Now that we have some people thinking on the subject let me purpose
another more terrestrial problem.

How much would a recieving station cost, where could it be located,
and what kind of maintenance are required?

Talking about the space side of things is very fashionable on this
list because everyone (including me) wants to see space colonies in
space before our death, but the very real and practicalproblems of the
earth based systems must also be overcome.

In North America today, the neglect of a generation has left the
electrical grid in very bad shape. The estimate in August 2003 was 100
billion to repair it. How would that repair requirements impact SPS.
Will it. Can building recieving antennas be piggy backed on those
costs, or are they different costs.

The reason I ask this question is to flesh out what the entire system
from lunar mining to hooking up to the grid would look like. I
beleieve its many peoples heads, but I think many people have a
different view of what it will look like.

If we can create a consistant view of the system we are talking about,
we can evaluate the alternatives in a better manner.

Bill

> In North America today, the neglect of a generation has left the
> electrical grid in very bad shape. The estimate in August 2003 was 100
> billion to repair it. How would that repair requirements impact SPS.

Not only that, but if everyone relies on the grid for all their power
instead of oil and gas pipelines and truck deliveries, the grid would
need to be greatly expanded.

The grid is one of the biggest weakness I see to SPS systems. About half
my local power cost is for "delivery" cost as opposed to power cost. So,
even if the power was free, I'd still be paying around $0.6/kwh.

TangoMan and I had a long discussion about this, and while he disagrees,
ultimately this is why I think local renewables (especially
photovoltaics) coupled with energy efficiency (including rebuilt homes
with more insulation) will ultimately be cheaper than SPS (remote
renables), because there is no need to pay a third party to maintain a
power grid. In the short term, until batteries get cheaper and PV
prices move to their expected ultimate (1/10 current) prices, local PV
can be supplemented with 10-20% of annual power produced from truck or
pipeline delivered liquid or gaseous fuels (oil, hydrogen, propane,
natural gas, etc.) produced from fossil fuels or centralized plants (SPS
rectenna farms, coal, nuclear, remote solar energy farms in deserts,
etc.) See for example this offgrid home in Toronto:
http://www.cmhc-schl.gc.ca/popup/hhtoronto/works.htm

--Paul Fernhout

> How much would a recieving station cost, where could it be located,
> and what kind of maintenance are required?

Ideal location would be where there's already installed electrical
transmission - i.e. in or near existing power plants. Those are
generally pretty well isolated already. Cost estimates I've seen are
about 1/10th the cost of the space components; i.e. for a $5 billion
system delivering a few GW of power, the ground station would likely be
somewhat under $500 million. Ballpark figures. Maintenance shouldn't be
bad - repair of damaged components etc. No moving parts, so it should
be basically the same as maintenance for an existing power plant's
electrical components - transformers, power conditioners, computer
controls etc.

>
> In North America today, the neglect of a generation has left the
> electrical grid in very bad shape. The estimate in August 2003 was 100
> billion to repair it. How would that repair requirements impact SPS.
> Will it. Can building recieving antennas be piggy backed on those
> costs, or are they different costs.

Different costs. Replacing coal plants with SPS receivers would have
little to no impact on the grid. Replacing our current use of oil and
other non-electric fuel needs would require either more grid capacity,
or industrial use of the electricity close to the source - for example
hydrogen electrolysis (likely not to be economically sound, though) or
production of fertilizers for biofuels, or other mechanisms for
converting electrical energy into fuel for transport. But the cost of
tripling our grid capacity (which is about what it would take for all
energy use to be supported by electric power) is minor compared to the
trillions of dollars involved in replacing the power plants themselves.

Arthur