How much Electricity costs, and how they charge you.
Here's how you can check if you have plan to buy/install a pump-motor to your pond.

What the heck is a kilowatt hour?
Before we see how much electricity costs, we have to understand how it's measured. When you buy gas they charge you by the gallon.
When you buy electricity they charge you by the kilowatt-hour (kWh).
When you use 1000 watts for 1 hour, that's a kilowatt-hour.

When the number is low we sometimes use watt-hours (Wh) instead of kWh. For example, we might say 240 watt-hours instead of 0.24 kWh.

Watts and watt-hours
Watts is the measure of the rate of electrical use at any moment. For example, a laptop computer uses about 50 watts.
If your device lists amps instead of watts, then just multiply the amps times the voltage to get the watts.
For example:
2.5 amps x 240 volts = 600 watts

Understand the difference between watts and watt-hours
* Watts is the rate of use at this instant.
* Watt-hours is the total energy used over time.

To measure use over a period of time, we use watt-hours, not watts. The way it works is, watts or kilowatts for the amount at a given instant, and watt-hours or kilowatt-hours for the amount over a period of time.

How much does electricity cost?
The cost of electricity depends on where you live, how much you use, and possibly when you use it. There are also fixed charges that you pay every month no matter how much electricity you use. For example, I pay $6/mo. for the privilege of being a customer of the electric company, no matter how much energy I use.
Check your utility bill for the rates in your area. If it's not on your bill then look it up on the utility's website. The electric company measures how much electricity you use in kilowatt-hours, abbreviated kWh. Energy cost can be determined by knowing the amperage of an equipment, which is always listed, Volts x Amps = Watts.
The formula for kWh is Watts multiplied by hours used and then divided by 1000. For instance, a 800-watt water pump used for 10 hours would use 8.0 kWh. At 0.22 cent per kWh it cost $1.76

Maximum Demand
What is Maximum Demand?
Maximum Demand is calculated and billed by a kW demand meter, which records the highest kW value consumed in one 15 minute period, over a monthly billing cycle.
Demand Charges
Some utility companies also impose an additional charge based on the maximum amount of electricity you draw at any one time. This is called a demand charge. The following chart illustrates the concept. The shaded area is how much electricity you used, and you know you get charged for that. But the black bar on top is the demand, how much energy you "demanded" at any given point throughout the day. If your utility company has a demand charge (ask them), then you can save money by spreading out your electrical use throughout the day. Running appliances/equipments one after the other rather than at the same time would reduce your demand. And better yet, running them when you're not using much electricity for other purposes will reduce your demand even more.




Cheaper in the evenings
Some utilities have cheaper rates in the evenings. (Check with them to find out.) That's because it's harder for them to reach peak demand during the day when everyone's running a load. So they might charge less in the evenings to try to get you to move some of your consumption outside of those daytime hours. And even if your utility doesn't have cheaper rates at night, if your utility has a demand charge (see above), it could still pay to shift your extra demand to the evenings, because running two big motors at the same time results in a higher demand.