Molten magnesium chloride is prepared as a working fluid for a solar power tower process in a smelting tank operating at 1000 °C. Solid MgCl2 rocks are pre-heated to 714° C and fed into the tank at a rate of 0.5 metric tons/hr. At the top of the tank, the MgCl2 rocks are crushed into a powder using a grinder which requires 10 kW of electricity to operate. The tank, which is 2 m wide, rotates at 2 rpm in order to mix the material. An electrical heater is placed in the middle of the tank to provide the additional heat needed to melt the powder. Liquid MgCl2 is withdrawn from the tank at steady state operation. If the electric heater is 75% efficient at turning electricity into heat, what power output does the solar process need to produce in order to create positive net electricity? (Clearly state any assumptions you make)