a box of 10 triple-insulated high-performance Clean Republic solar vacuum tubes, also known as Solar Evacuated Tubes. These high-quality solar tubes can boil water using only the power of the sun! They are great for hobby projects, and for building solar air and water heating systems. We have excellent customer service and a 100% shipping protection guarantee (make sure any other tube suppliers you're considering offer this type of guarantee because these tubes are fragile). These tubes soak up the energy in sunlight, absorbing it into the super-insulated inner tube of their incredible double-wall heating system. Once inside, the heat of the sunlight is trapped inside the inner wall of the inner glass tube. Highly-reflective layers of steel, aluminum, and copper trap the infra-red energy of the sunlight, and the nearly perfect vacuum between the inner wall and the outer transparent wall protect the inner tube from heat loss due to convection, just light a high-grade drink thermos. This thermos effect can quickly heat water to boiling temperatures in direct sunlight, and keep the water well over 100 degrees even over night!
Heats one appx. 1 liter water per hour (depends on geographical and weather factors)
90%+ energy conversion efficiency.
100% shipping safety guarantee.
20 1/2" long, 2 1/4" outside diameter, 1 3/4" inside diameter, Double wall structure with vacuum between walls
More details see http://www.electric-bike-kit.com/solar-tubes.aspx