Natural Gas Generator

   / Natural Gas Generator #1  

Rat Rod Mac

Silver Member
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Oct 22, 2006
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177
I have been seriously thinking about a generator for our home when the power goes out ( which averages about 1-2 times a year ). What I would like to have is a natural gas generator. Some thing I could store in the garage and when the power goes out push it out side and hook up a flexible gas line to a hard line in the house with a ball valve quick connection. First off,,, does anyone have one and how do you like it. I'm thinking in the 5500 - 6500 watt range. Any and all pro and con opinions are greatly appreciated. Thank you for your time and trouble. RRM
 
   / Natural Gas Generator #2  
Check Costco on line. Sometimes they have good deals on NG generators.
 
   / Natural Gas Generator #3  
We had one and I wouldn't have wanted to go out and "hook" it up in the weather generally associated with an outage.

Ours was a 20k permanently installed on a concrete pad. It had an auto self cycle every Sunday for 5 minutes. We also had a 250 gal gas tank (LP) tied to it and the office/hatching facility.

Even at 20k it would not run the whole building so we had designed electrical routes with red switch cover plates like they use in a hospital to identify "hot" circuits during outages ( required a transfer type box from the generator supply in the attic.)

Saved our hide a few times for sure. oh, bought ours from Graingers
 
   / Natural Gas Generator #4  
GENERATOR FUEL - WHAT GENERATOR FUEL IS BEST?
There are many advantages and disadvantages to different types of fuel. Nearly all Generators use either gasoline, diesel, natural gas or propane. The following information will hopefully answer any questions or concerns you may have concerning different fuel sources. Some general features of the generator itself influence purchase decision. Where possible we indicted hardware and environmental differences in generator set types. You should consider all the factors shown. POSITIVE, NEGATIVE, GENERATOR FACTORS, are shown by the color of the features.
Gasoline:

* Advantages:
o Common fuel source - easily obtained
o Increases portability of smaller generators


Check this one out

http://www.electricgeneratorsdirect.com/Generac-Guardian-5870-Standby-Generator/p4763.html#reviews




* Disadvantages:
o Highly flammable
o Short shelf life of fuel (approximately 12 months)
o Storing large quantities of fuel is hazardous
o May not be available during power outages
o Somewhat expensive fuel, check your local prices
o Inefficient

Diesel:

* Advantages:
o Least flammable fuel source
o Fuel easily obtained (fuel is easier to obtain during a disaster because it is a necessary fuel for the military, trucking industry, and farming operations)
o On site fuel delivery available
o Engine life for liquid-cooled 1800 RPM engines can approach 20,000 hours if properly serviced depending on the application and environment.
o High speed 3600 RPM diesel engines normally have a 10,000 to 15,000 hour life expectancy with proper maintenance and service under most conditions
o Less expensive to operate. The general rule of thumb for fuel consumption is 7% of the rated generator output (Example: 20 kW x 7% = 1.4 gallon per hour at full load).
o Designed for off-road applications and can operate on dyed or farm/construction diesel fuel which is sold without the road tax and thus is considerably cheaper to purchase.
o Engines designed to work under a load for long periods of time and perform better when worked hard rather than operated under light loads.
o Can operate in sub-artic conditions with fuel additive.
o Equipment is competitively priced for a comparative sized water-cooled gaseous models with the same features.
o In high use situations overall long term cost of operation is much lower than gaseous GenSets.

Diesel Fuel Use Chart



* Disadvantages:
o 18-24 month shelf life, without additives
o Installing large storage tanks raises cost of system
o May not be available during power outages.
o Diesel fuel storage must be considered relative to required run time in your geographical area. If you live in hurricane country you might need a large fuel tank due to the high possibility of extended power outages
o Engine noise is higher on a diesel compared to a gaseous engine. Use of a properly designed enclosure and sound attenuation system is more critical on a diesel engine system.
o Subject to "wet stacking" or over fueling if run for long periods of time with ultra light loads (less than 40% of the rated output). "Wet Stacking" causes the engine to smoke and run rough because the injectors become carbonized. Running a heavy load will usually clean up the over-fuel condition and allow the engine to perform normally. Diesel engines operate better and are more fuel efficient when loaded (70-80% is optimum).
o In sensitive emission areas in some states diesel engines are prohibited from operating over a prescribed number of hours per year to help reduce pollution levels
o Requires clean moisture free fuel and a bit more maintenance than a comparable gaseous unit;
o Some cities and counties require the generator on-board fuel tanks to be double-wall containment type which can increase the cost of the generator system.
o Typically heavier and require more planning to load and unload than a lightweight gaseous GenSet.

Bio-Diesel:

* Advantages: (Same as Diesel see above)
o Least flammable fuel source
o Easily obtained
o On site fuel delivery available


Bio-Diesel is a cleaner-burning diesel replacement fuel made from natural, renewable sources such as new and used vegetable oils and animal fats. Like petroleum diesel, Bio-Diesel operates in compression-ignition engines. Blends of up to 20% Bio-Diesel (mixed with petroleum diesel fuels) can be used in nearly all diesel equipment and are compatible with most storage and distribution equipment. These low level blends (20% and less) don't require any engine modifications and can provide the same payload capacity as diesel. Using Bio-Diesel in a conventional diesel engine substantially reduces emissions.



* Disadvantages: (Same as Diesel see above)
o 18-24 month shelf life, without additives
o Installing large storage tanks raises cost of system
o May not be available during power outages
o Obtaining oils and other fuels.
o Mixing and maintaining proper percentage of oils/fuel

Emulsified Diesel:

* Advantages: (Same as Diesel see above)
o Least flammable fuel source
o Easily obtained
o On site fuel delivery available

This is diesel that is mixed with a small percentage of water and an agent that keeps the water and diesel mixed. By adding the water to the diesel a smaller amount emissions are created when the fuel is burned.



* Disadvantages: (Same as Diesel see above)
o 18-24 month shelf life, without additives
o Installing large storage tanks raises cost of system
o May not be available during power outages
o Obtaining oils and other fuels
o Mixing and maintaining proper percentage of water/fuel


Propane:*

*See propane notes below.


* Advantages:
o Long shelf life
o Clean burning
o Easily stored in both large tanks or in smaller 5 - 10 gallon cylinders
o Obtainable during power outages - gas stations may be unable to pump fuel during an area wide outage
o Home delivery available for larger tanks
o Quieter engine noise level
o More emission compliant
o Gaseous engines do not have a problem with "wet stacking like diesels
o Less expensive units with air-cooled engines are budget priced.
o Engine life for liquid-cooled 1800 RPM engines can approach 5,000 to 6,000 hours on industrial quality gaseous GenSets



* Disadvantages:
o Pressurized cylinder of flammable gas
o Fuel system is more complicated (increased possibility of failure)
o Larger tanks are not aesthetically pleasing (unsightly)
o Fuel system plumbing results in higher installation cost
o Somewhat expensive fuel, check your local prices
o Propane can become very dangerous if lines are broken.
o Propane begins to derate around -20 degrees above zero
o Initial cost of generator is somewhat higher, 15 to 20% especially in sizes larger than 30 kW.
o More expensive to operate by as much as 3-times the fuel consumption compared to diesels;
o Shorter life expectancy by a factor or 10 to 1for air-cooled models and 3 to 1 for water-cooled models compared to diesel powered GenSets
o Smaller air-cooled gaseous engines are less expensive than comparable diesels but have a short life expectancy as low as 500-hours depending on engine make and use
o Shorter life than diesel engines

Natural Gas:


* Advantages:
o Unlimited fuel source - refueling not necessary
o Clean burning
o More available during power outage.
o Quieter engine noise level
o More emission compliant
o More convenient fuel source (natural gas)
o Gaseous engines do not have a problem with "wet stacking like diesels
o less expensive units with air-cooled engines are budget priced.

Natural gas is a mixture of hydrocarbons (mainly methane (CH4)) and is produced either from gas wells or in conjunction with crude oil production. Because of the gaseous nature of this fuel, it must be stored onboard a vehicle in either a compressed gaseous state (CNG) or more commonly as liquefied state (LNG).



* Disadvantages:
o May be unavailable during natural disasters (earthquakes, etc)
o Lower power output (30% less BTU's per unit than gasoline.
o Fuel system plumbing results in higher installation cost.
o Fuel not available in many areas.
o Natural gas (NG) begins to derate at +20 degrees above zero.
o Initial cost of generator is somewhat higher, 15 to 20% especially in sizes larger than 30 kW.
o More expensive to operate by as much as 3-times the fuel consumption compared to diesels;
o Shorter life expectancy by a factor or 10 to 1for air-cooled models and 3 to 1 for water-cooled models compared to diesel powered GenSets
o Smaller air-cooled gaseous engines are less expensive than comparable diesels but have a short life expectancy as low as 500-hours depending on engine make and use.
o Hurricanes and earthquakes can disrupt the flow of natural gas lines with up-rooted trees
o Natural Gas can become very dangerous if lines are broken.
 
   / Natural Gas Generator #5  
I did some very serious study last year into standby generators. As an electrician I was looking at the idea as a side business. The idea of connecting onto the gas supply as you have suggested does not sound like a safe idea. If you want a NG installation I believe it must be hard plumbed for gas and on a permanent pad. You can use a propane generator and run from 100 LBs tanks and not have to get into the gas code. Propane will last forever in tanks. Gasoline is good for 4months +-, diesel for years.
Craig Clayton
 
   / Natural Gas Generator #6  
At work, had a small 5,000 W natural gas unit that was 25 years old... absolute zero problems... it was retired last year because natural gas lines are vulnerable to earthquakes and we have a 150Kw Diesel Unit to tap into for emergency power.

The other choice would have been an easy conversion to propane and have on site propane storage... the permits were more trouble than it was worth.

The Boss told me to scrap the old unit and I asked to take it home... got it in my garage under the bench.
 
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   / Natural Gas Generator #7  
I perfer NG because of the end less supply that I have. You can buy your generator & purchase a tri fuel kit that will let you run all 3 fuels for about 200.00. Simple to install. You will have to condiser that you derate your generator by about 10-15% with NG
 
   / Natural Gas Generator #8  
I am currently piping a natural gas genset for a customer. It uses so much fuel we had to run a dedicated line from the meter to the genset that was 1". We are currently waiting for the power company to install a larger meter because his wasn't large enough to handle the genset and his house load. I will have to go back and connect the new meter when the power company installs the new one. Big bucks!
 
   / Natural Gas Generator #9  
At work, had a small 5,000 Kw natural gas unit that was 25 years old... absolute zero problems... it was retired last year because natural gas lines are vulnerable to earthquakes and we have a 150Kw Diesel Unit to tap into for emergency power.

The other choice would have been an easy conversion to propane and have on site propane storage... the permits were more trouble than it was worth.

The Boss told me to scrap the old unit and I asked to take it home... got it in my garage under the bench.

A small 5000 Kw. generator under the bench in your workshop. What did you move it with.
maybe a 5 Kw. instead.
ken
 
   / Natural Gas Generator #10  
To the original poster, if you want a NG portable generator, I urge you to get a tri-fuel model such as a Winco (with a honda engine) or Yamaha (by US Carburation, reportedly a factory authorized and warranted conversion). I also own a portable 5K generator due to infrequent outages and not being able to mentally justify the $$$ for a whole house system. It is gas only and after a 10 day outage in 2006 I kicked myself for not spending the extra to get the Winco tri-fuel. I still mean to upgrade my current one with a trifuel kit, but I'm kind of hoping for a reason to replace it. I do keep several gas cans around, but it gets to be a pain to find fuel 2-3 days into a wide outage. Had the builder of our new house leave me an extra NG "T" in the basement and an oversize line to plumb into. Don't forget with a portable generator, you will need a way to connect to the house/furnace/sump pump/water heater/lights/TV. Check out an Interlock Kit, is the cheapest code option versus a transfer switch. You won't want to deal with extension cords in bad weather.
 
 
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