مصطفی رجبی مشهدی

In this paper, using Thevenin’s theorem and also nonlinear Lambert W function, a novel two-diode model of photovoltaic cells is presented in mathematical explicit manner. In comparison with existing explicit models in the literature which are valid exclusively for n2=n1 and n2=2n1, this model includes a wide range of silicon-based cells with arbitrary diodes ideality factors. Acquiring regulating parameter (a) of the proposed model, its suitability to conform the real data is verified at standard test condition with maximum error of 10-5. Moreover, recreating the changes in weather condition, the proposed model performance is validated for irradiations between 50 up to 1100 Watt/m2. Finally, with series and parallel configuration of the PV cells and analytic derivation of maximum power point, the two-diode model for PV modules is simulated in SimPowerSystems of MATLAB software for research and engineering applications.

The most prominent characteristics of the electricity market in our country are thepay as bid to market winners. However, in most countries, a uniform payment method is used to clearing the market.In this paper, the effect of these two methods on the productivity and efficiency of the power industry in the manufacturing sector is compared. For a closer look, the model is designed for three hours of low load, normal load, peak, and yearly. For this purpose, with the use of the Q-Learning method, which is a subset of multy-agent models, Iran's electricity market model with all its features and limited to Khorasan power plants is simulated in two different ways and efficiency is compared in two scenarios. The results indicate that a uniform payment method leads to the use of higher power plants to supply electricity. Therefore, in this way, the cost of electricity is lower than the pay as bid method.

The most important property of the Iranian Electricity Market is the pay as bid method for the winning power plants. However, in many developed countrie's electricity markets, uniform payment method is used. In this paper, we compare the uniform payment method and pay as bid regarding price and cost price of electricity in the Iranian electricity market using a Q-learning model in three periods of low, normal and peak loads. Due to insufficient and in many cases, inaccessible data, this study is mainly concentrated on power plants located in Khorasan Province. According to the results, the price of electricity in the pay as bid method is lower than the uniform payment method. However, the cost of electricity in a uniform layment is less than the pay as bid method. In other words, in a uniform payment, power plants with higher efficiency win the bids resulting into lower fuel consumption and less greenhouse gase emissions

Zero-energy city, sustainable City and zero-carbon city are new terms in cities’ energy management. In this study, a framework of designing a Low-Carbon Eco-City (LCEC) in urban sector of Mashhad with focus on sustainable supply of electrical energy has been simulated. For this purpose, the maximum potential of biomass renewable electricity and expansion of photovoltaic capacity- required to cover remaining electricity demand in urban sector of Mashhad has been entered in Hybrid Power Generation System by using an analytical programming approach. The results indicated that biomass technology is superior technology for designing LCEC with less volatility and lower cost of production and it enters into the fossil-renewable hybrid production system with high penetration. Despite increasing capacity of photovoltaic technology up to 8GW, because of high investment cost problem, photovoltaic power generation cannot utilize in competition with the production of biomass technology. Hence it is suggested that biomass technology of sustainable development energy in the urban sector of Mashhad to be regarded as a city on the path LCEC. On the other hand, supportive policies should be adopted to reduce the cost of photovoltaic technology in order to provide the competitiveness of this technology in high capacities.

Background and With influx of sustainable and renewable energy with high penetration into the production system, Compressed Air Energy Storage (CAES) could be used for creation of an acceptable adequate and smooth Electricity production system. CAES plants operate on electricity markets by storing energy when electricity prices are low and producing electricity when prices are high. An essential condition for the profitability of the CAES in hybrid systems is appropriate strategy for CAES operation about the sale and purchase of energy. This study aimed to determine optimal operating strategy for CAES systems fluctuating-hourly electricity market with high penetration of renewable wind power.
In this study, with simulation of production system of Khorasan Regional Electricity Company power plants which among all, the theoretical optimal strategy provides the highest net income for the storage unit. But since the market price of the upcoming hourly-fluctuating market is not pre-determined, two prognostic and historical practical-operational strategies have used for Setting up compressed air energy storage system.
Findings: The results show that prognostic and historical practical-operational strategies, on average have 93% and 89% of theoretical optimal strategy s’ net income, respectively, in all six simulated capacities for compressed air energy storage system.
Discussion and Counclusion: Based on the results, it is necessary to use power storage in order to increase grid stability and reliability of production in hybrid systems with high renewable power penetration; because a Black-Start must be ready in grid for Possible Black-Out situations which could provide load of grid in the least possible time. Use a CAES could be a great way that not only guarantees reliability and stability of grid in emergencies, but also is economically feasible and have operational suitable profit.

Renewable energy is derived from the natural processes that are replenished constantly. In its various forms, it derives directly from the sun, or from the deep heat generated from the earth. It isdefined as the electricity and heat being generated from solar, wind, ocean, hydropower, biomass, geothermal resources, biofuels, and the obtained hydrogen from the renewable resources. The renewable energy resources exist over the wide geographical areas in contrast to other energy sources, which are concentrated in a limited number of countries. The rapid deployment of the renewable energy and energy efficiency result in the significant energy security, climate change mitigation, and the economic benefits. The results of a recent review of the literature concluded that as the greenhouse gas (GG) emitters begin to be held liable for the damages emerging from GHG emissions in which lead to the climate change, the liability mitigation value would increase to provide powerful the incentives for the deployment of renewable energy technologies. At the national level, at least 30 nations around the world have already renewable energy contributing to more than 20% of energy supply. The national renewable energy markets are projected to continue to grow strongly in the coming decade and beyond while some 120 countries have various policy targets for the longer-term shares of the renewable energy including the 20 percent of the targeted electricity generated from the European Union by 2020. Some countries have much higher long-term policy targets of up to 100 percent renewables. Outside Europe, a diverse group of 20 or more other countries have targeted the renewable energy shares in the 2020-2030 rangimg from 10 to 50 percent.
This study is an investigation of the climatic characteristics of the regions of Khorasan and the neighboring areas within the interior regions (Semnan, Sistan, Yazd, and Mazandaran) as well as the foreign regions (Turkmenistan and Afghanistan). Besides, it is probingthe technical-economic conditions of the renewable-fossil hybrid power generation along with the impact of the implementation of 2030 renewable energy outlook policies of Khorasan regional electricity hybrid production system as well.
Analytic programming was inspired by the numerical methods in Hilbert functional spaces and by GP. The principles of AP are somewhere between these two philosophies: The idea of the evolutionary creation of symbolic solutions arise from GP, whereas the general ideas of the functional spaces and the construction of the resulting function by means of a search process (usually done by the numerical methods such as Ritz or Galerkin method) are adopted from Hilbert spaces. Like GP or GE, AP is based on a set of functions, operators and so-called terminals, which are usually constants or independent variables. All these ‘mathematical’ objects create a set from which AP tries to synthesize an appropriate solution. The main principle of AP is based on Discrete Set Handling (DSH), proposed by Zelinka (2001). DSH can be seen as a universal interface between EA and the problem to be solved symbolically. That is, why AP can be carried out using almost any evolutionary algorithm. The set of the mathematical objects are functions, operators and so-called terminals (usually constants or independent variables). All these objects are mixed together consisting of functions with different number of arguments. Because of the variability of the content of this set, the article purposes of General Functional Set (GFS) is required. The structure of GFS is nested, for instance, it is created by the subsets of functions according to the number of their arguments. The content of GFS is dependent only on a user. Various functions and terminals can be mixed together. The subset structure presence in GFS is vitally important in AP. It is used to avoid the synthesis of the pathological programs, for instance, programs containing functions without arguments, etc. Performance of AP is, of course, improved if functions of GFS are expertly chosen based on the experiencies with the solved problem. The important part of the AP is the sequence of mathematical operations which are used for the program synthesis. These operations are used to categorize the individuals of the society into a suitable program. Mathematically saying, it is mapping the individual domain onto the program domain. This mapping consists of two main parts. The first part is called Discrete Set Handling (DSH) and the second one is the security procedures which do not allow for the pathological programs synthesis.
Simulation results show that the implementation of 2030 renewable energyies outlook policies will lead to 18.62 TWh optimal inter-regional and trans-regional exports which 2.32 TWh of this optimal export will be generated because of implementation of 2030 renewable energy outlook policies. This 14 percent increase in the inter-regional and trans-regional exports creates 5,000 jobs in Khorasan and increases the associated cost by 32 percent, but there would be little impact on the environmental emissions’ reduction. The related reason for this insignificant reduction in the environmental emissions is the low limited renewable power generation in the production system. Besides, thereason for the significant increase in the price is the high capital cost of the solar and wind production which needs strong financial support from the technical-engineering wind and the solar projects as they share the cost of production with the customers. The maximum potential production capacity in order to cope with the fluctuating nature of the renewable generation, is thebasic attempt for the development of the renewable electricity generation.
Most of the world's leading countries in the field of renewable energy have used Feed-in Tariff to create an affordable price for the renewable power generation systems. It achieves this by offering long-term contracts to renewable energy producers, typically, based on the cost of generation of each technology. In addition, feed-in tariffs often include tariff degression which is amechanism according to which the price (or tariff) ratchets down over time. This is done in order to track and encourage the technological cost reductions. Also, developing the required financial incentives and promoting the standards for connecting the renewable sources to the grid is called for. In addition, the rules regarding the sharing of costs with the common network can also provide the necessary legal and technical infrastructure to make the hybrid production system.

In the environmentally sensitive scenario we estimate the potential production of a hybrid wind-solar-fossil fuel system that uses 100 % of the wind and solar potential, while ensuring grid stability, in order to minimize environmental emissions. Maximising the use of renewable energies requires storage systems to deal with the fluctuating nature of such power production in order to ensure a reliable and stable grid. Our study finds that introducing the maximal extent of potential solar and wind power production, along with modification of Compressed Air Energy Storage (CAES) for gas turbines, reduces CO2 emissions by 4.28 million tons and increases the cost of production ten times over the current production structure of the Khorasan Ragional Electricity Co. It is thus clear that adoption of this environmentally optimal scenario requires substantial financial support of the government plus localization of renewable technology to reduce the cost of production. We also find that increasing the capacity of CAES from 50 to 100 MW produces the outcome with the highest reduction in prices, the lowest increase in environmental emissions and the highest rate of growth of net income. We thus find a CAES capacity of 100 MW to be the optimal starting point for moving towards an environmentally sensitive electricity production system.

One of the greatest challenges of renewable resources is unpredictable nature of these resources. Nevertheless use of fossil-renewable integrated hybrid system, which uses some renewable resources rather than a single source, for the supply of power, is the most affordable and the most reliable method. In this study by use of analytical programming approach and 2012 base year statistics, production system of Khorasan Regional Electricity CO. has been simulated and the maximum renewable electricity potential, entered into power generation system. Results show that among all of solar, wind, biomass, geothermal and hydro, only solar power have enough capacity and potential to be substituted with fossil power. The comprehensive system, which uses all renewable potential power capacity, causes 6.38 TWh reduction in fossil power, 4.28 million tons emission, 10-fold increase in spot-hourly price and 21% reduction in grid stability which shows necessity of using stabilizer and storage equipment in the hybrid integrated production system and Technical and financial support from the government to reduce the cost of solar equipment.

Frequency control, as an ancillary service, is usually provided by generation reserves. In modern generating units the ramp rate limit can be selected; e.g. their ramp rate can be selected to be either normal or fast. In this paper, the impact of selecting the fast ramp rate of generating units on electricity price and its volatility is investigated in simultaneous scheduling of energy and primary reserve. Simulation results show that using this capability of generating units, results in reduction of both the electricity price and its volatility. While, in minimum load condition, this capability may not necessarily be effective, it will be very essential for peak load condition. The effectiveness of this capability for medium load conditions depends on the load value and the units committed.