# An Enhanced System Architecture for Optimized Demand Side Management in Smart Grid
## 4 Results and Discussion
### Aggregated and Total Energy Consumption Results  
This section is dedicated for discussion of aggregated energy consumption of five major modules used in four different cases of CHEMA. The section also includes a comparison of total energy consumption of the four cases. As discussed earlier, the five major modules include: space heating, refrigerator, water heater, lighting and burst load/scheduling module. Case one shows the operation of these modules without any scheduling or controlling technique except the use of regular load thermostats with predefined temperature settings. Aggregated energy consumption of five major modules for case one is shown in Figure 17. In Figure 17 and similar figures of following cases, modules 1 to 5 correspond to HVAC, \begin{table}
\begin{tabular}{c c c} \hline
**No.** & **Case** & **Total Cost (USD)** \\ \hline
1 & Unscheduled without PPC & 15.96 (1692.3 PKR) \\
2 & Unscheduled with PPC & 12.27 (1301.1 PKR) \\
3 & Scheduled with PPC & 12.14 ( 1286.3 PKR) \\
4 & Load Flexibility (UCI) & 11.86 (1257.1 PKR) \\ \hline \end{tabular}
\end{table} 
Table 2: Cost comparison of different cases. Figure 16: Refrigeration cost (Case 4). \begin{table}
\begin{tabular}{c c c c} \hline
**No.** & **Case** & **Total Load (KWh/day)** & **CO\({}_{2}\) Emission (Kg/day)** \\ \hline
1 & Unscheduled without PPC & 188.4860 & 126.2856 \\
2 & Unscheduled with PPC & 145.1734 & 97.0429 \\
3 & Scheduled with PPC & 144.8401 & 97.0429 \\
4 & Load Flexibility (UCI) & 140.2925 & 93.9960 \\ \hline \end{tabular}
\end{table} 
Table 3: Carbon emission reduction of different cases. refrigerator, water heater, lighting and burst load/scheduling modules, respectively. It is clearly seen that the highest consumption of energy is made by the space heating module (121.76 kWh) because of continuous usage and temperature limits. The minimum energy consumption corresponds to the lighting load, which is 1.92 kWh while total energy consumption for case one is calculated as 188.486 kWh. The second case of the CHEMA is unscheduled load with PPC controller, and the strategy of PPC consists of two parts: one is the control of lighting load according to the presence of persons at home, and the second is the control of regular loads according to the forecasted consumption of water demand. The forecasting is based on the EPRI model. The basic purpose of the EPRI model is to control the consumption of energy according to demand and save the wastage of energy on basis of forecasted demand. Loads with thermal storage capacity are ideal for DSM and application of the EPRI model on a regular load is helpful in saving total energy consumption and ultimately a reasonable reduction in energy cost. The EPRI model has been designed on the basis of data collected by eleven different companies. Parameters recorded during collection of data include latitude, air temperature, water temperature, _etc._ The model is based on strong statistical analysis, and it considers various categories of users along with the demographic and climatic factors. Initially, 16 variables were considered for the model, but, finally, the interdependent variables were dropped off and only 7 independent variables were included in the model. Results of the aggregated energy consumption of the second case are depicted in Figure 18.  
Figure 17: Aggregated energy consumption (case 1). Figure 18 reveals a reasonable reduction in consumption of the HVAC, water heater and lighting load which is 19.17 kWh, 23.08 kWh and 0.78 kWh, respectively. Second case corresponds to total energy consumption of 145.17 kWh. The third case of CHEMA includes scheduling of burst loads. The scheduling is based on the single Knapsack algorithm, which is inspired from an example of a thief with a sack in a shop to decide optimally the weights and values of the items constrained to the total capacity of the sack. Results of the third case are shown in Figure 19, and it can be seen that only a minor reduction in aggregated energy consumption and cost has been obtained.