Westinghouse
was convinced that the
technology of alternating
current was the key to
the 
electrical 
future He founded the famous
Company named after him
and enlisted the services
of 
Nicola 
Tesla 
and
other inventors in the
development of alternating
current 
motors 
and
apparatus 
for 
the
transmission 
of 
high
tension current, pioneering
in large scale lighting not mean that the average power consumed is zero and
that there is no dissipation of electrical energy As you
know, Joule heating is given by i2R and depends on i2
(which is always positive whether i is positive or negative)
and not on i