/ Maggie Koerth-Baker / 2 pm Fri, Nov 2 2012
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  • In backup generators we trust?

    In backup generators we trust?

    It's normal for backup generators to fail. If we want a more reliable system, we'll have to change the way the grid works.

    Image: Photo: Jemimus shot this photo of a new backup generator (cc-licensed).

    Backup generators exist anonymously. They are metal boxes, squirreled away on a roof or near a loading dock. You are meant to not see them. The point is that they are there when you need them and, the rest of the time, they do their best to be unobtrusive.

    The problem is that this very job description makes it more likely that your emergency generator won't work in an emergency.

    On Monday, New York University's Langone Medical Center lost power during Hurricane Sandy, and ended up having to evacuate 215 patients when the generator that was supposed to keep its charges alive and its critical systems running failed to turn on. Across the United States there are about 12 million backup generators. Most only operate during blackouts — times when a hospital, or a laboratory, or a bank, needs electricity and can't get it from the larger electric grid.

    But backup generators aren't 100% reliable. In fact, they won't work something like 20%-to-30% of the time, said Arshad Mansoor, Senior Vice President for Research & Development with the Electric Power Research Institute. The bad news is that there's only so much you can do to improve on that failure rate. The good news: There are solutions that could help keep a hospital up and running in an emergency, even if the emergency power system doesn't work.

    So why do backup generators fail? The short version is that we only use them, you know, for backup. Most of the time, these generators just sit around, doing nothing. It might seem like you're keeping them safe, but it's actually a pretty rough way to treat a mechanical system.

    If, like me, you've ever owned a scooter in a cold climate, you'll be familiar with this paradox. You store the vehicle away, nice and safe for the winter, and when you get it out in the spring it actually runs worse than it did back in October. Maybe the battery is dead. Or the oil needs drained and replaced. Whatever happens to be specifically wrong, leaving mechanical systems to sit around for long periods of time isn't really good for them. This is why the spring tune-up exists.

    "It's not an issue with the actual quality of the generators," said Dan Zimmerle, assistant research professor at Colorado State University's Engines and Energy Conversion laboratory. "It's maintenance related. For instance, if you don't burn deisel fuel sitting in the tank, it will start to degrade and clog the fuel filters. Things that don't get used tend to fail."

    Together, the combination of nationwide electric grid and backup generator means you'll most likely have the lights on at any given point in time. But it's not a guarantee against blackouts.

    Instead, Zimmerle and Mansoor say we need other lines of defense, if we want to avoid hospital evacuations in the future. And microgrids are one possible solution.

    Today, we rely on an electric grid that stretches coast to coast, throughout the United States and Canada. Large areas of that grid can be managed independently — everything east of the Rocky Mountains, everything west of the Rocky Mountains, Texas, and Quebec — but for the most part, small hyper-local bits of the grid can't really break off and do their own thing in an emergency.

    There's a few reasons for that. First, most of our workaday electric generation is done in bulk. By which, I mean that it happens at very large power plants, which each serve millions of customers, and those power plants are located relatively far away from the people who use the power. The second issue has to do with the way the grid operates. Electric grids have to maintain a constant, almost perfect balance between electric supply and electric demand, and that means maintaining a constant voltage and frequency.

    Right now, your neighborhood gets that voltage and frequency signal from the larger grid as a whole. If you're suddenly cut off from the signal, your neighborhood will cease to have a working electric system — even if there are sources of generation right there down the block.

    In an emergency situation, we do suddenly have lots of hyper-local generation sources — those 12 million backup generators. What we don't have is the infrastructure in place to take advantage of that. A backup generator can power a building, but, in general, it can't share resources with the building next door.

    A microgrid would change that, enabling areas the size of neighborhoods to operate independently in the event of an emergency. "Your backup generators are tied together and then you can redirect power from where it's available ... say at a bank ... to a hospital, or a fire station, or someplace more critical," Zimmerle said.

    Doing that means updating technology, but it also means changing the way we think about legal and regulatory frameworks. In particular, Zimmerle pointed to power purchase agreements — contracts between the people who get electricity to your house and the people who generate it. In some places, those two jobs are done by the same people. But where they aren't, power purchase agreements usually limit the amount of electricity that can be generated locally. That cap can be as low as 5% of total and it includes everything from college campuses that make their own steam and electricity, to the solar panels on your neighbor's roof. The contracts aren't evil. But they do make it difficult to set up microgrids.

    The other big problem is cost. Updating infrastructure is expensive. And it's been hard to convince utilities to spend billions on a system that they're only going to use in rare emergencies. Even when, in one case, you're spending billions in small doses over a long period of time, as opposed to having to spend billions (and possibly a greater amount of billions) all at once to deal with storm damage and shutdowns. Basically, we don't have microgrids now because utilities have looked at the balance between cost and benefit and didn't see a big enough benefit.

    But, as 100-year storms become more frequent, the outcome of that analysis could start to change.

    Check back on Monday, when we'll talk about smart grids and how they can help keep the lights on during a storm.

    / / COMMENTS

    / / / / /


    1. I used to work for our state road authority. We did operations across the road and highway network. Mainly emergency phones, traffic signals and incident management. We had a good UPS and it was set up to run for one hour in every three weeks. To my knowledge we never used it. The mains supply was pretty good but if it wasn’t going to work we would have known at most three weeks after the fault occurred.

      The funny bit is that the UPS knocked us off line for a weekend. A security contractor needed a new power circuit so he attempted to wire a cable to a hot circuit breaker. His screwdriver slipped and he shorted the white phase active to the breaker panel chassis and blew two 100A fuses, one going into and one exiting the UPS, as well as the power supply on one of our two redundant alpha servers, though I only found out about that when we got the power up the next day. Those 100 amp fuses are big bits of metal. Must have made a hell of a bang.

      1. Wiring a hot breaker that deals in 100A fuses? Either the contractor was nuts or had some big ones…

        1.  There are old electricians and there are bold electricians. There are no old, bold electricians.

    2.  Owners of large permanently installed backup generators generally have them due to mission critical purposes.  Even a ‘small’ 100kW permanently installed generator costs about $20,000. Owners protect their substantial investments with periodic maintenance and (at least) monthly testing. Diesel and petrol fuels are preserved with stabiliser additives, making it useful for about 2 years or more.

      There’s a very good reason why backup generators are isolated from the grid with devices known as transfer switches. If there’s a power outage in the area, linesmen need to know when the grid is energised and when it’s not. Secondary supplies such as grid-connected solar PV systems automatically detect when mains AC is not present and shut down precisely for this reason. It would be complex and difficult to arrange ‘microgrids’ which could still be serviced safely by workers.

      1. The other big reason that microgrids aren’t used is that you’d have to have very clever circuitry to do localized load shedding, since a couple megawatts from the nearby data center would only be able to power a building or two next to it. The microgrid would need a rather sophisticated comm network and algorithms (augmented by payments to the local power Mafia) to select which loads would be fed and which would be shut off.

      2.  At my previous position with MaAndPa Internet provider (No fooling, they started their business in ’93 by leasing a T1 and reselling terminal services to their friends!), we had a big 40Kwh jobber around back near the smokers alley. Tested it every week on Monday. Of course, that was still when I was smoking a pack a day, and I’d always jump out of my skin when the thing fired up. Worked like a charm. Never failed the 5 years I worked there.

      3.  automatic exercising usually takes care of the routine “will it start?” question but does not usually transfer any load to the engine.  this can result, particularly with diesel engines, in the buildup of carbon which can cause misfires and loss of engine power.

        maintenance chiefs need to run the systems under load periodically to verify operation of transfer switches and other equipment.  the loaded run also minimizes deposits in the engine by bringing it up to full operating temperature for an extended period of time.  the best way to test the entire system is to run a simulated power failure on a schedule that minimizes interference with site operations.

        of course, this presupposes that the maintenance staff is familiar with the system (management didn’t just let the guy who understands the system go as a cost-cutting measure) and that management understands that the cost of a little fuel is worth it.  and they really should refill the tank!

        another good reason not to feed back into the grid is the likely possibility that the outage was caused locally by downed lines shorting to ground.  connection to the grid would just cause the system to trip offline anyway.  if for some reason it didn’t, downed lines could be energized and a hazard to anybody coming into contact with them or something that they have inadvertently energized, like a puddle, or a utility worker.  the liability enormous too.

    3. I worked in a place with three backup generators – one generator was all we needed for emergency power, but we needed to have it when the grid failed – the generators were tested weekly, run for a period of time, and shut off. If they didn’t work, the generator guy fixed it. I imagine this was an expensive but very effective method of ensuring 100% availability of a generator in an emergency.

    4. I work on big radio telescopes in Arizona, and we use backup generators due to the unreliable nature of electric power on mountaintops. Our generators are quite reliable, but mostly because they get used often, for periods of hours rather than minutes.

      I can see how a generator in a city would have little chance to get used, so its maintenance would be suspect. Those big Diesels really like to be run regularly.

      We had one amusing incident when there was an all-day power shutdown at the telescope to work on the 25KV wiring. The generator’s engine is normally kept warm by an electric block heater, so that it will be ready to start. But since the power was off all day, the generator got cold, and it had a lot of trouble starting. I learned that a backfire from a megawatt generator is impressive.

    5. My company has a large, backup generator, and they test it once per month for about an hour.  How do I know this?  Because my office is 15 feet away.

    6. Didja know it’s pretty easy to hack a Prius into the mother of all UPSes?  You can get 1KW of 113 VAC true sine wave by putting a cheap inverter on the 12 volt bus… leave the key on, and whenever the battery gets low the engine will start.  When you don’t need it as an UPS, you can drive it to the grocery store, keeping the engine and fuel conditioned.

      Personally, I have so arranged my life that I do not really need electrical power.  This required literally decades of planning, though.  Our culture makes it expensive and difficult, and people treat you differently (usually, they will assume you are a violent, dangerous conspiracy theorist) if they find out that you’ve gotten anywhere near self-sufficiency.  And some people, frankly, are physically incapable of living without external assistance, and that doesn’t necessarily mean they are bad people in any way or that they should be abandoned to their fate as soon as the lights go out.

      The power companies will never willingly allow a distributed co-generation system to replace the grid.  They are pushing as hard as they can in the opposite direction, and the only US Presidential candidate likely to change that is Jill Stein.  Who I’m pretty sure you won’t be voting for.

    7. Any business that isn’t doing regular (weekly, here) tests of their generator(s) must not be very concerned with business continuity. 

      At home, too, its a good idea to test it at least before the beginning of the storm season..that gasoline doesn’t last forever, for one thing. Which reminds me..I have some Fall maintenance to do.

      1. That or the bean counters think the time and fuel for such a test is too expensive. It’s all about the numbers these days, and short term expenses needs to be avoided like the plague…

    8. I concur that the utility model is outdated and that diesel back-up generators are unreliable and environmentally unfriendly. However, commonly omitted from most discussions on our energy future is the role of combined heat and power (CHP), commonly known as cogeneration. Unlike other forms of distributed generation (e.g. solar PV), these systems provide 24/7/365 baseload power to serve most of a facility’s electricity and heat needs independent of the grid–with roughly twice the efficiency, half the emissions, and dramatically less water use compared to power plants. Since most CHP systems are fueled by high-pressured underground natural gas pipelines (not a perfect fuel, admittedly), adopters can remain operational in the event of natural disasters. For instance, the NYU campus has kept its lights on in the aftermath of Sandy thanks to its CHP system. Similarly, the Jackson Medical Center in Mississippi remained operational during and after Hurricane Katrina. (More info on these case studies below.)

      The superb, non-profit regional Clean Energy Application Centers provide general outreach about CHP as well as project support for prospective adopters. (URL below)

      More on NYU’s CHP success story:

      More on Jackson Medical Center’s CHP success story:

      More on the DOE Clean Energy Application Centers:

    9. Minor comment for those considering big generators…  Dual and triple fuel models are available, which run on any of Diesel, Natural Gas, and (for triple) Propane.

      Diesel is more portable and likely to be faster resupply in a disaster; for non-earthquake disasters the natural gas lines may be on when roads are impassable or flooded or snowed in; propane is reasonably resupplyable and will last forever without fuel conditioning in your propane tank, so you don’t have to worry about testing and reconditioning and rotating your diesel supply, which is both hard and easy to get wrong by accident.

      Slightly more costly than single-fuel models, but for flexibility in an actual serious disaster well worth it.

    10. The other issue is that charging the electrical lines can potentially lead to a fatalities among linemen.  Backup generators are designed only to supply energy to a building when the power is disconnected from the grid.  Linemen need to know whether a power cable is charged or not otherwise they could be electrocuted.  Further, a key issue with distributed power is making sure that all the AC current is on the same phase.  Sure they may all be running at 110/120 Volts at 60 HZ, but for it to work all the generators must be phased the same.  

      The reality is that the grid in the US although in need of some updates, especially for the switch from to alternative energy sources that are likely to be much further from urban centers, is very robust.  Black outs are in frequent and thus individuals don’t really plan for them.  For example, a small generator that can run 50% of the time that is capable running your fridge and a few appliance would be sufficient for most families.  Do I have a backup generator?  No, but its on the list, is it on yours?  

    11. Six years ago, after four failures in ten years, we installed a natural gas home generator; my wife was at home dying of cancer. The generator worked perfectly during three power failures and then failed, after my wife’s death, because we had not checked the oil level in the machine.

      We now have a yearly checkup by the electrician who installed the generator, and I run it manually once a month.

      Any suggestions for getting my failure rate below the 20-30% predicted in this article?

      Many thanks, Robert

      1. Depending on the size of your generator, you may want to schedule annual load testing with a local generator servicing company.  The load testing will guarantee that your generator can run up to its 100% capacity, and that all the components are in good working order.  Things like leaky gaskets will become visible at higher loads, and then you can get them fixed before they become a problem during a prolonged emergency.

    12. Keeping a generator happy and healthy isn’t any harder than keeping your car happy and healthy. Don’t let it sit. Oil and filter changes at regular intervals. Give it fresh fuel. Follow manufacturer’s recommendations for service intervals. The problem is that many people and organizations treat these devices as install-and-forget. I worry that your 20-30% failure rate is misleading, because it suggests that the failure rate of the generators themselves is much higher than it is, when in reality, the failure is of the owners to maintain the devices.

    13. After experiencing three or four outages a year here, I bought a 30KW Kohler model that runs on nat gas. We have it programmed to run once a week, long enough to re-charge the car battery that starts in an emergency and chase the mice out of the housing. We have it serviced twice a year and it has never failed to engage as advertised. I have four furnaces and five AC units in our house (7200 sq ft) and it will run everything, although they say if all the AC units try to start at once, it could be a problem, but they usually don’t and when I am going to be gone, I turn several of them off. It is also a good idea to still turn off everything that is not necessary as the more you use, the more nat gas it uses. The cost about five years ago was $23,000. It is essentially a 4cyl GM engine. Pay the few extra bucks for the noise suppression kit. The neighbors will thank you. They will thank you even more if you let them run an extension cord to an outside plug to keep their fridge running and phones charged. This unit also runs on propane and gets slightly better milage on propane, but nat gas is much easier. The cost to run a day is around $200, which is a bargain when you figure how much it costs to send the family to a hotel and lose all the food in the freezers. 

    14. fyi – a California company, Capstone Turbine has microturbine generators that are extremely reliable and clean. They have only one moving part – frictionless – because it floats on an ‘air bearing’, needs no lubrication, no maintenance, runs on many fuels, is virtually emission-free, and has 100% ‘black start’ reliability.  No comparison with diesel/etc. reciprocating engines – not even in the same league – also much quieter.

    15. Any good, modern generator automatically tests itself periodically, usually once a week.  Even the small residential generators do this.  The ones at work sound like a freight train and come on for I think 30 minutes every Tuesday morning at 7AM.  They get used fairly frequently and they’ve never failed. I have not heard of one of the good residential ones failing either.

      As with computer backups and any other seldom used emergency measure, you can’t say you have the measure in place unless you test it periodically.  Almost nobody tests computer data backups until they really need them, and as a result, they wind up losing data. Part of deploying any emergency system is to make and stick to a plan to test it on a regular basis.

    16. Regarding fuel storage, the reason why gasoline and diesel “go bad” is because they are a mix of many different molecules, some light, some heavy. If you let them sit, the heavy stuff sinks and the light stuff rises. Most tanks draw off the bottom, so fuel that sits pulls the heavy stuff first, which gums up the engine and doesn’t burn easily. Ideally, long-term storage tanks should have agitator stirrers or jet pumps in the bottom to periodically circulate the fuel and mix it up before use

      Second, although gas and diesel tanks are normally unsealed and vented to the atmosphere, ideally they should be sealed and designed to hold pressure. The lighter hydrocarbons evaporate and slowly boil off, especially if the tank is aboveground and warms up during the day. Eventually you are just left with a thickened sludge after many years of storage.

    17. Plenty of great comments here with good advice!

      Before you start worrying about maintenance, it’s important to consider whether or not the correct type of generator is installed.

      Making sure that the generator is correctly sized is crucial.  You’ll want your total electrical demand to be 60% to 80% of the generator’s rated capacity, so that the engine isn’t running at either extreme for long periods of time.  If your power demand is highly variable, you may need two or more generators to keep the generator engines running in their midranges.

      Another thing to consider, when using natural gas, is the capacity of the local distribution system.  Capacity can vary within cities, particularly in older areas where it can be undersized, and this will affect the size of your generator.  Not only will you want to check with your natural gas provider before purchasing a generator, you’ll want to verify their numbers with load capacity testing while your generator is being commissioned.  If capacity is a severe problem, you’ll want to consider other fuel sources.  Also, load testing will verify that the piping system that ties your generator into the distribution system is properly designed and installed.

      Purchase a common model of generator, because this will affect how easy and expensive it is to service and to obtain spare parts.  Find out what’s installed in your local area, and talk to service companies (not the manufacturer) about what generators they have experience working on.  Avoid exotics at all cost.

      The more you know!

    18. I meant to also include above the importance of oil. Before installing the 30KW stand-by model, I had a portable generator which put out about 5000 watts. The manual said you have to change the oil every 12 hours of operation. I would bet most people do not do that. These babies eat the oil. My Kohler unit has a large oil reservoir that automatically replaces spent oil. The two big reasons they fail are: not running them enough to exercise the engine and charge the battery and not changing the oil. Mine is as dependable as the electric company here losing power at the worst possible time. 

    19. i used to work in a Recording Studio and a back up generator was installed in response to the UK’s ‘three day week’ when a strike by miners actually killed a government, later a government pretty much killed that union but that’s another story.  We ran the generator (much bigger than it really needed to be and of v high quality) every week for about 30mins – it made a ridiculous strangled sound and belched diesel and oil smoke as it kicked in went to high revs and then stabilised.  People recording didn’t realise they were on emergency power isolated as they were in the studio.  I don’t know how the oil and fuel were maintained I do know that in my five years there it never failed and it was also never used in a real power failure.  This doesn’t seem to be that difficult to achieve and it is a worry if places like hospitals don’t do these rather basic maintenance tasks.

    20. A lot of great comments on the importance of generator maintenance and the difficulty of creating microgrid schemes. Something else to keep in mind with a back-up generator is the need to locate it in an area which has adequate protection against damage from the cause of the power outage. If a generator is in the basement, and the basement floods, you’re out of luck. Similarly, if it is on the roof, hurricane winds can cause damage. Unfortunately, this often means the ideal location is somewhere you would rather not have a big diesel engine.

    21. The sub-title for this article is really misleading: “It is normal for backup generators to fail”. That just isn’t true. Some of the article confirms that it isn’t true, by emphasizing how most failures are due to lack of periodic maintenance as recommended by the manufacturer. There are also 25 comments, all credible, to similar effect.

      Why say that the fault for failure of backup electricity generation is due to utility company stingyness about micro-grid’s, and that they will be forced to change their penny-pinching ways, now that once-in-a-100-year storms become more frequent? I don’t question the concern and inevitability of adverse climate change. But the topic of backup generator reliability is very tenuously linked to climate change. And it is big-company bashing (and frightening to the public, like me) to read that emergency generators for back-up power will “normally fail”, as this article started out by saying! They don’t fail, not unless they aren’t maintained at all! Or in unusual circumstances. Unusual is not “normal”.

    22.  I have a 20 kW stand-by, natural gas powered generator.  It auto-test every Saturday.  I wanted a genset that would take care of the entire house. The house is about 2500 sq ft, 3 bed/2 bath.  The electric panel box shows I could theoretically use about 18kW (with every single thing on, which never happens) so I have a 2kW+ buffer for surges, like when the 3.5 ton AC kicks on.  But since I would realistically only use 25%-50% of the generators capacity, I have a lot more than a 2kW surplus capacity/buffer.  The generator motor is a 4 cylinder GM truck engine.

      I paid about $8,000 for the whole setup, i.e.
      – about $4500 for the generator & Automatic Transfer Switch (ATS) & delivery (this includes the $200 extra I paid for an aluminum frame box so it would never rust in the brutal Houston summer heat and humidity)
      + about $1,500 for the plumber (to run a pipe to connect the natural gas to the generator)
      + about $1,500 for an electrician to do the electrical work, including installing the Automatic Transfer Switch (ATS)
      + about $200 in city permits – one for electric, one for gas, one for structural (for the slab where the generator sits) & the city inspectors
      + about $300 to have it powered on, tested and configured (there is a small LCD display to change some settings, like when it does its weekly power on test, etc.) properly by a Generac certified installer.  I was told if a non-certified tech did the start-up & set-up, it might void the Generac warranty.

      – The company that did the start-up offered an extended warranty, beyond the standard Generac warranty, for about $800 for three years.

      My elderly mother lives with me and we lost power after Hurricane Ike came through Houston.  Never again.
      We have used the generator a few times due to short outages (1-5 hours each) from thunderstorms. 

      We used it once during a non-outage.  I had my electricity billed to a credit card.  I was on balanced billing, so it cost the same amount each month. As a result sometimes I did not bother to open the electric bill each month. Then the card expired.  Since I did not open the bill I did not know I was receiving shut-off notices.

      I was at work on a Friday afternoon.  My mom saw the electric guy but thought he was here to read the meter.  He cutoff the electricity.  The generator kicked on.  Mom says mostly on one side of the house, so she did not know the house was on generator power, so she did not call me.  Once I got home she realized the generator was running, told me, I called the power company, they said the card had expired.  I gave them my new card info.  Since it was after 5 pm on Friday, no tech was available until the next Tuesday (they already had other appointments on Monday).  So the generator ran from Friday afternoon to Tuesday afternoon.

      Regarding the issue of a micro-grid –
      I paid to have the generator installed.  I am not interested in sharing my power during a storm with the neighborhood.
      1) They did not pay to have it installed, I did.
      2) They have more than enough affluence/resources to have their own stand-by generator installed.  Many of them instead have portable generators (like they used during Hurricane Ike, or left town).
      3) My house would already use up 50%+ of the generators power.  I do not want a lot of my power being pulled to various neighbors houses who invited all their family over to stay with them during the storm, because they knew they could take electricity from me.  I do not want to reward them for failing to plan ahead.  Before getting the genset I failed to plan and suffered the consequences.  That is often what it takes for people to learn. Something has to hurt enough, like no AC for three weeks in the Texas summer heat and humidity.
      4) I want all those people to flee before a storm.  That means fewer people staying behind to tax an already over-burdened support system (fire, EMS, police, rescue, etc.).  That means fewer people will die (from drowning, fires, etc.).
      5) There is an outside access panel on the generator where you could attach two extension cords.  I keep it locked to prevent the possibility of electrical theft.

      All of these may make me seem like a grouch, and maybe I am, but I have to look out for me and my elderly mother.

      1.  Two comments:

        First, I agree with Chris and also have a fully integrated back up generator.  If you have ever come home to a refrigerator full of spoiled meat or a basement flooded due to offline sump pumps, you will appreciate a back up power source.  Natural gas is the best way to go.  Propane, second.  Diesel is last.

        If my power fails for 10 seconds, the generator starts up, the load sharing system shuts down my heat pump and one element in my water heater for 5 minutes as the aux power picks up the load.  The initial spike is due to motors (fans, compressors, etc.,) that have stopped.  Once these motors spin up, the current drops off and the water heater and heat pump come back on line.  When power is restored, the system matches phase, transfers the load back to Alabama Power, runs to cool down for 10 minutes and shuts off.  If you are away when power is lost, the only indications of a power failure are all the blinking digital clocks.  There are two weekly self test modes – generator only and full loading.  Recommend using the full load, so the switching system is verified as well. 

        Second, if you have a critical requirement such as a neonatal care facility (or as I encountered, a drone control system), consider redundancy.  It’s more cost effective to buy two medium costs systems than a single system that will work forever, and in the process, double the national debt. Also, pare down power to minimal essentials and then pick up the nice to have stuff like plasma TVs and parking light flood lights with the second generator.  Integration can be a problem, but everyone will understand that lighting Dr Kildare’s BMW or catching the last quarter of the Alabama-LSU game are less important than having a premature baby’s oxygen continued.

    23. Have a redundant system which rotates the down generator; ‘A pair and a (non) spare’ for example.

    24. 20-30% failure rate is horrific.  I wonder about the safety-critical nature of the population from which that statistic was created.  It is sad that some bed-wetter at EPRI provided that ‘data’ and went along with this scaremongering.

      The author of this article should have checked out the requirements of NFPA 110 ( http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=110&cookie%5Ftest=1 ) which is usually a state code requirement for hospitals and some nursing homes. 

      The hospitals in NYC whose generators failed have negligent maintenance staff / facilities engineers.  Those people need to be fired, sued, and/or prosecuted.

      The diesels at the various nuc plants in the northeast affected by Sandy last week all ran when required. All of them.
      In August 2011 the Mineral VA earthquake did not bother the 4 emergency diesel generators at North Anna nuclear plant which all started and ran fine (one had a minor jacket water leak and was shut down and load transferred to an alternate AC source generator (yeah – the plant needs 2 generators but they have 6!).
      In March 2011 the diesels at Fukushima all started and picked up load after the massive quake – they ran fine until the tsunami carried away their fuel tanks and flooded them.
      Good equipment maintained properly will work ( =this link is to a pdf!= http://www.nrc.gov/reading-rm/doc-collections/reg-guides/power-reactors/rg/01-009/01-009.pdf ).

      The whole microgrid discussion is a red herring and pie-in-the-sky theorizing by academics who don’t seem to do any real engineering.

    25. I used to work in a building with backup-backup-backup generators as well. Well maintained, too. Then there was some sort of big cable break just up from ups on the power. Primary jenny worked fine, and of course the backup-backup and backup-backup-backup were in good order.

      Then the power company came knocking on our door, asking if they could use our spare jennies to power the rest of the block while they worked on the problem :) So it seems the idea of a microgrid isn’t entirely foreign, even if it’s only practical in a few cases at the moment.

      I believe they paid for the fuel.

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