# Energy Management of Virtual Power Plant Considering Distributed Generation Sizing and Pricing
## 6 Simulation Results and Discussion
### Reliability Effects  
In Table 12, the effect of increasing system reliability (\(ELF(t)\) or reliability index reduction) has been shown on the optimum size and cost of performing grid. \begin{table}
\begin{tabular}{c c c c} \hline Efficiency of DC/AC Converter (\%) & 70 & 90 & 100 \\ Number of Wind Turbines & 231 & 225 & 201 \\ Number of Photovoltaics Units & \(1671\) & \(1364\) & 201 \\ Number of Electrolyzers & 2314 & 2290 & 1561 \\ Number of Hydrogen Tanks & \(1741\) & \(1635\) & 1116 \\ Number of Fuel Cells & \(432\) & \(370\) & 310 \\ Number of Batteries & \(33\) & \(27\) & 21 \\ Incidental Costs (\$) & \(1.52\times 10^{4}\) & \(1.29\times 10^{4}\) & \(1.17\times 10^{4}\) \\ Transmission and Transformer Lines Cost (\$) & \(1.419\times 10^{6}\) & \(1.282\times 10^{6}\) & \(1.1001\times 10^{6}\) \\ Cost of Electricity Cut-Off (\$) & \(5.82\times 10^{5}\) & \(5.17\times 10^{5}\) & \(4.63\times 10^{5}\) \\ Electricity Revenue from Sales to the Upstream Network (\$) & \(8.828\times 10^{6}\) & \(9.472\times 10^{6}\) & \(1.012\times 10^{7}\) \\ Total Cost (\$) & \(1.9103\times 10^{7}\) & \(1.772\times 10^{7}\) & \(1.6117\times 10^{7}\) \\ \hline \end{tabular}
\end{table} 
Table 10: Effect of the DC/AC converter efficiency on the optimum size and cost. \begin{table}
\begin{tabular}{c c c c} \hline Electricity Sale Price to Upstream Network (\$) & 0.1 & 0.2 & 0.25 \\ Number of Wind Turbines & 225 & 183 & 132 \\ Number of Photovoltaics Units & 1364 & 2783 & 5132 \\ Number of Electrolyzers & 2290 & 3297 & 4519 \\ Number of Hydrogen Tanks & 1635 & 3542 & 4391 \\ Number of Fuel Cells & 370 & 430 & 541 \\ Number of Batteries & 27 & 53 & 64 \\ Incidental Costs (\$) & \(1.29\times 10^{4}\) & \(1.39\times 10^{4}\) & \(1.452\times 10^{4}\) \\ Transmission and Transformer Lines Cost (\$) & \(1.282\times 10^{6}\) & \(1.371\times 10^{6}\) & \(1.51\times 10^{6}\) \\ Cost of Electricity Cut-Off (\$) & \(5.17\times 10^{5}\) & \(5.87\times 10^{4}\) & \(5.98\times 10^{3}\) \\ Electricity Revenue from Sales to the Upstream Network (\$) & \(9.472\times 10^{6}\) & \(1.108\times 10^{7}\) & \(1.838\times 10^{7}\) \\ Total Cost (\$) & \(1.772\times 10^{7}\) & \(1.036\times 10^{7}\) & \(9.752\times 10^{6}\) \\ \hline \end{tabular}
\end{table} 
Table 11: Effect of the electricity sales price on the optimum size and cost. * Compared to the use of storage systems, combining different energy sources that have complementary production characteristics (such as wind and sun) are considered as a convenient and inexpensive way to improve system reliability. The proposed grid has such a structure to overcome the above problems. * Comparison of the results of determining the optimal capacity of the three hybrid systems suggests that using the battery as a storage device in a hybrid system instead of a fuel cell would increase system costs which increase the cost of the system by increasing the system's ability to track the load. * The results show that simultaneous use of fuel and fuel cells as a storage medium in the hybrid system, in addition to reducing costs, also increases the system's ability to track the load. In addition, considering the disruptive load model as a virtual power plant reduces costs. * The results of determining the size of resources distributed energy microgrid suggested that in view of the uncertainty in the power output of wind turbines increased costs (loss of income) of the system during its life, is that the increased cost (reduced revenue) is justified by increasing the level of reliability in the power output of wind turbines. * Ability to cut off removable loads in case of necessity increases the reliability of the system and (possibly) reduces the cost of the grid. M.M. ([PERSON]): writing and simulating original paper; A.N. : conceptualization, supervision, methodology and revising; R.G. : editing, data analyzing, funding acquisition; M.M. ([PERSON]): Revising the paper; E.M.G.R. : editing. [PERSON] would like to acknowledge financial support from Fundacao para a Ciencia e Tecnologia (UID/EMS/00667/2019).