Register with GEF for FREE to enjoy these great benefits! 

    • member only contests and raffles

    • sustainability program news and updates

    • significant discounts at GEF Institute

Note: If you have problems registering, contact This email address is being protected from spambots. You need JavaScript enabled to view it.


Taking a GEF Institute Course? Login by clicking here.






Join Us

Sign Up for National Green Week!
Please note: Your privacy is very important to GEF. We do not share or sell any of your data.  It is with the sole purpose of providing you with relevant information that GEF will contact you.

Welcome to the Sustainability Lesson Clearinghouse

Here, you can find free sustainability lessons to use in your class and upload your own lessons to share. Be sure to rate the lessons you use and leave comments for your colleagues!

All of GEF's lessons and programs are offered at no cost.  Become a member to support GEF and enjoy member only benefits! 
Join button_03

Professional Development

GEFinstitute LOGO_WEB GEF Institute offers affordable, online sustainability courses eligible for professional development or academic credit.
Give your resume a boost!

Sponsor a Teacher

Support educators in your community by helping them earn a Certificate in Sustainability or take an online course. Find out more about sponsorship!
Sustainability Lesson Clearinghouse

Be “Sun-sible” About Heating Water

Lesson Description:
In this inquiry-based lesson, students will work in groups to build a solar water heater and will investigate which colors absorb more radiant heat and transmit it to the water, and study the relationship between insulation and heat loss. Teacher background, assessment questions, and extensions are provided. The expected out come in this activity is for students to understand how solar energy can reduce the hot water energy bill.
The student will do the following:
  • Construct a simple solar water heater.
  • Investigate color and heat. 
  • Investigate insulation and heat.

Lesson Type:
  • Group Work
  • Project

Sustainability Topic:
  • Energy
  • Water

GEF Program Category:
  • Sustainable Water Challenge
  • Green Energy Challenge

Time Needed:
120 minutes
Materials Needed:
  • Juice cans
  • Paint (white, black, green, red)
  • Very hot water
  • Food colors
  • Ice cubes
  • Thermometers
  • See attached sheet for complete list

School or Group:
Tennessee Valley Authority
Contact Email:
Lesson Documents:
application/pdf solar_water_heating.pdf

The Sustainability Lesson Clearinghouse is brought to you in partnership with

Center for Green Schools