In a message written on Fri, Apr 04, 2003 at 04:13:46PM -0800, Bill Woodcock wrote:
Right. So if you have a choice of storing gas or diesel, and gas usually
doesn't have to be replentished by truck, since it's _usually on-tap_, but
diesel _always has to be replentished by truck_, since it's _never
on-tap_, why would one ever choose diesel unless, as per previous caveat,
clueless fire marshalls thought it was really preferable?
I'm not an expert but:
1) Storing natural gas is significantly harder (both in the containers
and permiting) than Diesel. It also has less energy density, so it
takes more space.
2) Having natural gas trucked in, rather than delivered via pipeline
is also extremely difficult, and possibly impossible in some areas.
The infrastructure simply doesn't exist.
On the other hand I could pick up the phone and have a semi-truck
full of Diesel in any major metropolitan area in an hour or so
for cheap. Indeed, it's very easy to get "guaranteed responce
time" diesel contracts for emergency generators, I'd love to know
if anyone has even attempted that with Natural Gas delivery by
3) Getting a natural gas feed for a large data center (read a couple
of megawatts) is probably impossible in most areas. The distribution
network for natural gas just isn't set up for it. Much less of a
concern for the people who need a few hundred kilowatts.
4) In larger sizes, Diesel gensets are _cheap_. Remember, the thing
sitting outside the data center is essentially the same as every
diesel-electric railroad locomotive, every portable power source,
and a whole number of other things. Natural gas isn't generally
a good idea for your train locomotive, so the gensets are less
tested, harder to find, and more expensive.
So, IMHO, natural gas is good for smaller applications (probably
under 250Kw), in areas where the gas is stable so you don't have
to do on site storage. Otherwise Diesel is probably cheaper (both
in genset cost and fuel cost), and easier to obtain.