2.5.1. Engine Power

The power generated by an engine connected to a single-phase alternating current (AC) generator can be calculated by the equation [33],

$$N\_b = \frac{\text{E.I.} \, pf}{746 \, \text{eg}} \tag{3}$$

where:

*Nb* = Engine Power (HP); *E* = Voltmeter Reader (Volt); *I* = Ampere meter Reader (Ampere); *pf* = Power factor for one single phase = 1; eg = Efficiency of electric generators for engines under 50 kVA = 87–89%, for generators using V belts, the power generated is divided by η*b* = 0.96.

### 2.5.2. Specific Fuel Consumption

The SFC is defined as the amount of fuel consumed by the engine to produce power denoted in kW/h. This SFC of an engine is usually measured by the mass of fuel consumed for the power output. The SFC can be calculated by the following equation [34]:

$$sfc = \frac{mf}{N\_b} \tag{4}$$

where:

*sfc* = Specific fuel consumption (kg/kWh); *mf* = Total fuel consumption (kg/hour); *Nb* = Engine power (HP).

#### 2.5.3. Thermal Efficiency

Thermal efficiency is defined as the heat-use efficiency of fuel to be converted into mechanical work. The thermal efficiency (ηth) can be calculated using the equation [34]:

$$\text{right} = \frac{N\_b \times 632.5}{\text{mf} \times \text{LHV}} \tag{5}$$

where:

ηth = Thermal efficiency (%); *Nb* = Engine Power (HP); mf = Fuel Consumption (kg/hour); LHV = Fuel Calorific Value (kcal/kg).

#### **3. Results and Discussion**
