoon recycling the building’s used water.
In this green breathing space at the heart of Paris the Montparnasse Tower will be covered with an insulating bio-facade producing biofuel. Green micro algae will be cultivated in curtain-walls in flat and triangular photobioreactors built in laminated glass. They will capture the thermal solar energy generating the biomass used to produce methane. CO2 will be used as nutrient for the algae which will proliferate in solar radiation. These bioreactors will improve thermal inertia, with up to 50% economy in heating and air conditioning, and a biofuel refinery will be integrated into the base of the building.
75010 – Gare du Nord
The network of Paris’ seven SNCF train stations (Gare du Nord, Gare de l’Est, Gare Saint-Lazare, Gare Montparnasse, Gare d’Austerlitz, Gare de Bercy et Gare de Lyon) represents a total surface area of several tens of hectares. The Gare du Nord is Europe’s first station in terms of traffic and the third in the world after those of Tokyo and Chicago!
Over 700,000 people travel daily in the 2,000 trains on the 32 tracks. The Mangrove Towers will be built on this territory of iron, steel and intertwined rails. They will go well with the modernist neoclassical architecture of the Gare du Nord whose Great Hall dates from the universal exhibition of 1855.
The « Mangrove Towers » are inspired by mangrove trees with their pneumatophores and their stilt roots. Built directly on the platforms of the Gare du Nord, the towers will accommodate offices, hotels and housing for international and traveling populations. This urban mangrove will be energy positive, producing more energy than it uses.
Using state-of-the-art renewable energies with a zero carbon footprint, the station platforms will be equipped with piezoelectrical captors operated by the mechanical walking action of travelers. The tubular facades will be composed of Grätzel cells forming a photo-electrochemical skin, which, when exposed to the light, will produce electricity by electrolysis. The towers will not only be self-sufficient for energy but their titanium dioxide structure will also contribute to purifying the surrounding air.
Using the sun’s rays and oxygen and humidity in the air this branch structure will be able to break down organic, solid, liquid and gaseous matters in the urban smog.
75016 – Pont Aval – 75013 -Pont Amont
As illustrated in Nicolas Jean-Baptiste Raguenet’s beautiful painting, in the Middle Ages bridges were inhabited and created a functional, cultural and merchant continuum between the right and the left bank of the Seine.
The “Bridge Towers” project, which aims to make the city denser with inhabited vertical ecosystems, proposes the construction of two green bridges at Paris’ river gates. Two bridges, with the silhouettes of jellyfish emerging from the water, will link the 15th and the 16th arrondissements in the west to the 12th and13th districts in the east.
The towers will be supplied with electrical energy via multi-blade wind turbines and hydrokinetic turbines using kinetic energy from the river. A heat pump will capture the calories of the Seine to heat the towers, making them energy positive.
See all the designs on www.vincent.callebaut.org