Karbon marjinal azaltım maliyet yönteminin konut sektöründe uygulanması

Abstract

Sera gazı emisyonlarının hızlı artışı ve iklim değişikliği, ülkeleri emisyonları azaltmaya sevk etmiştir. Birleşmiş Milletler İklim Değişikliği Çerçeve Sözleşmesi'nin 3. Taraflar konferansı olan Kyoto'da, Kyoto Protokü imzalanmış ve taraf olan ülkeler sera gazları için sayısal azaltım emisyon sınırları belirlemişlerdir.Sera gazı emisyonlarını azaltma hedefleri ve yasal taahhütler, birçok ülkedeki karar vericileri düşük maliyetli karbon salım azaltım yolları bulmaya itmiş ve bu amaçla, Marjinal Azaltım Maliyet Eğrileri, iklim değişimindeki etkileri azaltmak amacıyla ekonomik ve teknolojik fizibiliteyi görselleştirmek adına sıkça kullanılmaya başlamıştır.Türkiye'nin, Kyoto Protokülü'ne taraf olmuş olsa bile, özel konumu itibariyle herhangi bir sayısal salım azaltım hedefi yoktur. Ancak Türkiye, geliştirdiği politikalar, yönetmelikler ve stratejiler ile enerji verimliliği ve dolayısıyla karbon azaltım hedeflerini de belirlemektedir.İleride Türkiye'nin zorunlu bir karbon azaltım hedefi olması durumunda, toplam enerji tüketiminde %35 gibi büyük bir yüzdeye ve dolayısıyla enerji tasarrufunda geniş olanaklara sahip bina sektöründeki uygulamalar önemli olacaktır. Bu uygulamalarda, MAC eğrilerini kullanmak azaltım teknolojilerinin seçiminde karar vericilere kolaylık sağlayacaktır.Bu tez çalışmasında, öncelikle MAC eğrilerinin kullanım alanları ve oluşturulma yöntemleri açıklanmıştır. Model türevli ve uzman bazlı MAC eğrisi oluşturulma yöntemleri, bunların oluşturulması sürecinde karşılaşılan zorluklar ve birbirlerine göre üstünlükleri ve sakıncaları açıklanmıştır.Son olarak bina sektöründe konut bazında uzman bazlı MAC eğrisi hazırlanmıştır. Bunun için öncelikle İstanbul'da ortalama büyüklükte varsayılan mevcut bir daire için, belirli enerji tüketim noktaları belirlenmiştir. Belirli bir enerji tüketim seviyesinde belirlenen referans noktasına göre, binada EPS ve taşyünü ile yalıtım uygulaması yapılması, buzdolabı, klima gibi enerji tüketimi yüksek elektrikli ev aletlerinde enerji tüketimi düşük olan tasarruflu cihaz kullanımına geçilmesi, aydınlatmanın LED ve kompakt flüoeresan lambalar ile sağlanması, ısıl geçirgenlik değeri düşük pencere kullanımına geçilmesi, elektrik ihtiyacının bir kısmının güneş panellerinden karşılanması gibi durumlarda sağlanacak enerji tasarrufu ve dolayısı ile alınan her bir önlem başına azaltılan eşdeğer CO2 salım miktarı hesaplanarak, varsayılan bir konut için karbon marjinal azaltım eğrisi oluşturulmuştur. Bu oluşturulan eğri, salım azaltım hedefi olması durumunda, bina sektörüne veya ev sahibine dairesi için yapacağı yatırımları önceliklendirmesi için bir öngörü sağlayacaktır.

Rapid rising of greenhouse gas emissions and climate change, has led countries to reduce emissions. According to this, in the scope of UNFCCC, The Kyoto Protocol was adopted at the third session of the Conference of Parties(COP 3) in 1997 in Kyoto, and member states set quantitative goals to reduce and limit the emissions.These targets and legal commitments to reduce greenhouse gas emissions require policy makers to find cost-efficient ways to meet the obligations. Marginal abatement cost (MAC) curves have frequently been used in this context to illustrate the economics associated with climate change mitigation and to illustrate the technological feasibility.Although, Turkey is Annex I Parties, because of its special conditions, it does not have first-round Kyoto targets. However, by developing new policies, regulations and strategies, Turkey sets its own targets in order to improve energy efficiency and reduce greenhouse gas emissions In the event of Turkey has quantitative international or national emission reduction targets, it will be essential to reduce emissions in building sector, which has %35 share of energy sector, and has essential reduction potential to meet the targets. In such conditions, using MAC curves enables decisions makers to decide most cost-efficient emission reduction technology, easily. The earliest cost curves are developed after the two oil price shocks in the 1970s with the aim of reducing crude oil consumption and later electricity consumption. Then they became popular with Mc Kinsey&Company's global cost curves. Mc Kinsey published its first MAC curve in 2007. That curve shows the emission abatement technologies and their abatement costs globally. In that study, they assumed three emission limits which of them is the highest limit for their advocates to stop global warming. Later, McKinsey updated their cost curve in 2009 in a more detailed and extended way. In 2010, McKinsey updated the curve to reflect a more realistic reduction in emission according to global financial crisis and higher fuel price expectations. Afterwards, McKinsey published cost curves for 14 different countries.A MAC curve is a graph which shows the marginal costs of the various emission abatement alternatives. A MAC curve represents the extra ( or marginal) carbon reduction (or abatement) potential of these alternative technologies relative to a baseline. Typical technology options in a MAC curve are improvement of energy efficiency and clean energy usage. To start with, the first important thing in MAC curve desing is to make a decision about the emission baseline. In order to desing a reliable MAC curve, it is essential to indicate the assumptions underlying the calculations. There exists different kinds of approaches to generate MAC curves with different strengths and weaknesses. They are called expert-based MAC curves and model derived MAC curves.Expert-based MAC curves assess the cost and reduction potential of each single abatement technology based on educated opinions individually, while model-derived curves are based on the calculation of energy models. They have different advantages and disadventages because of their different formation approaches. To give an example; expert based MAC curves contain technological detail, while model-based MAC curves don't. Nevertheless, since expert-based MAC curves evaluate the emission reduction technologies individually and are not based on a model, they might not assess the real total reduction potential. Although, both expert-based and model-derived MAC curves possess important disadvantages that limit their usefulness for policy makers, they are very useful tools for policy makers to have vision about carbon abatement technology investments, in the end.In this study, the design methods, types and advantages-disadvantages of the aforementioned types of MAC curves are explained in details. Also, the positioning of Turkey about emission reduction is described. Finally, an expert based MAC curve is formed for an assumed residence in order to visualise the emission reduction potentials of possible emission reduction technologies for the so-called residence.The curve is formed for a residence in İstanbul, Turkey, which has specific conditiones, according to assumptions. Primarily, the baseline scenario for the study is determined and energy consumption spots are specified. Later, energy saving potentials of each spot is examined.The assumptions are suitable to the assumed location of the residence, to the surveys, to the sale rates of the devices and materials. The existing aforementioned residence is located in İstanbul, on the ground floor of an uninsulated building, over basement. The building construction materials are mainly brick on walls and reinforced concrete on post-and-beam. Heating is provided by natural gas. The windows are wooden window. For cooling needs in summer, an air conditioner is located in living room in an energy class of B. No renewable energy system is located for electricity generation. Lightning system is based on incandescent lamps. The refrigerator, which has the highest energy consumption rate of a residence, is chosen as B energy class, according to sale rates and surveys.Projections are made for year 2015. Therefore, electricity and natural gas price forecasts are made according to the past prices. Monthly electricity prices between 2005-2015 are obtained from TEDAŞ, a firm which is responsible for the distribution of electricity in Turkey. Monthly natural gas prices between 2010-2015 are obtained from İGDAŞ, a local natural gas supplier. Accordingly, price forecasts are made for 2015 by linear regression method. In regard to the predicted prices, the average assumed prices between 2015-2025 are calculated in order to use in MAC curve calculations for ten year period.For the uninsulated building, the use of EPS (expanded polystyrene) and rock wool is investigated. In accordance with TS 825 Thermal Insulation Requirements in Buildings in Turkey in Terms of Solar Radiation, an insulation board with 5cm board thickness is enough for external thermal insulation application. Also, it is assumed that an insulation of 3cm thickness EPS will be implemented over basement in both calculations, since the residence is located over basement floor. The assumptions for investment costs such as material costs and implementation costs have been made over market prices. Electricity savings and greenhouse gas reduction potential is calculated accordingly and added in final MAC curve.For windows, energy savings and emission reductions with the use of PVC frame with double-glazed windows, with a better thermal transmittance value (U value), is investigated. The assumptions for investment costs such as material cost and implementation costs have been madeover market prices. Natural gas savings and greenhouse gas reduction of the measure is calculated accordingly and added in final MAC curve.Refrigerators, lightning systems and air-conditioners are the most energy consuming systems in a residence; therefore improvements are investigated in these systems as well. For refrigerator and air-conditioner, savings from the utilization of a better energy class, hence less energy-consuming devices are calculated. For the lightning system, by using Dialux program electricity savings with the use of compact fluorescent light bulbs and LED lamps instead of incandescent lamps are investigated. Electricity savings and correspondingly greenhouse gas reduction of all the measures are calculated accordingly and added in final MAC curve. Finally, electricity generation by the implementation of solar panels on the roof of the building is investigated. It is assumed that a part of the consumed energy will be supplied from these mentioned panels. Investment costs such as device costs and implementation costs are assumed according to market prices. Natural gas savings and correspondingly greenhouse gas reduction of the measure is calculated accordingly and added in final MAC curve.In the formed curve, KFL and LED usage, exterior insulation and window changing practices stayed on the left side and negative part of the curve which means by reduction of one unit of emission saves the investor money in the determined projection time with these abatement technologies. Other technologies such as, change of refrigation and air-conditioner and solar panel implemantation, are the projects in which one unit of emission abatement is expensive, relatively.As a conclusion, it is important to remark once more that, the aformetioned formed expert-based MAC curve, does not give the total emission reduction potential since it is an expert-based MAC curve and does not based on energy models. In the event of emission reduction limits exists, this final MAC curve will give the householder –or building sector- a broad perspective to limit the emissions in an economically efficient way.