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Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
reply to dick white

Re: Using a hybrid car for power in case of blackout

said by dick white:

Jack, the first iteration of your link in an earlier post did work correctly, only the second iteration just above here didn't. No harm, no foul. There are already some cars in the market now with a low-rated 120V plug in the console for powering small electronics, etc., just plug it in like inside the house. It can be done, but my personal opinion is that it probably won't be done on any large scale. Plugging in your laptop while sitting in the car is an entirely different beast than running household appliances. The moment you depart from a simple plug for a laptop and move toward larger-scale external applications, you enter a zone where significant judgement is required by the end user. Whenever such significant judgement is required, the manufacturers are going to be leery of the liabilities. If the ordinary bozo has a car with a plug under the hood labeled "In case of emergency, plug in your refrigerator here," what is to stop him/her from adding the toaster and the coffee pot and whatever else can be strung off the extension cord(s)? When the car electrical system blows out or the house burns down, who takes the blame? Car manufacturers just aren't going to put themselves in the middle of that. JMO, however nice the idea might be.

Dick from what I saw on the various sites that's a big part of the problem for the manufacturers. They are working on it but aren't there yet. According the the one site they stated that in Japan the average electrical demand was 10 kWh and since the batteries were 20 kWh that would power the house for at least 2 days. That is significant. The article didn't state how long it would take the engine/generator to recharge the battery.

The whole concept unless they can just provide a simple plug that's protected it will not be for the average person.

dick white
Premium
join:2000-03-24
Annandale, VA

said by Jack_in_VA:

According the the one site they stated that in Japan the average electrical demand was 10 kWh and since the batteries were 20 kWh that would power the house for at least 2 days. That is significant. The article didn't state how long it would take the engine/generator to recharge the battery.

Well, there you have the USA problem in a nutshell. Just grabbed a recent electric bill from the drawer, I'm using ~20 kWh daily, and I live by myself in a small house with modest demands. In Japan, living spaces are much smaller and less stuff consuming power. Even so, I'd have to go back over the math before I'll believe there is enough juice sitting under the back seat of the Prius/Camry to run my whole house all day, presuming that we had an easy, convenient, and safe way to plug the house into it.

I once toured a "solar" house that the owner was touting as grid-tied net-zero-metered, meaning he had enough PV panels on the roof to, on average, generate more power back into the grid during the day than he took out at night. Nothing unusual there. What was unusual was that he had off-the-grid backup capability with a basement wall full of lead-acid batteries that could, if the grid went down, keep the house running forever. However, he said that during an extended outage, he had to carefully manage the high demand appliances (stove/oven, HVAC) to keep from discharging the batteries at night or on cloudy/short winter days. No way that the batteries under the back seat of my Prius/Camry could match his basement wall.


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom

I have the same problem. I average over 1000 kWh/mo and I checked once on Solar Cells and it would have been $33k for enough cells for 1/2 of my demand. We only pay about 10.5 cents per kW including all taxes and fees, here so it's hard to justify some of these things.

I'm very familiar with inverters and battery backups. We had them all over the plant on our switchgear to operate the trips in case of power failures. Each one had a universal motor with a gear head. The batteries were a major problem as they required constant maintenance.

Also the power plant had the same set up but in addition had a very large 240 volt inverter that floated on the line to provide power to the instrumentation to be able to shut the high pressure boilers (1500 psi) down without them blowing up and shut the turbines down without damage until the emergency generators kicked in.

I've got a Honda EB5000X non-inverter industrial generator I've used since 1997 with no issues. I power tv's, computers, modems, and everything else except my heat-pump. I've used the heck out of it given I'm in the middle of no-where so we have a bunch of long outages.


Bob4
Account deleted

join:2012-07-22
New Jersey
Reviews:
·Optimum Online
reply to dick white

said by leibold:

The high voltage system is a completely different story. The Prius has two motor/generators. The larger one (50kW) cannot be used while the car is stationary but the smaller one (20kW) can and as long as the car is "Ready" it will automatically start and and stop the engine to keep the high voltage battery charged (using the 20kW generator).

said by dick white:

I'd have to go back over the math before I'll believe there is enough juice sitting under the back seat of the Prius/Camry to run my whole house all day,

If leibold is correct about the 20kW generator in the Prius, it should be no problem running an entire house. That's 90 amps @ 220 Volts.

And 20 kW is only 27 horsepower, so the engine should have no trouble keeping up.


Cho Baka
Premium,MVM
join:2000-11-23
there
kudos:2
Reviews:
·TekSavvy DSL
reply to dick white

Your 20 kWh daily usage presents no challenge whatsoever.

What would be more of a challenge are you peak loads, measured in kW.

The second gen Prius (2004-2009) has a 50 kW generator (MG1), and could easily handle anything a residence could throw at it.

What is necessary is an inverter to handle this. A vehicle could easily be built with an integral inverter (as opposed to a DC-DC converter + 12 V to 120V inverter) to access a good chunk of this power, but finding enough takers to make it a financially viable option on a hybrid is likely where the holdup lies.

Consider that all Toyota configuration Hybrids have at least 2 inverters + a boost inverter as things stand - these are used for control/operation of MG2 and MG1.

Here is a link that shows a system (previously alluded to) being developed for Japan based on the plug-in version of the Prius:
»www.4wheelsnews.com/toyota-prius···nerator/
--
The talented hawk speaks French.



M A R S
Premium
join:2001-06-15
Long Island
kudos:1
reply to haroldo

Slightly off topic. I used my 1993 Volvo 240 with a 750 watt inverter for 8 days i had no power during the aftermath of the Sandy. I ran my furnace a few lamps with CLF's and a LCD TV. I would let the car idle for 3-5 hrs at a time 2 times a day. Oil pressure, volts and temp were spot on and this used a small amount of a gas a day. This set up saved me. People were amazed i could do this but it was just common sense to me. I had heat and light.

I Should also add, i did this because i let my generator to a family with an infant and there was no way you could get one in the days after the storm. We here on Long Island got hit very hard. I was lucky my house made it with only a few trees that fell around it. The Volvo on the 750 watt inverter i had truly saved our ass.


Bob4
Account deleted

join:2012-07-22
New Jersey

How many Watts can a typical automobile alternator provide?



leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET

said by Bob4:

How many Watts can a typical automobile alternator provide?

Car alternators are usually spec'd by current instead of power and 50A to 100A seems to be a common range with high-power after-market car alternators going up to 200A. At 15V charging voltage that would be anywhere from 750W to 3kW.
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dosdoxies
Premium
join:2004-12-15
Wallingford, PA
reply to haroldo

If I recall correctly, back in the early to mid 70's Ford had an option on the T-Bird called the Sierracin option in where the alternator had a 120V output for the grid style defroster in the windshield. Only think I ever ran across one in my 40 years as a mechanic.
--
The more people I meet, the better I like my dogs.



ArthurS
Watch Those Blinking Lights
Premium
join:2000-10-28
Hamilton, ON
reply to haroldo

Here's an interesting product:
»www.aurasystems.com/pages/prod_intro.html



cowboyro
Premium
join:2000-10-11
Shelton, CT
reply to haroldo

I will chime in.
A battery-driven power source is just not worth it. Yes you can power few lights (CFL) with one. I've done it after Irene last year... just hooked an inverter to car's battery and had power. But there is a bit more than few lights that needs to be powered. You will want to power a fridge. The inrush draw when the motor starts is in the 15A range. Only a beefy inverter will be able to sustain it. Then you want a space heater - even at low power that's typically 750W. Full power (cold day) you're looking at 1500W (~12A).
So you'll need not one but 2 very powerful inverters. You can buy a small generator for the price of a single one.


garys_2k
Premium
join:2004-05-07
Farmington, MI
Reviews:
·Callcentric
·callwithus

It's a good option, though. In a long outage you can run the gennie for a couple or few 1 or 2 hour periods each day. That's enough to ensure the refrigerator stays cold and charge phones but not use the gas too quickly. When getting ready to go to bed and all you need are a few lights, then using an inverter off the car battery is a lot easier on the gas supply than the generator.



cowboyro
Premium
join:2000-10-11
Shelton, CT

said by garys_2k:

In a long outage you can run the gennie for a couple or few 1 or 2 hour periods each day. That's enough to ensure the refrigerator stays cold.

It's not nearly enough. A refrigerator's typical duty cycle is ~50% - that means the compressor must run 12h a day to maintain the temperature. Sure one could handle with 4hrs of run every 8hrs but that's not quite practical...
It's much easier and practical to have a real generator that can power everything that one needs. Gas usage isn't that bad, my 7200W ETQ generator ate 10gal/day running non-stop.

garys_2k
Premium
join:2004-05-07
Farmington, MI
Reviews:
·Callcentric
·callwithus

Yes, I stand corrected, thank you. It seems that the maximum time a refrigerator should be left without power is four hours, not the eight I'd thought was correct. It would definitely be inconvenient to power up the generator in the middle of the night, four hours after it was last shut down, to re-cool the fridge. Still, running the generator just to power a few lights is a waste of fuel.



Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom

said by garys_2k:

Yes, I stand corrected, thank you. It seems that the maximum time a refrigerator should be left without power is four hours, not the eight I'd thought was correct. It would definitely be inconvenient to power up the generator in the middle of the night, four hours after it was last shut down, to re-cool the fridge. Still, running the generator just to power a few lights is a waste of fuel.

If you don't open it 8 hours is no problem. After Isabel we turned off the generator at 11pm and restarted it at 7am. All the neighbors here did the same to eliminate the generator noise pollution. 17 days with no refrigerator problems or freezer problems.


cowboyro
Premium
join:2000-10-11
Shelton, CT
reply to garys_2k

said by garys_2k:

Still, running the generator just to power a few lights is a waste of fuel.

You're talking about $1.50/h in fuel, even less for smaller units. Meh...
Mine ran for 4+ days straight, then shut it down when the office opened.

garys_2k
Premium
join:2004-05-07
Farmington, MI

It's not always about the cost, but about not running out.



leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET
reply to Jack_in_VA

said by Jack_in_VA:

If you don't open it 8 hours is no problem.

For most refrigerators this is correct. Modern high-efficiency refrigerators tend to have better insulation and may stay cool even longer if the doors are kept closed.

The more important difference between old and new refrigerators (and freezers) is the time it takes to cool them back down. High-efficiency refrigerators have compressors that are sized to optimally maintain a cold temperature but take a very long time to cool down once the temperature inside has risen. Older (or current non-HE) refrigerators tend to have more powerful (less efficient) compressors that cool quickly.

This does have an impact on how you use your generator. The HE refrigerator needs you to run the generator most of the day but because of its smaller compressor can be used with other loads concurrently even on a small generator. The non-HE refrigerator has a significant start-up current but will be happy with a few hours of generator runtime allowing long pauses in between runs.
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Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom

said by leibold:

said by Jack_in_VA:

If you don't open it 8 hours is no problem.

For most refrigerators this is correct. Modern high-efficiency refrigerators tend to have better insulation and may stay cool even longer if the doors are kept closed.

The more important difference between old and new refrigerators (and freezers) is the time it takes to cool them back down. High-efficiency refrigerators have compressors that are sized to optimally maintain a cold temperature but take a very long time to cool down once the temperature inside has risen. Older (or current non-HE) refrigerators tend to have more powerful (less efficient) compressors that cool quickly.

This does have an impact on how you use your generator. The HE refrigerator needs you to run the generator most of the day but because of its smaller compressor can be used with other loads concurrently even on a small generator. The non-HE refrigerator has a significant start-up current but will be happy with a few hours of generator runtime allowing long pauses in between runs.

Well mine is a 2003 and if it's not HE that so much more the better. A little more electrical usage is of no consequence. As long as it keeps the food cold using the generator is the primary requirement.