50kW question...

I assume you mean 1900 kWh/month (though that sounds very high to me, unless you all live in mansions or run the A/C 365 days/year)

In theory, a 50kW output could power your entire neighborhood. The problem is that you'd drain the battery immediately, and then the motor would stop.

In practice, you can power your house off of any car. Buy a power inverter online or at your local hardware superstore (BJ's wholesale club carries them, even). You can get inverters that give several kilowatts of output. Then you can run a lot of stuff using your car's engine as the generator.

 

Well, the key is the "per month" part. You use 1835kWh per month, not all at once. Your peak use is probably more like 4 or 5 kW -- running the A/C, the oven, the fridge, three TVs, the computer, and then turning on the microwave with a bunch of lights on, for example. I can't really imagine that kind of draw, but at 1835/month, you must have it. On average, you're using 60 kWh per day, or 2.5 kWh/hour which is a heck of a lot.

The definition of kWH is that if you use 5 kW constantly for an hour, that's 5 kWH.

I have no idea how deep the battery's charge really is.. My real point was that yes, the electric motor generates 50 kW, but the ICE generates a bit more than that, and the ICE in a normal vehicle generates yet more (kW and "horsepower" measure the same thing, just like "farenheit" and "celcius" do). The electric motor is only interesting in that it can run off the battery.. without the battery, it's still essentially gas-fed and no better than just using the ICE.

 

The biggest problem with electric vehicles hasn't been power, its been longevity. As the Toyota salesman told me, the Prius has more raw torque than the Tundra - but don't try towing things around with your Prius. The electric motor is very powerful, its just that the battery drains out. The best research I've seen has been to use ultra-capacitors to augment or replace the batteries we have now. That way you get all the juice for longer times, not just at start-up (which is what we basically get out of the Prius).

 

This is fascinating, but I'm curious. My display doesn't say KWH, it says just plain WH. Is mine different, or do they *mean* KWH?


I must admit I *thought* it said KWH, so I went out and looked. What have I missed?

Peace

 

1kWh= 1000WH
Another way to estimate power usage is to look at your circuit breaker box. Most houses built in the 80's have a 200A capacity. At 110V, that's 110x200=22000W or 22kW maximum power draw by your house. Older houses have less, newer houses have more. Things like heat pumps and air conditioning use lots of power.

 

The Prius is rated in WH which means a 50WH is the amount of energy to power a 50 watt light bulb for 1 hour. Way different than KW which is how most household appliances are rated. It takes 25 of the little cars to generate 1.2KW the draw of the average kettle would use in an hour.

 

The smaller of the two electric motors is actually the only one turning with the engine running and the car sitting still. I belive it is rated at 10KW and woould assume you could regularly draw 5 KW from the High Voltage pack/supply to feed an inverter. 750 watts is about one horse power.
In my neighborhood if you use more than 350KWH a month they start charging more per KWH :guns: .My real cost per kwh is about 15 cents.(total electric charges divided by total consumption) They like to play games with how they actually add up the charges. :cussing:

 

Wow 1835 KWH per month!!!!
I live in the Bay area in Northern California and use about 275-320 KWH/month ( Gas appliances & hot water heater and heat, no AC lots of fluorescent bulbs). During the most severe part of the Manufactured energy crisis 2 years ago I managed to get down to 8KWH/day without it severely affecting our lifestyle. Electricity is 12-18 cents/kwh here.

 

I happen to have me e- bill right in front of me. Last 30 days I used 259 kWh, or 8.6 kWh/day. $.065894 /KWh winter price.

(Gas heater, Gas H2O heater, e- stove)

But thats only fo 1 person.

Brian

 

I also use around 250 kwh/month, also for one person. One day I'll get a PV array on the roof and run it to a net of zero. I can dream, can't I? :mrgreen:

Peace

 

So how many WH (or KWH) does it take to move the Prius some given distance/speed, etc.? E.g., Accelerate gently from a stop to 20 mpg and travel over level ground for a mile. Or any other specific terms for which info is available. I understand that a 100-watt bulb uses 100 WH in an hour, but how far would that get my car?

 

oh, this is going to get ugly.....

thanks for the other link, but by the way, http://www.toyota.co.jp/IRweb/special_rep/...sII/ths2_7.html is a really good page for how the doggone power split works and which part is connected to which....

ok, back to the question..... one horsepower is roughly equal to 750 watts. that's great if you want to know how much electricity your vacuum cleaner or table saw is burning, but not nearly as good when you're talking about moving vehicles.

next step is f=ma, the force needed to accelerate a mass. torque = force x distance, which is what makes the wheel turn which pushes against the pavement, which makes the car go.

now, toss all that out.

you've got a 20HP motor in the car, and it provides all of the acceleration needed to get the car going up to about 20mph, right?

which lasts all of what, three seconds if you floor it?

20HP x 750Watts x 3 seconds = 45000 watt-seconds, /60= 750 watt-minutes, /60= 12.5 watt-hours.

if you're in the 300KWH range for your house, that's 300,000 watt-hours per month, or 24,000 times as much power as your battery put out during that burst of acceleration.

isn't math grand?


ok, math wizards....... ATTACK!