What is the monthly energy use of an off-grid installation with a 1HP pump operating 10% of the time and a 20W light operating 100% of the time?

To determine the monthly energy use of the off-grid installation, we need to calculate the energy consumed by both the pump and the light.

Starting with the pump: 1 HP (Horsepower) is equivalent to 745.7 watts. If the pump operates 10% of the time, that means it runs for 2.4 hours each day (10% of 24 hours).

Now, we can calculate the monthly energy consumption for the pump:

• Daily energy consumption of the pump = Power (in watts) × Hours of operation per day
• Daily energy = 745.7 W × 2.4 hours = 1,789.68 watt-hours (or 1.79 kWh).
• Monthly energy consumption = Daily energy × Number of days in a month
• Monthly consumption = 1.79 kWh/day × 30 days = 53.7 kWh.

Next, we calculate the energy consumption of the light:

• The light operates at 20W continuously for 24 hours a day.
• Daily energy consumption of the light = 20 W × 24 hours = 480 watt-hours (or 0.48 kWh).
• Monthly energy consumption of the light = 0