[HN Gopher] Turning an old car into a powerful generator
___________________________________________________________________
Turning an old car into a powerful generator
Author : jdmark
Score : 229 points
Date : 2023-09-22 10:25 UTC (12 hours ago)
(HTM) web link (blog.arduino.cc)
(TXT) w3m dump (blog.arduino.cc)
| blibble wrote:
| are cars designed to be left stationary with the engine running
| for long periods of time?
| intrasight wrote:
| No - but used this way it's no longer a car.
| asciimov wrote:
| Not at the rpms he is running.
| alistairSH wrote:
| Nope, you'd need to find a way to cool the engine. A car has a
| water pump that moves water through the engine and to a
| radiator. The cars motion moves air across the radiator. Most
| cars have an electric fan so they can run at idle, but they
| aren't designed to idle indefinitely. Police cars in the US
| often have (or at least had) beefed up cooling system to allow
| them to run at idle.
| yetihehe wrote:
| Cars during tests on dynamometer have to have a big fan
| blowing constantly on radiator. If you provide a big enough
| fan, you can run it as long as you want, even with big load.
| I was once doing 140km/h on autobahn uphill with fully loaded
| passenger car with additional fully loaded roof trailer. The
| car managed half an hour of fully open throttle without any
| problems, but If your home needs to use 40kW for more than a
| hour, maybe investing in proper generator is a better
| solution. In typical applications, engine will not be running
| at full power.
| AngryData wrote:
| Depends on how much power you pull out of it and the model.
| Every decent car in working order should be able to run at an
| idle witho AC and such running without getting dangerously hot.
| But your intuition is correct, they aren't expecting to be
| outputting that much power without also getting additional
| airflow from moving.
|
| With a water cooled engine though all you really have to do in
| most cases is either put more fans on the radiator or hook up a
| larger radiator to increase cooling levels if the stock
| equipment can't keep up.
| bluGill wrote:
| Engines are designed and built for cars, but there is a
| secondary market for stationary engines for various other
| applications. None of them are large enough markets to design
| their own engine (even all together), but they are large enough
| market that if you have already are designing an engine it is
| worth making a few changes to better serve other markets.
|
| If you buy direct from the manufacture they probably have a
| custom computer code for generator use. This includes a pin, to
| select between 50 and 60 hz. If you are buying for a different
| use you won't get that pin, but might get some other controls
| not needed on a car (you will have to pay for custom
| programming of course). You have to check with your manufacture
| rep to see details - some companies are more interested in this
| business than others.
| [deleted]
| graycat wrote:
| When our electric power went out 2 months ago, I started thinking
| about emergency power. Our outage was unusually long, 2 days,
| because lightening hit a tree which fell on our overhead power
| lines to the house and pulled down all the lines, conduit,
| electrical boxes, etc.
|
| Got a little electrical meter and showed that usually my office
| (I'm writing software) uses a grand total of 55 Watts, maybe 100
| W if I do more, maybe 1000 Watts if I use the laser printer, boot
| my tower case Web server with several hard disk drives and an AMD
| 8 core processor, a little more in the kitchen for the
| refrigerator and occasional use of the microwave oven and
| toaster, a little more if I want to keep the winter heat, fueled
| by natural gas, going. For the hours of an outage, I'll f'get
| about running the air conditioner, oven, washer, and dryer.
|
| Soooo, I can get by at 50 Watts and can do pretty well for a few
| days at peaks of 2000 Watts and an average over time of likely
| under 1000 Watts.
|
| Okay, and I have a car! Yup, a car has an engine and generator,
| both very well designed!
|
| A little shopping shows that I can get a _box_ that will output
| 3200 -- 15,000 (in steps of about 2000) Watts, a different box
| for each step of 2000, of US standard 60 Hertz (Hz, cycles per
| second) A /C (alternating current, with a good approximation to
| the standard _sine wave_ ) at 120 Volts from any 12 Volt DC
| (direct current) storage battery. Just clip two leads onto the
| battery and run extension cords from the output of the box and
| keep the electrical loads I mentioned running.
|
| So, I could get a box that can output 4000 Watts ...!
|
| And I have a car! Hmm. Soooo, back the car out of the garage,
| raise the hood, set the box on a front fender of the car, attach
| the two leads from the box to the car battery, start the engine,
| just let the engine idle, run the extension cords from the output
| of the box to my office, kitchen, and, maybe, natural gas powered
| furnace, and, ..., check the amount of gasoline in the car's
| tank!
|
| Since I don't need much power, the car and the box would keep me
| going for a few hours or ~2 days of an outage.
|
| Uh, ..., don't have to be very inventive because there is
| something of an industry serving people with campers, trailers,
| _off-grid_ cabins in the woods, etc. who do a lot with getting
| power from batteries, gasoline powered generators, etc.
|
| In short, just clip two leads onto the car battery, start the
| engine, let it idle (the car knows how to keep the battery
| charged without overcharging), run the extension cords, and wait
| for the local electric power utility to get the outage fixed!
|
| For the horrors of _back feeding_ power to the whole house and
| maybe electricuting utility workers, etc., "no worries, mate":
| Are NOT trying to power the whole house. Instead, are just
| powering a few loads with extension cords. E.g., my office loads
| plug into the _female_ sockets of a _power strip_ which plugs
| into the wall. Soooo, just unplug the power strip from the wall
| and plug its _male_ plug into the female socket at the end of one
| of the extension cords. Same for each of the microwave oven,
| toaster, refrigerator. For the electric power used by the natural
| gas powered furnace, that will have to be a little more involved.
| But, again, are just running the electric loads much like would
| on a camping trip. "No worries, Mate!".
| seabrookmx wrote:
| If the car's alternator is for example, 100A like it is in my
| car, that means the maximum output is 1200w. So if you use a
| 2000w inverter you'll be draining the battery at peak load.
| Just something to keep in mind so you aren't stuck with a car
| that won't start (or even run if it gets too low, as the fuel
| injectors will have too little voltage to fire).
| rft wrote:
| tl;dr: This setup worries me a bit, maybe talk it over with
| someone qualified in this, e.g. electrician, off-grid electrics
| expert.
|
| At 4000W you are looking at around 300A on the 12V side. This
| requires chunky copper and clamps. Keep in mind the already
| quite big cables to jump cars are only rated for very short
| usage. Not saying it can't be done, but this amount of current
| certainly worries me.
|
| Then you have the issue of protecting the 120V loads. You can
| get more than 20A of current out of the alternator, which
| pushes what you can safely put through standard extension
| cords. Usually running a single device off an alternator or
| generator is fine, but once you have multiple devices, hooked
| up to power strips, you can run into failure modes (with
| defective devices) that can cause shocks.
| owenmarshall wrote:
| In the "quasi-DIY power generation space", take a look at Lister
| engines & their clones (Listeroids)[0]. You end up with a
| surprisingly efficient[1] engine when you run diesel that drives
| any belt system you want: flip from a generator to a mill to a
| water pump. They can run on most any alternative fuel you want to
| use - biodiesel, waste oils - and their simple low RPM
| construction means they are durable and easy to work on.
|
| [0]: http://www.justliveoffgrid.com/InstallationGuide.html
|
| [1]: https://diesel-bike.com/Lister_Gen/Lister1.html
| s3krit wrote:
| Lister engines also sound fantastic, in my opinion. Due to
| where I live, I often hear them going past me and it's
| wonderful to hear them throttle up as they potter on by.
| bluGill wrote:
| If you want to do this, you should put a gear box between the
| engine and generator. Sure your car engine can run at 3600 rpm
| (I've seen exceptions, but they are rare), but typically it is
| most fuel efficient when run at closer to 2000 rpm at high load.
| At lower loads lower RPM is more efficient (but not as efficient
| as high load at 2000 rpm) - but your car probably doesn't have a
| large enough cooling system to handle high loads for very long,
| so perhaps run the engine at 1800 rpm and use a 1:2 gear box to
| get the right rpm for the generator, which makes design simple
| and is "close enough" to ideal without needing to see the exact
| efficient/power/rpm curves of your particular engine (a 3d
| graph).
| tantalor wrote:
| > cooling system
|
| Didn't watch the video yet, but under normal conditions the car
| is flying down the freeway so (I'm assuming) gets some cooling
| effect from that flow of air. But that's not happening in this
| case. Might be a problem.
| dghlsakjg wrote:
| In this case the generator is drawing off 5.5kw of power, if
| it is maxed out.
|
| This engine is capable of around 150kw of power, and the
| cooling system is capable of keeping up with that at highway
| speeds.
|
| My guess is that if they are using the standard cooling
| system, it isn't even close to being taxed with a 5.5kw load
| even at 3600 RPM. That's less power output than you would
| expect while running the ac in stop and go traffic.
| adrianmonk wrote:
| I'd bet this car engine will be lightly loaded since it's
| many times bigger than the engine in a generator.
|
| From what I was able to dig up[1][2], the generator (that the
| alternator came out of) has a 1-cylinder, 4-stroke, air-
| cooled, 305cc engine.
|
| A Toyota Sienna minivan's[3] engine is around 3L, so it's
| basically 10 times as big.
|
| ---
|
| [1] generator product listing: https://www.lowes.com/pd/Troy-
| Bilt-5-500-Running-Watts-Porta...
|
| [2] similar engine:
| https://www.briggsandstratton.com/na/en_us/product-
| catalog/e...
|
| [3] https://en.wikipedia.org/wiki/Toyota_Sienna
| bombcar wrote:
| Most cars are cooled by a fan these days, and many use an
| electric fan that can vary speed to keep the engine cool.
|
| Best efficiency would be to use the fact you're not moving to
| have more radiator surface area available but it's probably
| not worth it.
| yetihehe wrote:
| The fan in cars is typically not enough to keep it cool
| while stationary under load, but in typical home
| applications you won't have that big load anyway. Big load
| for a car is >10kW. You can also pretty cheaply get a
| bigger external fan, like those used on dynamometers.
|
| One nice side effect of using car as generator - free heat
| in winter if you extend cooling loop to your home.
| philsnow wrote:
| > Big load for a car is >10kW
|
| I don't have any idea if it's relevant at all (or how
| much the number can be trusted), but when I floor the
| accelerator in my Bolt, the dash indicator says it's
| using about 120kW.
| dylan604 wrote:
| How is a stationary car engine under load? Oh right, like
| my asshat neighbor that likes to sit in the driveway a
| 6AM revving his engine every. single. morning.
| IE6 wrote:
| fwiw revving the engine while stationary wouldn't really
| put much (if any) load on the engine
| sp332 wrote:
| When you put a generator on it, which is what the thread
| is about.
| dylan604 wrote:
| it wasn't a serious question looking for an answer.
| rqtwteye wrote:
| The fans cars have are not sufficient to cool the engine at
| high load.
| bluGill wrote:
| Your car engine can typically deliver 150 horse power to the
| wheels, but after 6 seconds of that you are at freeway speeds
| and then your engine is only delivering about 25 horsepower.
| A cars cooling system is designed around that and the case
| where you need all 150 horsepower for 5 seconds, then drive
| for 30 seconds at 20 horse power before slamming on the
| brakes (6 horsepower to run the AC) for the next red light
| where you wait for 10 seconds (again 6 horse power for the
| AC).
|
| Cooling from running down the freeway is easy to replace with
| a bigger fan. However the radiator itself is not large enough
| to get all the power the engine is capable of. (I also didn't
| watch the video, but I'm guessing the donor generator had a
| 12 horsepower engine so the radiator should be more than good
| enough). Of course there are other trade offs - many
| mechanics have a sign "speed costs money, how fast do you
| want to go", this sign isn't referring to the initial cost to
| tune the engine for max power, it is referring to max power
| means your engine needs a full rebuild every 20 hours of
| operation.
| yetihehe wrote:
| > A cars cooling system is designed around that and the
| case where you need all 150 horsepower for 5 seconds, then
| drive for 30 seconds at 20 horse power before slamming on
| the brakes
|
| My old 2004 Opel 1.6, 105hp could deliver almost full load
| (car fully packed with passengers and baggage, with roof
| trunk also packed, going 140km/h uphill with fully open
| throttle, fuel usage was reported as 16L/100km, typical
| road usage was 8L/100km) for about half an hour without any
| problems.
| numpad0 wrote:
| 25hp = 19kW or ~1x standard 42U rack, 105hp = 78kW or 20x
| typical households. Cars are powerful machines!
| Retric wrote:
| That's the useful work which represents ~1/3 of the
| energy in gasoline. ICE cars needs to deal with ~2x that
| energy in waste heat.
| Baeocystin wrote:
| A good rule of thumb is 1/3 of the energy into mechanical
| work, 1/3 into the cooling system, and 1/3 out the
| tailpipe. The actual numbers are pretty close to this
| across a wide range of operating conditions.
| Retric wrote:
| With the caveat that in cars the very long exhaust system
| dissipates a great of the heat rather than all of that
| energy literally coming out of the tailpipe as hot gas.
|
| Also catalytic converters provide more complete
| combustion and thus generate even more heat.
| Retric wrote:
| In the end it's all about the load not the horsepower.
| Doing the job of a 100hp engine with a 300hp engine
| doesn't require 3x the cooling. So companies happily sell
| higher trim levels with more HP while keeping the same
| radiator.
|
| Smaller engines are designed to operate at higher
| percentage of maximum capacity at lower speeds. Roll back
| to the days of 40hp engines and they max out highway
| speeds and can sustain that for hours. As you keep adding
| HP the maximum sustained load at a given speed doesn't
| increase. So, 1000+ HP super cars can make use of that
| power at 200+ mph, but they don't waste weight having
| radiators large enough to dissipate that heat
| continuously at 85mph because there's no way the car is
| staying that slow while applying that much power.
|
| External temperature also plays a role, cars need to be
| able to handle highway speeds at 45C adding headroom at
| lower temperatures. Trucks also need to be able to do
| that while towing a large load.
| ilyt wrote:
| with 140km/h wind to cool it in addition to radiator fan
| yetihehe wrote:
| I don't think fan was engaged anyway, never noticed it
| working when moving, only when stationary. I don't think
| it would help anyway.
|
| What I mean - cars can do fine for long periods under
| load as long as they are cooled appropriately, not only
| for 10s of full power.
| NoImmatureAdHom wrote:
| >Your *American car engine can typically...
| thsksbd wrote:
| Agreed, only in America; and thank goodness for that.
|
| I literally stopped at the Ford dealer today; there, I
| told the sales lady trying to sell me on the F150 that,
| for a few more thousand dollars, I prefer the F250
| because I don't want a dinky euroboost 2.7 L turbo V6.
|
| Luckily the F250 has a 6.8L V8 base.
| thsksbd wrote:
| "Your car engine can typically deliver 150 horse power to
| the wheels, but after 6 seconds of that you are at freeway
| speeds and then your engine is only delivering about 25
| horsepower."
|
| Unless you're in Colorado doing 80 mph, uphill for ten
| miles, fully loaded with cargo - then you engine brake (ie
| dissipate your KE into the engine block) on the way down.
| Or you take you car to the track. In both situations your
| cooling system is still expected to deliver, and does,
| since its not that big an issue to size it properly and a
| massive reliability issue if it isn't.
| KennyBlanken wrote:
| A car alternator is typically 2kW-3kW at most, and is very
| roughly 50% mechanically efficient, so it uses 4-6kW of
| mechanical power. Ie: 1/18th of the 150hp (111kw) engine's
| capacity...about 5%.
|
| Cars are already designed to run A/C and alternator almost
| continuously, and the AC not only generates load, it pumps
| a lot of heat into the air coming through the radiator
| because the condenser is in front of the radiator. They're
| designed (if the manufacturer did their environmental
| testing properly) to do that even in ~110+ degree weather.
|
| Methinks you should stick to things you know something
| about.
|
| PS: Many cars, even regular passenger cars - can handle
| being driven around a track, where you can go through a
| full tank in under an hour's worth of driving, and are
| either on the gas or braking during most of the session.
|
| There are also things called hills and mountains, which may
| take minutes to climb, or more. Plenty of cars make it up
| the Mt. Washington auto road (where the challenge is making
| it back down without overheating one's brakes; engine
| braking must be used.)
|
| There's something called "towing", which lots of people do
| the world around with minivans and passenger cars (not just
| pickups and SUVs.)
| bluGill wrote:
| Even on the track you get some cooling time while on the
| brakes. And cars do overheat on the track if the driver
| is not careful. You are correct though that cars are
| designed for up a mountain on a hot day with the AC on -
| which uses more than 25 horsepower - but that is still
| less than max power. That leaves a lot of headroom for
| racing on a level track, but you do need to watch the
| temp gauge (or update the cooling system is done on the
| track if the race rules allow)
| seryoiupfurds wrote:
| This is an interesting and informative comment, but it
| would have been much better without the condescending
| snarky tone.
| itsoktocry wrote:
| > _A cars cooling system is designed around that and the
| case where you need all 150 horsepower for 5 seconds, then
| drive for 30 seconds at 20 horse power before slamming on
| the brakes (6 horsepower to run the AC) for the next red
| light where you wait for 10 seconds (again 6 horse power
| for the AC)._
|
| I'm no expert, but I can't imagine that this is true. I
| agree that is "average driving conditions", but there are
| plenty of times you're driving way outside of those
| conditions. That can't be how the cooling system is
| designed. I've never seen a car even tick up in
| temperature, under all kinds of tom foolery.
| jaggederest wrote:
| The limiting factor in average horsepower output over
| time is definitely the cooling system on most cars. It's
| just that most people don't run their car at 80% of rated
| output for extended periods, otherwise you would
| absolutely overheat it.
|
| I've towed large loads up extended grades (hello shasta
| and grapevine) and you absolutely will overheat on a hot
| day. And that's with an uprated towing rig that had a
| radiator sized for the job - imagine that same horsepower
| of engine in a passenger car with 1/3rd the radiator
| surface area.
| dTal wrote:
| Amusingly, this is also true for modern laptops.
| realo wrote:
| Subaru engines are sometimes used in DIY small airplanes
| and they work well without overheating.
|
| This, it can be done.
| jaggederest wrote:
| The airflow differences between airplanes and cars are
| pretty significant, much higher near ground level and
| much lower at altitude, so they're kind of a different
| beast than a static generation setup.
| toast0 wrote:
| Depending on your route, there's some big mountains
| leaving Los Angeles, if you've got a lot of stuff in your
| car, it's pretty easy to get the engine and transmission
| warmer than usual. Engine heat isn't too hard to manage
| if it's just for a little while --- roll down the
| windows, turn the fan to high and the heater to max. May
| be unconfortable, but better than overheating.
|
| Afaik, that won't help your transmission though. If you
| run that at high loads often, you'll want enhanced
| cooling for that; often part of a factory tow package,
| but often available from the aftermarket as well.
| thsksbd wrote:
| You can instal a transmission cooler if you live in that
| region.
| aidenn0 wrote:
| 25hp is probably enough to power your household (18kW or
| 170A at 110V). It's certainly well over the mean summer
| usage, but peak usage is probably higher in hot climates (I
| couldn't find any typical peak usage numbers).
| taneq wrote:
| Peak potential usage is way higher than peak convenient
| usage after a couple of trivial optimisations. Just
| "don't run the dryer, the kettle and the toaster at the
| same time" will knock 4-5kW off the max. Schedule your
| hot water system to only run off peak and that's another
| 2.4-3.6kW.
| t0mas88 wrote:
| In many European houses the main power line into the
| house has a 35A fuse at 230V, so that's only 8kW maximum
| load.
|
| Heating (and water) comes from natural gas, or a high
| efficiency electric heatpump.
| bluGill wrote:
| In the US I've seen one house with 30amps at 240V (I also
| heard about a house from that era getting 30 amps at 120
| volts), and it was from the 1930s with no updates. Even
| in the 1950s houses were getting 60 amps at 240V - which
| allowed for an electric stove to draw 40 amps 240V, and
| have enough for the rest of the house. These days small
| houses get 100amps, while large ones get at least 200.
| Very large houses sometimes get 400 amps. If you install
| geothermo you get 300 amps because even though geothermo
| is highly efficient in the worst case it can draw 80 amps
| at 240 volts (you only see those worst cases when doing
| the max power test at install time).
|
| Unless it is a tiny house I wouldn't not expect 35amps to
| be enough to run a heat pump any everything else in a
| house (at least none of the houses I've seen in Europe,
| though I've only been there for a few weeks total so
| there is much I have not seen). Large RVs in the US get
| 50 amps at 240volts, while small ones get 30 amps at 120
| volts - both compare to a tiny house in size.
| carlhjerpe wrote:
| Isn't that 35A fuse at 400V?
| nkg wrote:
| I learn so much on HN.
| Animats wrote:
| This is a reasonable desperation setup for emergency power,
| but not a great off-grid solution.
|
| Highway cruise for a compact car needs around 7 to 20HP, so
| a reasonable target output is in that range. That's 5 to 15
| KWh. Seems small, but as others have pointed out, auto
| engines have peak outputs far beyond their continuous
| rating.
|
| 1800 RPM 60Hz generators are available, and larger
| generators tend to run at 1800 RPM. Or you could do
| something with belts or gears to keep the engine RPM down,
| as others pointed out. Running at low RPM is good if you
| want to run for a long time.
|
| Probably a good idea to have the system disconnect output
| power until the frequency reaches at least 50 Hz, because
| this thing needs quite a while to reach operating
| frequency. Bringing up something like a refrigeration
| compressor (a likely emergency load) from 0 Hz to 60 Hz
| over the course of a minute may burn it out. Under-
| frequency operation is very bad for AC motors; they draw
| way too much current and overheat, because the inductance
| of the motor isn't able to oppose the lower frequency. Put
| an ohmmeter across an AC motor and note how low the DC
| resistance is.
| taneq wrote:
| Depends on... well, everything, but towing a 1-tonne
| trailer up a long hill is far more taxing on a car's
| cooling system than this. I'd expect any decent car to be
| designed to handle continuous running at peak torque, if
| not peak power.
|
| (Why peak torque? Because that's peak efficiency, for
| petrol engines at least. Makes sense if you think about
| it.)
| bluGill wrote:
| Cars are not built to run at peak torque for long as
| nobody does that. Cars are design for maximum power for
| long enough to get up to speed, and which makes for a lot
| more power at peak torque than they need for running at
| highway speeds.
|
| Sometimes a truck will be designed to run near peak
| torque while towing uphill on a hot day (AC) with a
| headwind, but when you do that it takes a long time to
| accelerate to highway speed and so truckers typically
| just buy more peak power (trucks are already notorious
| for slow acceleration). Running at less that peak torque
| isn't too much a loss (and diesel engines don't suffer
| nearly as much from running at less than peak torque so
| the savings doesn't add up very fast for trucks)
| dotancohen wrote:
| This actually sounds like quite the argument for electric
| trucks.
| lisper wrote:
| > max power means your engine needs a full rebuild every 20
| hours of operation
|
| Top fuel drag racers need a rebuild after every run, which
| typically lasts 4-5 seconds. Their engines can produce
| 10,000 HP, which is about 7.5 MW.
|
| https://en.wikipedia.org/wiki/Top_Fuel
| brucethemoose2 wrote:
| And other race cars get the best of both worlds.
|
| Le Mans cars and other touring cars are famous for
| holding up 24hrs under very high loads, even with the
| engine strung out beyond its street legal spec, but I
| think the most impressive feat is the Baja 1000.
|
| Modern trophy trucks make ~1000 horspower, and the load
| is insane. The engines are running a pretty high average
| throttle, at high RPM, pushing a giant, heavy truck
| through sand, in a blazing hot desert. The fine dust can
| clog the filter, radiators, and get in all sorts of
| crevices. The whole drivetrain is constantly being
| shocked as the wheels _leave the ground_ then jolt back
| to the correct RPM when the truck lands. And the _whole
| truck_ is constantly being G-shocked, crashing into
| terrain you wouldn 't even want to hike over at highway
| speeds, over and over again, for 1000 miles.
|
| This was impressive back when the trucks were making a
| mere 300-600 horsepower, but honestly I have no idea how
| the modern turbocharged monsters even hold up.
| brucethemoose2 wrote:
| Also, the engine throttle is open for a long time on the
| flat, barren stretches.
|
| That seems minor, but there are _no_ paved racing leagues
| where a 1000hp+ engine can run flat-out for a long time.
| Le Man 's formerly 6 km straight was the extreme, and
| they eventually shortened that with chicanes.
| pdonis wrote:
| Even 25 hp is large compared to the generator output shown
| (about 5 kW or about 7 hp).
| rqtwteye wrote:
| It gets most of its cooling from the air flow. Cover up all
| openings if your car and you will overheat the engine very
| quickly. If you put a car on a dyno you usually put a big fan
| in front of the car to provide cooling.
| asciimov wrote:
| You could do few things to mitigate this issue.
|
| 1. install larger fans on to the radiator.
|
| 2. use a big shop fan to blow air over the radiator.
|
| 3. remove the mechanical thermostat on the engine, so that it
| takes longer to get to operating temperature.
| bluGill wrote:
| Install a larger radiator is the correct fix if this is a
| concern. While the stock fan is not the most airflow, if it
| isn't enough you want the bigger radiator.
| yetihehe wrote:
| > 3. remove the mechanical thermostat on the engine, so
| that it takes longer to get to operating temperature.
|
| Modern engines are designed to work at preferred
| temperature. They have two cooling loops, one small which
| is constantly cooling cylinders and one big (with radiator)
| which cools the small one to keep engine at proper
| temperature, not too high and not too low, by mixing some
| of small loop coolant with large loop coolant.
|
| Point 2 is the best solution.
| pdonis wrote:
| As another poster has pointed out, the power output is very
| small compared to the engine's capacity. So cooling is not
| really a problem. From the engine's point of view it's pretty
| close to idle, and the car's fan should have no problem
| pulling enough airflow.
| lloeki wrote:
| Car gearboxes are a spectacular cause of power loss (in the
| order of 20% IIRC), so probably better to come up with a simple
| gear reduction or a belt-driven pulley system.
| bluGill wrote:
| Some car gearboxes are that bad. However others are much
| lower. Are we talking about a "slushbox" automatic without a
| locking torque converter, or an all gear manual transmission
| - there is a big difference.
|
| I didn't specify what type of gear box because there are many
| different options. Belts of the front pulleys would work. You
| could rig up a chain drive system as well. there are pros and
| cons to each.
| ehaliewicz2 wrote:
| I'm curious what the loss for a typical constant-mesh manual
| gearbox would be. I assumed 90% or more efficiency.
| dylan604 wrote:
| They didn't say use the car's transmission. The suggestion of
| a 2:1 gear reduction could easily be a simple gear reduction
| or a belt-driven pulley. You've tried to inject something on
| your own accord for possibly a misunderstanding??
| cduzz wrote:
| Yeah, they didn't mention many specifics; I also imagine
| that they're just pulling the power off the engine using
| the accessory belt connected to their existing alternator
| -> inverter setup.
|
| Similarly -- the concerns about how to cool the device if
| it s putting down 100hp -- that's 74570 watts; it's
| unlikely they're using a harbor freight generator's
| alternator to generate that kind of power.
| lloeki wrote:
| I read "gearbox" as, well, an automotive gearbox, which
| would hardly be surprising in the context of the article.
|
| 2:1 could easily mean crank the gearbox into a gear that
| approximately produces that ratio.
|
| > You've tried to inject something on your own accord for
| possibly a misunderstanding??
|
| WTH is that supposed to mean? If I misunderstood anything
| it was a honest mistake. GP suggested a RPM reduction for
| fuel efficiency reasons, it would be counterproductive to
| offset that efficiency gain with a high-loss mechanical
| device. There was neither ill intent nor hidden agenda.
| polishdude20 wrote:
| What about them makes them so inefficient?
| bluGill wrote:
| If the torque converter doesn't have a lock that is a big
| loss. Those same transmissions also tend to have low
| efficiency hydraulic pumps internally to select the gears.
| Modern automatic transmissions tend to be much better than
| older ones.
| Aurornis wrote:
| You're right that the best Brake Specific Fuel Consumption
| (BSFC) occurs at higher loads. If anyone wants to see a map of
| this, search for "brake specific fuel consumption map". More
| modern engines might actually have their peaks closer to
| 3000RPM due to improved technology. The trend is toward smaller
| engines that rev higher, so peak efficiency is steadily
| shifting to the right.
|
| However, it probably doesn't matter due to the extreme mismatch
| between the engine's output and the generator's maximum power.
|
| The generator appears to be rated at 5500W, which is 7.4HP.
| Efficiency of electrical generators is high, so we'll call the
| load 8HP maximum.
|
| An Toyota Sienna engine has a peak power output around 200HP.
|
| For reference, a car air conditioning system might consume
| around 4HP, or half of this generator's load. The generator is
| barely more than running the air conditioning.
|
| So ideally, you'd pick a set of pulleys that let the engine
| basically idle. The goal is to minimize internal engine losses
| at this level, because you're nowhere near the peak efficiency
| islands on the BSFC map.
| foota wrote:
| Wow, I had no idea that a car engine produced more than a
| hundred kilowatts of power, that's ridiculous! (For
| comparison, an average household consumes something like tens
| of kilowatt hours per day, so driving for an hour (I guess at
| peak, which an engine wont always be) may be similar to 5 or
| 10 days of a household's power usage, and not to mention much
| less efficiently generated.
| infinityio wrote:
| petrol is roughly 9.5kW/litre (~35kWh/US gallon) if that's
| a better reference for consumption (of which maybe 30% will
| make it to energy through a modern engine?)
| lapetitejort wrote:
| And in many cases, that much power transports a single
| person and occasionally a few bags of groceries.
|
| edit: By point of comparison, a good cyclist produces about
| 100 watts, probably less if they're on a leisurely cruise.
| That's about 2% of the wattage of a car engine.
| xattt wrote:
| > And in many cases, that much power transports a single
| person and occasionally a few bags of groceries.
|
| Is there any comparable mode of transport that can
| accommodate all of this in poor weather (i.e. a
| snowstorm) without having to wear burdensome clothing?
|
| I realize 150 years ago people wouldn't venture out in
| those conditions, but they also didn't move more than 50
| km from their birthplace over their lifetime.
| ska wrote:
| For more direct comparison, there are motorcycles on the
| market that can produce ~150kW , to transport about the
| same amount of stuff.
|
| Bicycles are really efficient (and those motorcycles are
| very fast)
| AnotherGoodName wrote:
| Modern cars are powerful. Today there's no car on the
| market today that doesn't have enough power. The cheapest
| cars you can buy, small sub $20k hatchbacks, are all around
| 100kw. They all have performance figures that beat sports
| cars from the 1970s.
|
| The limiting factor on early acceleration (0-60kph) today
| for all cars is now tyres. Beyond that air resistance might
| make more engine power matter but in general it's all about
| the tyres. Every car can spin their wheels at the lights if
| they want to. If you feel the need to floor it at the
| lights you're showing off your tyres not your engine power
| (and also wearing them out).
| toss1 wrote:
| "There's nothing like bad tires to make it sound hot off
| the line..."
|
| (racetrack joke -- -- who needs a big engine to squeal
| the tires when a set of crummy tires will do it even
| better?)
| carlosjobim wrote:
| The continuation of this thought is to realize what an
| immense amount of power there is in a gallon of gas. It is
| basically free energy compared to using serfs or beasts of
| burden to do the work.
| djaychela wrote:
| I saw something the other day - the numbers aren't
| exactly right, but it was along the lines of there's the
| same amount of energy in a barrel of oil as one man
| working full time in a manual job FOR SEVEN YEARS.
|
| This is why we've (unfortunately) built modern societies
| on fossil fuels. The amount of work done as a result of
| it is immense, and probably explains why there aren't
| vast numbers of people enslaved for manual labour any
| more.
| Negitivefrags wrote:
| The rediculoussness of the energy use of transport is
| especially noticeable when you are driving a Tesla which by
| default shows you a dial of power consumption and
| generation in kW.
|
| When rolling down a hill with regenerative breaking, the
| car is generating 50kW.
|
| You can literally power many average homes with that.
| m463 wrote:
| On the other hand, pedaling a bicycle, or pushing a car
| is a lot of work.
|
| It's not ridiculous until you compare against people
| doing it manually.
|
| also, teslas are really quite efficient and it's amazing
| how they recover energy as well.
|
| I wonder if there are efficiencies to be had recovering
| energy to come, since they can only recover what the
| batteries can absorb.
| stefan_ wrote:
| Of course it's ridiculous to have 300kW car engines
| racing from light to light averaging 10mph in the city
| when someone on a bike can do that faster with 100W.
| 4gotunameagain wrote:
| Pedalling a bike is not a lot of work. Old people do it
| daily.
|
| Thrusting a car through air at 100kph though, that takes
| _a lot_ of work. Drag scales with the square of the
| velocity and proportionally to the frontal surface area.
|
| Cars are a fast, but woefully inefficient means of
| transport.
| [deleted]
| imoverclocked wrote:
| You lose a lot of energy to drag, friction and
| resistance(aka: heat.) Battery capacities are almost
| never the limiting factor in this equation. This is
| especially so when you don't top the battery off to begin
| with.
| cduzz wrote:
| If by "gearbox" you mean "Pulley" -- a setup such as this is
| probably most efficiently done by just putting a big (wide)
| pulley on the front crankshaft accessory belt and correct
| diameter pulley on the alternator, to get to whatever the
| target RPM of the alternator and whatever low RPM works under
| maximum load for the motor. Put the whole thing on a reinforce
| pallet and you're done.
|
| This whole setup almost certainly isn't going to be able to
| supply "north america normal household power demand" volumes of
| power reliably for months at a time, but almost certainly do
| whatever a cheapo generator was doing before that cheapo's
| sketchy 150cc motor crapped out.
| bluGill wrote:
| By gearbox I mean anything to change from one RPM to another.
| Chains, belts, or gears are the obvious options. They all
| have pros and cons, but any would work. There are other
| options as well, but they tend to be a lot less efficient
| which destroys the whole point.
| lostlogin wrote:
| I'm very much not an engineer, but a below and pulley
| changing the ratio _seems_ the most efficient.
| costanzaDynasty wrote:
| The main problem I see here is that everyone I've known with
| spare old cars littering their property seem to always be missing
| the engine.
| doubled112 wrote:
| In people's yards, this is often the case.
|
| There must be 1000s of cars in scrap yards, though, with
| perfectly functional engines and front ends.
|
| Both my wife and myself have had a car written off after being
| rear ended. It is a common story.
| KennyBlanken wrote:
| There is a term for this: a "front clip." The recycling yard
| chops the car somewhere behind the firewall.
| cjrp wrote:
| If they're in a scrap yard they're most likely being parted-
| out, so the engine will be bought and put in another car.
| bluGill wrote:
| The engine is for sale if you want to buy it. Most engine
| will last longer than the car if you take care of it. Back
| in the 1950s engines were a lot more likely to fail and so
| people would keep an old car running by buying a junkyard
| engine. Now that isn't very popular (it still happens, but
| it isn't popular)
| doubled112 wrote:
| I think this is what I was trying to point out. Engines
| are everywhere.
|
| Winter and road salt ends way more vehicle lives than
| engine failure where I live.
|
| My 2011 Ford Focus, for example, is slowly returning to
| nature. I can find dozens of them with engines in great
| shape, but also with body problems. Body work is
| incredibly expensive.
| jandrese wrote:
| Yeah, if frame rot doesn't kill the vehicle (maybe you
| don't live in the rust belt for instance), then it's
| usually the transmission that sends the car to the
| chopper. Engines tend to outlast the rest of the car as
| long as the owner keeps up with basic maintenance. Plus,
| when things break on the engine they're usually fixable
| short of blowing a crank through the side of the block or
| something catastrophic like that. A body that is rotting
| out is hopeless, nobody is even going to try to fix it.
|
| Where you'll have a lot more trouble is finding a large
| generator to bolt onto that engine. Those are far more
| rare. As many people have pointed out, sticking a little
| 5kW generator on the side of a full size car engine is a
| hilarious mismatch that's going to burn way more fuel
| than necessary. Sure it's a fun project, but quite
| impractical. Harbor Freight actually sells the
| appropriate replacement engine for $180, that van is
| worth more in scrap value than that. Plus it takes
| forever to stabilize the frequency so it's not even as
| good as the standard setup.
|
| Maybe the best use for this would be some Mad Max style
| post apocalypse where most all technology has been lost,
| but gasoline is abundant and apparently free so people
| spend their time making heavy metal looking art cars and
| sports equipment.
| AngryData wrote:
| There are tons of old functioning car engines out there. Go
| check out any state that salts their roads, the bodies of older
| cars are almost gone but thanks to the consistent oil leaks and
| oil spills over the block the engines are generally clean
| underneath the grime. If you don't got anything special that
| people like to tune up and it doesn't self destruct for being a
| shitty design then there isn't much demand for them, most of
| their cars are scrapped with another 150K miles or more left on
| the block.
| sllabres wrote:
| Fascinating to watch the larger (professional) generator doing
| their work
|
| https://m.youtube.com/watch?v=SzKu9QBGI4s
|
| I always think what happens when they fail to sync in time -- a
| bad day for a datacenter or worse
| aporetics wrote:
| The DIY is fun, but if you want to think about it on a larger
| scale:
|
| https://academiccommons.columbia.edu/doi/10.7916/D81N8CPF
|
| From the abstract:
|
| > This thesis specifically highlights the value of small, mass-
| manufactured internal combustion piston engines retrofitted to
| participate in non-automotive system designs. The applications
| are unconventional and stem first from the observation that, when
| normalized by power output, internal combustion engines are one
| hundred times less expensive than conventional, large power
| plants.
|
| And:
|
| > The largest single component of this thesis is modeling,
| designing, retrofitting, and testing a reciprocating piston
| engine used as a compressor. Motivated again by the low cost of
| an internal combustion engine, this work looks at how an engine
| (which is, in its conventional form, essentially a reciprocating
| compressor) can be cost-effectively retrofitted to perform as a
| small-scale gas compressor.
| danans wrote:
| > when normalized by power output, internal combustion engines
| are one hundred times less expensive than conventional, large
| power plants.
|
| That's quite the caveat because with the higher power output
| comes far lower efficiency. That's fine for an emergency backup
| scenario, or for spinning reserves as the paper mentions, but
| it's a very operationally expensive for normal power
| generation. The idea of modularity is good, but that's already
| a part of the VPPs that are being built now.
| cortesoft wrote:
| Isn't that market already served by portable generators? Engine
| manufacturers like Honda have been selling gas generators
| forever.
| walnutclosefarm wrote:
| I don't see how this conversion makes much sense. He started with
| a generator that was junked because the ICE was shot. He could
| have replaced that ICE with an off the shelf 4 cycle engine for
| under $1000.00. Instead, he's got a car that even as junk was
| worth half what the new engine would cost, with the space
| requirements that come with a car, the investment in electronics
| and build, and the net result is a junked nearly 200hp car
| running an generator that can only use maybe 10HP tops. A great
| job of McGivering up something, but I can't imagine why anyone
| would do the second one.
| iancmceachern wrote:
| Plus now no one but him can repair it.
|
| It's a super cool learning experience, and that's the value.
| 4gotunameagain wrote:
| It is a seemingly free drivable generator. What's not to love?
|
| When you disengage the cruise control clutch the car is still
| drivable, and he uses it to hoist around stuff and weld things.
| gabereiser wrote:
| This is awesome. I lived on a sailboat for a while and sometimes
| you get cloudy weather for days, blocking your ability to use
| solar to top up your batteries. The small M35 universal diesel
| engine I had had one thing going for it, it had a lot of torque.
| Torque I use to turn a 110V 120A alternator. The alternator (like
| a car's) charges the battery, except in my case it was charging a
| lot of battery. 6 12V 200AH Lithium Iron batteries. These
| batteries ran all the "home" appliances for several days before
| needing a recharge. 120V 3000W inverter, A/C, Fridge, coffee
| maker, water maker, electric stovetop, lights, navigation, radio,
| Starlink, Xbox.
|
| If having a vehicle is unsightly, you can remove the engine onto
| a stand and wire it up exactly as described in this video. The
| only thing you'd need to run an engine is a fuel line, a spark,
| and compression.
| bluGill wrote:
| You also need a cooling system to run nearly all engines.
| Generally a car engine doesn't have enough cooling system to
| run at max power for very long (it is only a few seconds
| between the light turning green and you being at speed, then
| you need much less power). Your sailboat as the nearly infinite
| ocean to cool itself with.
|
| Most likely your engine also needs a computer, which implies an
| electrical system.
| rcostin2k2 wrote:
| Living on a sailboat, the cool water would not be a problem.
| Just some filters to avoid clogging the cooling ducts.
| numpad0 wrote:
| I think everyone here is underestimating power density of a
| car engine. GP's alternator is 110V/120A, that's 13.2kW, or
| up to 8-way tea kettle boiling or Xeon workstation use
| simultaneously(1.5kW each).
|
| Chances are you won't be running 4 YouTuber editing machines,
| 2 pots cooking on IH stoves, 2 air conditioners and a USB-PD
| laptop charger all drawing full amount inside the living
| quarter on a sailboat. That's before counting in 6x 12V/200Ah
| = 14.4kWh battery system which safely doubles, possibly
| quadruple instantaneous draw.
| JoeAltmaier wrote:
| Most household requirements are about 13kW. So not much
| different than your suburban bungalow needs.
| numpad0 wrote:
| I think there's something wrong with your palace if
| you're maxing out 100A breakers, that's 720[hr] x 13[kWh]
| x 0.30[$/kWh] = $2.8k/month. Even if you meant 1/3 duty
| it's $936/month.
|
| Average household usage in US is 20-40kWh/day... not sure
| where does 13kW figure fits in that picture.
| mschuster91 wrote:
| > Most likely your engine also needs a computer, which
| implies an electrical system.
|
| Old diesel clunkers not really, at least if you don't care
| about emissions control. Fuel injection / exhaust valve
| control is purely mechanical, all they need electricity for
| is the engine starter and, depending on age, the cooling fan.
|
| Modern engines, on the other hand, these can be really hard
| to run on their own outside of a car, at least from hearsay -
| I only have had experience with an 1994 VW T4 van.
| doodlebugging wrote:
| >all they need electricity for is the engine starter and,
| depending on age, the cooling fan.
|
| If you get an old enough diesel engine or can do the mod
| yourself you don't even need an electric starter. The first
| diesel engine I worked on used a gasoline engine as a "pony
| motor" to spin the diesel engine flywheel enough to
| generate the compression needed to start the diesel engine.
| From memory (probably wrong haha) you cranked the gasoline
| engine and brought it up to high rpm and then you started
| the diesel engine using a lever that gradually engaged the
| diesel engine flywheel bringing it up to operating speed.
| Once the diesel engine was running you backed off the lever
| and killed the gasoline engine.
|
| An obvious disadvantage would be the necessity to maintain
| stocks of two fuel types. Other than that it is a near
| fool-proof way to handle cranking a diesel engine. The
| electric starter is replaced by the gasoline engine and
| flywheel linkage. You effectively roll-start the diesel
| using the gasoline engine.
| jaggederest wrote:
| Video of this in action:
|
| https://youtu.be/AL0ls_UpT8w?t=361
|
| The whole video is worth a watch, but I linked directly
| to the timestamp where he begins to explain how the
| engines are started with a petrol starter. To power a
| foghorn. Amazing stuff.
| doodlebugging wrote:
| Yeah that is amazing and it is just like the engines we
| had on those post-WWII bulldozers and maintainers. Fire
| up the gasoline engine and get it screaming at high rpm
| and then use that high rpm to transfer power to the
| flywheel of the diesel engine which will crank and run
| once the compression is high enough to ignite the diesel.
|
| Here is a video of a guy cranking a Caterpillar D2 like
| we had to crank our D4 back in the day. [0]
|
| When I started working with that small family-owned
| company I had no real experience with mechanical things
| other than my own pickup truck. When I finally moved on
| from them a couple years later I could maintain, tear
| down, and rebuild gasoline and diesel engines,
| compressors, hydraulics, air brakes, etc. We did all of
| that ourselves in addition to the real jobs of pipeline
| maintenance and repair and oil spill cleanup. I don't
| remember all the times I spent laying on the dirt floor
| of the "shop" there in central Texas and cursing all the
| oily sand and crap that fell in our eyes and faces as we
| tried to fix things after the day's work was done.
| Luckily beer-thirty was a cherished event that came with
| hang-down (summer sausage), cheddar cheese chunks, fresh
| onion slices, cold milk and saltine crackers. We finished
| most days in the domino shack trying to avenge the
| previous days' losses. Good times indeed.
|
| [0]https://www.youtube.com/watch?v=Ck210eL9qcI
| ComputerGuru wrote:
| > An obvious disadvantage would be the necessity to
| maintain stocks of two fuel types.
|
| Wouldn't a starter motor running off a battery charged by
| the very generator you are running just be an all around
| better solution? You can run some modern starter motors
| off a tiny 12x8 in AGM.
| yetihehe wrote:
| I've tried with Opel from 2004. I had a very modern version
| (with everything over CAN, even gas pedal) and I had to
| disconnect A LOT of sensors in order for it to no longer
| start (don't ask why). Modern diesel cars are a little
| worse for this, because of all the emissions regulations
| requiring adblue and dpf filters to work correctly. If you
| run out of adblue in some cars, you have to get it towed to
| dealer for checkup and reset.
| [deleted]
| zirgs wrote:
| Wouldn't it make more sense to install 230V on a boat? Modern
| electronics handle 100-240 anyway and you can save on cables.
| rightbyte wrote:
| Typically you don't want lethal potential in such wet
| environments. Ever wondered why emergency lights on ferries
| are different than the standard ones? Also, you don't want
| any earth breaker since you really want the lights, pump and
| motor to be working no matter how much water you have on the
| wrong side of the hull.
| bluGill wrote:
| Boats are typically so small that you can use smaller cables
| without problem even at 120 volts. Many of them run only 12
| volts (often most things like lights and radios are run on 12
| volts, but the owner as an inverter for a couple appliances
| they can't find in 12 volt). Of course nobody runs smaller
| cables at 120 volts because you would need an engineer to
| figure out the proper rating - it is cheaper to just use the
| standard code wires. If you do pay an engineer you will
| probably discover on boats you need to use the larger wires
| anyway for mechanical reasons.
| LeifCarrotson wrote:
| Having wired up a couple travel trailers and a boat (and,
| incidentally, being an EE who can theoretically run those
| calcs), I agree with the parent: It would be better if the
| industry switched to 120V/220V AC for more parts, and away
| from 12V.
|
| The problem is that the ampacity in a 12V DC light circuit
| is 10x that of an equivalent-power 120V AC system. And
| worse yet, power dissipation in a resistive element is
| equal to I^2 R, so you're heating the wiring harness with
| power losses are 100x worse than in a 120V system and
| almost 200x worse than a 220V system. So you have to
| oversize the wires to reduce R, which adds weight and cost.
| And if you drop 2V to line losses in your 12V system, your
| device is seeing 83% of the nominal voltage, while if you
| drop 2V in a 120V system (you won't, because Ohm says
| voltage drop is equal to IR, and I is 1/10th that of a 12V
| system), but still, you're 98% nominal.
|
| They're running 12V because that's the voltage of a classic
| 6-cell lead-acid battery, and you probably didn't want 220V
| in your Model T, even with felted asbestos insulation, but
| I'd be confident enough to lick a modern XLPE wire carrying
| 220V. A century of using those lead acid batteries (and
| worse, 3-cell 6V systems...can't endorse converting your
| classic car to 12V enough...) created now-entrenched
| economies of scale for lamps, and switches, and pumps, and
| radios, and fans, and most of the other things you need in
| a boat or camper. The only advantage of using those 12V
| parts is that their manufacturers put a little more effort
| into making them efficient. No one (sadly) will notice or
| care if the AC-DC converter that runs the clock on your
| stove burns 5W at idle even though your wall clock can run
| on one AA battery for years, but they will notice and care
| if their camper battery is dead after leaving it parked for
| a couple weeks.
|
| Today, I recommend using LiFePO4 batteries in whatever
| series cell arrangement gets you the required watt hours,
| regardless of that output voltage. Then run a modern, high-
| efficiency (high-frequency) digital inverter to bump the
| voltage up to whatever your local AC grid runs at. You can
| go 220V AC in the US if you really want more efficiency and
| smaller wires, and are willing to deal with the hassle of
| finding the right lightbulbs and international power cords
| and so on.
| jwr wrote:
| Doesn't a 48V DC installation provide a very reasonable
| compromise?
|
| That's what I use for my off-grid solar installations,
| and it works pretty well. 4x less amps, and you still get
| a safe voltage.
| LeifCarrotson wrote:
| Yep, that's a great compromise. 40V, 56V, 80V, 48V
| outdoor power tools use the same voltage for many of the
| same reason (they're slowly moving away from 18V battery
| packs for anything high-power). Maybe after a few
| decades, RV suppliers will standardize on 48V DC lighting
| circuits, a standard 48V DC receptacle, and provide fans
| and smoke detectors and pumps and sensors and so on that
| run on 48V DC. Integrated circuits will emerge in
| quantity designed to rectify 48V down to whatever the LED
| drivers and microcontrollers and so on use, and
| eventually compete in economies of scale with those used
| in the 12V automotive world.
|
| But good luck finding those parts today.
| creeble wrote:
| Yes, but there aren't many 48V DC appliances -- radios,
| lights, gauges, etc.
|
| Many larger boats have 24V DC systems, and there are
| quite a few boat electronics that run on either 12V or
| 24V (though you will still need either a 24->12v
| converter for many things, or be able to tap 12v from the
| battery bank).
| s3krit wrote:
| 12VDC is the standard on boats, campervans, RVs, etc because
| it can be delivered straight from the batteries. In order to
| deliver 240/120VAC you'd need an inverter to generate the
| signal, and this obviously introduces loss during conversion.
| For cable runs through the length of my boat (52ft), the
| cables aren't particularly thick - the thickest cables are in
| the engine bay, going from the alternator on the diesel
| engine to the batts, and again from the Solar controller
| (MPPT) to the batts.
|
| There's a plethora of stuff you can use with 12VDC to the
| extent that the only things I run off 240VAC is the vacuum
| cleaner and the TV (12VDC TVs are available but the cost vs
| quality payoff isn't really worth it).
| AngryData wrote:
| I would think 110v would be a little bit safer in the wet
| environment. Not perfectly safe but better.
| doubled112 wrote:
| If you go diesel, you remove the need for spark, but perhaps
| starting is a greater challenge.
| Toutouxc wrote:
| While most people here seem to worry about cooling the engine, if
| you did this with a modern high-efficiency diesel, like a recent
| VW 2.0 TDI, the engine would probably struggle to reach any kind
| of operating temperature at all.
| alistairSH wrote:
| 3600rpm is pretty high. This thing must suck gas. You'd want to
| do some math to figure out if this approach was actually saving
| any money over a proper consumer generator. Reliabilty would also
| be a concern. Not the engine itself, but the integration of parts
| by the user.
| giantg2 wrote:
| Depends on the situation. Very occasional use and already
| having the engine is probably fine. If you have to buy an
| engine, or use it often, then the math is more important.
| stonedautist wrote:
| looking at the video and his responses to comments, buddy is a
| machine-recycling nut just using this to give himself a mobile
| welder on his acreage or whatever.
|
| he definitely knows it's a mad-max-by-way-of-something-awful
| "look what I made out of shit I had lying around" solution to a
| thoroughly solved problem. it's conceptually cool but it's a
| weird narrow use case and it's not an objectively good idea.
|
| you could address cooling by using a motor with a big clutch
| fan and a well-shrouded rad, and you would probably be better
| off using the engine's idle control system to manage this at
| lower RPM to save gas, but it'd still be lipstick on a pig and
| you could go to harbour freight and buy a prettier pig.
| gambiting wrote:
| Why would the high RPM necessarily mean using a lot of fuel?
| I've had a little VW Polo 1.0L that used to sit at 4000rpm just
| to go 70mph on the motorway, and it still returned like 50
| imperial mpg(~6L/100km).
| rightbyte wrote:
| Essentially you want the motor to makes as few turns as
| possible for the same power output. At some low rpm the burn
| cycle gets bad though. Depends on motor.
|
| Fuel effeniency charts need constant power lines to be useful
| or they fool people.
| alistairSH wrote:
| Most Toyota Siennas were delivered with a 3.5L V6. The
| earliest models had a 3.0L. And they usually have an idle RPM
| around 700-800rpm.
| quickthrower2 wrote:
| How do you make this safe, electrically? In terms of earthing,
| circuit breaking, etc.?
| bluGill wrote:
| hopefully you reuse the circuit breaker from the original and
| so are fine.
|
| If you are running your house use a proper line/generator
| selector, and then your house grounds take care of earthing.
|
| If you are running tools outdoors on a cord you don't want an
| earth, just make sure all your cords are in good shape. With no
| earth connection if you touch a live wire you won't get a shock
| as there is no circuit. Although this is safer for temporary
| use you can't do it for indoor/permanent use because you can't
| insect the wires in your walls to ensure they are in good
| shape, and so you can get a lot of failure modes that running
| good cords prevents, and earth protects against those.
| sp332 wrote:
| Parts 1 and 2 do explain a lot of the decisions made, and I liked
| the process of improvising with lots of experience.
| NoNameHaveI wrote:
| Silly question: since a hybrid like a Prius is MEANT to be a
| generator (of sorts), would an old Prius be a better choice for a
| stationary generator? Lord knows they are pretty abundant and
| fairly cheap now. Having lived 5 days without power in the wake
| of the Iowa derecho in August 2020, I now fully appreciate having
| an emergency source of electricity. Generators were not to be
| found, and many were stolen from people's yards, including one
| from an animal shelter. Gas and ice were hard to come by. Cooking
| was challenging for us since our stove was electric. My pellet
| grill was/is electric so we were unable to cook. After 3 days, we
| had to toss everything from the fridge and freezer.
| bbojan wrote:
| I believe that the Japanese version of Prius (not sure if the
| regular one or PHEV) comes from the factory with this option -
| it can work as a full house generator as long as there is gas
| in the tank.
| snthd wrote:
| Joey Hess's solar powered fridge system[0] is neat - instead of
| just storing energy in batteries he uses extra thermal mass[1].
|
| [0] https://fridge0.branchable.com/ [1]
| https://fridge0.branchable.com/thermal_mass/
| MyNameIs_Hacker wrote:
| I have an 1800 watt 12v inverter in the trunk of my Prius and
| have pre-wired AMP cables to the battery for easy hookup for
| any family member not as technically inclined. This is limited,
| but I was able to run the oil heat and Internet for a few days
| when a winter storm took out power. The engine only runs when
| it needs to recharge the hybrid battery, so it is very
| efficient compare to a standard generator.
|
| You could probably get more power out with a custom inverter
| tied to the 140v hybrid battery, but this was quick and easy.
|
| I tried to swap in the refrigerator for the heat, but I had
| grounding issues that was tripping the inverter. Fortunately it
| was cold out so I was able to manage. Just remember a DR plan
| isn't done until you have tested it all the way.
| rainbowzootsuit wrote:
| If you tapped the traction batteries' output to an inverter
| there wouldn't be a way for the Prius to realize it wasn't
| operating normally with its strategy to keep the pack voltage
| in a ~30%-80% state of charge. It doesn't have a particularly
| large battery for the traction battery so I'd imagine it would
| run a lot unless you tie it to a larger pack. There are some
| folks retrofitting LiFePO4 cells with individual charge
| controllers to trick the NiMH hybrid system into using them.
| All the car controls look at is cell voltage.
| ChumpGPT wrote:
| Apparently they can only provide a maximum of three kilowatts
| of continuous power. Not enough for most folks but better than
| nothing in an emergency.
| KennyBlanken wrote:
| Yes, because it's an Atkinson cycle engine so the engine
| efficiency is much better, and also because normal car
| alternators are absurdly inefficient; about 50% or so, I think.
| The Prius's motor-generator is more like 90%+ efficient.
|
| The Prius's motor-generator might not be able to run at 100%
| duty cycle, but they're tens of kilowatts max output so you'd
| need a pretty big load.
|
| Many car alternators also won't run at full load for very long,
| and can only do about 2kW, so definitely a risk. Either the
| windings overheat, or the voltage regulator will. They're
| sometimes thermally regulated, but not always. You can sort of
| band-aid it with forced cooling to supplement the centrifugal
| fan on them.
| cjenkins wrote:
| https://www.plugoutpower.com/ makes a kit for the Prius (and
| others) to do just that!
| toast0 wrote:
| Not a budget option now, but this is a factory supported
| application on properly equipped F-150s. 240v@30A, available on
| the hybrid or EV only model (IMHO, more useful with the hybrid,
| cause you can probably drive to get more gas, or store some
| onsite, where it might be hard to find somewhere to drive to
| charge)
| supergeek wrote:
| If I recall correctly, the prius ICE and EV systems are totally
| isolated and only connected by the road in between the front
| and rear tires. The ICE runs the front tires and the EV system
| is hooked up to the rear tires. You mostly charge the battery
| up by slowing the car down with the rear tires, so you'd need
| to modify the car with some belts or linkage between the front
| and rear drives.
| camhenlin wrote:
| In Toyota's hybrid synergy drive, the electric motor system
| is inputting to the same transmission as the ICE engine, and
| is an integral part of the casing. You can see a cutaway of
| it here to get an idea of what it looks like in practice: htt
| ps://en.wikipedia.org/wiki/Hybrid_vehicle_drivetrain#/med...
| What you're describing is indeed how the E-Four system works
| for the rear wheels on the AWD versions of the Prius
| matt-attack wrote:
| I suspect there can be much improvement in his rudimentary
| "control" algorithm. A simple PID controller could react much
| faster and zero in on the right throttle position in response to
| a varying load.
|
| It was a bit painful watching that controller creep along.
| js2 wrote:
| Comment on the video asked the same. Reply:
|
| > That did occur to me and I think it's a good idea. I'll
| likely circle back to this project as my coding skills improve,
| I left a USB cable connected to the Arduino so updating the
| code will be super easy!
| jensenbox wrote:
| The entire time I was watching this I was thinking that a PID
| controller is exactly what is needed here.
|
| Any idea why he did not opt for that?
|
| Heck, he could have hacked the cruise controller itself to set
| the "speed" to 60 Hz.
| kortex wrote:
| Yep. Also the main loop should cycle as fast as possible, and
| only execute the control loop as needed. Or really use a timer
| interrupt.
| deepspace wrote:
| Also, look into controlling the ECU directly instead of
| futzing around with mechanically controlling the cruise
| control (yuk).
|
| And this really, really needs a proper RTOS and "software
| written by someone more professional than someone who tinkers
| with Arduinos", since malfunctioning software can destroy the
| engine and/or burn your house down.
|
| For the same reason, it requires a proper PCB, not some yanky
| box of protoboard and wires.
| savrajsingh wrote:
| Arduino is single threaded on bare metal -- you don't
| _need_ RTOS in this case, afaict
| ska wrote:
| You don't really need an RTOS to do something like this
| safely, but agree you need more firmware knowledge than
| "tinkers with Arduinos" to stay clear of possible
| unfortunate failure modes. You definitely need to build in
| some interlocks and/or other sanity checking.
|
| Similar with the PCB's, many of the better dev boards are
| pretty decent, the problem comes with poor connections
| designed for easy access, etc. This can be resolved without
| spinning a new board though, or perhaps designing a simple
| extender.
| ikekkdcjkfke wrote:
| Could jack up a working car and put it in cruise control and
| fasten the alternator directly to a wheel hub
| xyst wrote:
| Good "hack" but when that jack you picked up at your discount
| hardware store fails. That vehicle will become a projectile
| oh_sigh wrote:
| Take the wheels off, it won't go anywhere.
| actionfromafar wrote:
| Bingo.
| saalweachter wrote:
| Tractors have PTOs and are meant to be run at high load for
| long periods of time while stationary.
|
| On the family farm, we had a PTO driven generator for use when
| the power was out.
| glitchc wrote:
| A working car already has an alternator. Just plug in to that.
| ikekkdcjkfke wrote:
| I don't think that will be able to power up my home defense
| tesla coil
| sneak wrote:
| Or replace it with a bigger one that has more output (and
| thus more drag on the engine), and upgrade the belt for
| longevity. Then the car's built in electronics will handle
| keeping the throttle in the right place for idle.
|
| I'm in the process of designing a Sprinter mobile office
| roadtrip starlink vehicle with an asston of batteries in it,
| and upgrading the alternator so that the batteries are always
| charging from the diesel engine whenever underway is like
| step #1.
| BizarroLand wrote:
| A high powered alternator and a carbureted engine with
| mechanical timing and nothing else on the engine but a
| starter, exhaust, flywheel, and cooling seems ideal.
|
| Something like this: https://www.powerbastards.com/proddeta
| il.asp?prod=Fitzall-22...
|
| That way you can set the starter idle for high RPMs to get
| the system up to speed with the resistance from the
| alternators and then set the idle speed at the ideal speed
| for the alternator to produce the most power.
|
| But even on a 4 cylinder engine you're going to have
| horsepower to spare, so you may want multiple alternators
| wired in series with beefy transfer bars, so build a custom
| mounting plate for as many as it takes to almost bog down
| the engine at 1200 rpm or so.
|
| These $350 alternators produce 220 amps at 14.6 volts at
| 1200 rpm, or 3200 watts each. I imagine you could run at
| least 3 of them on a properly set up 4 cylinder engine.
| That's getting close to 10 kilowatts of power before
| conversion and you would probably still not be taxing the
| system.
|
| On the other hand, at this point you've spent $2,000 or so
| and a month of backyard engineering time to build an 8000
| watt generator when you can buy a 13,500 watt generator at
| lowes for $1,300 dollars.
|
| If you have a good motor you can run on a stand and a bunch
| of cheap or free alternators, then you just need the
| mounting system and inverter. Typical alternators put out
| about 40-80 amps, or 580-1200 watts. That at least has a
| chance of being cheaper.
| Toutouxc wrote:
| I don't think most differentials would enjoy that, even open
| ones.
| xattt wrote:
| How is the "school bus on front lawn" aesthetic avoided?
| brocha wrote:
| Easy! Keep it in the backyard
| justinclift wrote:
| Might need to be careful about doing that:
| https://www.youtube.com/watch?v=BAjAySmuvz0
| mindslight wrote:
| More unaccountable nonsense "technocratic" fake job
| bullshit. Get mandated rent from the boring beige-loving
| 90%, dump the 10% that somehow stick out.
|
| Also, that backyard looks like the least cluttered part of
| that neighborhood. I can't imagine being so scared of
| living in a multi story building that I'd do that to
| myself.
| bombcar wrote:
| Bury the schoolbus as a fallout shelter!
| swamp40 wrote:
| 120VAC is a waste if you are trying to generate power locally.
| Unless it's just for a few days or a week.
|
| Better to have 12VDC backups of whatever you need. Lights,
| refrigerator, fans, electronics. Like a semi cab. Then a wood
| stove for heat and cooking.
|
| Then the 12VDC can come from solar, wind, batteries, car engines,
| bicycles, etc.
| ianburrell wrote:
| Everything you talked about generally runs on 120V DC. You are
| basically suggesting changing everything in your house to save
| some money on inverter.
|
| It isn't possible to run full-sized fridge on 12V DC with
| reasonably sized wires. It is more efficient to run 12V
| generator through inverter, 120V AC over the wires to AC gear,
| and convert back down to 12V for the things that need it.
| chakintosh wrote:
| Here in Morocco, 80s era car engines are still being converted to
| run on butane/propane and used to generate electricity to run
| well pumps (their favorite is the Mercedes M102 E23).
| slowhadoken wrote:
| Something hippies and cab company owners have known for decades.
| Very cool.
| MisterTea wrote:
| That 2 pole generator is meant for single cylinder gas engines
| screaming at 3600 RPM _. Larger generators are 4 pole so they can
| turn at 1800 RPM for 60Hz and 1500 for 50Hz.
|
| And 5500W is not powerful IMO. That is a standard portable gas
| generator head. The car engine is way overpowered and likely not
| operating near efficiency.
|
| [_] AC motor or generator speed: RPM = 120f/p, where f is in Hz,
| p is number of poles.
| naikrovek wrote:
| I don't think this is a solution one would consider when
| perfection is desired, so I wouldn't worry much about
| critiquing projects like this one.
| BizarreByte wrote:
| I find it interesting how folks here are always so much more
| critical of things like this, despite being generally outside of
| what the average HNer is experienced with or knowledgeable about.
|
| Is this an ideal setup? Not even close, but you'll find
| mechanical people love to tinker with this kind of thing, myself
| included.
| HumblyTossed wrote:
| We got a whole house generator this year. It's tied into the
| natural gas line and has a transfer switch that auto switches
| over when power is lost.
|
| I like DIY stuff, but the convenience of not doing DIY for
| something like this is great.
|
| Now... one thing that could be improved is there's an 8 or so
| second loss of power while the generator spins up. If the whole
| house could run on batteries and the generator charge the
| batteries when mains can't that would be awesome. But that
| solution would be very expensive right now.
| [deleted]
| Temporary_31337 wrote:
| 60.73 is not great
| sgt wrote:
| 60.73 roentgen? Not great, not terrible.
| r2_pilot wrote:
| 60.73 is the frequency in hertz from the picture in the
| article.
| postexitus wrote:
| It's a Chernobyl reference.
| [deleted]
| ivix wrote:
| They gave them the propaganda number.
| bob1029 wrote:
| For 99.9999% of applications it won't matter.
|
| If you are powering your home with a Toyota minivan, I don't
| think you are concerned with grid sync or accurate time
| keeping.
| [deleted]
| hammock wrote:
| Is this safe? It's a cool idea and I'd appreciate even the
| slightest discussion of potential risks of the motor coming
| apart, or whatever else failure mode (I don't know)
| KennyBlanken wrote:
| If there's no system to shut down the engine on overheating of
| coolant or oil, you're definitely looking at a fire hazard.
|
| The bigger issue is the terrible efficiency; alternators are
| about 50% efficient, whereas proper mechanical generators are
| 90%+.
|
| The better solution would be to buy a "generator head" and
| connect it to the engine...but by the time you get done making
| a frame to hold the generator, engine, fuel tank, radiator,
| expansion tank, etc - as well as the necessary safety systems -
| you might as well just have bought an used generator.
| deepspace wrote:
| Hell, no, it is not safe. That box of Arduino madness is going
| to fail sooner rather than later, and destroy the motor, the
| person's house wiring or both.
| dghlsakjg wrote:
| About as safe as any other use of a motor. Moving parts like
| belts and fans are potentially a problem.
|
| The engine won't come apart in a dangerous way. It might
| overheat, which creates superheated water in the cooling
| system, which is designed to handle that. Although I sort of
| doubt it since they are basically using about 1/20th of its
| maximum power output.
|
| The most dangerous thing about this is likely the standard
| risks of any generator, fuel and electricity.
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