# Used Prius as a generator for off-grid property?



## Badfish740

Some of you may have heard of turning a Prius into a generator already, but in case you haven't, check this out:

http://www.converdant.biz/plug-out/

As it turns out, a Prius is the most efficient way to generate power since it is essentially a rolling generator and battery bank.  With one of these kits, you can draw power out of the battery, rather than directly from a generator, as with a conventional portable unit.  When either the battery level drops too low or the load demand is greater than the battery can supply, the gas engine kicks in to recharge the battery/feed juice directly to the load.  The result is a quiet, efficient generator that sips fuel.  Right now my daily driver is a 2001 Toyota Corolla with 213K miles.  I get a consistent 33 MPG out of it with a 72 mile round trip commute and a mix of highway and city driving, but I think I may be persuaded to look at a used Prius when the Corolla finally gives up.  

The plan would be to use it as my daily driver and convert it so that I could use it as an emergency generator at my house via a connector cord and transfer switch when needed.  Unlike my current Generac rattletrap 4800W jobsite unit, I doubt I (or my neighbors) would notice a Prius running in my driveway all night.  What really appeals to me would be the possibility of using it as a portable power source for a planned off-grid cabin in Maine.  Getting it there could be a bit of a challenge depending on location and time of year though   Think Toyota will ever build a hybrid 4Runner?


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## valuman

Badfish740 said:


> Some of you may have heard of turning a Prius into a generator already, but in case you haven't, check this out:
> 
> http://www.converdant.biz/plug-out/
> 
> As it turns out, a Prius is the most efficient way to generate power since it is essentially a rolling generator and battery bank.  With one of these kits, you can draw power out of the battery, rather than directly from a generator, as with a conventional portable unit.  When either the battery level drops too low or the load demand is greater than the battery can supply, the gas engine kicks in to recharge the battery/feed juice directly to the load.  The result is a quiet, efficient generator that sips fuel.  Right now my daily driver is a 2001 Toyota Corolla with 213K miles.  I get a consistent 33 MPG out of it with a 72 mile round trip commute and a mix of highway and city driving, but I think I may be persuaded to look at a used Prius when the Corolla finally gives up.
> 
> The plan would be to use it as my daily driver and convert it so that I could use it as an emergency generator at my house via a connector cord and transfer switch when needed.  Unlike my current Generac rattletrap 4800W jobsite unit, I doubt I (or my neighbors) would notice a Prius running in my driveway all night.  What really appeals to me would be the possibility of using it as a portable power source for a planned off-grid cabin in Maine.  Getting it there could be a bit of a challenge depending on location and time of year though   Think Toyota will ever build a hybrid 4Runner?


Do they still make a Highlander hybrid? That might get you there if the cabin's not way on top of the mountain on the other side of the hollow across the clear cut.


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## peakbagger

I think the Prius is the only plug and play setup but any hybrid could work. The trick is finding a commercial UPS that will take the voltage that the hybrid is pumping out. I would be curious if the old model ford escape hybrid has the same voltage as ford sourced much of  the hybrid tech from Toyota. There is long thread on using a prius as a home generator on solarpaneltalk.com


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## Badfish740

valuman said:


> Do they still make a Highlander hybrid? That might get you there if the cabin's not way on top of the mountain on the other side of the hollow across the clear cut.



Thanks for that suggestion-I had forgotten about the Highlander.  I shot an email to ConVerdant asking if they had ever adapted one of their units to a Highlander. From my understanding, the systems (Prius and Highlander) are identical, so I would hope it would be possible.  The real advantage the Highlander would have over the Prius would be ground clearance and the availability of more aggressive tires.  Most off-grid parcels are on marginally maintained unpaved roads-not exactly 4x4 trails, but full of potholes, washouts, loose gravel, etc...  A Prius would be scraping bottom often if not getting hung up if a washout was particularly bad.  The availability of AWD certainly wouldn't hurt either.  

The 5kVa 120/240 system would be a godsend because it would allow me to drill a deep well and operate the pump without having to operate a conventional portable genny screaming at 4K RPM every time we needed water.  I thought about filling a cistern every couple of days, but that could get problematic in cold weather when we'd plan to be there for snowmobiling/ice fishing, etc...


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## woodgeek

RE the high voltage battery....many of these vehicles have a beefy DC-DC converted to charge the 12V accessories and batt.  So if you can find the rating (e.g. on a forum) you can just buy and wire up a 12V inverter.

Apparently my Leaf has a 1.5 kW converter, so with batt buffering I can run a 1.7 kW continuous, 2 kW surge 12V inverter, and be safe with simple 'clamp on' cabling.  Priced it out at $300 bucks for all the bits, but can't quite pull the trigger when I am happy with my little genny.

As for getting the Prius up a hill in winter...get a nice set of snows.


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## EatenByLimestone

Buy a prius cheap with body damage, get it up there in summer, and build a shed around it.  Maybe you can even get a totaled one from an insurance company or junk yard.


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## begreen

I considered doing this to our Prius but we bought it new and I was reluctant to risk violating the warranty. For ground clearance, another vehicle that adapts to this style conversion is the Ford Escape Hybrid.


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## Where2

Badfish740 said:


> The 5kVa 120/240 system would be a godsend because it would allow me to drill a deep well and operate the pump without having to operate a conventional portable genny screaming at 4K RPM every time we needed water.



If I had to go that route, I'd be looking for a 1800rpm diesel generator. I've spent plenty of days after hurricanes listening to the 3600rpm gas generators screaming 24/7.


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## begreen

A buddy has the Honda 6KW(?) generator for his well pump at the yurt. It's pretty quiet. You can barely hear it 100 ft away.


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## Badfish740

woodgeek said:


> RE the high voltage battery....many of these vehicles have a beefy DC-DC converted to charge the 12V accessories and batt.  So if you can find the rating (e.g. on a forum) you can just buy and wire up a 12V inverter.



I've seen that done quite a bit as well,but you're limited to about 1.5kW as you mentioned.  The plug out kit accesses the high voltage battery and will do as much as 4kW.



woodgeek said:


> As for getting the Prius up a hill in winter...get a nice set of snows.



I wouldn't be worried so much about snow performance as I would rough road ability.  The Prius seems quite low to the ground so I'd worry more about bottoming out/high centering.  



begreen said:


> I considered doing this to our Prius but we bought it new and I was reluctant to risk violating the warranty. For ground clearance, another vehicle that adapts to this style conversion is the Ford Escape Hybrid.



It's actually against federal law for the dealer to void the warranty for adding bolt on, aftermarket accessories.  Nothing on the car is permanently modified and the plug out kit can be removed at any time-just a little food for thought.  

I'm pretty sold on the idea at this point.  Basically the Toyota Hybrid Drive system is what many off-grid folks spend a couple thousand dollars putting together with a generator, batteries (which don't last nearly as long as the lithium ion battery in the Prius), and a charge controller.  If you spend a lot of money you can get a system when the generator starts and shuts down as needed.  All of this functionality is already built into the Prius and on top of that, it was designed and built by Toyota   A little more reading yielded the fact that even with the 5 kVa (3-4kW) kit, you're not asking the vehicle's generator, charging system, or batteries to do anything that they wouldn't normally be doing during normal driving.  As for using it with a Highlander, I haven't heard from ConVerdant yet, but the brochure does mention consulting with them before using the kit with other models, so they're at least open to the idea.  I have to believe that everything would be basically the same, just with maybe different locations for some of the connections.  Sitting here watching the morning news I'm wishing I had one sitting in my driveway right now-looks like the Northeast is in for a big one Monday into Tuesday!


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## mass_burner

I paid $99 for my 1.5k inverter, $99 for local performance shop to install. Plug is hidden in the right light access cubby, inverter with prewired plug in box under rear deck. $358 seems $150 too much.


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## begreen

IIRC the Escape Hybrid's system was licensed from Toyota and is similar to the Prius. Here's a link to a DIY system:
http://priusgen.sandbox.org/


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## semipro

The Highlander traction battery voltage is higher than the Prius so a different inverter is required.  The voltage on the Highlaner is 288 VDC nominal and the Prius is quite a bit less, around 230 VDC?  
We bought a Highlander with use for backup in mind.  However, at the same time we're working on the design for a solar PV system.  Integrating the two has been challenging and its led me to hold up on the Highlander backup gennie plan, at least for now.


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## woodgeek

My EV is ~400 VDC, I do a lot of wiring around the house, but 400 VDC with >100 kW surge power....no thank you.  

If I did, I'd definitely take off my ring.


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## Badfish740

semipro said:


> The Highlander traction battery voltage is higher than the Prius so a different inverter is required.  The voltage on the Highlaner is 288 VDC nominal and the Prius is quite a bit less, around 230 VDC?
> We bought a Highlander with use for backup in mind.  However, at the same time we're working on the design for a solar PV system.  Integrating the two has been challenging and its led me to hold up on the Highlander backup gennie plan, at least for now.



Ahhh..crud-maybe I'll look into the Escape?



woodgeek said:


> My EV is ~400 VDC, I do a lot of wiring around the house, but 400 VDC with >100 kW surge power....no thank you.
> 
> If I did, I'd definitely take off my ring.



ConVerdant recommends you have the high voltage connection made by a qualified hybrid mechanic.  Once that's done everything else is safe for a layman to handle.


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## semipro

I was planning to use a single-phase server room UPS as my inverter.  Some of the medium sized units (6-10kw) use 24 12-VDC batteries.   One of these would probably work with a Highlander.


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## Badfish740

semipro said:


> I was planning to use a single-phase server room UPS as my inverter.  Some of the medium sized units (6-10kw) use 24 12-VDC batteries.   One of these would probably work with a Highlander.



Ok...I'm just getting the hang of all of this, so tell me if I'm understanding so far:  

http://priusgen.sandbox.org/

Here it looks like this guy has essentially done the same thing.  The Prius is connected to the UPS (which is connected to the load center), which basically just serves as an inverter, converting the DC to AC power.  I'm guessing that the reason for this is simply because a UPS is the best "off-the-shelf" equipment that is capable of converting the currents at the needed voltage?  If so, then all I need to do is figure out the battery voltage of the vehicle I end up with along with the desired output wattage, and find a UPS that fits the specs, correct?


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## Jags

Either of you guys ever hear a large UPS kick into battery power (which is basically what it would be doing)?  Both that I have had (commercial micro ferrups) are on the annoying side to say the least.


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## Badfish740

Jags said:


> Either of you guys ever hear a large UPS kick into battery power (which is basically what it would be doing)?  Both that I have had (commercial micro ferrups) are on the annoying side to say the least.



I never have-what kind of noise are we talking about?  The folks who have done it usually put the UPS right next to the electrical panel which is conceivably near the living area.


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## woodgeek

I'm usually the last to complain about safety....but you will want an appropriate fuse on the traction battery end of things...with a safed 'hot' side so nobody gets zotted changing a fuse.


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## Badfish740

woodgeek said:


> I'm usually the last to complain about safety....but you will want an appropriate fuse on the traction battery end of things...with a safed 'hot' side so nobody gets zotted changing a fuse.



I'd want multiple redundant safety systems built in (for me and the car) which seems pretty doable.  I think I may have found a simpler alternative though. The guy who did the "PriUPS" project did his webpage sometime around 2007-2008 and conceded that the UPS was the best possible method of doing this at the time because he could not find an inverter that would handle the high DC voltage of the Prius battery and put out 240V AC.  Seven years later, however, it looks as though the solar market may have provided an answer in the form of an off-grid solar inverter:

http://www.sma-america.com/products...-5000tl-us-6000tl-us-7000tl-us-7700tl-us.html

From what I can tell, this inverter will take up to 600VDC on the input side and put out 240VAC/5200W (6000W Surge).  Sounds pretty straightforward to me without messing with UPS batteries, settings, etc...  The PriUPS guy already had a UPS hooked up to his house because he is a computer/HAM guy and has a need for truly uninterrupted power which makes the system very complicated.  I envision my system working like this:

Grid goes down
I open the garage door, drag out the cord to the inverter, connect it to the car
Throw the transfer/interlock switch
Start car
Go inside and flip on the TV

Does this sound like it will work or am I missing something here?


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## Jags

Badfish740 said:


> I never have-what kind of noise are we talking about?  The folks who have done it usually put the UPS right next to the electrical panel which is conceivably near the living area.



Think of a 60hz buzz at the equivalent volume as your grampa's TV when he doesn't have his hearing aids in.


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## Badfish740

Jags said:


> Think of a 60hz buzz at the equivalent volume as your grampa's TV when he doesn't have his hearing aids in.



LOL...'nuff said.  What do you think of the solar inverter idea?


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## Jags

Badfish740 said:


> LOL...'nuff said.  What do you think of the solar inverter idea?


Out of my wheelhouse on that one.  I just don't know what I don't know.


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## jeffesonm

No Prius and no off grid property, but subscribing because this is a brilliant idea.


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## Badfish740

jeffesonm said:


> No Prius and no off grid property, but subscribing because this is a brilliant idea.



I don't have either at the moment, but I'm trying to plan for the future.  Peakbagger turned me onto a community of folks who can probably advise on the inverter idea I posted above.  In the near term, I would love to have this setup as an emergency generator.  I see that you're in Central NJ (I'm in NW Hunterdon County) so you would know what I'm talking about.  In the last six years we've lost power (Sandy included) for more than a week three times.  I did have a generator so my food didn't spoil and my basement didn't flood, but it was an awful, grueling, seven to eight days each time, getting fuel, starting the thing, cycling it every four hours, etc...  

The off-grid cabin is a nice dream for down the line, but the hybrid as an emergency power source beats the pants off of anything else out there in terms of efficiency and convenience.  How many generators can you hop into and drive to the gas station when they're low on fuel?


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## Badfish740

OK, trying again, any of you solar gurus on the forum I could really use your expertise here-the SMA inverter I cited a while back is actually not suitable for this purpose.  This one, however, might be:

http://www.sunfinepower.com/en/Product_show.asp?Bid=28&id=162

Input range is 180-360 VDC and output is up to 4800W continuous - 220VAC/26A.  From what it looks like (It's tough to tell because the product description is in that awkwardly translated English), its meant to power irrigation equipment with no battery storage, so it's an "all or nothing" affair-either PV or AC from the grid/a generator.  I would think that I could connect the DC inputs to the car/AC outputs to the transfer switch, and simply never use the AC inputs?


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## begreen

Hmm, looks like it might work.


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## Badfish740

begreen said:


> Hmm, looks like it might work.



We'll see-they are Chinese made and I'm not even sure you can get them in the U.S.-I emailed them-will report on what I hear back.


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## dougstove

Yes, please!


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## begreen

There have been several threads on this topic over on the PriusChat forums. Here's a couple:
http://priuschat.com/threads/using-car-as-generator-for-house-power.117507/#axzz3QQeD7WMS
http://priuschat.com/threads/anybod...nstalled-on-their-prius.119798/#axzz3QQeRiWzL

and this is if one just wants to inverter connect to the 12v system:
http://www.peakprosperity.com/wsidblog/79974/running-inverter-prius-backup-power


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