Using a Prius as a generator

245

Comments

  • techntrektechntrek Solar Expert Posts: 1,366 ✭✭✭
    Re: Using a Prius as a generator

    Glad to see you made it here. As I said in my last email, you will need to use the two brown plus that attach to the UPS just above where the battery trays slide in. As you look at the front of the UPS you will use the left-most pin of the left plug and the right-most pin of the right plug. I believe + and - are marked on the plugs. If you need a pic I can take one - but mine is not attached using these plugs, I used one of the white plugs on the back. I think it will be clearer to you once you have the unit in your hands.

    If you find a good source for that 3 kw transformer at that price, let me know. I've been considering getting a smaller one than the one in that picture for mobile use.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • techntrektechntrek Solar Expert Posts: 1,366 ✭✭✭
    Re: Using a Prius as a generator
    techntrek wrote: »
    Another data point. I ran another test last night for 12 hours using the new UPS. This time I remembered to turn the car's A/C system off, plus I turned off the touch screen and the radio. Same routine in the house as the last test - 3 hours with TVs, lights, 2 fridges, 1 freezer, wood stove blower, and various minor loads. Overnight with fridges/freezer/minor loads, then an hour this morning with the same plus some lights and an electric heater.

    Impressive results this time. 1.6 gallons of gas used in 12 hours, about 0.13 gallons per hour which puts it dead even with the smaller 1 & 2 kw Honda/Yamaha inverter gensets. It would run continuously for 2.5 to 3 days on one tank of gas.

    Sandy left us without power for 55 hours, and I used the Prius for about 27 of those hours. At one point it ran for 24 hours straight. Fuel consumption was very close to the test I ran, around 0.1 gallons per hour or about 2.4 gallons per day for all of the loads above. The numbers this time are more of an estimate since I refilled from a gas can at one point so I mostly eyeballed the amount I added. Perfectly quiet at night and cleaner output through the UPS than my large genset. Now that the Prius setup has been proven I will most likely not replace my battery bank when it is time - but I will buy a set or two of the small gel-cells that the UPS uses so I can ride out all of the smaller blips we always get.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: Using a Prius as a generator

    you never know how things will go until they go. odd having a car supplement your power, but whatever works.:cool:
  • mrbighmrbigh Registered Users Posts: 3
    Re: Using a Prius as a generator

    I'm a new member to the website and owner of a 10KW grid tied system.
    Certainly I will keep an eye to this thread, we have may thing in common, primarily a Prius; mine a 2008 and the newest PiP.
    I would like the have the chance of a portable power source with the Prius for eventual power losses like the last one (Sandy) and other planned events.
  • jransuejransue Registered Users Posts: 1
    Re: Using a Prius as a generator

    This is fantastic- you are a hero to your fellow man for sharing. During Irene and Sandy I successfully used a 12v inverter clamped on the accessory battery, but it failed to recharge either of my small APC UPS's that I used to run CFL lights, charge cell phone, radio, etc. I guess I probably could have popped the SLAs out of them and charged them in parallel, but once they were close to dead I just switched to the Prius powered 12v inverter and a power strip. It also failed start the blower on our natural gas hot water heater... Because of this I didn't even try to push the blower on our forced air furnace. It looks like that is a something that would probably work with a better quality inverter (motor HP is probably 1/4 or so) unless there is some strange ground sense circuit on our HWH. What I am wondering is whether you have encountered any limits in the steady state operation of the liebert- it looks as though it is more or less designed to dump much of the battery capacity in couple minutes while a facility's diesel genset comes online. not having a stack of hungry servers helps, but running various loads averaging maybe 800 watts for hours is pretty different from the intended purpose.

    Wife and I have been thinking of getting the Plug in Prius- have you heard of anyone pulling this off with that? Probably not so different? A clever person might even be able to hack the V2G capabilities that Toyota is probably laying the groundwork for....
  • BB.BB. Super Moderators Posts: 26,768 admin
    Re: Using a Prius as a generator

    I am not sure I followed completely--But, in general, you need to "bolt up" inverters with short/heavy cables. Using "jumper cables" usually is not good for a few hundred watts.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • techntrektechntrek Solar Expert Posts: 1,366 ✭✭✭
    Re: Using a Prius as a generator
    mrbigh wrote: »
    I'm a new member to the website and owner of a 10KW grid tied system.
    Certainly I will keep an eye to this thread, we have may thing in common, primarily a Prius; mine a 2008 and the newest PiP.
    I would like the have the chance of a portable power source with the Prius for eventual power losses like the last one (Sandy) and other planned events.

    Welcome to the forum.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • techntrektechntrek Solar Expert Posts: 1,366 ✭✭✭
    Re: Using a Prius as a generator
    jransue wrote: »
    ... What I am wondering is whether you have encountered any limits in the steady state operation of the liebert- it looks as though it is more or less designed to dump much of the battery capacity in couple minutes while a facility's diesel genset comes online. not having a stack of hungry servers helps, but running various loads averaging maybe 800 watts for hours is pretty different from the intended purpose.

    Wife and I have been thinking of getting the Plug in Prius- have you heard of anyone pulling this off with that? Probably not so different? A clever person might even be able to hack the V2G capabilities that Toyota is probably laying the groundwork for....

    I can't take all of the credit, as I mentioned earlier on this thread the original idea comes from the priups.com site. However, I do take the credit for figuring out that some of the units in the APC SURT line are directly compatible.

    The Liebert and the APC SURT line are "online" UPSs. Which means they convert AC to DC, then back to AC. So their inverters carry the full load 24/7 and are designed for non-stop operation. The only difference when an outage occurs is the DC source for the inverter switches from the AC-DC stage, to the batteries (or in this case, the Prius).

    Look carefully at the traction battery specs on the Toyota site. Some of the current models still have the 201 volt nominal traction battery and should still be compatible with the APC SURTs. However, some of the current models have slightly and some have very different nominal voltages. The one that is close may be compatible but someone would have to take measurements to be sure. The ones that aren't close probably aren't. I don't know without looking those specs up which voltage the PiP uses. I seem to remember it is one of the versions that is very different. Doesn't mean you can't use it - but you'll have to find another UPS to use with it.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • mrbighmrbigh Registered Users Posts: 3
    Re: Using a Prius as a generator

    The 2012 Toyota PiP traction battery voltage is 200-/+ 5 VDC.
  • techntrektechntrek Solar Expert Posts: 1,366 ✭✭✭
    Re: Using a Prius as a generator

    Is that your actual measurement, or from specs?
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • mrbighmrbigh Registered Users Posts: 3
    Re: Using a Prius as a generator

    Actual reading in "park" mode straight out of the battery harness, no engine idling.
  • techntrektechntrek Solar Expert Posts: 1,366 ✭✭✭
    Re: Using a Prius as a generator

    That's a start, but you also need to measure it over several charge cycles to figure out the minimum and maximum voltages.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • techntrektechntrek Solar Expert Posts: 1,366 ✭✭✭
    Re: Using a Prius as a generator

    Bump, for those in the NE that could use this info this weekend with the blizzard at your back door. I realize its unlikely anyone could gather the right equipment at this point for a traction battery tap, but the 12 volt system can support up to 1000 watts if you have an inverter on-hand. More than enough to keep some lights and a TV on, or maybe a fridge overnight.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • techntrektechntrek Solar Expert Posts: 1,366 ✭✭✭
    Re: Using a Prius as a generator

    Forum member semipro contacted me about a month and a half ago to let me know about another UPS line which appears to be compatible with the Prius, and with other hybrids with higher DC voltages like the Highlander or Volt. I didn’t want this info to fall through the cracks so I'm posting it here. Unlike the APCs I've mentioned earlier in this thread I haven’t purchased/tested any of these, I’m just passing along the manufacturer info.

    The one he told me about is the Toshiba 1600EP, which after some searching I’ve also found under the Alpha brand name and at least one other, but most hits are on the Toshiba name so they are likely the original manufacturer. The more modern replacement of that line with the same specs is the 1600XP. Toshiba groups models with varying specs under the one model number so you must be careful to look at the kVA capacity to get the right ones. The 3.6 and 6 kVA versions have a nominal DC voltage of 216 volts, with an alarm at 192 and shutdown at 170. I estimate an upper voltage of at least 270, so they would be perfect for some of the Prii. The 8 kVA and above are spec’ed at 288 nominal, 246 alarm, 227 shutdown, with an estimated upper limit of at least 360, so these should work with the Highlander, possibly the Volt, and possibly some of the other Prii. Unfortunately as well-suited as these are there are two downsides. From everything I’ve read they can’t be cold/black started from the DC input, so without a temporary AC “jump start” they would be useless (the APCs can do a cold/black start). And while they can natively output 120/208/240, that is because they have a transformer built-in which makes them very heavy even without batteries, like the old Liebert Smart-UPS line. With batteries they are around 475 pounds. They would be fine permanently installed in a garage, just don’t plan on taking one on the road for portable power.

    I also found one version of their model 1000 line that might work with the Prius, the 6 kVA version, with a 240 nominal DC voltage. AC output is 208/240 with a weight of around 150 pounds with batteries – no transformer or 120 volt output (same as the APCs). So an external transformer will be necessary for portable power or sub-panel connection. I do not know if this can be cold/black started or any other specs.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • Ken MarshKen Marsh Solar Expert Posts: 114 ✭✭✭✭
    Re: Low-E vs regular windows in a south-facing room?
    techntrek wrote: »
    I like that idea.

    And I like the Prius for generator idea.
    I am dickering for a totaled Prius with usable engine/transmission/inverter.

    How come most of my projects start at the junk yard??
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Low-E vs regular windows in a south-facing room?
    Ken Marsh wrote: »
    ]And I like the Prius for generator idea.
    I am dickering for a totaled Prius with usable engine/transmission/inverter.

    How come most of my projects start at the junk yard??

    That's better than having them end up at the junk yard! :D
  • techntrektechntrek Solar Expert Posts: 1,366 ✭✭✭
    Re: Low-E vs regular windows in a south-facing room?
    Ken Marsh wrote: »
    And I like the Prius for generator idea.
    I am dickering for a totaled Prius with usable engine/transmission/inverter.

    How come most of my projects start at the junk yard??

    The junk yard is a good place to start for many projects. 8)
    I've considered doing the same thing - either finding a junked Prius that is still mechanically/electrically ok and ripping all of the components out and re-boxing it, or doing that to my own Prius if it gets into an accident and must be scrapped. But, it is a lot of work for what would amount to a 4-6 kw inverter genset and then you are back to maintaining it as a separate engine. Any one code thrown by the computer could make it unusable until you track it down. To make it more efficient you'd have to trick the computer into putting more charge into the battery each cycle which would get into overriding the OBD-II bus at the battery, etc. If you want to discuss go to the link in my sig.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • techntrektechntrek Solar Expert Posts: 1,366 ✭✭✭
    Re: Using a Prius as a generator

    One more new data point, the owner of the PriUPS site just told me about the AIMS Prius 2kw PSW inverter, specifically designed for this purpose. Can be found on ebay for just under $400.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • Ken MarshKen Marsh Solar Expert Posts: 114 ✭✭✭✭
    Re: Low-E vs regular windows in a south-facing room?

    Here is the plan. Highly subject to change.
    I hear that the Prius engine is a Atchsun sp?? cycle engine which I think means it has variable cam.
    I was planning to weld the cam solid, convert it to an Auto cycle and to propane.
    Probably will use distributor or perhaps waste spark ignition and scrap the Prius computer.

    We have an outside burner that circulates water into a hydronic heat system.
    Will run the water through the engine jacket to recover jacket heat.
    And run the exhaust into the wood burner fire box to try to get some of the heat out of that.
    This would make the generator only useful during winter
    This is just fine since we have an air cooled genset hooked in now.
    And the panels usually keep us well supplied during the summer anyway.

    Understand the motor/generators in the Prius are permanent magnet armature and 3 phase stator.
    Maybe we can lock the planetory transmission and get both generators to turn the same speed.
    With them locked 60 electrical degrees apart we would come out with 6 phase.
    Then with full wave rectification we would have a twelve step rectifier.
    This would output DC with less than 2% ripple to charge the battery directly.
    The engine would run flat out against the generator.
    The reason for all this is to avoid having to mess with throttle, governor, synchronization etc.

    Will have to rewind the stators since our battery is 48 volt.
    Still have to figure out some sort of inverter to get the engine started.
    Maybe we can use the existing inverter for most of it.
  • BB.BB. Super Moderators Posts: 26,768 admin
    Re: Low-E vs regular windows in a south-facing room?

    Probably does have a variable cam, but that is not what makes an "Atkinson Cycle" engine:

    Atkinson cycle - Wikipedia
    Recently, Atkinson cycle has been used to describe a modified Otto cycle engine in which the intake valve is held open longer than normal to allow a reverse flow of intake air into the intake manifold. The effective compression ratio is reduced (for a time the air is escaping the cylinder freely rather than being compressed) but the expansion ratio is unchanged. This means the compression ratio is smaller than the expansion ratio. Heat gained from burning fuel increases the pressure, thereby forcing the piston to move, expanding the air volume beyond the volume when compression began. The goal of the modern Atkinson cycle is to allow the pressure in the combustion chamber at the end of the power stroke to be equal to atmospheric pressure; when this occurs, all the available energy has been obtained from the combustion process. For any given portion of air, the greater expansion ratio allows more energy to be converted from heat to useful mechanical energy meaning the engine is more efficient.
    The disadvantage of the four-stroke Atkinson cycle engine versus the more common Otto cycle engine is reduced power density. Due to a smaller portion of the compression stroke being devoted to compressing the intake air, an Atkinson cycle engine does not take in as much air as would a similarly designed and sized Otto cycle engine.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • techntrektechntrek Solar Expert Posts: 1,366 ✭✭✭
    Re: Low-E vs regular windows in a south-facing room?

    Sounds like a heck of a lot of work with lots of potential for not working in the end. A conventional genset would be better for your needs, IMO. The biggest reason to use a Prius is to get 120/240 split-phase from it for little cash or modifications needed, and no extra maintenance since you are already doing that to keep it on the road.

    As I suggested in my last post, this discussion should continue in the thread in my signature - maybe a mod would move these posts over there?
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • BB.BB. Super Moderators Posts: 26,768 admin
    Re: Low-E vs regular windows in a south-facing room?

    Moved Prius as a Generator Conversations over here:

    http://forum.solar-electric.com/showthread.php?12962-Using-a-Prius-as-a-generator

    Thank you "TecknTrek".

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Ken MarshKen Marsh Solar Expert Posts: 114 ✭✭✭✭
    Re: Low-E vs regular windows in a south-facing room?

    Thanks BB for getting us straightened out here.
    I disagree a little with Wikipidia's description of the "Atkinson" cycle,
    but it is a moot issue since the engine will be running at one speed only.

    Techintrik, We have several generators around.
    None of them do what I want.
    I think I can make something better for this application.
    You are correct in that it will not be cost effective, not time effective.
    It isn't going to work the first time we try it.

    The system should be able to get 1.8 BTU of heat into the house for every BTU of propane used.
    The additional heat comes from the source water to the heat pump which is running on the electricity the generator produces.
    Anything the solar produces will add.
  • techntrektechntrek Solar Expert Posts: 1,366 ✭✭✭
    Re: Low-E vs regular windows in a south-facing room?

    Design goals: to harvest the waste heat from the engine, while charging a 48 volt battery, and do it while being efficient with fuel.

    The advantage of the Atkinson engine is a higher power-to-weight ratio at the expense of peak power and torque (the later being delivered by the electric engines in hybrid cars). You don't need those advantages in a stationary application. Any engine is most efficient when sized so it runs loaded around 75% of its rating. Personally I would take an off-the-shelf diesel genset for the best efficiency, sized so it runs at 75% output when your batteries are at their lowest state of charge. Have it drive a ~60 volt DC generator head which will then feed a charge controller. Tap the engine coolant for the heat.

    That meets all of your design goals without ripping out a Prius powertrain, figuring out how to make the engine run w/o its computers (or with it, clearing all potential codes), fiddling with the transmission (again, with or without the computers), and figuring out how to rectify and regulate the Prius generator output.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • Ken MarshKen Marsh Solar Expert Posts: 114 ✭✭✭✭
    Re: Low-E vs regular windows in a south-facing room?

    That is a good point Techntrek.

    We could leave the generator as is and convert it with a MPPT Charge controller.

    The problem with diesels is that you can't run them on propane.
    Propane is by far our the lowest cost fuel btu wise running 1/2 the cost of diesel fuel.
    You get it in 500 or 1000 gal lots delivered and it does not go bad with time.
  • techntrektechntrek Solar Expert Posts: 1,366 ✭✭✭
    Re: Low-E vs regular windows in a south-facing room?

    In my last post I should have said either "off the shelf diesel engine", or "off the shelf diesel genset... driving a 120 volt charge controller".

    Anyway, I do understand about the stability of LPG, I have a 500 gallon tank in my yard and fuel stability was one of the considerations when I bought my Generac. Normally diesel isn't a good choice for home backup since a diesel needs to be loaded above 40% and most homes only need a few hundred watts 2/3 of the day. They are good for business use since their energy use is large, and steady so the genset can be sized to meet that need. However, if it is primarily used to recharge a battery bank you can size it to stay between 40% and 75% most of the time. Diesels also use less fuel than gasoline or LPG gensets. Both of these reasons are why I'm suggesting it here. Also if the stuff really hits the fan you'll be able to scrounge/barter diesel and bring it home. You can't do that with useful amounts of LPG for a generator - 20 pound tanks may not evaporate fuel fast enough especially if it is cold.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • mike95490mike95490 Solar Expert Posts: 7,249 ✭✭✭✭
    Re: Low-E vs regular windows in a south-facing room?

    Subaru/Robin makes a couple small air cooled diesel gensets, 3KW and 5KW. electric start and recoil, but it's control box needs 12VDC to enable the injector. both produce 240V & 120V AC. best charger would be 240V forklift or golf cart charger, or an inverter/charger combo - put the power of 240VAC to work for you.
    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 ,

  • inetdoginetdog Solar Expert Posts: 3,121 ✭✭✭✭
    Re: Using a Prius as a generator
    techntrek wrote: »
    Thanks for all the reminders about CO and CO2, don't worry, my garage is used for everything BUT cars. Which I expect is true for the majority of garages. :-)
    Great cartoon strip of one kid telling another that if he were designing a house he would add an indoor parking place as part of the package. Other kid says "You mean like a garage?"
    "Yeah, only for cars."
    Chevrolet, I believe, offered a contractor's special pickup which was a hybrid with an inverter run from the traction battery. That made some sense, but I do not think it caught on.
    You can also get a riding mower/lawn tractor which is a battery/gas hybrid and has a built-in inverter output.
    SMA SB 3000, old BP panels.
  • inetdoginetdog Solar Expert Posts: 3,121 ✭✭✭✭
    Re: Low-E vs regular windows in a south-facing room?
    Ken Marsh wrote: »
    Thanks BB for getting us straightened out here.
    I disagree a little with Wikipidia's description of the "Atkinson" cycle,
    but it is a moot issue since the engine will be running at one speed only.
    The original Atkinson engine was an effort to avoid the Otto cycle patents and used a Rube Goldbergian crank mechanism (with epicycles, more or less) which actually resulted in a different length mechanical piston stroke for the two parts of the cycle. But thermodynamically speaking the valve timing mentioned in Wikipedia has pretty much the same effect.
    SMA SB 3000, old BP panels.
  • inetdoginetdog Solar Expert Posts: 3,121 ✭✭✭✭
    Re: Using a Prius as a generator
    techntrek wrote: »
    I will post some of the details I found from my tests. After getting the connection in place I decided to use the high beams and A/C on high as a test load. They were effective since I got it to cycle high-low-high fairly fast but I encountered one problem which worried me at first. Every time the engine started the voltage would briefly drop very low and then eventually would end up spiking around 300 volts for a few seconds, after a few minutes. Hardly the 210-235 range I was expecting! I finally came to the conclusion that while the A/C was a good test load from an amps-used standpoint it was most likely causing my erratic readings. Time to jump all-in and hook it up to my inverter. In the past I tested what would happen if I disconnected the battery bank and the charger/supply voltage shot up from 220 to 340 volts without causing the inverter to fault offline so I figured that even if my odd 300 volt readings were real it wouldn't do any damage.
    I suspect that part of the problem may be that the headlights are powered from the auxiliary 12V battery while the AC is run from the traction battery.
    Cycling to keep the aux battery charged would change the timing from what it would be just to keep the traction battery up. And the startup current surge of the AC compressor (even with an inverter/VFD in between) may be causing some problems too.
    Normally a dip in the traction battery voltage does not cause any problems since the drive components will just feed more power to the motor instead or just not deliver any greater acceleration.
    SMA SB 3000, old BP panels.
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