Zero Energy Buildings to Decrease Carbon Emissions
Zero Energy Buildings are perfect combinations of energy efficiency within the building and the use of renewable energy to suffice the energy demand of it through the year. As a result of the studies of the European Commission for energy efficiency by sector, 2020 Climate and Energy Package had 3 national targets:
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decreasing the greenhouse gas (GHG) emissions minimum 20% compared to the 1990 level,
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minimum 20% of the annual energy requirements should be fulfilled from the renewable energy sources
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İmproving the energy efficiency minimum 20% (“20-20-20 Targets”)[1].
These targets have been achieved by most of the European countries by the year of 2018. Similarly, the targets of 2030, decreasing GHG emissions minimum 40%, fulfilling the 32% of the energy demand from renewable energy and improvement of the energy efficiency by 32,5%, are being worked by the EU countries[2].
Net zero carbon building (ZCB) do not have any carbon emissions associated with their annual energy demand. They are designed and built to consume as little energy as possible. The very little energy needed for the operation is utilized from the renewable energy sources employed on the building[3]. The European Union aims to decrease the greenhouse gas emissions by 80% in 2050 compared to the 1990 level. The construction and building sector are attributed for 39% of energy-related CO2 emissions[4].
Cities and city life are responsible of more than 70% of global CO2 emissions. Most of those emissions result from energy demand of the buildings. Residential and commercial buildings spend a big share of the energy for heating, cooling, lighting and in various appliances that require energy for operation[5]. Additionally, the building owners and their awareness to the energy efficiency also play an important role in terms of less energy demand and less GHG emissions. Each of these variables participates in reaching the goal of net zero energy. However, an air-tight, highly-insulated building envelope is the heart of the energy efficiency. A big share of the energy of the building is used for heating and cooling demand of the people living inside the apartments.
Therefore, keeping the heated and/or cooled air inside, prevents the excess energy use as the main demand. The advantages of the thermal insulation are;
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Reduced energy costs
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Increased comfort, health and productivity for occupants
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Positive environmental impact
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Reliable and affordable operations
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Higher resale value
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Improved energy security.
In the direction of achieving zero energy buildings, the application of External Thermal Insulation Systems (ETICS) is the substantial and the easiest operation. According to the information gained from the biggest ETICS producer for 17 years in Turkey, with only 175 million m2 ETICS application, 17 million ton of GHG emission has been prohibited.
Energy efficiency and Zero Energy/Zero Carbon Buildings are the key solutions for the world to achieve the climate goals set at the Paris Accord. The world has to keep global temperatures below 2⁰C by 2050. According to the literature, every ton of CO2 emitted into the atmosphere results in 3m2 shrinks in the Arctic summer sea ice cover. Now the dramatic question rises; “When will the Arctic see its first ice-free summer?”[6]
References:
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https://newbuildings.org/making-the-transition-from-zero-energy-to-zero-carbon-building-policies/
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Principles for nearly Zero-Energy Buildings, Buildings Performance Institute Europe (BPIE), 2011
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Zero Energy in the Built Environment: A Holistic Understanding, Appl. Sci. 2019, 9, 3375; doi:10.3390/app9163375
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https://interactive.carbonbrief.org/when-will-the-arctic-see-its-first-ice-free-summer/