Evaluation economic and reliability issues for an autonomous independent network of distributed energy resources

•Evaluation effects of micro grid on energy cost and reliability for consumers.•Long term and short term decision making about power generation.•Reliability consideration as function of seasons and loads amount.

Electrical energy can be supplied in different ways, but consumers want to do it with the highest quality, lowest cost and highest reliability. The purpose of this paper is evaluating the effect of creating a micro grid and using of distributed generation resources to reduce costs and increase the reliability of supplying energy. Economic issues and reliability are two dimensions of proposed objective function. Economical dimension consists of the initial costs and operational costs. Reliability dimension includes non-delivered energy (NDE) for the consumers. The two dimensional objective function is optimized by using weighting method. For this, four scenarios are compared to each other in case of economic and reliability issues. The four scenarios are providing energy by main grid, main grid and distributed generation resources, isolated micro grid and a micro grid connected to an upstream network. Each scenario is considered in two cases for evaluating reliability. First, the loads on one feeder and second is the loads on separated feeders.The proposed method is compared with a similar method and the comparison results show that it is more efficient and applicable.