## 4 Results and Discussion
### Economic Aspects of Energy Saving  
The cost of electricity and fuel is computed based on the Tenaga National Berhad (TNB) electricity tariff [60] for a private dwelling as shown in Table 6 and by the Gas Malaysia 2020 fuel tariff rate of RM23.72/MMBtu or 8.094 sen (US 1.955 cent) per kW\(\cdot\)h for residential buildings [61]. The TNB's domestic tariff is highly subsidized by the Malaysian government at around 50% for the first 300 kW\(\cdot\)h per month of usage. The actual amount of cost savings would be much higher without the subsidy. The electricity tariff in Makkah is SAR0.18 (4.80 US cents) per kW\(\cdot\)h for the first 6000 kW\(\cdot\)h (SEC, 2019) [62] and the natural gas fuel rate is at SAR2.81 (USD0.75) per MBtu or SAR0.009588 (USD0.00255) kW\({}^{-1}\cdot\)h\({}^{-1}\) for residential buildings [63]. The electricity tariff in Istanbul is 12.67 euro cents (US14.19 cents) per kW\(\cdot\)h [64] with a natural gas fuel rate of 2.16 euro cents (US2.42 cents) per kW\(\cdot\)h for residential buildings [65]. The electricity tariff in Lillhardal is 20.15 euro cents (US22.57 cents) per kW\(\cdot\)h [66] with a natural gas fuel rate of 11.25 euro cents (US12.60 cents) per kW\(\cdot\)h for residential buildings [67]. Table 7 illustrates the energy cost per month for each unit and the relative cost savings between fibre-reinforced LWAC and NWC with its associated orientation using the respective country's utility rates. The increase in energy cost per month per unit in NWC is higher at USD5.41, USD2.84, USD3.04 and USD2.05 for Putrajaya, Makkah, Istanbul and Lillhardal, respectively, when the building is at a 0\({}^{\circ}\) to 90\({}^{\circ}\) orientation. In Putrajaya, the building at a 90\({}^{\circ}\) orientation had the highest solar heat gain and HST0.75 + PP0.1 had the highest energy cost savings of 4.04% compared with NWC. The order of energy cost savings based on the best of each fibre category from high to low is HST0.75 + PP0.1 \(>\) PP0.3 \(>\) ST1.0 + PP0.2 \(>\) ST0.25. \begin{table}
\begin{tabular}{l l l} \hline \hline
**Tariff Category** & **Unit** & **Current Rate** \\ \hline
**Tariff A—Domestic Tariff** & & \\ \hline For the first 200 kW\(\cdot\)h (1–200 kW\(\cdot\)h) per month & sen (US cent)\(\cdot\)kW\({}^{-1}\cdot\)h\({}^{-1}\) & 21.8 sen (US 5.27 cent) \\ For the next 100 kW\(\cdot\)h (201–300 kW\(\cdot\)h) per month & sen (US cent) kW\({}^{-1}\cdot\)h\({}^{-1}\) & 33.4 sen (US 8.07 cent) \\ For the next 300 kW\(\cdot\)h (301–600 kW\(\cdot\)h) per month & sen (US cent) kW\({}^{-1}\cdot\)h\({}^{-1}\) & 51.6 sen (US 12.47 cent) \\ For the next 300 kW\(\cdot\)h (601–900 kW\(\cdot\)h) per month & sen (US cent) kW\({}^{-1}\cdot\)h\({}^{-1}\) & 54.6 sen (US 13.19 cent) \\ For the next kW\(\cdot\)h (901 kW\(\cdot\)h onwards) per month & sen (US cent) kW\({}^{-1}\cdot\)h\({}^{-1}\) & 57.1 sen (US 13.79 cent) \\ The minimum monthly charge is RM3.00 (USD0.725) & & \\ \hline \hline \end{tabular}  
* Average exchange rate RM1.00 = US 24.157 cent for the year 2019.  
\end{table} 
Table 6: TNB Domestic Electricity Tariff Rates [60]. In Makkah with the building at a 90\({}^{\circ}\) orientation, HST0.75 + PP0.3 had the highest energy cost savings at 6.46% compared with NWC. The order of energy cost savings from high to low is HST0.75 + PP0.3 \(>\) PP0.2 \(>\) ST1.0 + PP0.2 \(>\) ST0.25. In Istanbul with the building at a 90\({}^{\circ}\) orientation, HST0.75 + PP0.3 had the highest energy cost savings at 5.09% compared with NWC. The order of energy cost savings from high to low is HST0.75 + PP0.3 \(>\) PP0.3 \(>\) ST1.0 + PP0.2 \(>\) ST0.25. In Lillhardal with the building at 90\({}^{\circ}\) orientation, HST0.75 + PP0.3 had the highest energy cost savings at 12.29% compared with NWC. The order of energy cost savings from high to low is PP0.3 \(>\) HST0.75 + PP0.3 \(>\) ST0.25 \(>\) ST1.0 + PP0.2. The effect of energy cost saving using PP0.3 fibre-reinforced LECA-LWAC is more significant in the sub-arctic region of Lillhardal.