# Assessment of Energy Use and Photovoltaic Energy Potential in Saudi Arabian Governmental Schools
## 4 Results and Discussions
### PV Systems Analysis
#### 4.3.1 Zero-Energy Balance Scenario  
Table 5 shows the technical and economic information for the three systems in the case of the required load in the first year. It is noted from the values that the available surface is sufficient to install the PV system to secure the required load and that the roof occupancy rate was 33% (school 1), 48% (school 2), and 77% (school 3). The nominal PV system capacity for schools was 63.8, 205.7, and 122.1 kW, respectively. As shown in the economic indicators, these resulted in an SPBP of about seven and a half years if the undiscounted condition was considered and less than 12 years if the discounted condition was considered. An LCOE ranging between 0.0229 and $0.0252 per kWh was obtained. As a result of comparing the current results with the results presented in Table 1, it can be found that the output values are often slightly higher in terms of SPBP and close to LCOE. The difference may be due to the price of the energy unit when determining these indicators: weather conditions, the system's cost, capacity, lifespan, and economic conditions such as loans, etc. The capacity factor is more than 22%, whereas the school's yearly yield is between 1950 and 1994 kWh/kW\({}_{\rm P}\). The three PV systems have a PR between  
\begin{table}
\begin{tabular}{l c c c c c c} \hline \hline  & **CDD (\({}^{\circ}\)C-Day)** & **HDD** & **AC (\%)** & **Light** (\%)** & **Other** (\%)** & **Reference—Date** \\ \hline School buildings in & 1972 & 588 & 80 & 11 & 9 & Present case \\ \hline School buildings in & 2419 & 390 & 71 & 9 & 20 & Alfaraidy and \\ Arar City, KSA & 2419 & 390 & 71 & 9 & 20 & Sulierman [4]—2019 \\ \hline Supervision Building, & 2391 & 44 & 72 & 10 & 18 & Bettayeb [46]—2019 \\ \hline Sulaiman Al-Rajhi University in & 1972 & 588 & 79 & 7 & 14 & Alfaroyzan and \\ Qassim, KSA & 1972 & 588 & 79 & 7 & 14 & Almasri [37]—2023 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Summary of the electricity usage.  
86.81 and 88.84%. These generally reasonable indicators encourage the usage of these three PV systems. The systems under investigation have similar performance indicators because they all use the same PV module and have the same meteorological data. They have different energy demands, which impact the size of the PV system but have no bearing on any of the performance indicators. These results are consistent with those published under the same climatic conditions as [PERSON] and [PERSON] [28], [PERSON] et al. [31], and [PERSON] and [PERSON] [32].  
Figure 3 demonstrates the electric energy produced by the PV system, taking into account the influence of the degradation coefficient on the output energy over the life of the PV system, the increase in temperature, and the required load, assuming an increase in the load at an average rate of 1% per year. Figure 3 shows that the three PV systems can achieve nearly zero-energy buildings for the required loads in the last year of the application's life, while the system produces more annual energy than the load in previous years. Excess electric energy produced decreases as the system ages.