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 truck. 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. -- Leo Bicknell - bicknell@ufp.org - CCIE 3440 PGP keys at http://www.ufp.org/~bicknell/ Read TMBG List - tmbg-list-request@tmbg.org, www.tmbg.org