There is no recycling of used solar energy in the industry! Since solar products have little recycling value, the cost of vacuum tubes is now very low and their recycling performance is poor, so no one will recycle them. Additionally, the inner tank of the water tank is made of stainless steel, but simply removing the water tank insulation is a thankless job. The value of the inner tank after removing the insulation is not enough for the labor cost!
So don’t think about recycling second-hand solar water heaters.