How to Heat Water Using Solar Energy

Solar energy is energy given off in the form of light and heat. There are many ways to turn this into energy we can use, from the high- to low-tech. This is a very low-tech and cheap method of heating water while running it though a garden hose


  1. Image titled Cut the bottom of large plastic bottles Step 1
    Cut the bottom out of large plastic bottles, the wider the better.
  2. Image titled Thread bottles onto a hose Step 2
    Thread the bottles onto a hose. Try to get enough bottles to cover as much of the hose as possible.
  3. Image titled Lay the hose out in full sunlight Step 3
    Lay the hose out in full sunlight, run a little water through it to make sure there is water resting throughout the length of the hose.
  4. Image titled Wait about half an hour Step 4
    Wait about half an hour for the air in the bottles to heat up.
  5. Image titled Run the water through the hose Step 5
    Run the water through the hose slowly and it will come out warm.
  6. Image titled Heat water using solar energy Intro


  • The longer the hose, the warmer the water will be.
  • Using a dark colored hose or painting the hose black will help heat the water.
  • While driving lay plastic bottles filled with water on the dashboard and you'll have hot water at your next rest stop. You will be surprised how hot the water gets.
  • This can be used on a camping trip if you have access to mains water.
  • Laying the hose out on a white or light surface with help the water heat up.
  • If you are using the water for a long time, keep moving the hose into the sunlight.
  • This method can be used to fill a paddling pool, wash the dog or as a crude shower.
  • During an emergency power outage, or while camping, use your car as a solar heater. Park the car in the sun and close the windows. Put large soda bottles filled with water in an area of the interior that is hit by direct sunlight. This method can be used to heat up canned foods as well as make tea, instant coffee, etc.
  • Removing the labels helps the water heat up.
  • You don’t have to restrict yourself to laying out the hose on the ground only. Try tying it to a fence, or wall, anywhere that has full sun.
  • You can lay a hose out without the bottles if it’s warm enough, but the effectiveness will be greatly reduced.
  • The faster you run the water though the hose, the cooler it will be, and vice versa.


  • It is NOT advisable to use a dark hose in a solar application for "cooking", as dark colored hoses when heated will leach plastic and rubber toxins from the hose into the water. This application is best for washing and showering, not for digesting.
  • This will only work if there is sunshine.
  • The water will never get as hot as that from a boiler.
  • It can take a while to collect enough bottles so start before summer. Keep them in a box for next time.

Things You'll Need

  • Hose (preferably dark coloured and long)
  • Plastic bottles
  • Sunny area

Article Info

Categories: Solar Energy