New member

Propane vs Diesel generator

[ Edited ]

We are looking at a 275kW diesel generator for our project but due to environmental issues associated with diesel fuel storage in a Water Supply Protection Zone, the possibility of using a propane-fueled generator was raised.  What are the pros and cons of each, based on the following comparitive criteria:


1.  Initial cost of equipment/installation.

2.  Fuel cost.

3.  Maintenance cost.

4.  Any other merits/limitations (i.e. run time of 300-gal diesel vs 1000-gal propane).

5.  Noise. 


Any feedback would be greatly appreciated.

Message Edited by woodag on 01-28-2010 09:46 AM

Re: Propane vs Diesel generator

I am a technician and don't deal with finance figures very often, but from my experience with Natural Gas/Propane generators vs. Diesel generators:


1. Initial cost of equipment and installation will probably be higher for Natural Gas/Propane generators because these generators don't provide as much power as Diesel will. To achieve the same required rated kW with a NG/Propane as a diesel generator, the engine and housing will be much larger with NG/Propane.


2. Fuel costs will depend on your area; check with your NG, propane, and diesel fuel suppliers to find cost/unit figures and you'll have to find specific fuel consumption figures from your generator manufacturer to do an accurate comparison.


3. Maitenance costs are going to be fairly similar, you just have to account for the larger generator engine size with NG/Propane, so parts costs and labor times may be more due to increased size. Propane/NG also has spark plugs that will require maitenance and diesel may require regular load banking if you can't achieve sufficient load regularly to avoid wet stacking.


4. Is this going to be used for prime power or standby? If at all it's going to be used for prime power, NG/Propane should be strongly considered. Diesel engines usually have much faster starting times. If a 10 sec power outage to NE transfer is required, you need to consider a diesel.


5. You can get sound-attenuated housings if you're keeping it outside. Sound-Attenuated Housing Info  Although they're a hassle to service with those housings, they're extremely quiet.


Also, about your environmental issues. At only 275kW, you can look at some pretty high tech emissions solutions; I'm not an expert on this, but it looks like Tier 3 is possible. Low Emissions Brochure  These new diesel generators burn very clean, very little soot (black smoke).