The deal of a lifetime …
Here’s a question that more of us should know the answer. How much water can you get for $1?
With a submersible water system, it’s easy to figure out. We just need to know 3 things:
- The GPM delivered by the pump
- The power consumption of the motor turning that pump
- The price of electricity.
For our example, we’ll use the most common unit in the United States, a ½ horsepower, 10 GPM pump. We can ignore whether its 2- or 3-wire, since the power consumption is identical for both units.
From page 13 of the Franklin Electic AIM Manual, the power consumption of a ½ hp motor is 0.96 kilowatts. But, we pay for electricity in terms of kilowatt-hours. That is, the number of kilowatts used multiplied by the number of hours we used those kilowatts. So, if we run that ½ pump for 1 hour, we’ll consume 0.96 kilowatt-hours (0.96 kilowatts x 1 hour).
According to the latest figures from the US Department of Energy, the average retail price of electricity in the US is 9.7 cents per kilowatt-hour. For the sake of keeping the math simple, we’ll just round that to 10 cents.
So, putting it all together, if we run that pump for 1 hour, we’ll pay:
0.96 kilowatt-hours x 10 cents = 9.6 cents
To get to $1, we would need run the pump about 10.4 hours, or 624 minutes (10.4 hours x 60 minutes in an hour). With our 10 GPM pump, that would mean 6,240 gallons for a dollar.
So, for $1, we provided over 6000 gallons of water. A pretty good deal, huh?