/ ITA Institute of Technology in Architecture Faculty of Architecture / ETH Zurich 12.07.2012 Power to the People – Sustainable Infrastructure and Architectural Interventions at the Torre David Jimeno A. Fonseca, Arno Schlüter. Grafics: Anja Willmann, Barnim Lemcke. Architecture & Sustainable Building Technologies Prof. Dr. Arno Schlüter ETH Zurich / Building HPZ / Floor G Schafmattstrasse 32 / CH-8093 Zurich www.suat.arch.ethz.ch Architecture & Sustainable Building Technologies Prof. Dr. Arno Schlüter OUTLINE 1 INTRODUCTION 3 The Context 3 Project partners 3 2 APPROACH 4 A Sustainable Tower? 4 Potentials of the Site 4 Technologies 4 3 STATUS QUO 5 Water, Heat and Electricity 5 Resource Demand and Dynamics 5 Vertical Mobility 7 4 SITE ANALYSIS 8 Solar 8 Wind 8 5 THE CONCEPT 11 Demand Reduction 11 Water Supply and Storage 12 Wind Energy 13 A New Vertical Mobility System 14 6 A SUSTAINABLE FUTURE 16 Improving Living Conditions without Increasing Environmental Impact 16 Architectural Interventions 16 7 BIBLIOGRAPHY 19 8 ANNEX – SWOT ANALYSIS 22 2 / ITA Institute of Technology in Architecture Faculty of Architecture / ETH Zurich 1 Introduction Climate change (IPCC, 2007) and depleting fossil fuels force societies and econo- mies to rethink how much resources and energy we use, the way we use it and from which sources we obtain it. A dramatic shift, even a new industrial revolution neces- sary (Rifkin, 2011) is, moving from fossil fuel-based, centralized energy systems to- wards decentralized systems based on renewable energy sources. An increasing urbanization manifests in exponentially growing cities, they mark the place where this shift has to be effective. The Torre David represents a unique setting in an exemplary context. It is a challenging task to think about changing patterns of energy use and harvesting re- newable energy when it is about the basic needs. In an admirable effort, the inhabit- ants of the tower have organized and established an improvised infrastructure of electricity, water and mobility. Only this infrastructure makes living in the abandoned tower even possible. Its maintenance and operation creates jobs and identification. Improvements are only possible by acknowledging the community, by asking the inhabitants to contribute with their knowledge, power and ingenuity. Realizing and integrating the environmental potentials at the site, the existing architecture and its verticality as well as the strong community of inhabitants opens up the path towards a livable and sustainable present and future. The Context The Torre David consists of a once abandoned complex of buildings nowadays host- ing a community of 3000 inhabitants in Caracas, Venezuela. This community occu- pied peacefully the set of buildings in 2005, where a tower of 190 m, planned to be the second tallest and more expensive project of Latin America, arises among the financial core of the City. Since the occupation, the community characterized by a low-income status, low conditions of living, but nonetheless, a strong character, struggles to rise up its standards of living and the acceptance of the City’s society. Our approach outlines the circumstances where the inhabitants of the Torre David can enjoy fair living conditions and a well-earned place in the widely uneven Vene- zuelan society. It is based on the integration of social, environmental and economic aspects for a future low-energy consumption society. Project partners Urban-Think Tank Chair – ETH Zürich Prof. Brillembourg & Prof. Klumpner Michael Contento, Rafael Machado, Alfredo Brillembourg, Hubert Klumpner, Daniel Schwarz, Ilana Millner. Architecture & Sustainable Building Technologies Prof. Dr. Arno Schlüter 2 Approach A Sustainable Tower? Today the concept of sustainable architecture is characterized by an environmentally sensitive design, based either on the reduction of energy consumption and carbon footprint or on the achievement of self-sufficient structures, which mitigate a build- ings environmental impact (Jarzomberk, 2003). Both approaches do not seem prop- er for a context like the Torre David, where environmental impacts are already much lower than the average. Concerning sustainability, occupying and reusing the aban- doned tower can already be considered exemplary, finally making use of the enor- mous amount of land and resources spent its construction. The maximum reduction of the currently low energy consumption of the inhabitants is therefore not a priority. Low standards of living, social isolation and lack of infrastructure are a main concern in this context, inferring the need to take an approach capable to involve the social and economic aspects for a sustainable architectural solution. Our approach on sustainable architecture of the Torre David therefore aims at im- proving current living conditions through improving and extending the existing infra- structure, while maintaining the current low consumption of resources and low envi- ronmental impact of the community during time. The measures taken will also trans- form the appearance of the Torre, visualizing the integration of the tower community into the city yet acknowledging its uniqueness. Potentials of the Site Our approach is based on realizing and harvesting existing potentials of the building site. Environmental potentials such as local renewable energy sources facilitate the introduction of a decentralized and more reliable infrastructure in the Torre David, which often faces power shortages. Among renewables, human power - the inhabit- ants - represents the strongest potential. The active participation of the community in activities related to the enhancement of services and current living conditions is not only the condition sine qua non but also facilitates the realization and operation of the infrastructure over time. Technologies Sustainable technologies constitute the toolset to achieve a solution that integrates social, environmental and economic aspects. The technologies to choose must facili- tate a high social involvement, but also be of low cost, low maintenance and low en- vironmental impact. An active participation of the community during the construction and operation of infrastructure not only leads to the reduction of costs, but more im- portant, to a greater knowledge and awareness of the inhabitants about the need to maintain and preserve the infrastructure. 4 / ITA Institute of Technology in Architecture Faculty of Architecture / ETH Zurich 3 Status Quo Water, Heat and Electricity The current water infrastructure in the Torre David consists of a limited pumping and distribution system connected to the central Caracas grid and operating once or twice a week. The improvised system lacks the network required for continuous op- eration and distribution to the tower apartments. It is susceptible to intermittence dur- ing dry seasons, when water is scarce in the grid. The same applies to the electricity infrastructure. It comprises a self-constructed connection to the local grid and a local distribution throughout the tower. Although every family is connected to the grid, the tower system is susceptible to overloading and loses in the capacity during peak periods and dry seasons.1 For cooking pur- poses, all 750 dwellings located in the complex make use of propane/butane barrels that have to be manually transported to the apartments. The demand of resources in the tower follows a dynamic pattern, which is characterized by several fluctuations throughout the day (see figure 2). The pattern shows peak periods usually in the morning, at noon and in the evening, where 40% of all the resources are consumed and the highest needs in terms of power are at- tained. This fact leads to propose a decentralized power system to sustain the sup- ply with electricity and thus level the peaks. Resource Demand and Dynamics The water consumed per dwelling unit (3.6 m3/DU per month) equals one third of the regional average and only one forth of the European average. This low water de- mand is caused by to restrictions of the water accessibility, distribution and storage infrastructure. In terms of its dynamic behavior, the daily water consumption is char- acterized by two demand peak periods in the morning (6am – 8am) and in the after- noon (6pm-8pm). During these periods of time, 41% of the total demand of water is consumed. Comparable to the water demand, the electricity demand (155 kWh/DU per month) represents just a fraction of the regional and European average consumption (1/3 and 1/4 respectively). The number of electrical appliances of every household in the Torre David is slightly lower than the ones in households with a higher income; however, low electricity consumption is due to lack of high energy-demanding appli- ances for cooling/heating purposes such as HVAC systems, domestic hot water heaters and dishwashing machines. Regarding its dynamic behavior, the demand of electricity presents two demand peak periods in the morning (9am – 12am) and in the afternoon (6pm-9pm). During these demand peaks 38% of the total demand of electricity is consumed (figure 3). 1 Empresa eléctrica socialista CORPOELEC, ”Profesionales debaten interrupciones eléctricas”. Cor- polec Informa 1, No 1 (2011), http://torre- http://www.corpoelec.gob.ve/corpoelec-informa (accessed 02 June 2012). During extreme dry seasons and high periods of demand, hydroelectric plants, which generate 66% of the total electricity of Caracas, run out of capacity, and the demand of electricity cannot be satisfied, in the same way, a supply