Using PIP As A Generator

Failsafe? What protects the traction battery if the car develops a fault like high temps in the battery and shuts down? Is not your UPS taping the battery at the cells and the only thing keeping it from completely discharging is maybe a low voltage cutout of the UPS which may be less than Toyota's recharge minimum? Just concerned about cooking a $4k to $8k? battery and warranty.

Tapping the 12v DC system at the fuse panel and not the jumper points, which have an unknown current rating, would leave the protection electronics in control. Anyone know what the max DC branch amperage is and what fuse slots are open?

Looks like your using gas at the ICE idle rate. Scangauge or Torque would give 1/100's of gallons per hour.

Would forcing the ICE on with a high heater setting result in recharging the PiP EV battery? Thinking like the excess generation that happens during warm up and or light loads on the ICE. Any other possible ways to do this?

 

That's like saying I'm a nice guy, because I'm comparing myself to Charlie Manson. A 2k Honda inverter is not efficient. The 240v honda inverter is less inefficient, but both are still inefficient. Running gas to put keep the traction pack up and collaterally use to run a fridge is inefficient, as the post directly above shows j- in more detail than I mentioned prior to that. But for emergencies, yes, it still works.

 

No, you miswrote your numbers. A watt-hour is not a watt/hour, it is, in fact, a watt*hour. A watt-hour per hour is a watt. So you are saying you are drawing 1500 watts for 5 hours in the evening (7.5 kWh) plus 1500 watts * 3 hours (4.5 kWh) plus 250 Watts for the remaining 16 hours (4 kWh) = 16 kWh, in a day (equivalent to 1/2 gallon of gasoline). Or an efficiency around 16%.

 

Not to mention the 'efficiency' of being able to drive your generator to the gas station... Ask those folks in NJ/NY what that's worth.

 

Yes, and by my description I was showing my rate of consumption during specific hours of the day. If I had just used the term "watts" that would have been incorrect because that is energy used at a specific point in time.

 

What would you recommend as an efficient deliverer of electricity?

 

You can't run any generator for only a couple of hours a day, unless you only want to power your fridge and TV for a couple of hours a day.

A standard generator will be most efficient only when run at full RPM (or near RPM, in real life 85% is the max for various reasons). However, most of the time - as demonstrated by my description of my own house's useage - a standard generator will only be loaded to a small percentage of its potential output. During blackouts most people are scurrying around to find an open gas station because their generator is sucking down a ton of gas running at full RPM all the time but they are only using a little bit of the gas' energy. I have a 12 kw LPG generator which burns 1.5 gallons of LPG per hour from 2 watts to half-load at 6000 watts.

A capstone micro-turbine has the same problem. Sure, it has a very high efficiency at full RPM, but like any other engine-only generator it doesn't matter if you only need 2 watts or 2000 watts, you are still burning a ton of fuel and using a small percentage of the potential energy.

Enter the inverter-generator in the last decade. That improves on the problem above because now the house's electrical driver is the inverter and not the generator head. So the engine can be taken down to idle during low loading (or no loading). But that doesn't solve the problem, because the engine can't be shut off because there is no energy storage mechanism.

Which leads us to the Prius, which acts like an inverter-generator but with the addition of a battery. So now it can quickly store energy at high efficiency and then turn off, letting the battery drive the inverter. With my test load of about 1500 watts mine was coming on for about 2 1/2 minutes and then staying off for 4 1/2 - 5.

 

Exactly. People in NJ who (like me in northern MD) were without power for days because of Sandy needed 20 gallons of gas per day to keep their lights on. If they had an inverter-generator then they needed 5 gallons per day. I only needed 3, and still ran all 120 volt loads in the house normally (and could do the 240 volt loads since my UPS outputs 120/240 split phase). So with the 20 gallons of gas I keep on hand at all times I can keep my lights on 24/7 for nearly a week instead of only one day. No need to drive to the gas station for a week. After a week there will be some local gas stations open for business - but more likely I'll fall back to my LPG generator which has 400 gallons of fuel in the ground.

 

I tapped the battery on the far side of the computer-controlled relays (see the link in my sig for full pictures). If there is a fault within the Prius the computer will shut the high voltage system down via those relays which will also kill the UPS tap. If there is a problem outside of the Prius I can shut the Prius down which will kill the high voltage output the same way.

 

The 12 volt system can support 80 amps @ 12 volts for an external load.

Nothing you do will force the traction battery to recharge more than a minimum amount. Then the engine shuts down again. The system expects to recharge the traction battery the rest of the way while driving down the road.

 

Obviously due to economies of scale, the answer is "the grid" which is what I think Hill is alluding to. But we are talking about emergency and/or off-grid power here so the answer is in my post 328, the Prius is the most efficient for the loads expected for a typical house.

 

His point was that over the span of five hours, he used 1500 Wh at night (over the span of five hours, or 300 W for 5 hours), 1500 Wh in the morning (or 500 W for 3 hours), and 200-300 Wh during the rest of the day. Or, in other words, 3200-3300 kWh in a given day. So, a fully-charged Pip would last him about 3/4 of the day before the engine would need to come on.

I remember you guys jumped on me a few months ago when I made a similar statement about usage. It helps to read carefully before trying to school someone on units.

 

there is no such thing as efficient home emergency power . So it's a question of how much you can afford for what your family needs are. See my post above regarding the capstone turbine natural gas generator. I've seen used ones for about half price but that still costly. But some emergency power no matter how inefficient is better than none.

 

Actually as I explained in a later post, I used 1500 watt-hour in each of 3 hours, and again for 5 hours at night, then 200-300 for the other 16. Or about 15.2 kw.

 

And see my post to you above saying that even the capstone turbine generator doesn't touch the Prius. The capstone is just another engine-only generator that must run 24/7 to produce electricity 24/7, running at full RPM wasting tons of fuel while your house sits there sipping 200 watts overnight. The Prius gets to turn off for an hour or so, then back on a for a few minutes, each hour overnight. No comparison, your beloved capstone uses way more gas.

 

Looking even deeper into Capstones, from what I've read they are all 3-phase 480 volt units which is useless for home use unless you buy a very expensive transformer. And how much is the Capstone itself?

The Prius itself is a sunk cost, since everyone here already owns one. The additional cost for the UPS and transformer I bought is $500 total.

 

#1 Its not my beloved - It's just an example of high efficiency presuming you have larger than average loads. That's again why I said it depends on what your needs are. Our Montana home looses power regularly (maybe 2x or more each 5months) - and you can't run a 3/4 hp irrigation well pump late at night on 200 watts - good luck trying that. As if that wouldn't mean you're hosed enough - throw in a couple electric room heaters.(frosty 40 degree spring mornings) and the fridge starting? So I repeat - for the umpteenth time it turns on what your needs are.
#2. We have multiple redundant backups - none of which are microturbines. It's more than what we need. Then again if you had more than one backup power source, and your power was down for weeks (weather by hurricane , earthquake etc) you might be able to supply power to several neighbors and swap goods for service. I do like me some preparedness

 

You can run a 3/4 hp irrigation well pump from a Prius - and several electric room heaters all at the same time. It can handle 3 kw long-term continuous, 6 kw short-term continuous, and many times that in surge. Bottom line, the Prius is the most efficient option for backup power.

I have multiple backups too. 12 kw LPG generator, 22 kw battery bank, Prius, either of the last two driving either a 6 kw Liebert UPS or a 4.2 kw APC (both output 120/240 split phase). Lots of multi-week outages where I live too from hurricanes, ice storms, etc.

 

[quote="hill, post: 1731479, member: 6723 and you can't run a 3/4 hp irrigation well pump late at night on 200 watts - good luck trying that. [/quote]

Just curious as to why you need to run an irrigation well pump late at night. Is this for irrigating farm land? Is it for well water for a home?

Mike

 

post 13 of the link in your sig. Missed the caption. Hooked up after the relay. OK