Türkiye elektrik piyasasında kapasite mekanizması uygulaması ve santral gelirlerine katkısına ilişkin inceleme
Capacity mechanism in turkish electricity market and its contribution to power plant revenues
Yazar: HÜSEYİN VOLKAN YİĞİT
Danışman: PROF. DR. BİHRAT ÖNÖZ
İstanbul Teknik Üniversitesi / Enerji Enstitüsü / Enerji Bilim ve Teknoloji Ana Bilim Dalı / Enerji Bilim ve Teknoloji Bilim Dalı
Derece: Yüksek Lisans, 2018
Konu: Enerji = Energy
Dizin: Elektrik enerjisi = Electrical energy ; Fiyat tahmini = Price ferecasting ; Yasal düzenlemeler = Legal regulations

Özet:
Enerji piyasaları dünya çapında olduğu gibi, ülkemizde de sürekli bir gelişim ve dönüşüm sürecindedir. Tarihe bakıldığında, büyüyen ekonomiler ve artan elektrik taleplerinin geleneksel modellerle karşılanamaz hale gelişinin, enerji piyasalarının oluşmasına ve gelişmesine olanak sağladığı görülmektedir. Günümüzde ise politik, ekonomik ve teknolojik kısıtlar ve gelişmeler, sektör dinamiklerini halen önemli ölçülerde değiştirebilmektedirler.
Türkiye elektrik piyasasının gösterdiği gelişim ve arz güvenliği konusunda orta ve uzun vadede ortaya çıkabilecek riskler göz önünde bulundurularak 2018 yılı başında kapasite mekanizması devreye alınmıştır. Yalnızca belirli kriterleri sağlayan üretim santrallerinin yararlanabildiği bu mekanizmanın, elektrik piyasasındaki düşük fiyat seyrinden dolayı karlılık oranları beklentilerin altında olan santrallere ne kadar ilave gelir sağlayacağı, bu santrallerin bütçe planlamaları ve gelecek dönem yatırımlar için önemli bir sinyal konumundadır.
TEİAŞ tarafından işletilecek olan ve gün öncesi piyasasında gerçekleşen fiyatlar ile yönetmelik kapsamında belirlenen sabit maliyet ve değişken maliyet gibi parametreleri göz önünde bulundurarak gerekli ödemelerin hesaplandığı bir kapasite mekanizması kurgulanmıştır. 
Bu çalışmada Türkiye elektrik piyasasının tarihsel gelişimi incelendikten sonra, ülkemizde elektrik ticaretinin yapıldığı piyasalar sıralanmış ve açıklanmıştır. Bu aşamada elektrik enerjisinin özellileri ve bu özelliklerinin elektrik ticaretine etkileri de yorumlanmıştır.
Çalışmada kapasite mekanizması uygulamalarına dair detaylı bir literatür araştırması yapılmış ve kapasite mekanizmasına ihtiyaç duyulmasının nedenleri tartışılmıştır. Bu nedenler ile paralel olarak, özellikle Avrupa ülkelerinde uygulanan yöntemler incelenmiştir. Türkiye elektrik piyasasında kapasite mekanizmasının gerekliliği geçmiş dönem gerçekleşen elektrik fiyatları ve arz güvenliği kriterlerinin analizi doğrultusunda tartışılmıştır.
Santrallere bu mekanizma kapsamında yapılacak olan ödemeleri tahmin edebilmek için öncelikle saatlik bazda elektrik fiyat tahminine ihtiyaç duyulmuştur. Bu ihtiyacı karşılamak için APLUS Enerji tarafından geliştirilen uzun dönem fiyat tahmin modeli AVIEW | MarketSIM kullanılmıştır. Elektrik talebi, yenilenebilir enerji kurulu güç gelişimi ve kapasite faktörleri, yakıt fiyatları, USD kuru tahmini gibi girdiler kullanılarak 2017 – 2027 dönemi için saatlik bazda fiyat tahmini çalışması gerçekleştirilmiştir.
Kapasite mekanizması yönetmeliğinde belirlenmiş olan parametreler ve yapılan diğer girdi tahminleri (USD/TL kuru, enflasyon, yakıt fiyatları vb.) kullanılarak 10 yıllık dönemin her saati için yerli kömür, doğal gaz ve ithal kömür santralleri için kapasite mekanizması gelir tahmini yapılmıştır.

Abstract:
Energy markets in Turkey, like those around the world, are in a continous development and transition process. It is clear that the traditional models become incapable of meeting the increasing electricity demand in emerging economies, which leads to the creation and/or development of energy markets. Nowadays; political, economic and technological progress and constraints, can still change the sector dynamics to a considerable extent.
Turkish electricity market has shown a significant growth in recent years, with its electricity demand and installed capacity increasing. This growth has led to discussions on the implementation of a capacity mechanism in the country, not because of a short-term threat to its security of supply, but because of signals for mid to long term risks. These risks have risen from the fact that the oversupply capacity that Turkey is experiencing in its electricity market these days, have led to a drop in market prices. Existing power plants have often suffered from the low prices, where their operating hours and spark spreads have dropped significantly. Although it is still at a moderate level, the growth of renewable energy plants in the country have also added more pressure on thermal power plants (i.e. local coal and natural gas power plants). After lenghty discussions, Turkey's transmission system operator, TEİAŞ have decided to pursue options for a capacity mechanism. Such an option to implement a capacity mechanism in Turkey was already mentioned in the Energy market law, which paved the way for the introduction. Following a consultation period, the operator have approved the implementation of capacity mechanism in late 2017.
The regulation on capacity mechanism was published in late 2017, with the enactment of the regulation and the first implementation period starting in January 2018. With the introduction of the capacity mechanism, the amount of payment which power plants will receive from the mechanism, became a significant input for companies' budget planning purposes among others. The mechanism also enables (for the time being) new entrants in the market, albeit there is no written confirmation on how long the mechanism will last. It is said on the regulation that TEİAŞ will evaluate each year its needs to ensure security of supply and calculate a maximum budget TEİAŞ can pay. For new entrants, the possible income to be received via capacity mechanism is also very useful for investment planning process.
Within the scope of this study, the historical evolution of Turkish electricity market have been detailed, with a particular interest in the reforms experienced. The historical evolution have been divided into five stages; namely Before TEK period, TEK period, Reform Period, 1984 – 2001 period and liberalization period. The development of electiricity demand and installed capacity of the country have also been provided in this context.
Following the introduction into Turkish electricity market, the main principles regarding electricity trading have been reviewed, taking into account the special features of electricity as a commodity. It is a known fact that electricity is still not an economically storable commodity in large scale, therefore it has to be generated and consumed simultaneously, leading to some constraints in its trading.
There are many opportunities for electricity trading in Turkey. The alternative markets, including bilateral agreement and OTC, spot markets including day ahead market and intraday market, real time markets like balancing and ancillary services market are examples of a physical electricity trading opportunity in Turkey. There is also a chance to trade in futures contracts within Borsa Istanbul, with an intention to secure buyers/sellers from possible flunctuations in the market prices.
There are several constraints to be considered when setting up an electricity market. The most important of all is to create a market and transmission system enable to meet the future electricity demand. The market should also allow the end-user to procure electricity with the optimum price. The first article of Electricity Market Law in Turkey defines the aim of the law as creating a financially strong, stable, transparent and competitive electricity market in order to provide sufficient, continuous, low-cost and environment friendly electricity. The sufficiency and stableness of the electricity is directly linked with the security of supply, which is the main reason behind any capacity mechanism in electricity markets worldwide.
Capacity mechanism is the name given to any renumeration mechanism for power plants, in order to meet the future electricity demand and ensure security of supply. Within these mechanisms, participating power plant are being paid, not only for the electricity they generated, but also for being available to generate when requested by the system operator.
The reasons related to the necessity of capacity mechanisms have been detailed in this study under three main topics; economic, technical and political.
There are many methods when implementing a capacity mechanism, starting from capacity markets (where power plants bid for a pre-defined capacity requirement for a pre-defined period) and strategic reserves. The different methods for capacity mechanism implementation have been reviewed in this study. The associated risks in the market and their urgency level have also been brought together and the method which would satisfy the needs have been described. The review of capacity mechanism in European Union countries in this study has also provided more insight into the details of the implemented capacity mechanisms. When available, numeric details such as require capacity and payments made to power plants in the EU countries' capacity mechanism have been noted.
Turkey's installed capacity have grown very steadily over the last two decades. Although the electricity demand also increased, the growth in supply side have led to an over-supply situation, which inevitably led to low prices in the electricity market. When analysing the reasons to why Turkey needed a capacity mechanism, the peak demand and availablity ratios of power plants have been calculated. It has been noted that Turkey's peak demand has been shifted from winter months to summer, largely due to excessive use of cooling systems. The country's peak demand has now reached 47.062 MW in 2017. Between 2006 and 2016, the renewable power plants (including hydro, geothermal, wind and others) have contributed c.a. 34% to meet the peak demand, where the remaining 64% have been met by thermal power plants (lignite, imported coal, natural gas).
The reserve capacity of Turkey, calculated according to the installed capacity vs. peak demand have reached 67.9% in 2013 and have been c.a. 70.0% since then. The actual reserve capacity calculated according to the installed capacity sits at 69.7% in 2017. However, when defining the reserve capacity, a better approach to be used is using the available capacity numbers instead of installed capacities. When calculated according to the available capacity vs the peak demand, Turkey's reserve capacity is 13.6% in 2017. The reserve capacity ratio is indicating an over-supply in the market, since the expected reserve capacity would be in the range of 4-5%, according to a study by Royal Academy of Engineering. This figure might change from country to country and also according to the strategy of the transmission system operator. 
The downward trend in the electricity market prices in Turkey has a negative effect on the operating hours of natural gas power plants. The calculated number of hours, when market price is above the marginal cost of a CCPP (combined cycle power plant), for the year 2007 was c.a. 6.500, which is in the range of a targeted operating hours for a CCPP investment. However, the positive spark spread hours have dropped as low as 3.000 in 2015 and with a slight increase in 2017 (due to low generation from hydropower plants), have reached 5.274 hours.
Although Turkey is in a safe condition with respect to supply security, thanks to its reserve capacity, the drop in electricity market prices have led to concerns over some generators, who might not prefer to continue operations due to low income. The implemented capacity mechanism has aimed to keep these power plants in the system, in order to prevent any future problems.
Turkey's capacity mechanism is only applicable to a pre-qualified power plants, which can be summarized as:
•Local coal poewr plants above 50 MW installed capacity
•Natural gas power plants above 100 MW installed capacity and 50% efficiency threshold and below age of 10 (according to earliest commissioning date of any unit)
•Imported coal power plants which can generate electricity using local coal (below age of 10 according to earliest commissioning date of any unit)
The capacity mechanism has been set up in a way that is not effecting the electiricty market prices in the spot market (day-ahead market). The calculation method is a post-process based method. EMRA, the market regulator have defined three indexes for each fuel type: fixed cost component, variable cost component and anticipated utilization ratio. The capacity mechanism payments will be made according to the below defined rules:
(1)If market prices are below the variable cost component (Market Price < Variable Cost component)
the payment is calculated as
Capacity Payment = Fixed Cost Component * Anticipated Utilization Ratio
(2)If market prices are above the variable cost component, but below the total cost component (Variable Cost Component < Market Price < Total Cost Component)
the payment is calculated as
Capacity Payment = (Total Cost Component – Market Price) * Anticipated Utilization Ratio
(3)If market prices are above total cost component (Market Price > Total Cost Component)
there is no payment.
This study have aimed to forecast the capacity market income for power plants. In order to calculate the expected income, the hourly electricity market price forecast is required. The electricity market prices have been forecasted using the fundamental electricity market price forecast model AVIEW MarketSIM, developed by APLUS Enerji. The forecast period of this study is between 2018 and 2027, where all inputs to the price forecast study have been detailed, starting from demand forecast and commodity prices, as well as capacity growth forecast for renewable power plants. The special features of Turkish electricity market, such as bidding strategies of state owned companies EUAS and TETAS, have been taken into consideration when forecasting the hourly electricity market prices.
In addition to hourly electricity market prices, the forecasts for fixed cost and variable cost component indexes into the future are also required to forecast a capacity mechanism income for power plants. These indexes have been forecasted by using the USD/TL exchange rate, inflation and TEIAS system costs forecasts.
Once the hourly market prices and cost components are forecasted, another calculation tool has been studied on MS Excel format, in order to calculate the required capacity mechanism payments for each fuel type on an hourly basis. Since the number of power plants participating in the mechanism is known for year 2018 and possible entrants are defined, the duration of each power plant within the mechanism has been calculated with respected to given constraints in the regulation. 
The hourly calculated capacity mechanism payments have then been grouped according to fuel type, to calculate the total capacity mechanism payments for all power plants. Spefically, the capacity market income for selected reference power plants (600 MW imported coal power plant, 800 MW natural gas power plant and 600 MW local coal power plant) has been provided in the results sections.