[AR] Re: arocket Digest V3 #50

  • From: Pierce Nichols <piercenichols@xxxxxxxxx>
  • To: arocket@xxxxxxxxxxxxx
  • Date: Tue, 17 Mar 2015 08:23:43 -0700

Undersea high voltage DC interties are in operation today. NorNed (700 MW)
has been n operation since 2008. Atlantic Superconnection is working on
plans to build a gigawatt cable from Iceland to h UK. Once that's done,
building a transatlantic power cable is just a matter of funding.

-p
On Mar 17, 2015 12:00 AM, "Keith Henson" <hkeithhenson@xxxxxxxxx> wrote:

> On Mon, Mar 16, 2015 at 10:08 PM, Jim Davis <jimdavis2@xxxxxxxxxxxxx>
> wrote:
> >
> > Keith,
> >
> > 1. You seem to be deliberately avoiding the term specific impulse in
> > favor of exhaust velocity. Any particular reason for that?
>
> I just got out of the habit.  Done an awful lot of calculation for
> beamed energy and it was less trouble to use exhaust velocity to
> calculate the energy consumption of the engines.  Factor of ten is
> within 2%/
>
> > 2. Am I reading that graph on page 2 correctly? If Skylon makes "only" a
> > 100 flights per year the cost to LEO is over $5000/kg?
>
> That's what the graph from RE says.  If you build these things at all,
> you need a large space traffic model for them to make sense.  Like a
> power satellite construction project.
>
> snip
>
> > From: Ian Woollard <ian.woollard@xxxxxxxxx>
>
> snip
> >
> > Another type of power is peaker plants; those are used when the network
> > needs extra power, and they're often highly inefficient, but they can
> > command more than ten times the price per kilowatt. They run only a small
> > fraction of the time.
>
> In the long run, power satellites should cost less than peaker plants.
> So it makes sense to build out power satellites to peak demand, in
> fact well beyond peak demand.  Instead of managing the grid by
> generation, in the future we could manage it by load.  Any available
> power between current load and the capacity of the power satellites
> would be diverted into electrolysis plants to make cheap hydrogen.  We
> can use the hydrogen and CO2 salvaged out of the air to make synthetic
> hydrocarbons.  The energy to make the hydrogen for a bbl of oil is 20
> MWh.  The capital cost (based on the Sasol plant in Qatar) is around
> $10/bbl.  So one cent power would make $30/bbl synthetic oil, 2 cents
> would make $50/bbl etc.
>
> Solves both the fossil fuel problems.
>
> > From: Bill Claybaugh <wclaybaugh2@xxxxxxxxxx>
>
> (Keith)
> >>
> >> How do you reduce base load?  Base load feeds streetlights, domestic
> >> water pumping, sewer pumps, refrigerators and critical infrastructure.
> >> Shut it off at night and some people will get up the next morning knee
> >> deep in sewage.
> >
> > With storage and interconnection:
> > I assume storage is obvious; connecting U-rope with the Arabian
> peninsula--where the Saudi's and Oman plan to use the oil to build vast
> solar plants--extends the effective "daylight" period. Ultimately,
> connecting the future Arab, European, and North American grids will provide
> more than sufficient supply for the small nighttime load.
>
> The cost for sending power long distance is substantial, around a cent
> per kWh per 1000 km.  Plus as others have pointed out, there is no way
> to get it across an ocean.
>
> Keith
>
>

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