اثرات طرح های انتشار تجارت در تصمیم گیری GENCOs تحت محیط چند جانبه

The implementation of Emission Trading Schemes (ETS) in the electricity supply industry has driven generation companies (GENCOs) to put efforts to reduce their produced emissions. Under a multimarket environment, a GENCO generates electricity subject to physical, fuel and environmental constraints. Separate and evolving research efforts are currently shaping electricity market, fuel market and carbon market without paying adequate attentions to how each market affects the others, though the markets have overlapping goals with respect to the global economic and environmental benefits. Under this background, this paper investigates the impacts of carbon policies on a GENCO's decision making under multimarket environment. A dynamic decision making model is proposed to deal with the multimarket trading problem for a GENCO during each trading period. Differential Evolution (DE) algorithm is employed to solve the multi-period optimization problem for each time interval. Comparisons between different scenarios demonstrate the economic and environmental influences of different policies on a GENCO. With the proposed model, a GENCO can make a rational tradeoff between profit making and emission reduction under the three interactive markets environment. Policies defining the three interactive markets can accurately reflect the intended goals such as reducing emissions, promoting renewable and keeping electricity cost at a reasonable level.

Electricity industry worldwide has been deregulated on the generation and retail sides; as such there are two major changes: (i) generation companies (GENCOs) are free to operate and compete in the market. (ii) GENCOs are subject to competition in the electricity market (EM). The model proposed in this paper builds upon the EM consisting of a power pool and bilateral trades [1]. The primary goals of EM are to provide energy securely, reliably and efficiently. While EM usually meets these goals, other valued outcomes, including conserving finite resources, maintaining stable and reasonable electricity cost, and protecting the environment, are at the stakes. To address these problems, policies such as Emissions Trading Scheme (ETS) have been adopted to mitigate emission by market-based mechanisms. Under this scheme, specified amounts of emission allowances are allocated to various industrial installations, including generators. A unit of allowance is the permission to emit one ton of CO2 within the emission commitment period {0, C}. In this study, the planning period is assumed to be within the emission commitment period (0 ≤ d0 ≤ D ≤ C). A GENCO's stock of allowances is composed of two parts: initial allowance (allocated freely) and purchased allowance (trade or auction from a carbon market). Generally, initial allowances are assigned to a GENCO annually through grandfathering, output-based allocation or an auction based method [1]. These allowances can be used either for producing corresponding amounts of CO2 or trading in Carbon Market (CM). If the total emission over the emission commitment period (which is the period within which a country/region must remain the national/regional emission level specified by its target) exceeds the allocated allowances, a GENCO has to either purchase allowances from a carbon market or pay a penalty. Reference [2] indicated that EM would be affected by emission trading scheme. Electricity prices would be affected by the scheme as GENCOs seek to pass their additional cost to consumers. Operational decisions of GENCOs on electricity production and related fuel portfolio would also be affected significantly. The deregulation of EM and the implementation of CM require each GENCO builds up its own fuel portfolio according to the prices variation in Fuel Market (FM). In the long run, GENCOs therefore have to contract their fuels in an optimal way that allows them to operate in the multimarket environment without incurring any negative profits. In the daily operation, GENCOs have to decide the usage of their fuel according to the production with consideration of different fuel prices taken into account. The problem addressed in this paper is that separate and evolving public policy debates are currently shaping EM, CM and FM without paying adequate attentions to how each market affects the others, yet GENCOs are subject to the influences from the three interactive markets. Without a better understanding of how a GENCO would react to these three markets, it is difficult to design policies which can achieve the environmental and economic societal goals. To address the value of different market mechanisms, this paper proposes a dynamic decision making model for GENCOs to deal with the multimarket trading problems in each trading interval. The rest of the paper is organized as follows: in Section 2, some important issues relating to the proposed model are explained, followed by the model formulation described in Section 3. Section 4 describes the solution of the proposed model. In Section 5, case studies are presented to compare the multimarket performances under different scenarios. Finally, Section 6 concludes the paper.

For the purpose of analyzing the impacts of carbon policies with interactive markets on the decision making of a GENCO, this paper proposes a novel decision making model under multi-market environment. It has two sequential processes. The first one is the production process which is solved by DE and the second one is the trading process involving three interactive markets. The model accounts for emissions trading mechanisms by incorporating emissions constraints as well as the trading of emission allowances. Thus, this model allows for analysis of how different market mechanisms affect a GENCO's behavior and its overall profits. A comparative analysis is carried out to reveal a GENCO's operation subject to different policy scenarios. From EM's point of view, a GENCO would reduce its production so that prices in EM are expected to be increased in the short term. Furthermore, a GENCO would consider investing in some renewable units with merit priority in production planning. From CM's viewpoint, a harsh cap of emission would lead to a significant bring down of carbon in a short period while GENCOs are expected to pass the cost to their customers. On the other hand, CM might bring about a moderate level of emission and the market mechanisms are expected to reveal the true value of carbon allowances. From the standpoint of FM, transaction of fuel is a good supplement for GENCOs to operate in EM and CM. In summary, the proposed model lets GENCOs to make a good tradeoff between profit-making and emission reduction under three interactive markets environment. Furthermore, policies defining the three interactive markets may lead to a better environment for the electricity industry to achieve the intended goals such as emission reduction, promoting renewable and keeping electricity cost at a reasonable level.