They have multistage compressors that do it in high volume. I have seen them
aboard ships. The 2" drive impact guns to tear apart large diesel engines
run at 2,000 PSI. Never been to a gas plant though.
I agree. It's only a way to store the energy.
The real question is what is an effective means
to store energy for a time when you need it?
Ultra capacitors quickly loose their charge,
batteries lose their charge over time as well.
What's nice about gasoline, diesel, and jet-fuel
is that they don't loose the energy store inside
them even when the pressure varies. The
weakness with storing energy in hydrogen
gas, propane, methane, and compressed air
is that the energy storage device requires the
fuel be pressurized and that temperature
can significantly effect the power efficiency. .
Gasoline, diesel, and jet-fuel don't loose the energy store inside for sure.
and the energy density is high. But we do not have motors to efficient
enough and in reality only 25% of the energy in one litre is used, so making
the energy density quite low in real use.
Compressed air does not fade but affected by temperature, and air is free,
Brake regen can be via compressed air. Supercapacitors also will just last
and last, unlike a battery.
Work is ongoing with supercapacitors with charge retention increasing
dramatically. One company claims to have made one with the same size and
energy density of a Lith-Ion battery. The Prius was originally to have a
supercapacitor 10 years ago.
Supercapacitors offer great advances. There is lots going on in this field -
utracapacitors or supercapacitors. Ultracapacitors combined with a battery
is the answer to hybrids until batteries get developed even further. The
capacitors take in nearly all the kinetic energy of braking and slowing down
and can immediately give it back off. They will immediately take all of a
charge and give the lot back off immediately too. They do not go wrong,
deteriorate and will outlast the car. But existing Ultracapacitors hold 25
times less charge than a battery of similar physical size. There are
breakthroughs that promise it will be about equal in this respect.
Advances are so good that it is feasible that ultracapacitors can just
replace the battery set on a hybrid altogether. They can charge up in
seconds from the grid.
They have great potential for use in elevators where the downward energy is
stored to push the elevator back up. This would make a huge impact in the
energy in the running of millions of elevators and other electrical
equipment. Knock-on effects are great.
"China is experimenting with a new form of electric bus (capabus) that runs
without powerlines using power stored in large on-board electric
double-layer capacitors, which are quickly recharged whenever the electric
bus stops at any bus stop (under so-called electric umbrellas), and fully
charged in the terminus. A few prototypes were being tested in Shanghai in
early 2005. In 2006, two commercial bus routes began to use electric
double-layer capacitor buses; one of them is route 11 in Shanghai.
In 2001 and 2002, VAG, the public transport operator in Nuremberg, Germany
tested a hybrid bus which uses a diesel-electric drive system with electric
Since 2003 Mannheim Stadtbahn in Mannheim, Germany has operated an LRV
(light-rail vehicle) which uses electric double-layer capacitors to store
MIT Builds Efficient Nanowire Storage to Replace Car Batteries
Why Ultracapacitors Will Be Your Hybrid's New Best Friend
"The Zenn Motor Company is waiting until a new power storage technology is
ready before it releases the vehicle, called the cityZENN, which will
achieve 80mph speeds and have a range of 250 miles.
"Rechargeable in five minutes, the vehicle will use ultracapacitors from
Texas-based EEStor instead of conventional lithium or lead acid batteries."
"Based on these claims, a full charge should give the capacitor sufficient
energy to drive a small car 300 miles (480 km). Although the technology
should allow very fast charging (e.g., 5 minutes), "
EEstor have not come up with the goods yet. Scam? We shall see.
And for another refreshing dose of reality, check out the history of that
endeavor and note for how many years they have been promising to start
production "next year".
There are sound physical reasons why you don't see compressed air cars on
the street. Energy storage density is the first big problem, and then there
is the inconvenient fact that compressing air is a highly inefficient way
to store energy. (40% or less efficiency) See
What if after pressuring the air tank to 300 psi with a regular
at 75 degrees fahrenheit, the air tank is heated?. If the air tank
the increase pressure - would the increasing pressure several folds
by heating it in the tank create enough power? Or would the weight of
tank be so massive that it would be not feasible?