from stuff posted here:
http://www.talkaboutcomics.com/phpBB2/viewtopic.php?t=34294&postdays=0&postorder=asc&start=15

Gas might be coming back as the environmental thing. Distributed electric power is about 40% efficient (losses in electromagnetic radiation, wire and transformer heating, dielectric effect, and small conductivity of insulators). Distributed gas is almost 100% (some losses in pressure pumping heating the pipes) Electricity generators powered by the gas would be installed in each home (likely fuel cells) and the vast resources of coal will be converted to natural gas. There are inventions that are designed to create light directly from the natural gas with the efficiency of fluorescent light bulbs and without flame that may be used. I think the better way is for everyone to make their own power but for a distributed system, this looks like it will work.

Pottery works better in a oxygen free environment too so for electric kilns, people sometimes add things like coal and wood to burn off the oxygen when things heat up.
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MarkStanley wrote:
Ann, you are too kind. Just generating the power runs about 33 percent efficient. Then there are the losses in conversion and transmission. About 16 percent of the power actually gets to the homes in the form of electricity. If they could solve the fouling problem, fuel cells would be more efficient.

16% from 33% - less then 50% gets through the transmission part. Of course it depends on how far the electricity is being transmitted and the loading of the wires (I^2 x R=W so double the amperage and you quadruple the watts of loss and thus quadruple the wire heating related losses and for distance, it is a one-to-one relationship with resistance but to minimize the losses, more transformers are used to increase the voltage to decrease the amperage and so there are more transformer losses and losses from conduction through insulators and the air). The 40% quote was the average for North America a decade or two ago... since then, the system load has been moved to near capacity and the decommissioning of a lot of dams means that the electricity has to move further. Right now a good proportion of the electricity is being produced by burning natural gas anyways. Due to the greenhouse gas emissions from burning coal - lots more carbon compared to hydrogen (closer to 2 hydrogen per carbon) means lots more carbon dioxide compared to natural gas (with it's one carbon to four hydrogen) so gasification of coal is likely to be the only way to use this plentiful resource and still keep greenhouse gas emissions down (and the costs of scrubbing the exhaust of acid-rain causing nitrogen and sulfur emissions is reduced or eliminated too using technologies for cleaning natural gas of these impurities and then selling the sulfur and nitrogen in the form of fertilizer). Now that it is gas, there is little advantage to burning it in big facilities (over burning it in furnaces, stoves, and hot water heaters in homes and businesses) Fuel cells create a bunch of heat in the process of making electricity which would be wasted and an environmental concern if done on a large scale but on a small scale it can be used to heat the water in your hot water tank or heating system.
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CJ wrote:
Flashpoint of a gas?

Again, I'm wrong, wrong term - my bad - I am talking the speed that the fuel burns at from the point of ignition. Here is a quote

Quote:
In order to do work on a piston, the fuel-air mixture needs to burn at a speed faster than the piston is moving. Low hydrogen flame speed is a disadvantage shared with most other gaseous fuels. For comparison, a gasoline-air mixture has a flame front speed that ranges typically from 70 up to 170 feet/second in IC engines, while an ideal hydrogen-air mixture has a flame front speed of about 8 feet/second. An average vehicle engine rotating at 2,000 rpm (33 revolutions per second) produces piston linear speed of 45 feet/second in the middle-stroke, which is already 5 times faster than the hydrogen flame front speed ! The fact that a hydrogen-air mixture has a flame front speed of about 1/10 that of a gasoline-air mixture, contributes to explain why hydrogen engines only run at reduced power and low rpm under load.

Reese Tora wrote:
I don't think a lot of communities would support having to have noisy electric generators in every home

They would have to be quiet and efficient so likely fuel cells would be used but the technology still has lots of room for improvement as natural gas and hydrogen powered transit buses have shown (but these fuel cells do work). There are some small steam turbine systems that are incredibly quiet... place them in an insulated room in the basement and you will never hear it.

Reese Tora wrote:
the electric companies would probably lobby very strongly against anything that decentralized

Not if they also sold the natural gas or if the natural gas companies put in the system as an alternative to the electric companies... one bill, no outages, and it would only work if they could also give lower rates per kWh

CJ wrote:
the mixture of CO and H2 was directly sent into the pipes

I seem to remember hearing of such systems but modern gas processing facilities can make very clean gas now with minimal energy input. Another possibility is generating hydrogen gas at electricity generating locations (dams, windmills, nuclear facilities) then use the oxygen and hydrogen and waste CO2 gas to produce the natural gas in plants designed for that and send it down the existing natural gas pipelines. Someone might even have a process that can do the natural gas production in small scale at windmills and such and send the pure stuff right into the natural gas system.

Nightstar wrote:
What about digesters that produce gas from...well, from decomposition?

Remember that Methane is a greenhouse gas too (yes it is lighter then air) and every bit we can keep from floating away from feedlots and landfills is saving the environment. Some feedlots, waste treatment plants and landfill sites are already harvesting the methane and ethane coming off this waste.

Ron Bauerle wrote:
My apartment's all electric, and at least I don't need to worry about my rates going up 20% every year like I'm always reading for the natural gas users

My electricity rates are going up 40% this year but so is the natural gas rates. Price per kWh still puts natural gas considerably cheaper (enough to cover the inefficiencies of my furnace for now) but as things go up, that might change and they plan to build one of the world's biggest wind farms right near my place (part of the reason for the electricity increase... those windmills are expensive)
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I don't want to sound like a salesman for this gas-electric system because personally I would prefer if everybody just went solar and am trying to develop systems to help make such solar systems as reliable and cost effective as distributed systems but in the interest of looking at options I am presenting this

CJ wrote:
As long as the process is greenhouse gas neutral in the end, it shouldn't matter

I don't know how those two molecules compare with each other for reflection of radiant heat back to the earth (greenhouse effect) but for all the fuel that is NOT extracted from the ground because it is gathered from what would otherwise end up in the atmosphere anyways amounts to less carbon atoms in the air. Without concern for the environment, it can be argued that we are saving non-renewable resources for the future.

Reese Tora wrote:
seriously, i think the cost of installation would be rather high, and the decentralization would lead to a lot more inefficiency than the current system

In a lot of areas with electric systems running close to their maximum during peek times, the electric companies want to do anything they can do to avoid running more high power wires (buy land, build towers) and make more generating station (likely burning natural gas) or building dams (too much "environmental" concern regarding fish that would go extinct with a new dam and they have to buy up all the property up stream). This situation is having electric companies giving away fluorescent light bulbs and other electricity saving things as well as putting in time-of-use meters so people are charged more during peek times. Another thing to consider is that the electric system has to be good enough to supply the absolute peek of energy use including the source but gas can be stored and the pipes themselves are also a storage method so in the end the gas distribution system can be smaller. For efficiency, it is a trade off between the different efficiencies of the two transportation systems to the loss in efficiency of the small generating systems compared to the big systems As I mentioned, with fuel cells, you have to consider the use of the waste heat for local heating (hot water or furnace) making that waste heat into usable energy and not a loss compared to big systems needing to get rid of all that heat - a big environmental problem (hot water kills fish and such)

Reese Tora wrote:
in my area (CA, earthquakes!) the fewer and smaller gas lines to have break, the better

Of course there is that to consider OR in other places, the possibility of ice bringing down power lines makes such a system seem better in some places (like where I am). Overland pipelines seem to be better at handling crossing fault-lines then power wires because those wires shaking cause towers to collapse but the pipe is designed to handle all that expansion and contraction of the pipes due to temperature change so the pipes just slide around on their pedestals. Buried pipes are a different matter though but now that they use plastic pipes and they are always designed to handle some house settling, they might actually be more reliable in earthquakes (still, explosive gas leaks after a disaster are not a good thing where the electricity breakers would disable downed lines)

Reese Tora wrote:
having separate systems means that there's a certain amount of redundancy for homes

only if they are installed to supplement your electric lines instead of replacing them. Redundant systems could cause competition between the two systems and thus result in efforts made on both sides to be more efficient and thus have lower rates to compete better...more efficiency and lower prices, sounds good to me!