When designing solar systems in Enact, it is essential to accurately model total energy consumption, including both utility-supplied electricity and diesel genset (DG) usage. This comprehensive approach ensures that the solar system is designed to offset all sources of consumption effectively.

Methodology: Using Additional Meters

The key to modeling both diesel and utility consumption in Enact lies in the use of additional meters. Here’s how this can be achieved:

1. Base Meter for Utility Consumption

• The base meter is configured to capture all consumption sourced from the utility grid, either annual bill amount or monthly kWh units consumption
  

• Pick the right "Utility provider and rate" or use "Custom rate"

• This meter provides insights into how much power is drawn from the grid 
  
  

2. Additional Meters for Diesel Genset Consumption

• Additional meters are allocated specifically to monitor diesel genset consumption.

• These meters are set up to track power generation from the DG, helping to distinguish between grid and genset usage.

• Select "Custom" as the Utility Provider and add the "Rate/kWh"  and update the Annual amount spent or monthly kWh consumed 
  

• Here is how you can calculate the rate/kWh correctly
  

  Formula for Diesel Genset Cost per kWh:

  Cost per kWh=Fuel Consumption per hour (liters)×Fuel Cost per literEnergy Output per hour (kWh)\text{Cost per kWh} = \frac{\text{Fuel Consumption per hour (liters)} \times \text{Fuel Cost per liter}}{\text{Energy Output per hour (kWh)}}

  Step-by-Step Calculation:

  1. Determine Fuel Consumption (L/hr):

     • Check the diesel generator’s specification sheet for fuel consumption at a given load (e.g., 50%, 75%, or 100% load).

     • Example: A 100 kVA generator consumes 20 litres per hour at 75% load.

  2. Find the Energy Output (kWh):

     • Convert generator capacity (kVA) to kW:

       kW=kVA×Power Factor

     • Most diesel generators have a power factor of 0.8.

     • Example: A 100 kVA genset at 75% load produces:

       100×0.8×0.75=60 kW

  3. Get Fuel Cost per Liter ($/L):

     • Example: If diesel costs $1.20 per litre.

  4. Calculate the Cost per kWh:

     Cost per kWh=20×1.2060=2460=0.40 USD/kWh
     

3. Total Consumption Accounting

• The total energy consumption is determined by aggregating data from both the base meter (utility) and the additional meters (DG).

• Enact ensures that solar offset calculations account for both grid and diesel-supplied energy.