Many times it is in water column inches. I used to know the normal amount. 4 inches I think and Propane is 12? Something like that. Very low pressures. For high flow you use two regulators. On LP the first takes tank pressure down to 9 psi and then the one at the generator takes it down to 12 inches.
From: Lewis Bergman Sent: Saturday, December 03, 2016 2:24 PM To: [email protected] Subject: Re: [AFMUG] generator fuel I tried to put an NG gen set on top of a building and the has company said they didn't have enough pressure I think I needed a few pounds and they only had 6 ounces. On Sat, Dec 3, 2016, 10:04 AM Chuck McCown <[email protected]> wrote: Just cruising the used generators on Ebay. They seem to be a pretty good value. Found several with 250-400 hours in that price range. Wondering which brand has the best reputation of longevity. From: Mark Radabaugh Sent: Saturday, December 03, 2016 7:18 AM To: [email protected] Subject: Re: [AFMUG] generator fuel FWIW I purchased a new CAT 125KW diesel genset with a 420 gallon base tank and transfer switch for ~33k last year. I think 10k might be a little low, but not too far off. Mark On Dec 2, 2016, at 9:39 PM, Chuck McCown <[email protected]> wrote: It is more than a half mile away. Primary build. Not sure they would even do it as that is at the end of a crappy line feeding a center pivot irrigation pump and system. Up where I need it everything is underground. Right now I am paying about $2K/month at a different site for a similar load. They really screw you on the demand charge. I figure I can get a decent $100K NG 3ph generator for $10K. From: George Skorup Sent: Friday, December 02, 2016 7:29 PM To: [email protected] Subject: Re: [AFMUG] generator fuel OK, but what would be the cost to have your power co bring 3phase to you? More or less than a 3-phase generator? Or can they simply not do it? On the other hand, what would it then cost you for 3-phase service from said power co? I know of a couple grain handling sites around here pay about $1200/mo. But that's cheaper over the long haul than buying, maintaining and paying fuel cost for a 100kW genset, even NG. On 12/2/2016 8:18 PM, Chuck McCown wrote: Not bad considering my NG is going to cost half or less than diesel. And it will be periodic use, not constant. I need to make a boatload of 3 phase 480 where only single phase exists an the loads will be highly variable. I could use a big ass rotary phase converter but based on the cost of fuel alone, I will save money just running the generator when needed. Especially true if they charge me a demand charge. From: Eric Kuhnke Sent: Friday, December 02, 2016 7:11 PM To: [email protected] Subject: Re: [AFMUG] generator fuel Looking at it another way, I have calculated previously that the cost per kWh for 24x7 power from a diesel generator is in the range of $0.35 to $0.49 per kWh. That's including the purchase cost of the generator, maintenance, expected lifespan, cost of fuel, etc. If you want to see prime power examples of diesel used for islanded grid power, each town in Nunavut has its own set of diesel generators and tanks. There is no long distance transmission setup or inter-city grid. http://www.qec.nu.ca/home/ On Fri, Dec 2, 2016 at 5:57 PM, Chuck McCown <[email protected]> wrote: I agree, but my application is primary power, not emergency. From: Eric Kuhnke Sent: Friday, December 02, 2016 6:53 PM To: [email protected] Subject: Re: [AFMUG] generator fuel I don't think it's fair to directly compare diesel fuel to natural gas, because one is portable in just about any container (in a real emergency), the other is not. http://www.datacenterknowledge.com/archives/2012/10/31/peer-1-mobilizes-diesel-bucket-brigade-at-75-broad/ On Fri, Dec 2, 2016 at 5:49 PM, Chuck McCown <[email protected]> wrote: I am assuming a BTU of fuel will make so many Wh of energy. If perfectly efficient 1M BTU =292.3 kWh That would cost me $35 from the power utility. A gallon of diesel is abou $3.25 around here. 139000 btu. Diesel then is about $23 per 1M btu. However diesel engines are only 30% efficient so it will cost me $76 in fuel to make that 292.3 kWh If that assumption is approximately correct: I pay about $7.80 per decatherm in the winter for NG. A decatherm is 1 million btu About half that in summer. $7.80/.3= $26/293.3 kWh for NG not considering depreciation and maint of the generator. It seems to me that NG is the hands down fuel cost winner? Anyone see mistakes in this?
