Critical review of sustainable energy schemes of trias energetica

Critical review of sustainable Energy schemes of Trias energetica

 

Critical review of sustainable energy schemes of trias energetica Introduction

Growth in global energy demand has been accompanied by rising unease as to the security and long-term viability of energy supply. Such concerns are not only being felt by policymakers; every household has felt the negative effect of rising energy costs. But sustainable development with regard to energy use can only be achieved in an integrated way; no social or economic sustainability is achieved without environmental sustainability. The challenge of maintaining affordable long-term supplies of energy hits hardest at the individual level. As energy prices rise fuel poverty becomes a greater problem. Someone who spends more than 10% of their household income on heating their home is defined as fuel poor (Eurima 2012). By doing more to capture the full potential of energy efficient buildings, real sustainable progress of the environment can be shaped, green collar jobs will be created and economic and social conditions will be improved. But how could the full implementing potential of the energy efficiency plan could begin to resolve the energy security challenges, boost environmental sustainability goals in cities and greatly benefit reduce consumers' expenditure on energy supplies? The Trias Energetica is a model developed by the Delft University of Technology and acts as a guide when pursuing energy sustainability in urban design. The Trias Energetica makes clear that energy savings have to come first on the path to environmental protection. It points out that only when a building has been designed to minimize the energy loss, then after should the focus shift to renewable energy solutions and recovery systems. The major environmental benefit from reducing energy use in buildings is a decrease in carbon dioxide emissions. Currently over 40% of all energy is used in buildings; this is more than the energy that is used in either transport or industry. The Trias Energetica is a method in connection with energy optimization of a specific urban and building design after clarifying the user's requirements for the program and completing the Integrated Energy Design process. Can the Trias Energetica principle can be used as a principle under each step of the Integrated Energy urban Design process? The Trias Energetica method prioritizes various initiatives in connection with the use of energy. The method consists of 3 steps: 1. Reduce the demand for energy through the rational use of energy 2. Use sustainable sources of energy like renewable energy to fulfill demands 3. Use fossil fuels, if necessary, as efficiently and cleanly as possible. The paper analysis starts with a review of literature on the principle, scanning previously conducted projects where the principle was practical. This is followed by the identification of useful best practices and weaknesses where it is regarded insufficient for an adequate realization, in sustainability evaluation. Recognizing this, Can the principle be extended, covering different regions and contexts? This will lead to a significant understanding in the amount of situations where these principles are applicable, to best practices and outcomes that have their own negative ends. This principle prescribes it can be used to Limit the demand for energy by architectural and urban design related measures for example passive reduction of energy needs.re-use of waste streams and flow of energy and then after these process deemed insufficient provide renewable energy to fulfill the remaining demand in different contexts.

The Concept Securing a clean, sustainable and reliable energy supply through urban design is arguably the greatest challenge we will face in the 21st Century. The energy we rely on comes from finite natural resources and is subject to depletion. And it’s not only a question of when the fossil fuels will run out but the impact of fossil fuel consumption on global warming is also well comprehended now. There is a growing array of energy efficient principles and applications to assist today’s cities and neighborhoods become ‘green’ in order to reduce the carbon footprints from their buildings. Starting from solar energy to design systems, the possibilities are becoming endless. Trias energetica is a concept that deals with energy use in urban design. In Trias energetica urban design principle a substantial amount of energy use is optimized or attempts to reduce the demand for energy at the start. The three stepped principles can be applied in urban design as follows.

1.Limit the Demand for Energy in urban design It is an attempt to reduce consumption in itself as the objective. What’s needed now, is to go beyond user’s “perceived needs” and into “philosophical understanding” of what it means to build in an energy sustainable way. This requires the insight and knowledge into all current and foreseeable energy applications when designing urban facilities. A range of possibilities has been developed that can be applied to various areas. There is substantial possibility for reducing energy demand in cities by an integrated approach to the design of buildings, building clusters, the transport system and district or micro- power generation, with novel technologies. Their effectiveness can be evaluated by and assist governments in writing their strict energy policies. 2. Use Sustainable Energy Using natural resources wherever possible at any level, combined with reliable energy design choices. Using for instance the building facade and parking lots as solar collectors, and use that energy for heating and/or cooling also applying wind power, hydropower, geothermal power, biomass where possible. 3. Use Conventional Energy with Maximum Efficiency, Compensate After having applied the first two steps to the maximum possible, the remaining energy need, if any, will be met by applying fossil fuels as efficiently as possible, by applying state-of-the-art techniques, such as: CHCP: combined heating, cooling, and power generation , use waste fuelled biogas generators. The extent to which the use of fossil fuels disturbs the balance of Carbon Dioxide can also be a measure of the environmental damage caused by it. This effect can be fully compensated, for example by responsible planting of trees elsewhere.

Figure 1: The Trias energetica triangle scheme on utilization of energy Methodology A series of indicators for the following dimensions, set of energy indicators, for a more coherent methodological review are drawn-out for evaluation and for the purpose of sustainable future scenarios concerned with the Trias energetica principles. Building/ Green architecture Energy efficiency design

Protecting & enhancing green infrastructure

Urban design Eco-districts

Does not render the use Residual heat generated by of fossil fuels fully a large buildings in a unnecessary. neighborhood that + consumes huge amounts of Reduced nonrenewable energy, can make especially energy use be less energy selfdependent It is not recognized that much energy is lost in the production of energy supplies themselves + Transformation does Require to modernize all require a substantial electric networks in order to amount of infrastructural capture the production pick changes and to dispatch it

Town planning Eco-cities + Connect to communal energy grid Can generate sustainable energy centrally

+ Improve the environment + Minimize impact on nature Need to invest heavily in energy infrastructure development to achieve and

Mitigation

Socioeconomic benefits

+ Can use measures at architectural level Difficult to retrofit buildings with poor energy performance High impact on societal change. (Life style changes)

+ Can be applied to existing neighborhoods for e.g. possible to use heat pumps to transfer residual heat from industrial buildings to nearby homes and buildings. + Offers Alternative building forms and density, which impact on, movement and activities between neighborhoods.

Spatial integration

+ Spatial proximity of the different energy end uses with renewable sources.

+ Balance between strategies for urban in-fills and building clusters from the perspective of environment, energy use, and district level power supply.

Flexibility and adaptability by users

Not user friendly concept; applicable from top down approaches only

+ Increase energy-efficiency by promoting multi-family and connected residential housing + Cascade energy at the district level Exchange and balance

Re-cycle (Cradle to cradle)

Energy use

+ Waste flows on the building scale

+ Reduce consumption of natural resources

sustain socio-economic development goals. Has constraints in realizing the concept to a bigger scale because energy issues and conditions in urban schemes are more complicated than how its revealed in the concept Didn’t consider it’s a regulatory factor on the feasibility of the system. (Cost of services) + Increase employment opportunities in green jobs + Allows energy exchange and balance between districts for e.g. thermal Waste from the neighborhood could also be collected to produce biogas to other neighborhoods

+ Individual energy savings come first on the path to environmental protection which benefits the city If these energy supply buildings (industries) also become unsustainable through accordance with the cradle-tocradle principle, need other alternatives + Can’t solve all energy needs Balance could be achieved in a certain neighborhoods; from exchanging heat with a have to look elsewhere for neighborhood that has less supply. energy demands

Critical analysis As (Mackay 2009) demonstrated, it is very difficult to establish a society fully run on renewables. However, (Cullen & Alwood 2010) showed that most of the energy we use is lost as non-functional waste energy. So the initial demand can be reduced by more effective usage, such as by lowexergy means using the Trias energetica’s first principle. Globally speaking, though, the western appetite for energy is severely limiting the opportunities of developing and emerging regions to catch up in prosperity. Western countries owe their prosperity to limited use of energy in other parts of the world (Dobbelsteen 2011). Needless to say this situation deviates strongly from the equity goals posed by the Brundtland Committee in 1987.

Figure 2: Countries and the area of land respective to the amount of fuel energy they consume (Dorling et al., 2009, from www.worldmapper.org) How can an urban area become energy neutral? To accelerate this transition planning and design are crucial aspects to consider. Urban planners are in need of planning tools that bridge the gap between mapping, planning, zoning and designing on one hand and understanding of spatial implications of energy, technical energy data, energy solutions and energy scenarios on the other hand. Focusing on energy, all the different definitions of Cradle to cradle building or project are ones that is energy neutral or even one that makes energy for its environment” (Dobbelsteen 2003). Trias energetica is a new way of thinking, which goes, further than current sustainable approaches. Traditional views on building sustainable didn’t have this focus. A Cradle-to-Cradle approach with a focus on energy is not possible when the Trias energetica concept is considered literally. The law of thermodynamics states that there will always be a decrease in energy quality; this doesn’t fit the thought of re-use. However, the definition of Trias energetica within this research makes it possible to realize a cradle to cradle approach if the usage of any waste flows is included in the steps of the Trias energetica Strategy.

Case test (City of Amsterdam) The Trias energetica has been adopted in the city of Amsterdam and has been tested on two sites, one to be newly constructed and another to be redeveloped, and the incremental approach proved worthwhile, enabling energy neutrality in both cases. In Amsterdam, energy neutral is defined as "building without use of fossil resources for the building-related energy demand" [Ontwikkelingsbedrijf Amsterdam, 2009]. This encompasses heating and cooling, hot tap water, ventilation and lighting, all ingredients of the energy performance of a building. Through the avoidance of fossil fuels for building-related energy demands, emission of carbon dioxide, and a great deal of methane, nitrous oxide and water vapour is avoided, but not everything. Usage of biomass – provided it is replanted – may be considered as climate- or carbon- neutral, but the technical means to enable this may not be as such. The story is slightly different when using solar energy, wind and geothermal heat. These sources produce no CO2 and their equipment for energy conversion will be energetically earned back within a certain time-frame, leaving no climate marks on the planet. In this sense the Amsterdam definition rather equals climate neutral than energy neutral. Also carbon-neutral would describe the aim better than energy neutral. Perhaps even better would be 'fossil energy free': avoiding any use of fossil fuels in building-related energy consumption. The case has incited discussions on both short-term actions and long-term visions needed to facilitate real energy and further climate neutrality in the city of Amsterdam. It’s true that western societies heavily rely on energy, fossil fuels in particular. The Netherlands for instance produces less than 4% of its energy by means of sustainable sources [CBS, 2008]The New Stepped Strategy in the Netherlands Since the end of the 1980s, approaches to sustainable building have often followed the 'Trias Energetica' [Lysen, 1996](1)Reduce the demand (2)Use renewable energy (3)Supply the remaining demand cleanly and efficiently. The Trias Energetica forms the guideline for a logical, environmentally conscious approach. However, in the period it has been in use it has not led to the progress required. In particular the extent of penetrated renewable energy technology, step two, is minimal. Mainly in the Netherlands one mainly concentrates on step 3, after limited efforts with step 1 and skipping step 2. This is the reason why the Netherlands are still relying on non-sustainable energy for 96% of their demand. That step 2 is often neglected and so little use is made of sun, wind and other renewable energy sources has a lot to do with the step abruptly following a sub-optimal reduction in energy demand and with the fact that an important intermediate step is not explicitly mentioned in the Trias. This strategy needs to add an important intermediate step between the reduction in demand and the use of renewable sources, and it incorporates a waste stream strategy, inspired by the Cradle-to-Cradle philosophy [McDonough & Braungart, 2002]. The former last step, implying hence accepting the use of fossil fuels, is abolished. Based on the New Stepped Strategy, a team of people from the City of Amsterdam, architects and TU Delft [Tillie, 2009] developed the Amsterdam Energy Approach & Planning for a structural approach to urban areas. Therefore, the Trias energetica was not only connected to buildings yet also to clusters or neighborhoods, districts and the entire city. Trias energetica demonstrated that Amsterdam could become energy neutral without devastating demolition of existing building, however with smart exchange of waste energy streams from different urban functions, as well as some additions of greenhouses, green facades and roofs.

The essential novelty in this method is the explicit step of exchanging, balancing and cascading of waste energy in an urban context. Earlier approaches had neglected this safe energy potential in cities. The energy that becomes available after all these transformations has been sustainable energy. Until now, designers have followed three steps when building sustainable buildings using Trias energetica (Van den Dobbelsteen 2011). “Reduce the energy consumption, utilize sustainable energy and use fossil fuels as efficiently and cleanly as possible for the remaining needs. However, to date, this ‘Trias Energetica’ has not led to substantially more sustainable buildings. Therefore it’s necessary to device new way of adding sustainability to buildings. Like, there is an added step: reuse waste flows, such as wastewater, household and agricultural waste, and residual heat at the building or the neighborhood level. This method will ultimately render the use of fossil fuels unnecessary. Conclusion In this paper the first focus is on energy production and consumption with the concept of Trias energetica. Secondly, the focus is on its application across scales from building to urban design and to eco-regions. Urban designers and planners are facing a challenge in their roles: to integrate the new sustainable energy efficient Philosophy in their practice, to develop green designs and plans and to justify that the plan is sustainable. Traditionally energy systems are chosen after the main design decisions are made. Instead this concept model has been developed that can support the decision making process including the energy aspects at the start of the project. The Trias energetica, so far have only had been theoretic, though practical, methods that could help urban development towards energy, carbon or climate neutrality. Useful as they may seem, the proof is in testing it, so ongoing projects within the cities like Amsterdam will have to show whether the concept actually works. In cities the Trias energetica concept could be used to explore not just the technical consequences of energy use, yet also the legal, strategic, social and spatial consequences. The test-case in Amsterdam, this time, is a real project to be elaborated later by the municipality, giving it a proper meaning and insight to: What energy scenarios are possible at this local level; what are the building blocks used, to make combinations between scenarios; what are the legal, spatial and social consequences of using Trias energetica. Even though in Trias energetica, it is easy to recognize the environmental advantages of utilizing the alternative and renewable forms of energy but we must also be aware of the disadvantages that it is difficult to generate the quantities of energy that are as large as those produced by traditional fossil fuel generators. This may mean that we need to reduce the amount of energy we use or simply build more energy facilities. It also indicates that the best solution to our energy problems may be to have a balance of many different power sources. Another disadvantage of in Trias energetica in using renewable energy sources is the reliability of supply. Renewable energy often relies on the weather for its source of power. Hydro generators need rain to fill dams to supply flowing water. Wind turbines need wind to turn the blades, and solar collectors need clear skies and sunshine to collect heat and make electricity. When these resources are unavailable so is the capacity to make energy from them. This can be unpredictable and inconsistent. The current cost of renewable energy technology is also far in excess of traditional fossil fuel generation. This is because it is a new technology and as such has extremely large capital cost. Finally, Spatial dimension not enough considered and specificities of spatial dimension are not included in the equation

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Online sources www.changingroles09.nl www.triasenergetica.com www.tudelft.nl www.eurima.org