Sun-Etching is a novel method for etching metals. The process involves creating an electrolytic bath of water and lemon juice by utilizing the power of the Sun. Photovoltaic modules are used to electrolyze a body of water. Within that body of water are two pieces of metal. One piece is connected to the positive output of the solar module, or the anode and the other is connected to the negative output and is the cathode. This establishes electrolysis in the water. (Electrolysis is where the H2O is split into molecules of hydrogen and oxygen) With the addition of metals in the solution of water and lemon juice ionization occurs. To simplify the process one piece of metal gives up metal to the other therefore etching that piece. Most of the extremely small pieces of metal fall into the solution and some pieces bond to the opposite piece of metal. Sun-etching is unique to the art of Ed Eaton!
https://www.oursunsolar.com/sunetchings