Every storage tank has an efficiency rating. The efficiency rating refers to the fact that energy is partly stored in the storage tank but also partly released as heat. This heat energy can often no longer be used. picea stores the energy as hydrogen. The hydrogen is produced by the electrolyser and fills the storage tank. The electrolyser has a 70% efficiency. When energy from the storage tank is needed, the fuel cell comes into play and converts the hydrogen into electricity and heat. The fuel cell has a 50-60% efficiency. picea is installed in the house where electricity and heat are needed. When electricity and heat are produced in the conventional way, this produces CO2, which pollutes our environment. picea, on the other hand, uses only CO2-free solar energy and supplies both forms of energy – electricity and heat. picea is therefore highly efficient and achieves almost 90% efficiency. This makes picea one of the best energy systems available on the market today.