Plug into the wall, or use the truck, to power things while in the garage / outside?

[RickLightning]

Which is cheaper, if I have peak and off-peak electric rates?

I charge my EVs during off-peak, paying about 16.8 cents per kWh. I know my charger is 93% efficient. Therefore, if I filled the battery with 131kW, that would be 131/.93 x .168 = $23.66. So a kilowatt is 18.1 cents coming from the truck ($23.66/131).

Now, if I want to say run a 100 watt bulb for 10 hours. That's 1,000 watts. If it's during the day, that's peak rate. 24.7 cents. So it would cost 24.7 cents. So, if I wanted to run that same bulb cheaper, I could plug the lamp into the truck.

Therefore, if I'm out in the garage, and want to use a power tool, or charge my lawn trimmer, or blower, it's 36.5% more expensive to plug it into the house than to plug it into the car (24.7/18.1).

Of course usage matters. If I charge a battery for my tools, they hold 160 watts. So, it costs 4 cents to charge during the day, or 2.7 cents using the truck. Insignificant, not worth opening the tailgate to plug it in to save 1.3 cents.

Hadn't seen this math, now I have.

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[Tony Burgh]

What cost do you assign to battery degradation?

 

[RickLightning]

What cost do you assign to battery degradation?

I don't.

People think that every time they use a vehicle the battery is negatively impacted. The reality is that over a very long time, some degradation is measurable via instruments, human beings couldn't being to notice it. We drove a hybrid for 7 years, an a PHEV for 3 years. Noticed absolutely nothing.

Ford guarantees the battery will be at 70% capacity, or more, at 8 years / 100,000 miles. They plan to beat that for people that abuse their batteries, charging to 100%, always DC fast charging, never preconditioning, etc. I'm not anywhere close to that person. I expect that by the end of the warranty on either EV to be around 90% of capacity. I also expect Ford to release more usable battery prior to 8 years / 100,000 miles.

If I plugged in and used say a kilowatt of power, it's not even worth the math to project that impact.

 

[VTbuckeye]

What about the efficiency of getting power out of the truck. AC-DC-AC. The conversion back to AC also costs energy. The truck also needs to be on to power the outlets. There is some overhead in keeping the truck on (100W?? 250W??? 500W?? I don't know how much but it is something). This overhead cost of powering on would be less proportionally if delivering a bigger load, but for low power demands it is probably more efficient to supply from the grid.

 

[Karlos]

A bit off topic, but wondering what's the purpose of having the truck fully "ON" to run Aux power ? Why not just Accessory mode - seems like a bit less overhead & much less chance someone just driving off with the truck while it's "On" !!

 

[RickLightning]

A bit off topic, but wondering what's the purpose of having the truck fully "ON" to run Aux power ? Why not just Accessory mode - seems like a bit less overhead & much less chance someone just driving off with the truck while it's "On" !!

Can't drive without the FOB. Won't shift to D.

 

[Heliian]

What you are describing is starting to become a thing.

Using batteries to store off peak power for use on peak, it's one of the main intentions of ev home integration.

 

[mb0220]

The concept is sound. Basically you're wanting to use your truck like a PowerWall. The problem is you're only optimizing for the few items you're plugging in. Probably not even worth the hassle unless you run your whole house on it. And even then, it's not going to make you rich...

 

[sotek2345]

What about the efficiency of getting power out of the truck. AC-DC-AC. The conversion back to AC also costs energy. The truck also needs to be on to power the outlets. There is some overhead in keeping the truck on (100W?? 250W??? 500W?? I don't know how much but it is something). This overhead cost of powering on would be less proportionally if delivering a bigger load, but for low power demands it is probably more efficient to supply from the grid.

This is the key. Those factors will chew up most of the benefit you would be getting. probably not worthwhile for your rates, but could be useful for a bigger spread in peak vs. off peak rates.

For me - that very minor savings wouldn't be worth my time and effort.

 

[chl]

Which is cheaper, if I have peak and off-peak electric rates?

I charge my EVs during off-peak, paying about 16.8 cents per kWh. I know my charger is 93% efficient. Therefore, if I filled the battery with 131kW, that would be 131/.93 x .168 = $23.66. So a kilowatt is 18.1 cents coming from the truck ($23.66/131).

Now, if I want to say run a 100 watt bulb for 10 hours. That's 1,000 watts. If it's during the day, that's peak rate. 24.7 cents. So it would cost 24.7 cents. So, if I wanted to run that same bulb cheaper, I could plug the lamp into the truck.

Therefore, if I'm out in the garage, and want to use a power tool, or charge my lawn trimmer, or blower, it's 36.5% more expensive to plug it into the house than to plug it into the car (24.7/18.1).

Of course usage matters. If I charge a battery for my tools, they hold 160 watts. So, it costs 4 cents to charge during the day, or 2.7 cents using the truck. Insignificant, not worth opening the tailgate to plug it in to save 1.3 cents.

Hadn't seen this math, now I have.

Interesting. Watts time time is kWh = energy. Incandescent lights were a big waster of kWhs, only 2% efficient at making light, 98% is wasted as heat..

With only an 8 cent difference between the cost per kilowatt-hour peak and off-peak, maybe it is not worth worrying about for small energy uses like small tools, etc.? It could add up over time if there is a lot of energy used that way though.

In my area the difference in the summer is almost 10 cents. So I do move big users of energy to off-peak times, scheduling hot tub cycles for example, and clothes drying. And of course EV charging.

We have a 4 tier price plan, so in the Summer if I wait until after 7pm to bake my frozen pizza it saves about 6 cents per kilowatt hour of energy used. Say it's a 5000 watt oven, times 1/2 hour of use, that's 2.5kWh or 15 cents less than at 6pm. It seems small, but if I ate a pizza twice a week, 52 weeks a year, that's a $15.60 savings on my electric bill. Those are just hypothetical numbers.

That is just one small change I make to cut costs and save energy.

However, the biggest users of energy are generally HVAC (esp A/C), hot water heaters, refrigerators, lighting then everything else, in that order.

Bigger saving can be had by other means. Probably everyone already knows the following ways, so skip if not interested.

A hybrid water heater (w/heat pump) in eco mode saved me real money. With a couple kids and a wife who love hot showers, it cut the electric bill over $150 per month, no joke.

Turn down the A/C is a big one, probably the biggest.

A high-efficiency 90 SEER or better gas furnace will cut down on the carbon foot print and save money on the gas bill.

Adjusting the thermostat as high in the summer and low in the winter as you (or your wife) can stand is a big saver of energy.

Ceiling fans, window treatment (curtains and double or triple pane windows), more insulation in the attic, LED bulbs throughout (also really saw a significant difference from incandescent to CFL and then from CFL to LED because incandescent bulbs are only 2% efficient at producing light!), and adjusting things that use a lot of juice to off-peak hours (like the dryer, oven).

Also when replacing large appliances, like refrigerators and oven/ranges, always get Energy Star certified ones.

There are quite a few vampire users of energy, like things (tv etc.) that are in standby mode or quick start mode...it adds up. Most of them tell you in the user manual how much they use when in those modes and how to deactivate it, but there are inexpensive devices that you can use to find out if not in the manuals (WattsUp for example).

The pay off by doing some of the above is significantly better than using a small amount of the energy stored in the Lightning (stored during off-peak times) during peak times.

Maybe if you were powering your whole house, or up to 7.2kW (30A x 240V) or 9.kW if using home integration.

 

[hturnerfamily]

Which is cheaper, if I have peak and off-peak electric rates?

I charge my EVs during off-peak, paying about 16.8 cents per kWh. I know my charger is 93% efficient. Therefore, if I filled the battery with 131kW, that would be 131/.93 x .168 = $23.66. So a kilowatt is 18.1 cents coming from the truck ($23.66/131).

Now, if I want to say run a 100 watt bulb for 10 hours. That's 1,000 watts. If it's during the day, that's peak rate. 24.7 cents. So it would cost 24.7 cents. So, if I wanted to run that same bulb cheaper, I could plug the lamp into the truck.

Therefore, if I'm out in the garage, and want to use a power tool, or charge my lawn trimmer, or blower, it's 36.5% more expensive to plug it into the house than to plug it into the car (24.7/18.1).

Of course usage matters. If I charge a battery for my tools, they hold 160 watts. So, it costs 4 cents to charge during the day, or 2.7 cents using the truck. Insignificant, not worth opening the tailgate to plug it in to save 1.3 cents.

Hadn't seen this math, now I have.

for what I've highlighted in your original post, what we sometimes forget is the 'real life' part of the equation - while everything may seem to be about money, it's really about how and when we do things, just as much... for instance.

when you 'charge' an EV's HUGE Battery Pack, overnight, during off-peak hours, you are asking for CONSTANT, CONTINUOUS, and FOR HOURS, 240v 30amp power. That's a LOT.
when you 'use' or 'charge' your tools, and light bulb, and stuff, those are VERY Infrequent and NON-CONSTANT uses of mostly only 120v needs... that's a VERY LITTLE, compared.

don't sweat it, it's not worth the 'worry'...

I look at my own Georgia Power 'EV Plug-in Time of Use' 11pm-7am rate plan as a way to GREATLY lower my overall kWh per hour charges for our two EVs, and it works great.
BUT, that's not the whole story: the dryer running during those hours gets those same rates. The dishwasher running during those hours gets the same low rate. The air conditioner or HEATER running during those hours gets, yes, the SAME RATE.

It's NOT just about charging the EV that matters.

 

[RickKeen]

I have done it for convenience. Using the tailgate of the truck as a work bench and plugging power tools or a compressor into the truck because I was too lazy to go get an extension cord even though there is an outlet in the garage between the doors, 5 feet from the back of the truck.

Also saves the effort of lifting the compressor out of the truck and back in because I was borrowing the compressor from my shop..

 

[mr.Magoo]

The irony of using a $50-80,000 vehicle to "save" a cent or two on your utility bill !

 

[davehu]

I don't.

The concept is sound. Basically you're wanting to use your truck like a PowerWall. The problem is you're only optimizing for the few items you're plugging in. Probably not even worth the hassle unless you run your whole house on it. And even then, it's not going to make you rich...

there is a article probably linked from somewhere on this forum of an off the grid guy who wanted to install a bank of batteries (Powerwall? don't remember) for when the sun doesn't shine or the wind blow. He found that a Lightning cost about the same and he got a pickup truck for free!

 

[davehu]

I don't.

People think that every time they use a vehicle the battery is negatively impacted. The reality is that over a very long time, some degradation is measurable via instruments, human beings couldn't being to notice it. We drove a hybrid for 7 years, an a PHEV for 3 years. Noticed absolutely nothing.

Ford guarantees the battery will be at 70% capacity, or more, at 8 years / 100,000 miles. They plan to beat that for people that abuse their batteries, charging to 100%, always DC fast charging, never preconditioning, etc. I'm not anywhere close to that person. I expect that by the end of the warranty on either EV to be around 90% of capacity. I also expect Ford to release more usable battery prior to 8 years / 100,000 miles.

If I plugged in and used say a kilowatt of power, it's not even worth the math to project that impact.

just a correction. Ford warranties the battery for 80% capacity eight years or 100,000 miles

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