Prius as a power source?

<div class='quotetop'>QUOTE(icarus @ Nov 14 2007, 01:21 PM) [snapback]539568[/snapback]</div>

Emergency power, it provides enough to camp out at home.

<div class='quotetop'>QUOTE(icarus @ Nov 14 2007, 01:21 PM) [snapback]539568[/snapback]</div>

We're all hybrid owners in this group and in other 'average' groups, we're all crazy.

<div class='quotetop'>QUOTE(icarus @ Nov 14 2007, 01:21 PM) [snapback]539568[/snapback]</div>

The warranty is a real risk but in my case, I bought a used, 2003 Prius well beyond the 3/36000 mile warranty. So for me, it wasn't such a risk.

In my case, I already had the inverter:
http://hiwaay.net/~bzwilson/echo/

Now if you're already predisposed to using a standalone generator, go for it. But we've never had one and I I've got this $17k Prius that already generates 1kW:
http://hiwaay.net/~bzwilson/prius/priups.html

<div class='quotetop'>QUOTE(icarus @ Nov 14 2007, 01:21 PM) [snapback]539568[/snapback]</div>

At a full load, 1kW, it would take about 44 hours to drain a full tank and we have another vehicle with gas. But living in Huntsville, AL, we've had in the past two years, two outages from:

• high-winds, tornados - the weather was 85-90F, humid and the bedroom AC was what we needed to get a night's sleep.
• ice storm - tree limbs crashed the power lines and our street had the power out for 18 hours followed by another 6 hours. Having gas heat worked perfectly.

<div class='quotetop'>QUOTE(icarus @ Nov 14 2007, 01:21 PM) [snapback]539568[/snapback]</div>

We have slightly different priorities. I can get more food and as long as the fridge is kept closed, nothing will go bad for a day or so. But if you can't sleep because of the heat and humidity or a house that risks freezing the pipes, that really impacts the quality of life in a negative way.

<div class='quotetop'>QUOTE(icarus @ Nov 14 2007, 01:21 PM) [snapback]539568[/snapback]</div>

In engineering we get to pick two from:

1. Good
2. Fast
3. Cheap

I choose fast and cheap and the 1kW is enough. Eventually, I'll go with a traction battery system but that will happen after I go over 100,000 miles and the last warranty is gone. No need to trash a perfectly good warranty early. Right now, it looks like I'll be there late this spring or early next summer.

Eventually, I may come out with a co-generation system. When I arrive home, my Prius will plug-in and take over the house electrical, heating, AC and hot water load. It will burn natural gas and the next morning, it will disconnect, letting the house go back on the grid and I'll drive into work.

A warranty has value and shouldn't be compromised without good reason and understanding of the tradeoffs. But a 12 VDC inverter driven by our Prius is really a very simple, straight forward solution and quite affordable.

Bob Wilson

 

The Honda small generators are excellent products. I had the opportunity to compare the eu1000 (in my brother's RV) to a 2001 Prius with a 1 kw MSW inverter installed. Campground faceoff.

The sound levels were very similar when the Prius' engine was running (about 1/10 of the time). Our best estimates were that the specific fuel consumptions were also very similar. Presumably the Prius wins out in terms of pollutant emissions.

Based on a quick internet check, any price less than $700 for the Honda eu1000i would seem like a good deal. As I say, it is a fine unit and one could carry it to places where the Prius would not happily roll. However, there are many choices for pure sine wave inverters 1 kilowatt for $300-$600. Thus the added capability it brings to Prius deserves some serious consideration.

Perhaps later when there are more of these modifications made, we will hear of a case of damage to Prius. So far however all the installations have been done with due concern for safety and Prius' limitations, and apparently they have all been great successes.

There have been cases of major Prius damage by reversing polarity during jump-starting, so I will grab yet another opportunity to remind people to perform that operation with the greatest of caution.

 

<div class='quotetop'>QUOTE(bwilson4web @ Nov 15 2007, 04:21 AM) [snapback]539901[/snapback]</div>

Ok, here is my calcs. with my Eu honda.

44kwh is 44 hours of run time at full load. At full load, I use ~one quart per 4/hours= 1gal for four hours.@3:00= $.75 per hour, or .1875 per kwh. Not too bad compared to grid power. The effeciency numbers go up with a bigger (3kw) generator due to the inherent effeciency of the ICE on the generator, ie similar less heat loss per hp/kw. (I use the eu to charge my solar batteries with a 50 amp charger. It runs for almost 8 hours with that load,,, quiet too).

Of course none of this calcs the cost of purchase, maintence, repair etc, but neither do the examples of using the Prius connected to the stating battery as a stand by power source.

I stand by my earlier argument. Using the Hv battery makes much better sense due to the inherent effeciency of the engine, powering the bigger inverter. Running a 1.5 litre 4 cyl engine for ~1kw makes no sense. The honda eu does it with 50cc. If there were a plug and play system I would consider it, but as I have said, this is not a panacea for those that don't know an amp from a hole in the ground.

Icarus

 

<div class='quotetop'>QUOTE(icarus @ Nov 15 2007, 01:31 PM) [snapback]540118[/snapback]</div>

My fuel burn rate at 1kW is also 0.25 gal/hr., or 4kW hr/gal. measured at 30-40F, worst case. This is also the original specification in the Northern Tool catalog for the "eu2000" at half load, 1kW, temperature unknown. So here is a survey of Honda generator specifications including the 1kW Prius hack:

1. 6.1kW hr/gal@5000W, 5.4hrs - EX5500K2A
2. 5.9kW hr/gal@2800W, 7.2hrs - EU3000isA
3. 5.8kW hr/gal@1600W, 4hrs - EU2000iA
4. 5.7kW hr/gal@900W, 3.8hrs - EU1000iA2
5. 5.6kW hr/gal@4000W, 7hrs - EX4500SXK1A
6. 5.4kW hr/gal@400W, 15hrs - EU2000iA
7. 4.4kW hr/gal@2500W, 7.9hrs - EX5500K2A
8. 4.2kW hr/gal@2000W, 10.5hrs - EX4500SXK1A
9. 4.1kW hr/gal@700W, 20hrs - EU3000isA
10. 4.0kW hr/gal@1000W, 44hrs - Prius inverter
11. 3.1kW hr/gal@225W, 8.3hrs - EU1000iA2

Source for Honda generator performance:
http://bagleytractor.com/honda/gen/quiet/quiet_spcs.htm

We can now plot the efficiency, the kWh per gallon, for these generators and include an indication of how long they run before refueling:

From this we can conclude:

• dedicated generators can be 50% more efficient - 6kWhr vs 4kWhr per gallon
• many generators at partial power match Prius efficiency, 4kWhr per gallon
• The Prius run time, 44 hrs, is more than twice that of the next unit that is also at ~4kWhr per gallon
• Prius efficiency was measured in 30-40F temperatures, much lower than a standard day temperature

Recently, I began looking at inverters and found 1kW units run around $99-$130. The wiring and mounting cost an additional $20. This brings the Prius installation cost up to ~$150. The least expensive, standalone Honda generator, eu1000, runs about $350.

If a Honda generator were equipped with a continuous refueling system, the more efficient ones would only need ~7 gallons to match the 11 gallons needed by the Prius. This approach would also have the convenience, the constant power, so the owner doesn't have to respond to 'out of gas' by going outside to refuel the unit. I notice the larger units have a power sync option so two generators could work like one. This might provide a way to stagger refueling.

Bob Wilson
ps. Note, 11 gallons is the usable fuel from a Prius but I have put in 11.2-11.6 gallons in the past. A runtime of 44 hours presumes filling up the tank prior to the potential weather showing up.
pps. I retested the 1kW inverter load in 60-72F weather and achieved 4.3+ kW Hr/gal. But for emergency planning in a cold weather disaster, the 4.0 kW Hr/gal. figure makes more sense. We don't know how the Honda generators handle cold weather.

 

<div class='quotetop'>QUOTE(bwilson4web @ Nov 16 2007, 12:56 AM) [snapback]540449[/snapback]</div>

Oh and here I thought nobody had too much time on their hands! Now I find I am not alone.

In the interest in being nit-picky, If you take the Honda Eu 1000 and run it on full load, rather than 1/4 load as the bagley tractor site also shows, you have a rate of ~5.32kw/hours/per gallon, rather than the 3.1 stated. This makes good sense since the Ice of the Honda is way more effecient at load rather than partial idle, just like most gasoline engines.

While this is all an interesting exercise, I STILL stand by my previous arguement, that the ~$350-2000 Honda generators make much bettter sense than messing with and inverter plugged into the stating battery circuit.

Icarus

 

<div class='quotetop'>QUOTE(icarus @ Nov 16 2007, 06:27 PM) [snapback]540744[/snapback]</div>

There are 11 items on the list, two for each generator, a total of 10, and the Prius. Item #4 is the full load entry for the eu1000iA2. The list is sorted by efficiency in descending order and the Prius came in second from the bottom. Unfortunately, sorting made it difficult to match the full and partial power values for each generator. The chart now has connector lines between the full and partial power values for each generator and labeled for each.

For partial power, three generators use 25% load and the two others use 50% load. The Prius, no power, fuel burn is 0.06 gal./hr., which gives a maximum run time of 183 hours, just over a week. If we split the differences for run time and power, we get 500W over 103.5 hours, 51.7kW hr. For 11 gallons this would be 4.7 kW hr/gallon but that would be a calculated, not a measured efficiency . . . a paper exercise. At these low values, very small errors can multiply.

A Prius warranty can easily be worth several thousands of dollars, so it makes sense to be aware of the risks an inverter poses to a Prius, 12VDC system. Integration of an inverter has to be done carefully to avoid blowing the 100A fusible link, a repair that could cost the price of a Honda generator.

Inverters have an under voltage protection system that trips it off if the battery voltage is too low, typically 10 VDC. At 90A, my Prius inverter voltage had dropped to 11.5 VDC. A 0.0166 ohm shunt resistor would be enough to drop the additional 1.5 volts and lead to inverter shutdown but at the cost of a steady power loss, ~100W at 70A. This limits the inverter power to 900W.

A better solution would be an 80A circuit breaker, common in RV electronics that will trip out well before the 100A fusible link is at risk. This allows using an over-sized inverter and makes possible the addition of a surge energy source, a lawn tractor or motorcycle batter. Also, oversized inverters often have higher efficiencies than smaller units operating at their power limits.

A Prius using 12VDC inverter is not a universal solution and power limited to 1kW. It has to be driven to where the power is needed and parked with the keys running. A generator can be loaned and when generating power, the Prius can be driven off for other errands . . . like fetching gas for the generator. But a Prius power, 12V inverter is better than cursing the darkness.

Bob Wilson

 

All of this talk now brings up one point not discussed,

How much would a "normal" car use (in terms of gas) while running an Aims 1250 Inverter?

We know how much the prius would run but how much would a 'normal' car use?

I am asking this because I have 2 of those Aims 1250's on the way, and one will get hooked onto my Prius and the other can go onto one of my other cars.

For the other car I plan to hook it onto my beater work truck, 1994 Ford Exploder/Explorer 4.5ltr motor. How long will it take the exploder to run out of gas if it had a full tank? What would be the approximate burn rate?

 

<div class='quotetop'>QUOTE(Ecojosh @ Nov 18 2007, 10:03 AM) [snapback]541222[/snapback]</div>

I can't give any real numbers, but I will give you my inutition.

In the previous examples, you are using the Prius 1.5 litre Atkinson engine to power 1kw of power To use a 4.5 litre to power a similar load (I know you are talking 1.2kw, but keep apples and apples!) would take porportionaly larger amount of fuel. Added to that, the Ford engine is in it's basic design less effecient design than the Prius. So inutitivly, using 4.5 litres will have a terrible effeciency curve.
Remember, the Honda Eu 1000 puts out 1kw with .5litre. (50cc).

Icarus

 

I know that the Honda Generator would be 'great' but I already have a 6.5kw diesel generator. These inverters are actually backup to my backup (in case the Genset doesn't start). The Genset is new but CHEAP (bought on eBay for $900 with an ATS) so I don't fully trust it.

I want to have extra sources of power. Thought the 2 inverters would do it for me. Even if the exploder burns through 1 gallon per hour, it would still make an excellent double emergency 1250 generator. If it's going to burn 3 gallons though, it might run out of gas while we sleep

My super emergency load is just under 2kw, trying to power 2 800watt electric heaters to keep two rooms of the house warm enough.

 

<div class='quotetop'>QUOTE(Ecojosh @ Nov 18 2007, 10:51 AM) [snapback]541229[/snapback]</div>

The other half of my life is working with off grid solar powered sites. What I find with most people is that thier "emergency" loads are way bigger than an off grid load is in total. While I appreciate wanting to keep warm. 2 800 watt heaters running off two vehicle may not be the smart way to go. There are other alternatives that consume way less power. For example, one room in the house could be equipped with a direct vent propane/gas space heater. Many use no power at all, some as little as 50 watts, but put out ~35,000btu/hour, 100+ times that of the 800 watt heater. Very effecient, very safe. Electric blankets use ~125 watts, so if sleeping cold is a problem there is a better solution.



It seems to me, the "emergency loads" that we talk about, are first, life safety, water, heat etc. The preservation, ie fridges, freezers etc., and lastly luxuery stuff. Amazing how many people think the widescreen tv needs to be on the emergency circuits!

The first can be address quiet easily with a preparedness kit, ie bottled water, camp stove, warm clothing, etc.

The second can be helped by either using hi-ef appliances, or climate. Power outages in the cold weather mean the fridge and freezer will stay cold for long period if they don't get opened often. Covering them with a blanket also helps keep the cold in.

A widescreen tv is out, but a battery radio is essential, and perhaps a battery tv as well.

My point here is as with most things, but especially things that may never get used,,KISS.

We use about 400 watt/hours of electricity a day. Granted we have propane fridge, and wood heat, but we have all the lights and water we need, we run whatever gadgets we need to, and have the sattelite modem when we need it. (No Tv helps!)

Most grid power outages are comparativly short lived. In the event of a complete failure (earthquake, attack, melt down etc) your not going to be able to get gas for your xploder for long anyway. You'd be very much further ahead to be really prepared.

Icarus

 

<div class='quotetop'>QUOTE(Ecojosh @ Nov 18 2007, 12:03 PM) [snapback]541222[/snapback]</div>

The challenge for the gas car will be to spin the alternator fast enough to generate the amps needed:

http://hiwaay.net/~bzwilson/echo/

Fuel consumption trying to drive the alternator will be a challenge. Now if you could tap the radiator coolant loop or put a water loop in the exhaust flow, you'll have plenty of heat. Northern Tool sells quick release, hydraulic connectors that would be perfect to bring the heat into the house. Some assembly is required.

Bob Wilson

 

<div class='quotetop'>QUOTE(Solar_Powered @ Aug 24 2007, 04:09 PM) [snapback]501790[/snapback]</div>

I know you have all gone beyond this but here is another way- one of our OC Prius folks did a conversion and put up a pdf on it:

http://priuschat.com/index.php?s=&show...t&p=501790
If you power requirements are minimal (less than 7 amps at 120 VAC), I invite you to look at my inverter project "Prius as Back-up Power" at http://briefcase.yahoo.com/[email protected] .

by Solar_powered

 

The house is all concrete so cutting a hole in the wall for ventilation is not an option.

Also we get precious little sun so solar isn't an option.

Wind power is an option, but getting the power into a usable form from the roof is frightening to me. Anyone know a wind power expert?

 

<div class='quotetop'>QUOTE(Ecojosh @ Nov 18 2007, 02:39 PM) [snapback]541299[/snapback]</div>

Two quick notes. A rinnai propane or nat. gas space heater, (WWW.rinnai.com I think) vents through a ~3" hole in the wall. A core drill can cut it in a few minutes, for minimul cost.

Second, most renewable experts consider small scale wind the LAST option for most people, after conservation, solar (even in marginal condition) water and finally wind. The problem with small scale wind is that it is high maintence, quirky and somewhat difficult to tie in to house wiring due to voltage fluxuations.

(Large scale commercial wind makes great sense however. If you are looking for more information, I suggest that you try http://www.wind-sun.com/ForumVB/index.php. It is loaded with useful info, and some truly expert advice.

Icarus

 

<div class='quotetop'>QUOTE(MrK @ Nov 19 2007, 12:06 PM) [snapback]541613[/snapback]</div>

It's been done! There is another complete thread on using you Prius for back up power. In the thread there are details adinfinitum comparing various makes of gens sets vx the Prius.

Icafus


<div class='quotetop'>QUOTE(MrK @ Nov 19 2007, 12:06 PM) [snapback]541613[/snapback]</div>

It's been done! There is another complete thread on using you Prius for back up power. In the thread there are details adinfinitum comparing various makes of gens sets vx the Prius.

Icafus

 

<div class='quotetop'>QUOTE(MrK @ Nov 20 2007, 06:02 AM) [snapback]541916[/snapback]</div>

Turns out it was about three threads below, http://priuschat.com/Electric-Power-from-Prius-t37079.html

Icarus