This paper presents a method for economic evaluation and GHGs (greenhouse gases) emissions calculation from a GCRES (grid-connected renewable energy system). An investigation is made on large-scale operations of 67 MWh/day GCRES. A comparison is performed between a GCRES and a standard grid operation focusing on environmental and economic impacts. Emissions and the Renewable energy generation fraction (RF) of total energy consumption are calculated as the main environmental indicators. Costs including NPC (net present cost), COE (cost of energy) and payback period are calculated as the economic indicators. Using the hourly mean global solar irradiance, temperature and wind speed data relative to In Salah and Adrar locations characterized by an arid and hot climate according to the Koppen-Geiger climate classification, a long-term continuous implementation of hybrid renewable energy systems are simulated using HOMER software and are discussed. As results, it is observed that a GCRES reduce 30% and 35% of GHGs emission, and 81% and 76% of COE during the operation phase respectively for In Salah and Adrar. Investments in GCRES should be considered only by planning to produce parts of the equipment locally, which leads to significantly reduce the costs and, consequently, the emissions. (C) 2016 Elsevier Ltd. All rights reserved.