A "hydrogen economy" was once the Next Big Thing. The US was poised to run 240M cars and trucks on it, and wean itself off oil. There is no longer discussion of a hydrogen economy. Then Americans became drunk on ethanol. More than $20B in subsidies was spent turning 40% of corn crops into 10% of the country's fuel.

In 2009, US taxpayers subsidised 75% of each gallon of gasoline replaced with ethanol. Now the US has gone batty for natural gas.

Obama cited a huge estimate for natural gas supply in the US, the equivalent of 379B barrels of oil, enough to stisfy demand at current levels for a century. Published figures represent "possible" reserves, not certain categories, "proved" and "probable" gas that is likely to be producible under current conditions. When discussing proved reserves, the US possesses just 1/12 or 47B barrels. A lot but just 11 years supply. If we assume a 50 percent recovery factor for the 379B of probable gas, the US would have just 31-year supply.

A lack of data, bias toward optimism, underlies this perception gap. A well-by-well analysis shows “contrary to popular belief, gas production is not growing under current conditions; instead 80 percent of the country's shale gas production has flattened out or declined over the past year”. Total US production is on a "plateau" as new shale gas output struggles to compensate for a 32 percent-per-year decline in conventional gas production. This picture is missing from reporting/auditing.

There is great reason to disbelieve the sustainability of shale gas production. A growing parade of drillers has been sharply curtailing work gas, and shifting to production of natural gas liquids, which might permit them to eke out a bit more profit. The result will be further declines in gas production, despite forecasts suggesting the opposite.

The shale gas phenomenon is new, data thin, one wonders at the wisdom of making long-term decisions with perhaps irreversible consequences. The last two manias lived and died without a wisp of a memory.

This one, if it goes wrong, may not be so benign

579 – answers below:

Tsunamis and running out of coolant – don’t put the backup power supply underground

Earthquakes – not the direct cause at Fukushima – it was the above. Nuclear plants survive earthquakes all over the world.

Human mistakes – that’s the tough one. These cause all sorts of problems with all generating sources, PV and wind installers fall off roofs and nacelles or get electrocuted, wind turbines catch fire and spread dangerous debris, gas plants and steam turbines explode, hydro dams break. These accidents all kill many more people per unit of energy generated than nuclear plants http://externe.info

This is what I mean when I say defuse the hysteria.

Great article thanks Michael-in-Adelaide. A couple of years ago I was at the annual conference of the Association for the Study of Peak Oil and Gas (ASPO) in Denver when a guy from Brazil gave an excited presentation on the 400 billion barrels or so they had in pre-salt deposits off-shore i.e. ultra deep deposits. Given that the world has only had two trillion barrels of available oil and we have used up half of that, 400 billion barrels is quite a lot. But he was treated with general scepticism by an informed audience who questioned the ERoEI of producing from these deposits. Now it seems Brazil has increased its oil production but not quite at the rate anticipated. Instead, there seems to be general acceptance amongst analysts that we passed peak oil back in 2005 and that these unconventional sources are only filling the gap caused by the decline in conventional oil - hence the bumpy plateau we are on at the moment in terms of overall production.

But a complicating factor is one being expressed by Canadian systems analyst Nicole Foss, currently touring Australia,who says the most immediate crisis facing us is the bursting of the current credit bubble which will see another GFC characterised by deflation. That means demand will drop and the price of oil will fall, which means that oil companies will not be able to explore for new resources, partly because the returns if they do drill will not be enough to cover costs and also because of a general lack of investment funds (credit). That may exacerbate the supply problem and the price may then shoot up to unaffordable levels, say $500 a barrel. I think we can anticipate an end to industrialised society as we know it.

579;
Below is the answer I got to the CNG question.
It appears that the problem I mentioned refers mainly to Liquid Natural Gas.
Here he discusses the differences.

You ask about natural gas. Our experience was as follows; and it is different for CNG (compressed NG) compared with LNG (Liquid NG). NG is mostly Methane of course, but the percentage varies wildly depending on the source. The purer obviously the better but the methane content can be as low as 85% and the motor will still run. In UK I don't think the methane content (with NG from the North Sea) was ever more than about 95%. With CNG the purity doesn't matter all that much because you have just got compressed gas in large pressurised cylinders which stay relatively clean ( excepting over a long period of time oil carry over from compressors etc, despite filtration and all the rest.)

With LNG it is a different story. There you have liquid gas at low temperature ( -160 degrees C) in a cryogenic tank. The advantge is that the storage capacity doesn't need to be nearly so big and heavy as with CNG. The disadvantage is that the different gas fractions have different densities and tend to separate out with the longer carbon chain length impurities, being the denser. If a vehicle so equipped rests for a while e.g. a bus in a depot overnight, these heavier fractions sink to the bottom of the container. With constant refuelling these tend to build up so that if you run the tank low, a slug of longer carbon chain gas runs through the motor and jiggers up the sensors, plugs and sometimes the mechanical parts as well. Hence the need for periodic flushing out.

Cont 579

People got quite excited about LNG powered vehicles for a while until it was realised you need very pure methane to start with and it is also quite difficult to hold the low temperature on a road vehicle for any length of time. There are still CNG buses running around (I assume), but they tend to be temperamental (sensor and plug troubles with the Cummins motors that we used) and the tanks, although located on the roof weigh a lot and cut down on the legal payload.
unquote

So I think it sums up that LNG has the definate purging need but CNG
has over a longer time a need to clean compressor oil out of the tanks.
However with LNG the tanks are lighter and smaller.
I presume that the LPG system and tanks would be similar.
I have not heard of the need to purge LPG tanks.

hmmm...lot of good points but little in general direction...

ok...put this in another way...a possible future scenario...energy prices keep gradually increasing...the powers that control us(I dont mean politicians and governments) dont want a sudden jump that suddenly excludes large population percentage from our current way of energy squandering self_serving life...yep...anarchy...

then...sudden crumbling of all governing structure, media goes offline, food ceases in cities, no fuel...so basically your mad max situation...while the 'powers' are secure in some high tech bunker waiting it out..while population collapses...

opposite of this on scale(I doubt very much by the way)...governing continues to deliver energy, and unless some saviour energy source appears, population\economy growth will exceed energy, we are close to this by fact increasing numbers of us are barely making end of each month with some savings....and we all gradually move towards third world situation...and population gradually dies...

whichever it is...by fact warnings sounded long ago but no action was taken other than lip service, when it happens there will be no need for these discussions...it will be apparent to all...so from my personal view point...we are out of all time...

gltuag

sam