An ink tank cartridge includes a housing having a chamber in which ink is stored. The cell has increased efficiency and longevity by combining operations of the photovoltaic and thermoelectric elements in at least three different modes of operation to increase electrical output per unit of panel area and to increase cell life, improve performance, and provide operational benefits under different environmental conditions. In pressing the powder under the aligning magnetic field, the press machine 10 minimizes the disturbance in the orientation of the powder.