Charging an electric car vs AC

8 Sept 2017

[cynwoody]

What about electric heaters? Do they use as much as an AC?

For an amount of heating equal to an amount of cooling, a simple-minded electric heater will use several times the juice.

That is why heat pumps are used. A heat pump is an air conditioner operating in reverse. It pulls heat from the cold outdoors and dumps it in your house (provided the outside temperature is not too extreme). Over a wide range of outside temperatures, a heat pump will consume substantially less energy than simple resistance heating for the same amount of heating. If the outside temperature drops below the heat pump's operating range, it will turn on supplementary resistance heating automatically. Modern heat pumps operate until well below freezing.

[cynwoody]

But,,,but,,,if,,,if,,, If everybody drove EV's we wouldn't have these hurricanes.

The strongest hurricane on record to hit the United States was the "Labor Day" hurricane, which hit Florida clear back in 1935.

The hurricane washed this eleven car special train off the track soon after reaching the strickened area. The train was trying to rescue 683 World War I veterans in a rehabilitation camp, of which around 250 died as a result of the hurricane. The veterans, a remnant of the Bonus Army that marched on Washington, were employed for highway construction in the federal work relief project.

Climate change / global warming is bunk.

[PIF]

You can still see the twisted steel rails as you drive over the bridges toward Key West. One way to get rid of a political liability ... thanks to FDR - those wily Democrats.

After the storm passed, bodies were found tangled in the still standing trees ... the highest point in the Keys is on Big Pine Key coming in at six feet above sea level.

[norwaypinesavage]

"Many cars charge in 30-90 minutes"

Many versions of the Tesla Model S come with an 85 kilowatt-hour capacity battery. Let's say you use about half of that - 40 kWh. A charger on a 50 amp 220 volt circuit, using 40 amps so it doesn't pop the breaker, running at 80 percent efficiency, takes nearly 6 hours. (40,000/220/40/0.8 = 5.7)

BTW, at 12 cents per kWh, a common electric rate, the charge would cost you 6 bucks.

[norwaypinesavage]

"The correct unit for comparison between a A/C and electric vehicle is HORSE POWER (HP)."

All EV chargers and central air conditioner units use 220 volt power. Watts (Volt-Amps RMS) and horse power are both units of power. One horse power is 746 watts.

What matters most is energy, measured in kilowatt-hours (a kilowatt is a thousand watts). You pay about 12 cents for every kilowatt hour used at your house.

[Celerity]

“But that same 1 kW can remove and relocate 10kW (or more) of heat.”

what ? Show me that math !

[Celerity]

“could be used on an ICE exhaust to generate enough power to run a separate set of peltiers as thermoelectric coolers for the car.”

I dont’ follow you here. But when it comes to Peltiers, observe those little DC powered “heater/cooler” things that go in cars. It’s a cooler, but also claims to be a food warmer in one. (Basically, a peltier box)

They don’t work too well.

[Celerity]

Transducers. Like pedaling a bicycle to illuminate a lightbulb.

There are losses there. Cooling can be done in a lot of ways - heat exchanger is a broad term.

So I’m not sure about what you’re talking about here.

[MosesKnows]

based on Horse Power, as you correctly point out. It is NOT voltage or amps by themselves.

It is always voltage times amps, in this case 746 watts equals 1 horsepower.

746 watts is the product of voltage time amperage and it can happen many ways. 373 volts time 2 amps equals 746 watts or 1 hp. 2 volts times 373 amps also equals 746 watts as would any combination.

The punch line, if you will, is that all of this is determined by the internal resistance of the battery.

[SkyDancer]

I saw one at a motel in Oregon. There were multiple units. I didn’t look closer to see what the cost was. I’ve not seen any elsewhere. How long does it take to charge up at one of those places?

[Cboldt]

Basic Physics of refigeration, not accounting for the details of various compression/evaporation thermodynamic cycles.

I got the factor of 10 by mistake, mixing units and conflating COP with EER. EER is BTU moved vs. watt-hour in. COP is same units both sides.

Heat Pumps Work Miracles | Do the Math <- read this one first, I think

[Steven Tyler]

The fuel efficiency of an all-electric vehicle may be measured in kilowatt-hours (kWh) per 100 miles rather than miles per gallon. To calculate the cost per mile of an all-electric vehicle, the cost of electricity (in dollars per kWh) and the efficiency of the vehicle (how much electricity is used to travel 100 miles) must be known. If electricity costs $0.11 per kWh and the vehicle consumes 34 kWh to travel 100 miles, the cost per mile is about $0.04.

If electricity costs $0.11 per kilowatt-hour, charging an all-electric vehicle with a 70-mile range (assuming a fully depleted 24 kWh battery) will cost about $2.64 to reach a full charge. This cost is about the same as operating an average central air conditioner for about 6 hours. General Motors estimates the annual energy use of the Chevy Volt is about 2,520 kilowatt-hours, which is less energy than what is required to power a typical water heater or central air conditioning. To compare the fueling costs of individual models of conventional and plug-in vehicles, see the Vehicle Cost Calculator.

My electric bill contains charges for electricity, distribution, debt surcharges, etc.
My rate is about 18 cent a KwH.
Therefore, the cost of power to go 70 miles is the same or more than cost of gasoline for a small car

[SkyDancer]

But what happens in winter when you have to run the heater and lights? What does that do to the effective range? Do you calculate how far out you can go before either charging or returning home? Don't some EV's have a gasoline engine to charge the batteries?

(not being argumentative, just curious)

[deadrock]

Electric cars are the cherry on top of the global warming scam sundae.

[Ozark Tom]

Resistance heating versus air conditioning usage ratio perhaps 3:1 to 4:1 energy usage real world??? No AC delivers a 10:1 COP. Read all the Wikipedia entry and not just the SEER at the top. The COP is a functional engineering term. Notice they reference residential AC as 3.6 COP.

[Ozark Tom]

Those areas of Europe which have a future mandate of all electric vehicles, will needs complete a massive rewire of all residential for the electrical loads. Often they are hard pressed to have wiring capacity to run an air conditioner.

[entropy12]

No generator here...which means when electricity goes out, and it is 100% sure to go out here, there will be no wi-fi in my house, no computers, no FR, no Drudge, etc. Our condo rules state no combustion allowed on balcony, so we can’t even have a propane grill. We are 6 or 7 miles from Atlantic ocean as the crow flies, near Jacksonville.

[entropy12]

What you will not hear from EV proponents is how expensive it is to replace the batteries, which do not last life of the car.

[rey]

I know an electrician who tells of electric car purchasers who are told by the dealer that it is only about $750 to put in an outlet for their car. Quite often, new service inlets increasing power to the home are required with new panels. This averages in the thousands. The home owner/car owners are not happy.

[Calvin Locke]

If you heat up one side of a peltier, you generate electricity.

People that live "off the grid" have tried using wood stoves to generate power, but usually end up destroying the peltiers from overheating.