timO' wrote:
I am getting ready to pull an 220V/80A branch circuit to my new inside
heat pump. I am upgrading my 100A service to 200A locating the new
meter right next to the old one; and putting a new 200A load center,
then two branches; one to the existing 100A breaker box and another
branch circuit off the new 200A load center to the heat pump.

THE QUESTION IS:
I was advised to run a solid copper ground to my hot water heater, but
my water heater connects to everything with plastic pipe. I don't see
the point of running the wire to it.

I will be grounding the new meter; new load center, and existing load
centers to two existing ground electrodes right near the existing
meter. Since I already bought the 50' of #4 solid for the water heater
ground; I'll use that wire for this purpose
comments?

It might help to think as follows: The purpose of a "ground" connection to
the water system is not to protect you from the electrical distribution
network, it is to protect you from the water system. In other words, you are
grounding the pipes, not the wires.