Genset reliability ...

lasitterlasitter Solar Expert Posts: 56 ✭✭
I've had a difficult time coming up with good extensive testing data for generators. It's something I want to figure out, because some of the data I've seen has been very revealing ...

http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA569977

I've had a hard time finding anything this detailed about MTBF testing other than just a number from an advertising brochure. When you see how often these systems failed under continuous operation, it's really jaw dropping. The fact that MTTR was only four hours is pretty irrelevant for me, because I'm not going to have an Army maintenance specialist standing by to diagnose the problem and fix it. During a blizzard or other disaster, it could be days or even weeks before getting a service tech out.

Sandy, Katrina, tornadoes and other perils have been known to knock out the grid for weeks at a time, and if I invest in a generator, I actually want it to work when I need it.

Batteries are expensive, but the beauty of them is that there are no moving parts. And especially when they're installed in the basement, where they'll remain at a friendly 55 degrees, you know they'll hold their charge and work when called upon.

Other fears I have regarding gensets is that the battery is generally outside with the engine, in bitterly cold weather. Last year my truck battery was a bit drained (but only a year old), and when it got to 15 degrees below, it literally froze and split open. Batteries that get that cold just don't work without a battery heater, and gensets even need block heaters or fuel line heaters.

A lot of this is worst-case scenario, but then again, that's what generators are for.

So I'd like to hear from people that actually put generators thru extended running times and hear about what kinds of maintenance you have to do every "xx" hours of operation to keep them happy. And I know that portable gensets are handy, but right now I'm thinking about something larger (18-20 kw) run off natural gas.

Thanks in advance.

Comments

  • Dave AngeliniDave Angelini Solar Expert Posts: 4,871 ✭✭✭✭✭
    If it were me I would do what the moderator does here. Install a grid-tie solar system and use a small Honda generator to power in an emergency. Rotate/treat your stored gasoline or convert to propane/natural gas. Buy a second genny and have a spare. The 7000 watt Honda inverter genny easily runs a household as long as the air conditioning has been updated to modern energy usage.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • mike95490mike95490 Solar Expert Posts: 8,502 ✭✭✭✭✭
    Look for a genset with an 1800 RPM diesel, liquid cooled, and major engine mfg. Size it so your average running load is about 75% of it's 100% capacity
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • Dave AngeliniDave Angelini Solar Expert Posts: 4,871 ✭✭✭✭✭
    One has to be very good with taking care of Diesel fuel as it usually goes bad when you need it the most.

    I have a client with a Honda 6500i that runs from propane. I really do not believe the oil has been changed more than twice in 6 years. You can talk on a cell phone next to it running at 1/2 load.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • 2manytoyz2manytoyz Solar Expert Posts: 373 ✭✭✭
    The aftermath of the 2004 hurricanes in Florida resulted in a bunch of dead generators. The news crew did a story on the cause. The typical contractor grade inexpensive generators require an oil change after 20-25 hours. That's 1 oil change per day! People were running them non-stop for several weeks. Trashed the motors in the meantime. Air cooled motors do run hotter than water cooled. As a result, the oil needs to be changed frequently.

    The more expensive inverter type Yamaha and Honda generators only run as fast as the load demands. The oil change interval for mine is 100 hours (after break-in period). Still, after 4 days, the oil NEEDS to be changed. Plan accordingly, have plenty of appropriate oil on hand.

    I've owned my generator since 2006. Nine years worth of use so far, with no concern of ever wearing it out, even if we lose power for extended periods. Because of my webpage on the topic, I've talked with many owners over the years. One owner used his Yamaha EF2400iS to run his off-grid workshop exclusively. He had over 10K hours on it, and it only needed the pull cord replaced, along with routine maintenance. He was upset when he shared his story with Yamaha, and they never bothered to respond. Ya'd think this would be good PR for the company!

    Bill Paxton, a representative for the Onan generator corporation was quoted as saying generators don't die from use, but rather from lack of use. Run them every month whether they are needed or not. That means putting a load on them, and having them work for 1-2 hours each time. I have mine running in the back yard while I mow the grass. Still runs like new.

    Because of the frequent outages here in FL, more specifically, in lightning alley, I have no interest in a grid tie solar setup. Mine is an off-grid setup for many items via the 900AH battery bank. Other grid tied items automatically switch over to the inverter when the grid goes down. I can run all my critical loads at night on battery/inverter power. During the day, I can use a combination of solar and generator power to replenish the battery bank. Because the generator is only needed a portion of the day, the fuel consumption is even less. More importantly, my house is silent at night. Noisy generators invite unprepared neighbors with extension cords.
  • lasitterlasitter Solar Expert Posts: 56 ✭✭
    mike95490 wrote: »
    Look for a genset with an 1800 RPM diesel, liquid cooled, and major engine mfg. Size it so your average running load is about 75% of it's 100% capacity

    I've been lusting over a Perkins genset for some time, but I've been told that the install cost for air-cooled generators is much lower than water cooled. I can understand some price difference, but not a lot ...
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,871 ✭✭✭✭✭
    lasitter wrote: »

    I've been lusting over a Perkins genset for some time, but I've been told that the install cost for air-cooled generators is much lower than water cooled. I can understand some price difference, but not a lot ...


    If the installation is to the local building code, there is a large difference in price to install a fixed Diesel engine compared an air cooled gas or gasoline unit. My Perkins on my sailboat had over 9,000 hours when I sold her. They are great engines but as Robert wrote, you use them or lose them. Even more so with a diesel fueled unit as the fuel can really grow things in it in a warm environment. How much are you realistically going to need this?

    I still get the shakes when I remember my time in Lightning Alley! That is one nasty event in the afternoon! Really nice winter fishing! Lightning capitol of the world!
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • peakbaggerpeakbagger Solar Expert Posts: 341 ✭✭✭
    I worked for a firm at one point that specialized in way off the grid remote power systems for scientific and industrial sites (like Antarctica and Greenland and remote pipeline sites). They worked with manufacturers to buy critical grade generators. I seem to remember Kohler as a popular fit but they also had to design the off gird systems to make sure that they weren't abusing the diesel by running it at part load. I was on the mechanical side but the approach was to have a large battery bank and run it down enough that the diesel would run at full load during a charge.

    Pretty much standard for reliability are the the Lister Petter slow speed diesels, but the Indian clones had their issues and the EPA shut down importation several years ago.

    Unfortunately anytime something is bought on price is most likely going to be built cheap. Even the big names like Generac have built Hurricane/ice storm specials, they do it to stay in business and regard them as throwaways. Given the major ethanol issue with gas gensets these days, unless they are drained after use, they usually will not run again if the unit sits more than a few months. Even worse are the big companies who license their names with no concern for quality (like Honeywell).

    With respect to diesel, there are additives to kill off the nasties that will grow in it, usually in warm marine climates. Once the bugs get in the fuel system its very difficult to get them out. I think one product is Biobor.

    I guess if all heck breaks loose I have an air cooled Lister Petter AC1 pull start 12 volt diesel genset stashed in the garage. One of their many uses were the flashing arrow traffic signs, they would run for years in that use.
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    The Lister and Listeroid generators have one problem: The shaft speed varies significantly between power strokes, so anything that requires both stable voltage and stable frequency can have issues. Not the case for battery charging though.
    Just do not run your audio turntable off one.
    SMA SB 3000, old BP panels.
  • mike95490mike95490 Solar Expert Posts: 8,502 ✭✭✭✭✭
    inetdog wrote: »
    The Lister and Listeroid generators have one problem: The shaft speed varies significantly between power strokes, so anything that requires both stable voltage and stable frequency can have issues. Not the case for battery charging though.
    Just do not run your audio turntable off one.
    Aw, it only makes some of my lights (the cheap ones) flicker a bit. Lets the wife know we are on genset power.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • john pjohn p Solar Expert Posts: 814 ✭✭✭
    Mike 95490s advice is the best by far.... Any generator doing 3600 rpm is never going to last long. ..Lister ,Perkins are both excellent and have been in business forever. If you have the money and really want the absolute best buy a Northern Lights generator.... Last long enough for your grand children.. And are very easy to service.. but parts cost lots but you wont need them often..
    Also there are diesel additives you can use but need to be added as you add the fuel. not 6 months later..
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,871 ✭✭✭✭✭
    Even better reliability than a Perkins is not having the need for a generator.
    Over 30 of my clients in areas like the southwest have solar systems designed not to need a generator. The Honda inverter engines are a realistic choice for 2nd best if you need a generator.
    My brother has my 12+ year old EU2000i and it still does the job.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

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