# Watt is happening?

Understanding your electricity usage gives you the power!

[Warning: The author is in full pun mode today!]

We’ll look at some micro examples today and a macro approach
tomorrow.

This basic knowledge can

Save. You. Money!

First, we need to understand how we’re charged for electricity.

[The puns!]

We pay for electricity based on the number of kilowatt-hours
(kWh) we use.

An example:

Last week I set up 7 LED lights in the backyard.

The box said they were 5-Watt bulbs.

If I run them 12 hours a day, here’s the math:

7 bulbs x 5W each = 35W

In one hour they use 35 watt-hours of electricity.

Divide by 1000 to get the kWh.

35W/1000 = .035kWh

Multiply times 12 to get the daily usage:

12 x .035kWh = .42kWh

If I pay 15 cents per kWh, it costs 6.3 cents/day.

Light bulbs are great, because they tell us the wattage.

When it’s not straightforward, you can use a simple watt meter
like this one.

Plug in your device to the meter. Turn it on. And it will show
you the watts.

Divide that number by 1000 to get the kW.

Multiply times the hours of use to get your kWh.

What’s the point of all this nerdery?

Knowledge is power.

When you know how much electricity something requires

and know how to calculate the cost

that’s when the light bulb really comes on!