Among the types of renewable energy, solar energy has received more attention due to its ability to be directly converted into electricity and heat, ease of use, possibility of storage, and its endless nature. Therefore, in recent decades, a lot of research has been done on solar energy systems in Iran and the world. Makran region, located in the southeast of Iran, has one of the greatest potentials of using solar energy among other regions of Iran. In this research, a one-megawatt power plant in Chabahar city, located in Sistan and Baluchistan province, on the southeast coast of Iran, has been modeled using RETScreen software and issues such as return on investment, internal rate of return (IRR), net present value (NPV) and carbon dioxide emissions. levels have been investigated. Finally, according to the considered conditions of the investment return period, according to the guaranteed purchase contract with a tender price of 73 dollars, the amount of carbon dioxide production in the region will be reduced for about 3 years and about 1009 tons per year.

This study presents a RETScreen based economic analysis of switching from grid electricity to solar photovoltaic (PV) system for a medium sized residential building located in Ado ekiti, Nigeria. The building has an existing 2kW solar PV system in place. Input parameters in RETScreen included the solar energy resources, cost and financial data. Two cases were evaluated using the maximum unit price of electricity for a forecasted 10-year period as the cost of grid purchase. The first case considered 24hr availability of electricity from the grid and results show that the PV system has an equity payback period of 9. 4 years with an internal rate of return (IRR) of 15. 3%. The second case took into consideration the epileptic nature of grid electricity in Nigeria. This condition increased the equity payback period to 16 years and 7% IRR. This shows that a solar PV is more economically rewarding in location with reliable grid electricity and relatively cheap cost of electricity.

Energy is one of the most critical factors in economic development, but achieving sustainable development is impossible without environmental protection and improving economic conditions. If a country is dependent on energy, any structural reform policies to reduce energy consumption may reduce economic growth. Saving energy consumption and the development and application of alternative technologies, especially renewable energy, has a significant role in controlling and reducing the consumption of fossil energy carriers and, consequently, reducing the emission of environmental pollutants and achieving sustainable development. This article deals with the feasibility of constructing renewable energy power plants in Khoy city. First, using RETSCREEN software, the economic and environmental conditions of the construction of renewable energy power plants in Khoy city are examined. Using PVSYST software, the requirements for constructing solar power plants are discussed in a specialized way. In this article, the inflation rate is 12%, and the interest rate is 4%. The construction of solar and geothermal power plants in this city can be prioritized based on the results. The solar power plant has a production capacity of 30 MW. 212194 meters of land, and a capital of 40 million dollars are needed to construct this solar power plant. The payback period of this project in Khoy city is estimated at 25 years.

Sustainable Development Goal 13 is an activity committed with the intention of stabilizing greenhouse gas (GHG) levels in the environment to stop potentially harmful human meddling with the climate system. GHG are released into the environment from various non-renewable energy sources of power generation and many industries that cause extensive damage to the environment. Some countries have begun to implement various pollution prevention strategies, such as power generation from renewable energy sources, which emit no greenhouse gases (GHG) or CO2. This study focuses on an analysis of GHG emission reduction along with the financial feasibility of a grid-connected 100MW PV solar system. This study uses RETScreen software to evaluate the GHG emissions reduction analysis as well as a financial analysis of the system. The annual electricity supplied to the local grid of the proposed PV power plant is 137,481MWh. The cost of reducing CO2 emissions has a positive impact on the overall cumulative cash flow of the proposed system.

According to energy economists, increasing efficiency and utilizing renewable energy sources, especially solar energy, is the most effective way to achieve sustainable development goals, provide economic benefits, increase energy security and reduce environmental pollution. In the present study, technical and economic evaluation of the role of investment in the construction of solar power plants (photovoltaics) on sustainable development of Boroujerd city was used using engineering economics method and economic analysis method and RETScreen software. The results show that the assumed photovoltaic power plant has an economic justification with an assumed megawatt period with a return on investment of 4. 3 years, an internal rate of return of 28. 1%, a net present value of 645. 24 billion rials and a profit-to-cost ratio of 9. 8. This power plant will produce 2197 MWh of electricity per year (about 0. 39% of the total electricity required by the city) and 257 similar power plants are needed to provide the total electricity consumption of Boroujerd city. With the construction of this power plant, the annual emission of greenhouse gases equal to 365. 2 barrels of crude oil has not been reduced. Also, this one-megawatt power plant saves 8. 5 billion rials per year in fossil fuel, water and greenhouse gas emissions. This amount is equal to 11. 7% of the initial construction costs of this power plant, which in addition to selling electricity generated, has positive social effects on society. With the approximate extension of this power plant to a power plant that provides the total consumption of Boroujerd city, 21955. 65 billion Rials will be saved in the above cases every year. It is proposed that the government and the Ministry of Energy support the existing solar potentials in the city by providing the necessary funds and facilities for the construction of solar power plants (photovoltaics) with a capacity of one megawatt. Also, by doing this, a lot of savings will be made in the consumption of fossil energy resources, water and greenhouse gas emissions, and the interests of future generations of sustainable energy conservation and development in this city will be realized.

Transmission of gas from extraction wells is a precondition for transferring this resource to consumers, which in turn requires a comprehensive system in production, transmission, and distribution. The transmission cost varies depending on the transmission distance, route difficulty, number of stations, and decrease or increase in pressure. Hence, concentrating on another energy resource with low investment requirements that could be delivered for consumption at the production area can lead to reduction in costs and time efficiency as well. The present study attempts to compare the combined solar wind power plants with the gas transmission, in terms of cost and revenue in Andica county, located in Khuzestan province, using simulation tools for renewable power plants. The findings suggest that combined power plants have significantly lower cost than gas transmission power lines in terms of investment requirements. The operation cost of gas transmission lines has a significantly higher price in relation to its ensuing revenue, since the operation costs of combined power plants are covered by annual revenue from the electricity supply. In general, it should be said that the high cost of capital for gas transmission, considering the annual income from its sale, refutes its economical profit, while the combined power plant, due to the lower cost of capital than gas transmission, produces more revenue than gas sales, so it is more economically justifiable than gas transmission.

Software architecture is known to be an e, ective tool with regards to improving software quality attributes. Many quality attributes such as maintainability are architecture dependent, and as such, using an appropriate architecture is essential in providing a sound foundation for the development of highly maintainable software systems. An e, ective way to produce a well-built architecture is to utilize standard architectural patterns. Although the use of a particular architectural pattern cannot have a preserving e, ect on software maintainability, the mere conformance of a system to any architecture cannot guarantee the system's high maintainability. The use of an inappropriate architecture can seriously undermine software maintainability at lower levels. In this article, the e, ect of standard architectural patterns on software maintainability quality attributes is investigated. We develop a quality model for maintainability quality attributes, which is later used to compare various standard architectural patterns. We , nish by investigating two real-world experiences regarding the application of a particular pattern to two di, erent existing architectures, exploring the e, ect of the change in architecture on maintainability quality attributes.

In some cases, software companies condition the sale of computer software on acquiring hardware components or integrate computer softWare with complementary software and hardware when designing products. Complementary software and hardware must be interoperable in terms of functionality. The specifi c nature of computer software causes network effects and mass production savings in software industry. The majority of software right abuse arises when the developer conditions licensing a software on the complementary software and hardware that makes it impossible to buy these products independently. Such condition in license agreements of computer software violates U. S antitrust laws provided that the developer has tied independent products and the seller has essential market power in the created products market. This condition has different competitive effects. In the Iranian law, the Act on the implementation of article 44 of the constitution which has stated the basic rules of competition, has not dealt with the issue perfectly and there are provisions in the Act on computer software developers and its by-law on interoperability. Given the absence of independent studies in this field, analysis of rules can lead to clarification of the subject.