Man Uses Prius to Power House for 3 Days During winter storms

Bob, yes, I'd like to get your suggestions. Actually, I was using a full-size automotive battery (state of charge: 12.5 volts) with the inverter, trying to start the sump pump; the Prius wasn't involved. But I do have 4 gauge cables permanently attached to the Prius' 12 volt system, as I have previously used it to run the furnace blower, refrigerator, etc. And as Pat Sparks mentioned, I ran these cables to a deep-cycle battery for the surge capacity, connecting the inverter (1,500/3,000 surge watts) to the deep-cycle battery's second set of terminals.

This may all become academic for me, as I'm within 24 hours of completing my HV installation. [Tripp-Lite SU6000 produces 4,200 watts/6,000 vA, connected to the HV battery.] This ought to start the sump pump! We'll see.

Since we are getting off-topic, would it be preferable for you to PM me, or start a new thread regarding your ideas on the inverter surge issue?

 

Was it still dark?

If so, in my neighborhood, somebody would have turned the dogs loose to
scare away the whacko sneaking around and stealing stuff from peoples
yards!

 

You have a new system to test so lets see what happens. As for where to discuss this, either here or "Prius Techincal Stuff." This is good forum but "Prius Technical Stuff" has the hard core folks who have forgotten more than I've learned about power systems. But let me layout the approach:

• high speed current and voltage sensors - it is critical to measure the surge load and duration. This defines the load that has to be handled.
• survey or map the current system - we need to see what happens to the current and voltage during start attempts. We can also compare this against the specifications and determine if the parts are meeting spec.

What I'll do is suggest how to use a stereo microphone input and some simple 'glue logic' with audio recording to capture the stuff we want to study. Once you have the data in hand, diagnosis is trivial, and effective correction possible.

Bob Wilson

 

Whoa, partner!! I think you're coaxing me into the deep water now. It sounds like my cheapo multi-meter won't be able to to run these tests. Will a computer's audio input be sufficient, or possibly a tape recorder?

Let's me do this: with a little luck (and providing my wife doesn't have my evening planned for me!), I should be able to complete the installation of my HV system tonight. If so, I'll do a simple test with the sump pump, and I'll report with a new thread in the "Prius Technical Stuff" forum tomorrow.

Then you can explain to me how to test high speed current and voltage sensors, mapping, etc. I'll try to keep up with you. Thanks, Bob.

 

The horror ... the horror

Just kidding big guy!

Seriously, although the Prius *can* be used as an emergency power source, not sure if it would be worth the risk to the vehicle. That said, sensible precautions can be taken, and it would be trivial for Toyota to engineer a dedicated power port for the NiMH battery pack.

It's more efficient to use an inverter with a 200 vdc input, than an inverter with a 12 vdc input

Regarding the ability to run electric motors: this is perhaps the hardest load to start and properly run off backup power. THe load introduces a lot of capacitance and inductance, and the PF is *not* 1.0. Many cheap consumer-grade inverters cannot deal with that

Another thing to keep in mind with motor loads (Sump pump, freezer, etc) is that they cannot readily accept the standard - cheap - inverter square wave output. You will experience rapid motor heating, most likely burning it out if operated for long periods

Commercial/industrial inverters offer very close to pure sine wave output, and will reliably match the surge current needed for starting motor loads. Yes, this can turn out to be a very expensive proposition

Regarding the comment about Ford Super Duty trucks with the turbodiesel and two alternators, this is a useful option if one routinely expects to operate heavy draw electricals, such as a snowplow hydraulic powerpak, without putting strain on the primary electrical system

At my hobby farm, I finally settled on a Kubota diesel generator. There is an automatic transfer switch, and I have it configured to "exercise" once a week. I built it into a cinderblock room within my detached garage, with proper cooling vents.

The generator has an automatic coolant heater (Not a cheap block heater, it's thermostatically controlled to keep the block at 120 F), 50 watt oil pan heater, and a 50 watt heater for the generator itself to prevent condensation within the windings. This represents a 800 kwh/month electrical load which costs me around $44 dollars

Depending on how often you expect power outages, how critical it is to keep certain loads up, the level of reliability you expect from the backup system, and how large your budget is, a solution to run essential loads can cost as little as $800 to as much as $15,000

Regarding backup generators, you'd be surprised how often they fail due to the fuel going bad and gumming everything up. Proper additives are essential, as is proper filtration. For smaller gasoline generators, it's best to just drain the float bowl and leave it drained until needed

 

I agree, mrk. I love the PriUPS site, and love it when people 'discover' it as tho it were new



Our home's nearly 8Kw of PV panels will be on line in just a few days. Being grid tied, they shut off if power goes out. I'm looking into "fooling" them into thinking 220v is still being fed to the house (of course this has to be w/ a disconnect, so we don't feed power back onto the grid & kill some poor lineman). That way, we can still use their power, as well as the DC in the Prius batteries. Actually the battery supply in our AWD hybrid Lexus SUV is way bigger, so that might be a better way to go.
There’s a good amount of parasitic power loss with the Prius’ hsd, so I’m wanting to pull as much as possible to amortize the hybrid’s potential … kind of amortizing the battery usage. I note the SUV battery pack’s parasitic loss is much slower, since the pack is bigger. Of course, it's being regenerated w/ a V6 too, so it might be a wash.
I haven't yet figured out if the PV panel's 4kw inverters (2 of 'em) can work to convert the hybrid's power into AC. So many possibilities. Never hurts to be ready for the next disaster.

 

Excerpts:
...Our home's nearly 8Kw of PV panels will be on line in just a few days. Being grid tied, they shut off if power goes out. I'm looking into "fooling" them into thinking 220v is still being fed to the house (of course this has to be w/ a disconnect, so we don't feed power back onto the grid & kill some poor lineman). That way, we can still use their power, as well as the DC in the Prius batteries. ...
I haven't yet figured out if the PV panel's 4kw inverters (2 of 'em) can work to convert the hybrid's power into AC. So many possibilities. Never hurts to be ready for the next disaster.[/quote]


Wow!! 8kw of solar!! I'll bet that cost more than your Pruis! I guess, in Big Sky Country, it never hurts to be self-reliant.

Do your PV panels charge a bank of batteries, which provide the dc power to the inverters, which power your energy needs? If so, then why would you need to enlist your hybrids' batteries--unless it's simply a backup to the solar system's batteries.

What kind of voltage is input to your 4kw inverters by the solar panels? My Tripp-Lite is designed for 240vdc, but can operate between 205vdc-276vdc input. You may to see if the inverters can operate in the hybrid batteries' ranges. I think the Lexus has a higher nominal voltage than the Prius, doesn't it? You surely don't want to fry your inverters.

I'd be very surprised if your set-up doesn't already have a bypass to allow you to use its power when the grid goes down, so long as it's been disconnected from the grid. Like you said, you don't want to zap a lineman.

 

Being lazy, I would go directly into the computer after making sure we don't have a ground loop or other common noise problem. We'll explain how to test this.

Once the audio recording system is configured, we calibrate it using ... 100 W. incandescent bulb. This calibration is critical because it lets us know the scale for the recorded data and practice.

The last step is to actually do the measurements and analyze the results. If you have a small stereo recorder, we can use it to capture the data and then later play it back. The scenario will be:

1) calibration test with 100 W light bulb - you'll need your multimeter for this as well as the recorder.
2) grid pump test - this establishes the baseline load and the response of the grid to the startup load. We will need to understand the pump back pressure mode(s).
3) experiment pump test - this is where we find out what the inverter is doing with the pump. We may need to also look at the DC side.

These are not terribly difficult after you've done them several times but it helps to understand the theory. We'll be looking at 'inrush' and 'motor starter loads.' Not to worry, it will be interesting!

Bob Wilson

 

I agree about watching out for square wave inverters. Mine is a modified sine wave inverter and though less bad than a square wave, it has a significant voltage drop over a long extension cord. Also, any motors need to be tested with a temperature probe using grid and then inverter power. In my case, there was about a 3C temperature increase, well within limits. But testing when the weather is nice and repair services available is critical.

DON'T WAIT TO TEST IN AN OUTAGE!! (One of Murphy's laws.)

Bob Wilson

 

a large 12v... brilliant.. how about two huge 6v tractor batteries? i'm getting ideas... ( good testing grounds )

 

That is much better for inductive loads, than a square wave inverter. Actually, there are so many choices out there (Pure sine, modified sine, stepped/square, etc) it's hard to make a good choice. Especially on a budget

Load response is another key thing to look out for. If you scope the output of a lower quality inverter, it may be fine at less than 50% of its load rating

Ramp the load up to its rated capacity, especially in one step, and you will notice very odd things happening to the output. Eg sawtooth effects, ripple, etc

Consider older six pulse thyristor UPS's hooked up to a backup generator. One would assume you match the generator output to the UPS rated load capacity.

No!

Due to harmonics introduced by the six pulse thyristor, technically the worst at 5th and 7th order, you had better size that generator at least 3-5 times *higher* rated than the ups. Otherwise, you get great Special Effects from the generator

The nice thing about the Inverter generators from Honda is that they offer very stable output, ideal for motors and electronics

 

Well I'm still going to claim ignorance on the practical use of snow

However the way you're sounding is that snow will not ever be colder than 32°F, now I might be off on this, but snow can get colder than 32°F can't it?

 

The panels are on our southern home, 1K miles away, in CA. No there's no battery backup, because they almost double a system's cost & we can't afford the room anyway. That's why I want to inlist one of our hybrids ... not only to provide power (at NIGHT) but to fool the PV system into thinking it's still grid tied ... that would give us nearly 50amps of 120v during an outage ... if it works.

 

Sure, snow can get much colder than 32°F, but the key thing is latent heat of fusion. It doesn't take much heat to warm up snow until it gets to the melting point. Once there, the snow's temperature stays at 32°F until the snow melts, at which point it starts to warm again. It only takes one calorie to heat a gram of water 1°C, but it takes nearly 80 calories to melt one gram of ice. That's why ice cools better than cold water.

What does all this mean? It means that most of the cooling from snow comes from melting. The snow will warm to freezing fairly quickly.

Tom

 

I noticed the second location after I pushed the 'send' button.

If I understand you correctly, your PV system can produce 8kw of power and is tied into the grid. But if the grid is down, you cannot access the PV system's power, even during a sunny day, as there is some sort of lockout/diode to keep you from feeding power into the grid, ostensibly to protect those trying to get the grid back in operation.

And of course, you cannot use your PV system after dark. This is the first place where your hybrids might be able to assist. Again, you'll need to match the dc inputs of your inverters with the output of your vehicles, so you need to check their compatibility. Assuming compatibility, you follow Richard Factor's (PriUPS") directions for accessing the HV battery, and you set up your wiring to connect to the inverter. Now, you'll have 4kw at your disposal.

You don't want your PV system to feed power to your hybrid batteries, so you'll need to isolate the two power sources. As I don't really understand why the PV system requires grid power to operate, I can't address your thought of using vehicles to 'trick' the system into thinking you're still on the grid.

I just got my HV installation finished (at least 99% finished) and tested tonight. I'm going to post to the Technical forum.

 

One 'heads up,' some consumer and control electronics suffer problems:

• inrush - my Macintosh and the TV have significant inrush loads that can trip the overload feature of the inverter. I have a special "pig tail," a 110 VAC outlet and short plug, with an inrush, thermistor. Like 'startup loads,' these can be maddening, which is why it is important to test before a real power outage. Sometimes just ordering the loads is enough. But in some cases you can have power oscillations.
• noise sensitivity - actually a problem with poor power supply design, you might pickup the noise in amplifiers or some receivers. Our heater thermostat refused to work correctly on modified sine wave but otherwise is unharmed.

Still, having 1 kW from a modified sine wave inverter is better than cursing the darkness and winter cold. You'll have roughly 9 A. at ~110 V to work with and this can be the difference between evacuation and 'camping out at home.'

Bob Wilson

 

It probably wouldn't cost more than $3,500 for a decent backup generator with ATS

 

The older ones especially have this problem, in addition to PF <0.8. If you scope the initial power on, especially if the capacitors in the PS have been fully discharged, you see very characterisitc L/C effects from the transformer and capacitors

The newer high quality - eg very expensive - computer power supplies are much better at inrush and ripple. For example, a 800 watt OCZ Technologies power supply I tested this summer.

This power supply is "universal" from 110-250 vac, there is no switch to select different voltages. The inrush is very well managed, and it appears to tolerate even square wave with only minor complaint

If you intend to test the performance of devices under various AC "brownout" simulations and ripple/noise/distortion, I recommend the Agilent 6813. This is a very expensive power source, but has the ability to simulate a variety of noise and distortion events.

Many of the noise events are preprogrammed, but you can also custom program a noise event, eg "ringing," frequency jitter, etc

 

Limited but useful. We run LED lights for our Phoenix parade of light each year.

Now imagine a plugin prius that has more battery power , also check out the V2G options of an ACpropulsion eBox , Tesla or new MINI-E full electric with lithium batteries. With Vehicle To Grid you can charge, sell power or run almost anything. Your car could make money parked at home or work by charging on the off peak rates, then selling on peak. 4 cents off to 20-30 on peak.

Lots of power so it can charge off peak, sell on peak or run your entire home for a while. A lot more energy that the FULL hybrid prius.

The future is unlimited with Battery Electric.

 

Okay guys, lets lookat one basic common issue. Carbon Monoxide !!!

The gentleman admitted he LEFT THE CAR IN HIS CLOSED GARAGE while he was doing this. He blew it off based on "the car only turned on every half hour using gasoline".

I think it is great he was able to run his house with his car but he could have killed his family in the process.

Next time, buy a lead cord and park the thing outside.