The choice between underground or underwater depends upon local geography. Underground is cheaper if the land can be disturbed temporarily without high cost, such as across farm or ranch lands; underwater is cheaper if not.

The technology for both is quite old. DC is quite expensive for low voltages and because of the high cost of converting DC to AC. It’s good for high voltage transmission over long distances. An example is the DC line from hydropower resources in the northwest to southern California.

Wind power from large wind farms in the Plains states or in west Texas are likely to use DC lines buried underground. The problem now is the expense and, because of the high voltage requirement, the necessity for investing in something like 1000 huge wind towers all at once along with the DC line; “gradually” adding 100 at a time won’t do. The expense for both is above $2B.

The choice between underground or underwater depends upon local geography. Underground is cheaper if the land can be disturbed temporarily without high cost, such as across farm or ranch lands; underwater is cheaper if not.

The technology for both is quite old. DC is quite expensive for low voltages and because of the high cost of converting DC to AC. It’s good for high voltage transmission over long distances. An example is the DC line from hydropower resources in the northwest to southern California.

Wind power from large wind farms in the Plains states or in west Texas are likely to use DC lines buried underground. The problem now is the expense and, because of the high voltage requirement, the necessity for investing in something like 1000 huge wind towers all at once along with the DC line; “gradually” adding 100 at a time won’t do. The expense for both is above $2B.