Security ... think about it!
The cost of putting a cable under water can be lower than burying cables on land, because workers can lay the cables from giant reels, allowing stretches of more than a mile with no splices. The strategy is limited, of course, by the availability of rivers and lakes — they do not go everywhere power developers would like to run new lines. In fact, many of the country’s rivers run north or south, whereas much of the country’s power must move east or west. And underwater lines are still more expensive than lines on transmission towers. Mr. Stern’s 65-mile cable cost about $600 million, and a 53-mile cable under San Francisco Bay cost about $505 million. Much of the cost in each case is to transform the electricity to direct current, a form that is easier to use in buried cables. Standard lines hung on towers run from $1 million to $4 million a mile, depending on terrain and other factors. If more underwater lines are built, the higher costs would have a small impact on electric bills.
