Ignorant wannabe environmentalists

In news:_7eUc.1341$ snipped-for-privacy@tor-nn1.netcom.ca, Peter blithered:

By all accounts some one else already did!

LOL

Figure this one out then, if we all drove battery powered electric vehicles the electrictiy to charge them would still have to be generated somewhere, most likely inefficiently.

At least the pollution we cause is honest and visible.

Large power stations operate at much higher efficiency than petrol engines...

It is also much more practical to handle the attendant pollution when it is all in one high-value installation, rather than spread around the country and particularly localised in city centres and population centres.

You still have to distribute and then battery the electricity, which I suspect narrows the efficiency gap somewhat, but the control and centralisation is probably the biggest argument in favour of it.

Do not not let these people con you. Batteries have to be recharged at some time and then they give off serious life threatening gases. I have now retired so I do not have the report available. I was in charge of a workshop which maintained battery driven forklifts also small battery driven towing vehicles. The incidence of cancer among the workers caused an inquiry which failed to establish the cause. The manufacture of these motive power batteries is so poluting that the staff have to totally change their clothes before going home. Also the waste water is not allowed to enter the drainage system. Do not forget that there would need to be a lot more generating stations if we went over to electric vehicles and how would these stations be driven? Environmentalists seldom have the full picture and don't want to talk to people with the practical experience. Just like politicians! Robert

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Much ? No thermal power station can be more then roughly 30% efficient. What is the conversion efficiency of a car engine ? Steve

Batteries don't last for ever either, what happens to all the nasty stuff inside the battery when it's life is over? How much energy gets used making the sort of batteries that are used for motive power?

IIRC absolute max is 56%

You, however, seem to have established the cause all by yourself? I suppose you have eliminated the known carcinogenic effects of used oil, various solvents which would have been used in such a workshop or indeed normal statistical phenomena... The workshop was apparently somewhat unusual in having been run by a fully qualified pathologist.

The clothing regulatoins and control of waste effluent is more often than not just as stringent in food manufacture, medicine manufacture etc. It doesn't make the end product itself inherently dangerous to use or store.

Probably by fossil fuels, but also quite possibly by other renewable sources. I look forward to seeing your design for a car with a built-in hydro-electric power station...

You can go on forever with calculating the overall energy costs. How much fuel do we burn transporting fuel to petrol stations? The fact is that reducing car useage simply isn't happening and simply taxing pollution is only going to put the UK (or indeed European) economy in the doldrums whilst the Far East and 3rd World stay deregulated and flood us with cheaper goods. In a wider sense we need to incentivise people and businesses to reduce pollution, partly by stick but also by carrot.

Hydrogen ? only if you smoke too near it...

Steve

ISTR reading that large modern power stations achieve over 40% efficiency. I'll try to find out where I read it...

Typical diesel ~30-35% petrol ~20-25%

rest is heat given up to everything other than useful driving power

Terry

I was wrong. Combined Cycle stations in Japan are running at 54% and the next is expected to run at 60%.

They aren't alone.

Thermal stations do seem to be running in the mid to high thirties percent. That's still better than a car engine (even a well maintained one, which not all are). Not sure what the emissions are like, but I'd bet on the power station there as well.

It all depends on what you mean by efficiency. If a power station JUSt generates electricity - like almost of ours,the maximum efficiency is around 35%. If the power station supplies energy in thermal and electrical, then you go up to these 60-80% levels. Of course, if you increase the temperature differential in your process, you get better efficiency. Thats why a jet engine gets more efficient as it goes up.

Steve

Agreed. There are few options for CHP on a car.

Then again one chemical plant I am familiar with (and I'm sure they are not unique) has their own CHP station on-site and regularly export power to the grid. They could use that power to run their company cars and vans - it would work fairly well as drivers could recharge their cars at work during the day and the vans could recharge at night.

We tend to use two or three 8 megawatt gas turbines (Solar Mars) for electricity, depending upon demand, but each has a waste heat recovery unit for the exhaust gases to partly flow through. The control system balances the demand for energy required and efficiency. Must look to see waht the calculated figure is...

Dan

Hmmmm... not quite that simple. Jets become more efficient due to the lower mass of available oxygen at altitude requiring a lower mass of fuel to maintain a constant "mixture ratio". The output thrust is (very) basically the ratio between airflow velocity at compressor entry to airflow velocity at jet pipe nozzle outlet. This is clouded by modern high bypass-ratio turbines, but the basic theory is the same,- Take a mass of air, add a fuel to it and burn the mixture to create a velocity increase. That is why piston prop engines are more efficient at lower altitudes, at higher altitudes there is 1. less airmass to accelerate rearwards (creating thrust), necessitating the prop working harder, which it can't because 2. there is a lower available oxygen mass entering the engine in which to burn fuel.

Badger.

"Roberts" wrote

Yes they are called oxygen and hydrogen. But are not life threatening unless you add a spark and cause an explosion!

Reg

Missed that comment. I hope I don't appear to be that way inclined. FWIW, I don't care about anyones sexual orientation so long as they're happy and don't hurt anyone (without consent, obviously) :-)