efficiency loss

There are a lot of factors that come into play when your converting any form of energy into electrical energy. There are copper losses in the windings of the motor, friction losses, mechanical losses, heat losses, friction and windage losses, and so on. This would make the percentage loss very difficult to estimate. This comment might not help at all with the actual efficiency but, you now know a little bit more about energy conversion.

As a rough rule of thumb for IC engines, 30 to 50% of the energy goes to the engine shaft as useful housepower, 25-40% is lost through the exhaust stack as heated products of combustion, and 25-40% loss is through the radiator.

If you had more data we could do the calcs for you but your question is very general.

There are many different processes for each stage in the making of electricity so the design of the power station will make a huge difference.

Try to get the total output of the power station per hour (capacity) and see their consumption of gas per hour (max rated).

If you now take the caloric value of the gas you can calculate the amount of energy that was supposed to have in it. Take the power output figure and convert that to energy and you deduct the two. This gives you the loss.

This kind of loss is the gross loss of energy and gives you the overall efficiency of the station, normally indicated as a fraction of maximum available, which gives you percentage when multiplied by hundred.

Thank you for your response. I should explain my reason for asking. Anaerobic digesters are being used to create biogas which in turn is used to power generators to generate electricity. I would argue that we should clean up the biogas (mostly methane and pump it into the natural gas grid. Part of my argument would be to save energy loss as a result of conversion. I am not looking for an exact and specific example. A ball park percentage of +or- 5% would do. Thank you

If you ask me, the whole idea of biogas created by using crops is a farce and one I don't subscribe to for the moment.

It takes many more square miles of arable land to create enough crop for useful biogas production than many people realise. In the immediate future, i.e. next couple of years, I reckon we will see far more famine than we should have if we did not go for biogas.

The green issue is apparently more important to our politicians than the welfare of people in under developed countries.

Who said anything about using crops? This is not ethanol or biodiesel. In Sweden they have created 34 biogas plants using sewage waste. They are running trains on boigas. Our organic waste not new crops can be used for this process. That is why biogas is superior to ethanol and biodiesel. Our landfills waste methane that could be used. By capturing this wasted methanol and injecting it into the grid we reduce GHG. The byproduct is fertilizer that can be returned to the farms. Pacific Gas and Electric just contracted with a dairy farm to purchase gas derived from anaerobic digestion of Cow waste. This is a sustainable model. This process does not take anything from the food supply and it helps solve the landfill problem. Cars running on Compressed natural gas run cleaner. engines last longer and require fewer oil changes. It will be a long time before we run out of waste to produce the biogas. As the population grows,so grows the waste. this is a sustainable model. Where biogas is being generated in this country, it is wastefully used to generate electricity. It should be used as gas. I hope this better explains my reason for seeking this information.

My bad, I assumed too much as it is the "new big hit in the news" .

Sorry, what you are saying makes sense and it should have been done ages ago already. A friend of mine, died some years ago, did his doctorate in pig shit. He proved that for any farm with more than a certain amount of livestock, it could be self sustaining without any need for gas or electricity from the net. He passed his doctorate but the idea died off, why?

We have a power station near us that runs on chicken crap. I don't know how much of it or if it solely runs on the stuff but still, things like that should be done everywhere.

You are correct in saying that there are losses to the conversion and if you pumped the stuff direct into the grid for home use you would not have the extra losses.

Economically, in early days of biogas capture it was too expensive to purify the captured gas to recover methane. Obviously as energy costs increase and technologies change, recovery and purification is a viable solution, but all sewage works cannot change overnight. One problem with recovery I have heard is the corrosive gases besides methane, sulfur compounds, wet CO2, etc.

Hi, mschultz!

"This process does not take anything from the food supply and it helps solve the landfill problem."

Could you please enlarge upon how this helps solve the landfill problem? Current biogas technology includes using landfill, but as landfill employed as a biogas source ages, more landfill is required to maintian the level of biogas production, since wild anaerobic methanogenic bacteria (who create the methane in landfills) have only a 4-to-5 year useful life span. Surely this aggravates the landfill problem rather than solving it.

Mark

Hi, mschultz!

As you know from my last response to your blog #6, I am interested in the landfill technology. Just recently --and I have no references to back this information up as yet-- I read the following paragraph in the introduction section of a relatively new US Patent, #7,389,654 .

"Landfills provide the most complex issue to be faced in the entire realm of waste disposal, with the possible exception of long-term storage of nuclear wastes. Landfills are little more than holes in the ground into which massive volumes of wastes are dumped, compacted and covered, with an unsupported expectation that the material will eventually decompose and be absorbed into the normal ecology. This expectation is unsupported because excavations of earlier (19th and early 20th century) landfills have found that even paper products, including newspapers, are substantially intact (if not structurally pristine) over a time period where decomposition had been expected. Present attempts to moderate the impact of landfills have met limited environmental and limited economic success."

For some time, we have suspected that the long-term effects of landfills on the underground water supply might be adverse; and now we can add to the list of woes for this technology that it might take much longer to work than we had originally thought.

What might be needed to assist this technology is something buried along with the garbage, perhaps as a sprayed-on component that will act as a decomposition assist and at the same time ensure that harmful substances buried with the garbage do not enter the ambient ecological support systems.

Any chemical or biological engineers reading this who can come up with a couple of suggestions and/or develop them would be not only doing a huge service to mankind, but probably be extremely well rewarded financially.

Perhaps the CR4 crew might come up with a blogset for "throwing new untried technological ideas into the site" in such a way as to keep those ideas fresh without including stuff already being worked on by contributors.

Mark

Unless you can find a use for, and recover the waste heat from the turbines, you're looking at loses in the 60% range for the best large systems.

Hummmmmmmmmmmm......

1. IC - The best cars .... Mec & BMW - About 20%

2. Coal to Elec @ Power Station - About 35% Max.

3. Gas to Elec @ power Station - About 80-90% depending on Re-Coperators used ...

That's power extracted from energy input, most is losses in the form of low-grade heat, plus lots of other little stuffffffff..........

That's my rule of thumb ........... if you want hard data - "Go-Google"

Best regards,

Macker

Thank you for your comments. I will continue to do research in this area. If the problems can be worked out, we might create a sustainable model that would get us off petroleum. T. Boone Pickes has invested in a solar farm and a wind farm. He feels we should not use natural gas to generate electricity, but rather use it to run our vehicles. He claims this would reduce our oil imports by 40%. I would like to see us generate our own biogas fuels for transportation. That is my goal. I welcome any suggestion or comments.

Hi, mschultz!

Glad to see there are others who consider methane as a viable option in today's energy crisis contributions.

http://cr4.globalspec.com/thread/21843#newcomments

Mark

sorry i'm late. I did a report on methanogenisis [pig poo to gas ] in the early 70's for high school. the best book came out of south Africa at the time. printed in the 50's. the "natural gas" was about 55% methane/hydrogen. the rest was undesirable gases [carbon dioxide[25%?], ammonia, h2s etc] which the author claimed had no effect on his jury rigged generators. the engines were started on gas/diesel and then switched over [plumbing tap] to 1 to 2 psi gas. the internal combustion engines at the time were unsophisticated compared to todays engines.

running "bio gas" on a turbine may not be advisable without first scrubbing [to remove moisture, h2s, co2] the gas with expensive equipment to at least technical grade. additional moisture in high temp combustion with impure non combustable gases could wreak havoc on blades [corrosion] and oil contamination. plus emissions into the atmosphere.

the pulp and paper industry has an e magazine and i have seen technical databases for reference. i'm sure there is a consumption for natural gas to turbine electrical generation in there somewhere. if i find it in my old computer I will pass it on- best of luck.