I think this is the beginnings of an economy based on perpetual growth and fossil fuel energy running headlong into geological energy constraints. Basically I see an undulatory downward path for the rest of my life. From here out, I think any rallies in our economic condition are going to be met with spiking commodity prices that knock us right back down.
Joined: Sep 16, 2004 Posts: 4847 Location: Southwest WI
Posted: Sun Dec 26, 2004 12:52 am Post subject:
I don't know about others here, but i think using nat gas for electricity production is not wise. To me its greatest use is for heating/cooking. How much sense does it make to pipe it to a electricity producer, send it to a consumer, consumer uses it to heat up leftovers?
About the nat gas leakage. I live near(not close!) to a large nat gas pipe(pipes) and every time i walk past them(depending on the wind) you smell it(i know it doesnt have a smell/its the sulfer) and its obvious there is leakage, how much???
I don't know about others here, but i think using nat gas for electricity production is not wise. To me its greatest use is for heating/cooking. How much sense does it make to pipe it to a electricity producer, send it to a consumer, consumer uses it to heat up leftovers?
About the nat gas leakage. I live near(not close!) to a large nat gas pipe(pipes) and every time i walk past them(depending on the wind) you smell it(i know it doesnt have a smell/its the sulfer) and its obvious there is leakage, how much???
Frank,
I agree with you 100%. Consider for a moment how many energy transformations (increased entropy) take place to use natural gas to generate electricity:
Natural gas is used to heat water/to produce steam/the water is used to turn a turbine/the turbine spins a generator/the generator produces electricity/the electricity is sent to a step-up transformer/ it is converted to high voltage/ this is transferred over power lines to a substation/then sent to a step-down transformer/and finally transferred to your house/ where the light wiring (for ease of installation) losses even more energy. Every slash / bar represents energy being transferred from one form to another with a loss of available energy as dictated by the 2nd Law of Thermodynamics (entropy) at each point. These types of units, which use the high heat capacity of water to optimize thermal output, typically achieve 33 to 35 percent of thermal efficiency, meaning that about a third of the heat generated is converted into electrical energy. The two thirds of heat generated that is not used to produce electricity is exchanged with the environment surrounding the plant and is lost as far as function al work is concerned. If you have electric heat, hot water, or a cooktop, the efficiency just goes south, especially in the case of heating water--wasn't that what we started with?
The second traditional method for generating electricity from natural gas is the centralized gas turbines. Gas turbines do not utilize steam but instead turn the turbine with the hot gasses directly produced from combustion of natural gas. Since there is no need to wait for water to be converted to steam, the turbines begin turning as soon as heat is produced from the combustion process. This property lends gas turbines to primarily peak load production where quick electrical production is needed. The cost of this advantage over steam generation units is lowered thermal efficiency(massive decrease in EROEI). Natural gas is used widely in this peak load generation strategy due to its ability to be quickly and easily ignited. Again, a labor and time-saving utilization due to cheapness, that results in great thermodynamic waste.
Many of the new natural gas fired power plants are what are known as 'combined-cycle' units. In these types of generating facilities, there is both a gas turbine and a steam unit, all in one. The gas turbine operates in much the same way as a normal gas turbine, using the hot gases released from burning natural gas to turn a turbine and generate electricity. In combined-cycle plants, the waste heat from the gas-turbine process is directed towards generating steam, which is then used to generate electricity much like a steam unit. Because of this efficient use of the heat energy released from the natural gas, combined-cycle plants are much more efficient than steam units or gas turbines alone. In fact, combined-plants can achieve thermal efficiencies of up to 50 to 60 percent.
If we used natural gas at our home to heat water or cook, we would have only one conversion: gas to hot water or hot food. Whatever solutions we come up with must be focused on decentralization of energy production and point of use applicable to the available local energy. In some places direct heating of water by solar would make the most sense rather than natural gas.
Natural gas normally is non-toxic, tasteless, colorless and odorless. For safety, a scent known as--mercaptan--an acrid chemical, is added so that you will recognize it immediately, should there ever be a leak. Mercaptan makes natural gas smell like sulphur, or rotten eggs. I have no idea how much is loss into the atmosphere due to leakage. _________________ A Saudi saying, "My father rode a camel. I drive a car. My son flies a jet-plane. His son will ride a camel."
Live in Arizona? Check out: http://sustainablearizona.org and read my blog.
Last edited by MonteQuest on Tue Feb 21, 2006 10:53 am; edited 2 times in total
Joined: Jul 18, 2004 Posts: 198 Location: S. Yorkshire, UK
Posted: Sun Dec 26, 2004 1:25 pm Post subject:
Natural gas is very important fuel, and burning it for electricity, for which there alternative sources, is foolish. It is, for a start, the major source of energy for agriculture - in the form of fertilizer.
However, it wouldn't be done unless there were big advantages.
Natural gas has seen a big increase in its use for 'baseload' generation - the fraction that is always running at maximum capacity, because it provides high efficiency generation of electricity.
I don't know of any natural gas fired steam generation plants - such a system would have an efficiency of about 30-35% and be slow to respond to changes in demand.
The big advantage for gas is gas turbine generation which can offer either better flexibility (with small plants and cost of lower efficiency), or better efficiency (up to 40%) with large plants.
Most new baseload plants are now combined cycle (waste heat from the gas turbine boils water for a steam turbine), and there are plants operating with efficiencies of 58% overall.
Don't forget as well that burning gas at home is not perfectly efficient. If you have an older gas boiler, or water heater, it may well only achieve 70-75% efficiency. If it is of the design which keeps a pilot light lit, or keeps water constantly warm, then overall efficiency could be even lower.
If your boiler is over 15 years old, consider replacing it with a state-of-the-art condensing boiler, efficiencies of 92-95% are possible.
The best options for residential heating would probably be solar thermal (using either flat plat collectors - in warm climates, or vacuum tube collectors in cold climates), or in moderate climates an electrically powered heat pump.
Perhaps in the future, micro CHP will be practical - Small 1-2 kW generator/water heaters could provide residential heat and electricity at high efficiency (>90%). If utilities required a certain percentage of your electricity to be delivered at peak time, then this could be a realistic option for replacing the inefficient small 'peaking' power stations.
"Stranded" Natural Gas to Liquid Fuel, is it time?
Quote:
Every day natural gas flares blaze across swaths of Africa, Russia, Asia and the Middle East, burning off 10 billion cubic feet of energy--the equivalent of 1.7 million barrels of oil. There's more gas where that came from. Reserves of "stranded" natural gas--the stuff that's abandoned because there's no economical way to transport it--come to maybe 2,500 trillion cubic feet. If captured and converted, the gas would make (after conversion losses) 250 billion barrels of synthetics, from clean-burning diesel to jet fuel. That's like finding another Saudi Arabia."
Posted: Tue Feb 21, 2006 10:50 am Post subject: Re: Earth at Night: The Natural Gas Burn-off
Epyx wrote:
So what you're saying is that Natural Gas is the answer?
Not at all, Just posting an article that pertains to the thread topic. I do think that efforts will be maded to utilize NG in this way, but is it a solution?
No, only a small mitigation possibility. _________________ A Saudi saying, "My father rode a camel. I drive a car. My son flies a jet-plane. His son will ride a camel."
Live in Arizona? Check out: http://sustainablearizona.org and read my blog.
Posted: Tue Feb 21, 2006 2:57 pm Post subject: Re: Earth at Night: The Natural Gas Burn-off
MonteQuest wrote:
This map is a must see! More than 100 billion cubic meters are burned off annually, ... enough to power France and Germany for a year. Oil companies searching for oil regularly burn off the gas and consider it worthless unless it can be transported. It appears that 80 percent of the world's reserves lack pipelines to transport it to consumers. Sounds like a lot of pipeline building to me. Is this "big oil's " back up plan?
It would be nice to save it and use it, but it is about 1 % of USA uses.
now that is a lot of energy.
If this 1 percent actually can supply both france and germany for a year as stated above, then of course, our yearly use of oil can then run france and germany for about 100 years.
or our our yearly useage needs would supply 200 frances or 200 Germanys or france or germany could run hundreds of years while ...america can run 10 years. So basically without america there would be no oil crisis in our lifetimes. With america, that is shortened.
So if this is their backup plan and they build pipe everywhere in the whole world and bring it to market, it will lengthen the oil crises from lets say 10 years to 10 years and one month.
Posted: Tue Feb 21, 2006 5:00 pm Post subject: Re: Earth at Night: The Natural Gas Burn-off
grabby wrote:
MonteQuest wrote:
This map is a must see! More than 100 billion cubic meters are burned off annually, ... enough to power France and Germany for a year. Oil companies searching for oil regularly burn off the gas and consider it worthless unless it can be transported. It appears that 80 percent of the world's reserves lack pipelines to transport it to consumers. Sounds like a lot of pipeline building to me. Is this "big oil's " back up plan?
.
This is true, but you don't realy understand what it means:
Sure I do. It is a pittance. Maybe I should have put this smiley after :
Is this "big oil's " back up plan? _________________ A Saudi saying, "My father rode a camel. I drive a car. My son flies a jet-plane. His son will ride a camel."
Live in Arizona? Check out: http://sustainablearizona.org and read my blog.
Joined: Dec 27, 2004 Posts: 13064 Location: naive idiot fantasy world
Posted: Tue Feb 21, 2006 7:44 pm Post subject:
MonteQuest wrote:
Whatever solutions we come up with must be focused on decentralization of energy production and point of use applicable to the available local energy. In some places direct heating of water by solar would make the most sense rather than natural gas.
And of course there is the "Manure-powered Utopia" option of small scale methane digesters. We all have to poop, and this is a way of making a complete circle from pooping to cooking. Methane digesters are extremely easy to make and inexpensive.
But by advocating this solution I prove I am as evil as Pol Pot. _________________ "...powerdown so soft and fluffy you'll think you're living in a pillow." - jboogy
All times are GMT - 6 Hours Goto page Previous1, 2
Page 2 of 2
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
News
Discussions
Resources
Members
Forum FAQ
Search
Usergroups
Profile
Log in to check your private messages
Log in
