### The details of your contribution

So now you know that your purchase provides three watts of sustainable power, but what does that mean?

A watt is a unit of power used to describe the capacity of an object. Think of it like a horsepower, which is another way to rate the power capacity. Watts work the same way. The higher the wattage capacity, the more energy the device needs. For example, a 60-watt lightbulb is going to need a lot more electricity than a three-watt lightbulb, just like a 300 horsepower car is going to go a lot faster than a 60 horsepower car.

The second piece of the puzzle is the time of use. Going back to the vehicle analogy, horsepower is how strong the vehicle is, and the fuel consumption is dictated by how long the vehicle runs for. A vehicle with a higher horsepower rating will use more fuel over time than one with a lower rating. This is the exact same in electricity, where your liters of fuel consumed are called watt-hours. A watt-hour is found by taking the rating of the equipment (in watts) and multiplying by the number of hours it is "on". So a three-watt bulb that is on for 10 hours uses 30 watthours of power. A 60-watt bulb used for the same amount of time uses 600 watt-hours. These are the units you will find on your power bill and are the way electricity usage is measured.

Now, how does this all relate back to your contribution?

Our mission is to create 3 watts of sustainable power capacity. So your direct contribution is 3 watts of capacity. And that 3 watts will create electricity for as long as it is active. In the case of solar, panels are at peak generation approximately 5 hours a day. So every day your contribution is 15 watt-hours. But it doesn't stop there, it keeps generating for as long as the panel is active, which is usually around 25-30 years. That means that your 3-watt contribution will continue to generate 15 watt-hours of power every day for decades, providing a lasting impact. That's a total of 136,875 watt-hours of electricity just from purchasing one shirt.

Using this information is how we approximated how much your purchase can offset from the ABOUT page. A typical fluorescent lightbulb has a rating of 20 watts. The total lifetime power generation of your contribution is 136 thousand watthours, meaning that it can offset the lightbulb being on for 6500 hours.

The same method is used for approximating loads of laundry - washing machines are rated between 400 and 1300 watts, so a conservative estimate of 850 watts used for 45 minutes uses approximately 637 watthours of power. This means 212 loads can be done with the electricity offset from one shirt.

As appliances become more efficient and have a lower power rating your shirt will go even further! For example if we estimate the amount of laundry offset when using the most efficient washer (400 watts) that only runs for 30 minutes, one shirt offsets 680 loads!

Now, this is where the beauty of strength in numbers is obvious. The more shirts sold, the more power we can install. With just 7 shirts, we can offset the one-month power usage of a house. On a larger scale, with 3000 sales we can offset a house's lifetime power usage and make it completely self-sustainable.