Optimal stochastic coordinated scheduling of proton exchange membrane fuel cell-combined heat and power, wind and photovoltaic units in micro grids considering hydrogen storage Mosayeb Bornapour, Rahmat-Allah Hooshmand ⇑ , Amin Khodabakhshian, Moein Parastegari Department of Electrical Engineering, University of Isfahan, Isfahan, Iran highlights  Stochastic model is proposed for coordinated scheduling of renewable energy sources.  The effect of combined heat and power is considered.  Hydrogen storage is considered for fuel cells.  Maximizing profits of micro grid is considered as objective function.  Considering the uncertainties of problem lead to profit increasing. article info Article history: Received 19 November 2016 Received in revised form 17 April 2017 Accepted 18 May 2017 Keywords: Micro grid Optimal coordinated scheduling Deregulated electricity market Renewable energy sources Proton exchange membrane fuel cell- combined heat and power Hydrogen storage strategy abstract Nowadays, renewable energy sources and combined heat and power units are extremely used in micro grids, so it is necessary to schedule these units to improve the performance of the system. In this regard, a stochastic model is proposed in this paper to schedule proton exchange membrane fuel cell-combined heat and power, wind turbines, and photovoltaic units coordinately in a micro grid while considering hydrogen storage. Hydrogen storage strategy is considered for the operation of proton exchange mem- brane fuel cell-combined heat and power units. To consider stochastic generation of renewable energy source units in this paper, a scenario-based method is used. In this method, the uncertainties of electrical market price, the wind speed, and solar irradiance are considered. This stochastic scheduling problem is a mixed integer- nonlinear programming which considers the proposed objective function and variables of coordinated scheduling of PEMFC-CHP, wind turbines and photovoltaic units. It also considers hydrogen storage strategy and converts it to a mixed integer nonlinear problem. In this study a modified firefly algorithm is used to solve the problem. This method is examined on modified 33-bus distributed network as a MG for its performance. Ó 2017 Elsevier Ltd. All rights reserved. 1. Introduction Fossil fuel power plants are the main source of electricity pro- duction due to their high reliability and capacity, yet they come up with very high investment cost and environmental issues in which small capitals are required towards Renewable Energy Sources (RESs) at small scales [1]. Moreover, a new season has begun for power generation at high efficiency in power systems by the initiation of innovation in RESs and Distributed Generation (DG) sources. As a consequence, different RESs and DGs are used in small scales in Micro Grids (MGs). These MGs consist of distribu- tion networks with RESs such as Wind Turbine (WT); Proton Exchange Membrane Fuel Cell-Combined Heat and Power (PEMFC-CHP); Photovoltaic (PV) or other cases; and flexible loads [2,3]. MGs can be administered in two modes: non-autonomous mode when connected to the main grid and autonomous mode when not connected to the main grid [4]. While DGs are scheduled and coordinated properly, their operation in the network enjoys different advantages for the performance of the entire network [4]. The optimal operation in deregulated markets is one of the noticeable results of MGs which is by characterization the best amount of generation of all units to produce the maximum benefit. It is necessary to note that nowadays the operation of DGs based http://dx.doi.org/10.1016/j.apenergy.2017.05.133 0306-2619/Ó 2017 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail addresses: mbornapour@eng.ui.ac.ir (M. Bornapour), hooshmand_r@eng. ui.ac.ir (R.-A. Hooshmand), aminkh@eng.ui.ac.ir (A. Khodabakhshian), parastegari@ eng.ui.ac.ir (M. Parastegari). Applied Energy 202 (2017) 308–322 Contents lists available at ScienceDirect Applied Energy journal homepage: www.elsevier.com/locate/apenergy