kilowatt hours measures electricity, E-Cat produces heat.Actually, Watt is a unit of power, regardless of the source of that power.
No, KWh is a measure of energy period, electricity is just one form of that energy. Heat energy can also be expressed as KWh. Where do you think the electrical energy of a 100W incandescent bulb goes? After an hour, it has heated the room by 1KWh expressed as the temperature rise times the volume of the particular material.
A "watt" is a unit of work per unit time, like "horsepower." 745.7 watts = 1 horsepower.a watt-hour is a unit of energy, or work. Energy as work can be very readily converted into energy as heat, for example by use of a brake. Converting energy as heat into energy as work, OTOH, is more difficult. That requires an engine such as a steam engine - and the laws of thermodynamics explain some of the inefficiency in that conversion. Electric energy is work energy because it requires work to turn a generator to produce electric energy, and in principle you can make an electric motor with zero loss using superconductors.