Describe a beamed power solution. ( Digest Number 135)

Browsing the eia.doe.gov led me to home in on the situation surrounding "Path 15".

Currently the biggest choke point for the California grid is "Path 15",
a 90 mile ( 144 km ) stretch between Gates and Los Banos,
linking northern and southern California.

Then I found an article from the LA Times which has some interesting data points.

http://www.latimes.com/business/reports/power/lat_lines010131.htm

IT says that to add a third power line at Path 15 would cost $200 million.

Then, according to:

http://www.caiso.com/docs/2001/05/11/2001051110134222663.pdf

the Path-15 upgrade will increase capacity by 5 GW

I am not sure that the $200 million applies directly to the 5 GW upgrade,
I have no found a source which contains both numbers together.

But assuming they do,then we can derive a per kilometre capital cost as follows:-

$200M / ( 144km * 5GW ) => $278,000 per ( Gw.km)

Hence, to build a line for 5 GW over 720 km would cost $ 1 billion

A proper business evluation needs to figure a life cycle cost, which
would have to include operations costs (space versus terrestrial) as
well as the extra R&D cost for microwave transmission.

An interesting quote:-

" Expansion has been discouraged in part because...[snip]...
electricity is an interstate commodity, grid operations are
overseen by the Federal Energy Regulatory Commission, which
restricts the profit that utilities make on new transmission projects to
an annual average of 9% on investment. Such returns pale in
comparison with the 15% to 20% utilities can earn on other,
unregulated investments."