Re: Down with the government!
> Electronic forums are the ideal venue for brainstorming solutions for social > issues, as you can take time to edit your comments. It also affords more > people an opportunity to be less passive and have a voice. Moderated sites > work best to stay on topic and maintain civilized discourse. As long as the moderator isn't a censor. Doug I(ttb)AMoaC ___ http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com
Re: StratoSolar
Keith Henson wrote: StratoSolar This is off NDA so I can go into detail. ... > Ed's approach, which he named StratoSolar, was to reduce the mass from hundreds of kg per kW to a few tens of kg by moving the solar concentrator into the stratosphere as a large, lightweight, buoyant structure. ... The concentrated sunlight gets to the ground via a hollow light pipe lined with highly reflective prismatic plastic. Preliminary optimization for kg/kW leads to a 30-meter diameter light pipe with less than 10% loss. A larger pipe has lower losses but uses more total material per kW. Keith-- Hi. StratoSolar is interesting. I looked at the website when you mentioned it a month ago. At the time, this was my main objection: I see bigger problems with losses in the light pipe. The plan seems to be to have a flexible tube lined with reflective material to guide the solar radiation down to steam turbines or whatever on the ground. Most of the light would have to reflect off the sides many times, losing at least a few percent of its intensity at each reflection. So nothing makes it to the ground, and the light pipe melts. There may be solutions to this too, but they're going to be tricky. How many reflections are you assuming light will make as it goes down the pipe, and how glancing are they? ---David ___ http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com
RE: StratoSolar
Just a quick point. >Run 80,000 hours in ten years the return is $800 per kW >per penny payment for a kWh. For power satellites, assuming 5kg/kW, >$100 per kg lifted to GEO and about 1/3 of the cost going to >transport, you get the required $1600/kW for 2 cents per kWh. Well, that seems really low, so I looked up present costs. At http://crowlspace.com/?page_id=50 there is a talk promoting space based solar. It was honest enough to admit: The launch cost from Earth to low earth orbit is the greatest impediment to this project. It is currently about $5,000 per pound to low earth orbit, and it has been about that cost for a long time. Geosynchronous orbit would raise the cost to 10,000/pound. Given the fact that, as mentioned in the talk, lift costs have been fairly constant, where does the factor of 200 improvement come from? How do you know it will happen when it hasn't? Dan M. ___ http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com
Re: StratoSolar
Keith Henson wrote: > > Since the 1970s, US politicians have given lip service to "National > Energy Self-sufficiency." The US has failed to achieve anything, > largely because nobody had a good idea of how to make it work at the > same or lower cost than importing oil. This method might not work > either. However, it passes first-order physics and economics > analysis and seems to deserve serious further study. > You (USA) might be closer to self-sufficienty than you (Keith) think. Deepen the crisis (and reduce energy expendidure) and get a little more of shale gas, and you get there. Alberto Monteiro, minion of evil oil companies ___ http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com
StratoSolar
StratoSolar This is off NDA so I can go into detail. For a few years, I was working on a way to reduce the cost of space-based solar power to the point it could displace fossil fuels. That's two cents or less per kWh, which is half the price of electric power from coal, and low enough that (off peak) it can be used to make synthetic hydrocarbon transport fuels for about a dollar a gallon. The rough economic analysis is based on a ten-year repayment of capital cost. Run 80,000 hours in ten years the return is $800 per kW per penny payment for a kWh. For power satellites, assuming 5kg/kW, $100 per kg lifted to GEO and about 1/3 of the cost going to transport, you get the required $1600/kW for 2 cents per kWh. With the help of Jordin Kare, Howard Davidson, Ron Clark, Spike Jones and others, by last January I had a proposal that looked like it would reach $100/kg cost to GEO. The general approach was discussed in an article in The Oil Drum about a year ago. It proposes huge lasers to get the average exhaust velocity up to the mission velocity. This gives a mass ratio to LEO of about 3and a throughput to GEO upwards of 100 t per hour. Late last year Howard became aware of a project an old friend of his, Ed Kelly, was working on. Ed is best known as a principal with Transmeta, a company that developed low-power processors some years ago. Howard introduced me to Ed. I have spent a lot of time going over Ed's spreadsheets and other details since last January. In the post-analysis, the reason ordinary ground solar power is so expensive is the huge amount of materials that are needed because solar energy is so dilute. (Wind has the same problem.) Ed's approach, which he named StratoSolar, was to reduce the mass from hundreds of kg per kW to a few tens of kg by moving the solar concentrator into the stratosphere as a large, lightweight, buoyant structure. This has significant advantages over being on the ground. There are no clouds at 20 km. The winds are light and steady and the low air density reduces the force on the structure. Because the primary concentrator can be pointed directly toward the sun, it gives close to full power whenever the sun is above the horizon. (Rough pointing--one to two degrees--can be done with combinations of thrusters, aerodynamic fins and reaction motors, fine pointing by stepper motors moving the mirror segments.) They work as far north as Stockholm. The concentrated sunlight gets to the ground via a hollow light pipe lined with highly reflective prismatic plastic. Preliminary optimization for kg/kW leads to a 30-meter diameter light pipe with less than 10% loss. A larger pipe has lower losses but uses more total material per kW. Because the mass is dependent on the pipe diameter and the power capacity on the area, StratoSolar plants optimize in large sizes, around 1 GW. That means the primary collector is a bit over 2 km in diameter and 100-200 meters thick. That gives plenty of room for gasbags to offset its weight. While the concentrator has neutral buoyancy, the light pipe has a lot of excess buoyancy. If you just think about it as a force diagram, the buoyancy needs to be 3-4 times the wind force to keep the angle the light pipe makes with the ground within 15-20 degrees of vertical. The materials required—aluminum, plastic, steel wire, and hydrogen (for buoyancy)—are all inexpensive and do not need to be processed to tighter specifications than the norm for commercial products. The sunlight is absorbed and converted to heat at the bottom. The heat is used to run an ordinary, 45%-60%-efficient, one or two stage power plant. About half the heat during the day is used to heat a solid heat thermal storage medium. This will provide enough stored heat to run the plant overnight. Graphite is a good choice, but any high temperature solid would work. Cowper blast furnace stoves (regenerators, dating from 1837) produce air as hot as 1400 deg C, just about the limit for turbine inlet temperature. While stoves for this application are big (typically 70,000 cubic meters), they are dead simple and should cost well under $100 million for a GW plant. That cost adds 1/8 of a cent per kWh to the cost of power. This is less than 1/10th the cost of any other proposed storage mechanism. Our rough estimate for the cost is around $1.2 B per GW, or $1200 per kW. Using the above ten-year payback, the cost to generate power should be around 1.5 cents per kWh. It will take building a few to learn how to manufacture them and get accurate cost numbers. However, if this is close, it will solve the long-term energy problems and get the human race off fossil fuels by simply under pricing them. Like any other large project, there are a million details. We have given thought to such topics as ozone, lightning, hydrogen fires, thunderstorms, icing, interaction with aircraft, high wind loads, aerodynamic shrouds, UV damage, turbine throttling, maintenance access, an
Down with the government!
> This would be great internationally as well, > not just in the US. If you want a bit of > (free) adivce on websites, its what I do for > a living for my sins. > My Facebook and twitter profile is alexgogan > Good luck with the project love the idea! Thanks Alex I'll look you up. I pop up on FB as Jon Mann on Dr. Brin's page. My e-mail address is net_democr...@yahoo.com The concept of the "electronic village" is found in SF, especially if you've read "Earth". It's evolving on the internet as weblogs, etc. The Internet enables discussions to be held online and provides a way for the people to gather together, allowing everyone speak their mind, discuss an issue, make a decision, and vote to have it carried out. It is a means to implement direct participatory democracy, as opposed to representative government. Town halls can no longer work as they did in ancient times. They are a function of the size of the group, which places limits on speaking time. Within the decision making process some people talk more than others. Electronic forums are the ideal venue for brainstorming solutions for social issues, as you can take time to edit your comments. It also affords more people an opportunity to be less passive and have a voice. Moderated sites work best to stay on topic and maintain civilized discourse. ___ http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com
Re: DOWN with the government!~)
And there I was trying to add David as a Friend and Facebook say do I know David Personally!!! Well he doesn't know me but my bookshelf knows him very well >:¬} On Mon, Oct 11, 2010 at 12:38 AM, Dave Land wrote: > On Oct 10, 2010, at 3:45 PM, Dave Land wrote: > > Where would a guy find you on Facebook? Searching for >> "Jon Louis Mann" didn't cut it. >> > > Never mind. I remembered that you and I are both friends > of some guy named "David Brin". > > > Dave > > > > ___ > http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com > > > ___ http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com
Re: DOWN with the government!~)
BTW Jon, This would be great internationally as well not just in the US, If you want a bit of (free) adivce on websites, its what I do for a living for my sins. My Facebook and twit profile is alexgogan Good luck with the project love the idea! On Sat, Oct 9, 2010 at 7:41 PM, Jon Louis Mann wrote: > > I'm running because I want to oppose that system and give > > residents a voice in how those millions are spent with a > > virtual town hall forum on the city website, for > > transparency, and to hold city officials accountable. > > Jon > > > You sound like the kind of guy I might just vote for, > > name recognition or not! > > Dave > > > > Sounds like you got your priorities right to me. I > > > wonder if you couldn't have run under your old name, > > > or if people would just find that weird? > > > Charlie > > Thanks guys, if anyone is interested they can follow my > campaign by friending me on Facebook. I am trying to > figure out how to set up a website and am working on > putting it on smartvoter.org. > Jon > > > > > ___ > http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com > > > ___ http://box535.bluehost.com/mailman/listinfo/brin-l_mccmedia.com