Reduce CO2 from Buildings with Technology to Zero Emissions
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Sustainable Cities and Society 2 (2012) 29–36 Contents lists available at SciVerse ScienceDirect Sustainable Cities and Society j ournal homepage: www.elsevier.com/locate/scs Reduce CO2 from buildings with technology to zero emissions a,∗ b c d Forrest Meggers , Hansjürg Leibundgut , Sheila Kennedy , Menghao Qin , e f g Mike Schlaich , Werner Sobek , Masanori Shukuya a Singapore-ETH Centre for Global Environmental Sustainability, Future Cities Laboratory, Singapore b Faculty of Arch., Inst. for Technology in Arch., Building Systems Group, ETH Zurich, Switzerland c School of Architecture + Planning, MIT, Cambridge, MA, USA d School of Architecture and Urban Planning, Nanjing University, China e Institute of Structural Engineering, Technical University of Berlin, Germany f Institute for Lightweight Structures, University of Stuttgart, Germany g Faculty of Environmental and Information Studies, Tokyo City University, Japan a r t i c l e i n f o a b s t r a c t Keywords: This paper represents a unique collaboration between experts in architecture and engineering from Buildings around the globe to evaluate the true potential to reduce CO2 emissions from buildings. The result of CO2 this experiment in remote collaboration between Europe, USA, Japan and China, was a summary that Emissions was generated for the Holcim Forum workshop, “Reduce CO – With technology to zero emissions.” This Technology 2 covers challenges of reducing emissions from building construction, operation and maintenance while Systems Architecture also presenting an array of potential solutions. Here we expand on that work for the benefit of a broader audience. The paper covers the overall problem of building emissions, both direct and indirect. It discusses the often-overlooked impacts of building material use. It also reviews the problems related directly to build- ing CO2 emissions and energy consumption, as well as new analysis methods for better system design. Finally, many new processes are discussed that have the potential to drastically reduce building CO2 production to nearly zero. In summary we encourage new perspectives that increase the utilization of new methods and systems, thereby providing examples of technological groundwork that can incite new policy to reduce building CO2 emissions. © 2011 Elsevier B.V. All rights reserved. 1. Introduction previously described. In conclusion, we consider the potential (Section 7) Impact of Solutions that have been discussed in the In 2010 a group of experts were virtually assembled from around form of design and analysis methods as well as the innovative new the world to address the rapidly growing problem of CO2 emis- technological options. sions from the building sector. In this paper we present the results of this multidisciplinary cooperation between designers, architects 2. Overall problem and engineers from Europe, USA, Japan and China. The project grew from this team, who led the “Reduce CO2 – With technology to zero Contemporary building has inherited the assumptions and prac- emissions” workshop at the Holcim Forum in Mexico City. tice models of Modernism, methods of thinking and practice that We present our findings in a set of focus areas that guided our were developed in the last century, and are based upon historic concurrent intercontinental work, giving the paper a nontradi- cultural conditions of the 1940s, 1950s and 1960s. These inherited, tional structure. First, we address the (Section 2) Overall Problem and largely unquestioned assumptions of Modernism present us of buildings and their current impact on the environment. Then with a large problem when it comes to their construction, main- we consider more in depth the (Section 3) Material Problem and tenance and operation. At best they cater to a fundamental need the (Section 4) CO2 Problem of buildings. Next we discuss a sample in the form of shelter, and as a highly capitalized industry, their set of (Section 5) Analysis Methods and then (Section 6) New Pro- construction responds to prevailing market forces. But insofar as cesses that the team of experts compiled to address the problems we have extended their functionality and complexity to provide modern comforts, they are now the largest single contributor to global CO2 emissions. When all aspects of buildings are consid- ∗ ered, some estimate that over half of emissions are related to the Corresponding author. E-mail address: [email protected] (F. Meggers). building sector (Mazria, 2007). 2210-6707/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.scs.2011.10.001 30 F. Meggers et al. / Sustainable Cities and Society 2 (2012) 29–36 Fig. 1. Fraction of global emissions attributed to buildings. Often only the direct influence of residential and commercial buildings is considered as shown (a) in the data provided by the IPCC (Rogner et al., 2007). By considering the description of the IPCC (Levine et al., 2011; Nabuurs et al., 2007), estimates can easily be made of the sectors that are partially results of building sector demand (b), which demonstrates the potentially large overall impact in the range of 50% (c). This is due to a variety of factors. Buildings use 35% of energy in energy saving systems into buildings, and there are better analysis the world and are directly responsible for 35% of global emissions. methods to improve building design. We can look beyond simple Two-thirds of global electricity production is for building opera- energy balances and resource consumption, and evaluate their tions. When including construction and maintenance, it becomes direct and indirect impacts based on their quantity and quality clear that 50–60% of global resources are consumed by build- using concepts from the first and second laws of thermodynamics. ings while also causing more than 50% of global waste production The industrial revolution brought the ability to control and con- (Roodman & Lenssen, 1995). dition buildings, and this was achieved with the new widespread The range of direct and indirect impacts that buildings have on availability of high value energy sources. Now the consequences the environment makes it easy to overlook the full impact of build- of wasting those sources are clear, and we can use these new ings as an individual sector. The impacts are often grouped into concepts and ideas like exergy and anergy to exploit the potential other sectors even when their creation is actually a result of build- of lower quality renewable sources (Meggers & Leibundgut, 2011). ing construction, maintenance, or operation. This is illustrated in There is a vast potential in the integration of solar energy into Fig. 1 as reported by the IPCC (Mayer, 1999; Nabuurs et al., 2007; the supply of energy to buildings, both in centralized large-scale Rogner et al., 2007), where the true impact of the building sector plants (Mills, 2004; Schlaich, 1995) as well as in smaller decentral- is masked by the Energy Supply, Industry, and Forestry sector, all ized systems directly integrated into buildings (Kennedy, 2011). of which are heavily influenced by construction and operation of When it comes to finding a sustainable energy supply for build- buildings. ings, one can already recognize that there is more than enough Reducing the CO2 production of the building sector along with solar energy available. All that is missing is a feasible method to these other negative impacts is a challenge that must be met quickly capture it and supply it to buildings, which is influenced by a and decisively. Luckily there are many technical solutions that variety of factors from research and development to political will. already exist (Hoffert et al., 2002), and experts all over the world Therefore, it remains important to consider all potential renewable are implementing new strategies that will lead the way in chang- energy sources, because the best solution will always depend on ing how we produce and provide a modern built environment the available technology and its applicability in different locations (Meggers, Ritter, Goffin, Baetschmann, & Leibundgut, in press). This and situations. includes finding new materials and methods to address the some- It is one of our main tasks to put forward a selection of the most times overlooked CO2 produced directly in building construction practical and impactful energy solutions and an idea of how indus- while maintaining focus on reducing the massive amounts pro- try could get there from where we are today. The matter of climate duced from building operation. change is not an issue for academic and/or political circles alone, One important strategy involves changing the perspective peo- and it is our responsibility as a team of architects, engineers and ple have on building materials. Every component of a building has “experts” to put a solution mix forward. It needs to be a solution an associated energy use and CO2 emission inherent in its extrac- mix to address the political and industrial realities. We are not going tion, production, and transport. This “grey energy” and the resulting to have a single source of power or a single industry that is going “grey emissions” of materials are usually overlooked, and even to solve the problem. Different parts of the world will be able to when it is addressed, the data is not usually readily available. This bring different resources to bear, and all must be part of the overall aspect of building materials must be considered in every design if response. we are going to address the full effect of buildings on CO2 emissions Finally, a fundamental part of the overall problem is the building and pollution (Vieira & Horvath, 2008). user. The decisions made by users vary widely based on culture and Energy use from building operation is already often addressed lifestyle around the world. It is important to make the usability of as it causes the most significant and obvious impact, but there is buildings one that also encourages not just best practices in system still much more that we can do.