# Investigation of Nanogrids for Improved Navy Installation Energy Resilience
## 4 Case Study
### Step 4: Calculate Resilience
#### 4.4.3 Step 4.3: Calculate Mission Impact Across All Threats  
Table 8 shows the resulting mission impacts (\(M_{s}\)).  
We use Equation (3) to calculate the EEDMI of the proposed nanogrid to compare resilience against the existing microgrid. Table 9 shows the resulting EEDMI for the existing microgrid and proposed nanogrid.  
\[EEDMI_{t}=EEDMI_{load1}+EEDMI_{load2}+EEDMI_{load3}+EEDMI_{load4}+EEDMI_{load5} \tag{3}\]  
Figure 7: Threat of Fire Operational Concept View. The large shaded red circle indicates area destroyed by fire. In the microgrid scenario (top), the fire destroys the warehouse and large office building (Critical Loads 4 and 5), and both diesel generators. In the nanogrid scenario, the same buildings and associated nanogrids are destroyed.  
Overall the simulation results show that nanogrids improve EEDMIscores for a threat of an explosion, an insider threat, and plane crash, where both nanogrids and the baseline microgrid see similar resilience for all remaining threats. It is important to note that because of appropriate DER scaling for both existing microgrid and proposed nanogrid infrastructures, the loss of all diesel generators, the loss of all PV generation, and a disruption in fuel delivery do not impact resilience. However, if diesel generators, and PV and ESS were not appropriately sized to provide redundant generating capacity, this would not be the case. Having redundant generation capacity is realistic because many military bases already have redundant generation capacity already installed-in some cases redundant generation capacity can be an order of magnitude higher than average base loads.  
\begin{table}
\begin{tabular}{l c c c c c c c} \hline \hline
**Mission Impact (\(M_{s}\))** & **Total** & **Total** & **Total** & **Total** & **Total** & **Total** & **Total** \\ \hline Internal & & & & & & & \\ \hline Loss of all Generators & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ Loss of all PV Arrays & 0 & 0 & 0 & 0 & 0 & 0 \\ Insider Threat & 0 & 0 & 6201 & 16,884 & 0 & **23,085** & 50,800 \\ \hline External & & & & & & & \\ \hline Fire & 0 & 0 & 0 & 28,224 & 29,904 & 58,128 & 58,128 \\ Explosion & 4704 & 0 & 17,808 & 0 & 0 & **22,512** & 30,589 \\ Fuel Delivery & & 0 & 0 & 0 & 0 & 0 & 0 \\ Disruption & & & & & & & \\ \hline Cyber-Attack & 4704 & 4704 & 17,808 & 10,080 & 29,904 & 67,200 & 67,200 \\ Severe Storm & 4704 & 4704 & 17,808 & 28,224 & 29,904 & 85,344 & 85,344 \\ Plane Crash & 4704 & 0 & 0 & 0 & 0 & **4704** & 85,344 \\ \hline \hline \end{tabular}
\end{table}
Table 8: Mission Impact Simulation Results. The Mission Impact (\(M_{s}\)) values for the nanogrid and microgrid architectures are shown for each threat. The bold values indicate the lower mission impact (less impactful, better) outcome. In all cases, the nanogrid either performs the same or better than the microgrid architecture.  
\begin{table}
\begin{tabular}{l c c c c c c} \hline \hline
**EEDMI** & **Total** & **Total** & **Total** & **Total** & **Total** & **Total** & **Total** \\ \hline Internal & & & & & & & \\ \hline Loss of all Generators & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ Loss of all PV Arrays & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ Insider Threat & & 0 & 0 & 620 & 1688 & 0 & **2309** & 5080 \\ Sabotage & & & & & & & \\ \hline External & & & & & & & \\ \hline Fire & 0 & 0 & 0 & 1411 & 1495 & 2906 & 2906 \\ Explosion & 188 & 0 & 712 & 0 & 0 & **900** & 1224 \\ Fuel Delivery Disruption & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\ Cyber-Attack & 470 & 470 & 1781 & 1008 & 2990 & 6720 & 6720 \\ Severe Storm & 94 & 94 & 356 & 564 & 598 & 1707 & 1707 \\ Plane Crash & 94 & 0 & 0 & 0 & 0 & **94** & 1707 \\ \hline Total EEDMI & & & & & & & 14,636 & 19,344 \\ \hline \hline \end{tabular}
\end{table}
Table 9: EEDMI Simulation Results. These values are resilience measurements for each threat scenario and are compared between the existing microgrid and the potential nanogrid configuration. Bold values indicate lower (preferred) outcomes.