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 > >