Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net> Check out the Analog Devices ADE7753.. a single chip unit that measures active and reactive power, has a serial interface, can integrate the current (i.e. can use a Rogowski coil), etc. http://www.analog-dot-com/