Calculations for Tiny Watts Solar Sustainability

Utilize the Sun to Live a Sustainable Life!

The sun rises everyday and produces free power! Here are a few simple switches from using traditional powered appliances to utilizing the free energy from the sun. 

Lower your carbon footprint and blood pressure:

• Hanging your clothes on a clothesline rather than using an electric or gas dryer
• Drying your food from the sun rather than using an electric food dryer or oven
• Plant a garden to grow your own food
• Heat your shower water by the sun rather than from an electric or gas water heater

Hanging your clothes can save anywhere from 2,000 W-hr to 4,000 W-hr depending on the size of your load. To estimate watt-hours (W-hr) for hanging clothes to dry, the team did a simple calculation of the electrical energy avoided by drying outside. You could also use this simple calculator.

The team estimated 2,000 Watt-hour for a small load of laundry, 3,000 Watt-hour equivalent for a medium load of laundry, and 4,000 Watt-hour equivalent for a large load of laundry.

Drying your food from the sun rather than using an electric food dehydrator can save 464 Watt hour per pound of food dried, assuming a water content of 80%. 

It is assumed that drying grain takes 2000 BTU / lb. of water 

1 BTU / hr = 0.29 Watts (conversely, 1 Watt =3.14 BTU / hr)

therefore 0.29 W* 2000 BTU / lb = 580 W⋅hr to dry food that has 1 lb. of water.  

Most common types of food for drying are fruits and vegetables, which contain a lot of water. Melons can be 90% water, blueberries contain about 80% water. A banana has about 74% water. Zucchini, radish, and celery are 95% water, tomatoes are 94% water, broccoli is 91% water, carrots are 87% water, and green peas are 79%.

The Tiny Watts Team assumed 80% water content, so 580 W⋅hr / lb * 0.8 = 464 W⋅hr to dry a pound of fruits/vegetables.

Growing your own food is a great way to cut down on energy used in the transportation of goods. Gardening can be done in the ground or in smaller spaces using containers.  Home-grown food is often fresher and more nutritious than the store-bought alternative. Some may even find gardening to be a relaxing and satisfying activity. 

Learn more on agriculture emissions from our ZEN program. 

Heating your shower with the sun can save 2,000 Watt-hours per 10 minute shower. 

See the label of your water heater to know it’s maximum wattage (1200 Watts for example). Multiply that by your shower time in hours (10 mins= 1/6 hr) to get the electricity usage (1200*1/6=2000 Watt-hours or 2 kWh).

Learn more about our calculations for small scale solar!